/ main.c at [8edb983b]
Login

File src/main.c artifact 54d61d1e part of check-in 8edb983b


     1
     2
     3
     4
     5
     6
     7
     8
     9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
   100
   101
   102
   103
   104
   105
   106
   107
   108
   109
   110
   111
   112
   113
   114
   115
   116
   117
   118
   119
   120
   121
   122
   123
   124
   125
   126
   127
   128
   129
   130
   131
   132
   133
   134
   135
   136
   137
   138
   139
   140
   141
   142
   143
   144
   145
   146
   147
   148
   149
   150
   151
   152
   153
   154
   155
   156
   157
   158
   159
   160
   161
   162
   163
   164
   165
   166
   167
   168
   169
   170
   171
   172
   173
   174
   175
   176
   177
   178
   179
   180
   181
   182
   183
   184
   185
   186
   187
   188
   189
   190
   191
   192
   193
   194
   195
   196
   197
   198
   199
   200
   201
   202
   203
   204
   205
   206
   207
   208
   209
   210
   211
   212
   213
   214
   215
   216
   217
   218
   219
   220
   221
   222
   223
   224
   225
   226
   227
   228
   229
   230
   231
   232
   233
   234
   235
   236
   237
   238
   239
   240
   241
   242
   243
   244
   245
   246
   247
   248
   249
   250
   251
   252
   253
   254
   255
   256
   257
   258
   259
   260
   261
   262
   263
   264
   265
   266
   267
   268
   269
   270
   271
   272
   273
   274
   275
   276
   277
   278
   279
   280
   281
   282
   283
   284
   285
   286
   287
   288
   289
   290
   291
   292
   293
   294
   295
   296
   297
   298
   299
   300
   301
   302
   303
   304
   305
   306
   307
   308
   309
   310
   311
   312
   313
   314
   315
   316
   317
   318
   319
   320
   321
   322
   323
   324
   325
   326
   327
   328
   329
   330
   331
   332
   333
   334
   335
   336
   337
   338
   339
   340
   341
   342
   343
   344
   345
   346
   347
   348
   349
   350
   351
   352
   353
   354
   355
   356
   357
   358
   359
   360
   361
   362
   363
   364
   365
   366
   367
   368
   369
   370
   371
   372
   373
   374
   375
   376
   377
   378
   379
   380
   381
   382
   383
   384
   385
   386
   387
   388
   389
   390
   391
   392
   393
   394
   395
   396
   397
   398
   399
   400
   401
   402
   403
   404
   405
   406
   407
   408
   409
   410
   411
   412
   413
   414
   415
   416
   417
   418
   419
   420
   421
   422
   423
   424
   425
   426
   427
   428
   429
   430
   431
   432
   433
   434
   435
   436
   437
   438
   439
   440
   441
   442
   443
   444
   445
   446
   447
   448
   449
   450
   451
   452
   453
   454
   455
   456
   457
   458
   459
   460
   461
   462
   463
   464
   465
   466
   467
   468
   469
   470
   471
   472
   473
   474
   475
   476
   477
   478
   479
   480
   481
   482
   483
   484
   485
   486
   487
   488
   489
   490
   491
   492
   493
   494
   495
   496
   497
   498
   499
   500
   501
   502
   503
   504
   505
   506
   507
   508
   509
   510
   511
   512
   513
   514
   515
   516
   517
   518
   519
   520
   521
   522
   523
   524
   525
   526
   527
   528
   529
   530
   531
   532
   533
   534
   535
   536
   537
   538
   539
   540
   541
   542
   543
   544
   545
   546
   547
   548
   549
   550
   551
   552
   553
   554
   555
   556
   557
   558
   559
   560
   561
   562
   563
   564
   565
   566
   567
   568
   569
   570
   571
   572
   573
   574
   575
   576
   577
   578
   579
   580
   581
   582
   583
   584
   585
   586
   587
   588
   589
   590
   591
   592
   593
   594
   595
   596
   597
   598
   599
   600
   601
   602
   603
   604
   605
   606
   607
   608
   609
   610
   611
   612
   613
   614
   615
   616
   617
   618
   619
   620
   621
   622
   623
   624
   625
   626
   627
   628
   629
   630
   631
   632
   633
   634
   635
   636
   637
   638
   639
   640
   641
   642
   643
   644
   645
   646
   647
   648
   649
   650
   651
   652
   653
   654
   655
   656
   657
   658
   659
   660
   661
   662
   663
   664
   665
   666
   667
   668
   669
   670
   671
   672
   673
   674
   675
   676
   677
   678
   679
   680
   681
   682
   683
   684
   685
   686
   687
   688
   689
   690
   691
   692
   693
   694
   695
   696
   697
   698
   699
   700
   701
   702
   703
   704
   705
   706
   707
   708
   709
   710
   711
   712
   713
   714
   715
   716
   717
   718
   719
   720
   721
   722
   723
   724
   725
   726
   727
   728
   729
   730
   731
   732
   733
   734
   735
   736
   737
   738
   739
   740
   741
   742
   743
   744
   745
   746
   747
   748
   749
   750
   751
   752
   753
   754
   755
   756
   757
   758
   759
   760
   761
   762
   763
   764
   765
   766
   767
   768
   769
   770
   771
   772
   773
   774
   775
   776
   777
   778
   779
   780
   781
   782
   783
   784
   785
   786
   787
   788
   789
   790
   791
   792
   793
   794
   795
   796
   797
   798
   799
   800
   801
   802
   803
   804
   805
   806
   807
   808
   809
   810
   811
   812
   813
   814
   815
   816
   817
   818
   819
   820
   821
   822
   823
   824
   825
   826
   827
   828
   829
   830
   831
   832
   833
   834
   835
   836
   837
   838
   839
   840
   841
   842
   843
   844
   845
   846
   847
   848
   849
   850
   851
   852
   853
   854
   855
   856
   857
   858
   859
   860
   861
   862
   863
   864
   865
   866
   867
   868
   869
   870
   871
   872
   873
   874
   875
   876
   877
   878
   879
   880
   881
   882
   883
   884
   885
   886
   887
   888
   889
   890
   891
   892
   893
   894
   895
   896
   897
   898
   899
   900
   901
   902
   903
   904
   905
   906
   907
   908
   909
   910
   911
   912
   913
   914
   915
   916
   917
   918
   919
   920
   921
   922
   923
   924
   925
   926
   927
   928
   929
   930
   931
   932
   933
   934
   935
   936
   937
   938
   939
   940
   941
   942
   943
   944
   945
   946
   947
   948
   949
   950
   951
   952
   953
   954
   955
   956
   957
   958
   959
   960
   961
   962
   963
   964
   965
   966
   967
   968
   969
   970
   971
   972
   973
   974
   975
   976
   977
   978
   979
   980
   981
   982
   983
   984
   985
   986
   987
   988
   989
   990
   991
   992
   993
   994
   995
   996
   997
   998
   999
  1000
  1001
  1002
  1003
  1004
  1005
  1006
  1007
  1008
  1009
  1010
  1011
  1012
  1013
  1014
  1015
  1016
  1017
  1018
  1019
  1020
  1021
  1022
  1023
  1024
  1025
  1026
  1027
  1028
  1029
  1030
  1031
  1032
  1033
  1034
  1035
  1036
  1037
  1038
  1039
  1040
  1041
  1042
  1043
  1044
  1045
  1046
  1047
  1048
  1049
  1050
  1051
  1052
  1053
  1054
  1055
  1056
  1057
  1058
  1059
  1060
  1061
  1062
  1063
  1064
  1065
  1066
  1067
  1068
  1069
  1070
  1071
  1072
  1073
  1074
  1075
  1076
  1077
  1078
  1079
  1080
  1081
  1082
  1083
  1084
  1085
  1086
  1087
  1088
  1089
  1090
  1091
  1092
  1093
  1094
  1095
  1096
  1097
  1098
  1099
  1100
  1101
  1102
  1103
  1104
  1105
  1106
  1107
  1108
  1109
  1110
  1111
  1112
  1113
  1114
  1115
  1116
  1117
  1118
  1119
  1120
  1121
  1122
  1123
  1124
  1125
  1126
  1127
  1128
  1129
  1130
  1131
  1132
  1133
  1134
  1135
  1136
  1137
  1138
  1139
  1140
  1141
  1142
  1143
  1144
  1145
  1146
  1147
  1148
  1149
  1150
  1151
  1152
  1153
  1154
  1155
  1156
  1157
  1158
  1159
  1160
  1161
  1162
  1163
  1164
  1165
  1166
  1167
  1168
  1169
  1170
  1171
  1172
  1173
  1174
  1175
  1176
  1177
  1178
  1179
  1180
  1181
  1182
  1183
  1184
  1185
  1186
  1187
  1188
  1189
  1190
  1191
  1192
  1193
  1194
  1195
  1196
  1197
  1198
  1199
  1200
  1201
  1202
  1203
  1204
  1205
  1206
  1207
  1208
  1209
  1210
  1211
  1212
  1213
  1214
  1215
  1216
  1217
  1218
  1219
  1220
  1221
  1222
  1223
  1224
  1225
  1226
  1227
  1228
  1229
  1230
  1231
  1232
  1233
  1234
  1235
  1236
  1237
  1238
  1239
  1240
  1241
  1242
  1243
  1244
  1245
  1246
  1247
  1248
  1249
  1250
  1251
  1252
  1253
  1254
  1255
  1256
  1257
  1258
  1259
  1260
  1261
  1262
  1263
  1264
  1265
  1266
  1267
  1268
  1269
  1270
  1271
  1272
  1273
  1274
  1275
  1276
  1277
  1278
  1279
  1280
  1281
  1282
  1283
  1284
  1285
  1286
  1287
  1288
  1289
  1290
  1291
  1292
  1293
  1294
  1295
  1296
  1297
  1298
  1299
  1300
  1301
  1302
  1303
  1304
  1305
  1306
  1307
  1308
  1309
  1310
  1311
  1312
  1313
  1314
  1315
  1316
  1317
  1318
  1319
  1320
  1321
  1322
  1323
  1324
  1325
  1326
  1327
  1328
  1329
  1330
  1331
  1332
  1333
  1334
  1335
  1336
  1337
  1338
  1339
  1340
  1341
  1342
  1343
  1344
  1345
  1346
  1347
  1348
  1349
  1350
  1351
  1352
  1353
  1354
  1355
  1356
  1357
  1358
  1359
  1360
  1361
  1362
  1363
  1364
  1365
  1366
  1367
  1368
  1369
  1370
  1371
  1372
  1373
  1374
  1375
  1376
  1377
  1378
  1379
  1380
  1381
  1382
  1383
  1384
  1385
  1386
  1387
  1388
  1389
  1390
  1391
  1392
  1393
  1394
  1395
  1396
  1397
  1398
  1399
  1400
  1401
  1402
  1403
  1404
  1405
  1406
  1407
  1408
  1409
  1410
  1411
  1412
  1413
  1414
  1415
  1416
  1417
  1418
  1419
  1420
  1421
  1422
  1423
  1424
  1425
  1426
  1427
  1428
  1429
  1430
  1431
  1432
  1433
  1434
  1435
  1436
  1437
  1438
  1439
  1440
  1441
  1442
  1443
  1444
  1445
  1446
  1447
  1448
  1449
  1450
  1451
  1452
  1453
  1454
  1455
  1456
  1457
  1458
  1459
  1460
  1461
  1462
  1463
  1464
  1465
  1466
  1467
  1468
  1469
  1470
  1471
  1472
  1473
  1474
  1475
  1476
  1477
  1478
  1479
  1480
  1481
  1482
  1483
  1484
  1485
  1486
  1487
  1488
  1489
  1490
  1491
  1492
  1493
  1494
  1495
  1496
  1497
  1498
  1499
  1500
  1501
  1502
  1503
  1504
  1505
  1506
  1507
  1508
  1509
  1510
  1511
  1512
  1513
  1514
  1515
  1516
  1517
  1518
  1519
  1520
  1521
  1522
  1523
  1524
  1525
  1526
  1527
  1528
  1529
  1530
  1531
  1532
  1533
  1534
  1535
  1536
  1537
  1538
  1539
  1540
  1541
  1542
  1543
  1544
  1545
  1546
  1547
  1548
  1549
  1550
  1551
  1552
  1553
  1554
  1555
  1556
  1557
  1558
  1559
  1560
  1561
  1562
  1563
  1564
  1565
  1566
  1567
  1568
  1569
  1570
  1571
  1572
  1573
  1574
  1575
  1576
  1577
  1578
  1579
  1580
  1581
  1582
  1583
  1584
  1585
  1586
  1587
  1588
  1589
  1590
  1591
  1592
  1593
  1594
  1595
  1596
  1597
  1598
  1599
  1600
  1601
  1602
  1603
  1604
  1605
  1606
  1607
  1608
  1609
  1610
  1611
  1612
  1613
  1614
  1615
  1616
  1617
  1618
  1619
  1620
  1621
  1622
  1623
  1624
  1625
  1626
  1627
  1628
  1629
  1630
  1631
  1632
  1633
  1634
  1635
  1636
  1637
  1638
  1639
  1640
  1641
  1642
  1643
  1644
  1645
  1646
  1647
  1648
  1649
  1650
  1651
  1652
  1653
  1654
  1655
  1656
  1657
  1658
  1659
  1660
  1661
  1662
  1663
  1664
  1665
  1666
  1667
  1668
  1669
  1670
  1671
  1672
  1673
  1674
  1675
  1676
  1677
  1678
  1679
  1680
  1681
  1682
  1683
  1684
  1685
  1686
  1687
  1688
  1689
  1690
  1691
  1692
  1693
  1694
  1695
  1696
  1697
  1698
  1699
  1700
  1701
  1702
  1703
  1704
  1705
  1706
  1707
  1708
  1709
  1710
  1711
  1712
  1713
  1714
  1715
  1716
  1717
  1718
  1719
  1720
  1721
  1722
  1723
  1724
  1725
  1726
  1727
  1728
  1729
  1730
  1731
  1732
  1733
  1734
  1735
  1736
  1737
  1738
  1739
  1740
  1741
  1742
  1743
  1744
  1745
  1746
  1747
  1748
  1749
  1750
  1751
  1752
  1753
  1754
  1755
  1756
  1757
  1758
  1759
  1760
  1761
  1762
  1763
  1764
  1765
  1766
  1767
  1768
  1769
  1770
  1771
  1772
  1773
  1774
  1775
  1776
  1777
  1778
  1779
  1780
  1781
  1782
  1783
  1784
  1785
  1786
  1787
  1788
  1789
  1790
  1791
  1792
  1793
  1794
  1795
  1796
  1797
  1798
  1799
  1800
  1801
  1802
  1803
  1804
  1805
  1806
  1807
  1808
  1809
  1810
  1811
  1812
  1813
  1814
  1815
  1816
  1817
  1818
  1819
  1820
  1821
  1822
  1823
  1824
  1825
  1826
  1827
  1828
  1829
  1830
  1831
  1832
  1833
  1834
  1835
  1836
  1837
  1838
  1839
  1840
  1841
  1842
  1843
  1844
  1845
  1846
  1847
  1848
  1849
  1850
  1851
  1852
  1853
  1854
  1855
  1856
  1857
  1858
  1859
  1860
  1861
  1862
  1863
  1864
  1865
  1866
  1867
  1868
  1869
  1870
  1871
  1872
  1873
  1874
  1875
  1876
  1877
  1878
  1879
  1880
  1881
  1882
  1883
  1884
  1885
  1886
  1887
  1888
  1889
  1890
  1891
  1892
  1893
  1894
  1895
  1896
  1897
  1898
  1899
  1900
  1901
  1902
  1903
  1904
  1905
  1906
  1907
  1908
  1909
  1910
  1911
  1912
  1913
  1914
  1915
  1916
  1917
  1918
  1919
  1920
  1921
  1922
  1923
  1924
  1925
  1926
  1927
  1928
  1929
  1930
  1931
  1932
  1933
  1934
  1935
  1936
  1937
  1938
  1939
  1940
  1941
  1942
  1943
  1944
  1945
  1946
  1947
  1948
  1949
  1950
  1951
  1952
  1953
  1954
  1955
  1956
  1957
  1958
  1959
  1960
  1961
  1962
  1963
  1964
  1965
  1966
  1967
  1968
  1969
  1970
  1971
  1972
  1973
  1974
  1975
  1976
  1977
  1978
  1979
  1980
  1981
  1982
  1983
  1984
  1985
  1986
  1987
  1988
  1989
  1990
  1991
  1992
  1993
  1994
  1995
  1996
  1997
  1998
  1999
  2000
  2001
  2002
  2003
  2004
  2005
  2006
  2007
  2008
  2009
  2010
  2011
  2012
  2013
  2014
  2015
  2016
  2017
  2018
  2019
  2020
  2021
  2022
  2023
  2024
  2025
  2026
  2027
  2028
  2029
  2030
  2031
  2032
  2033
  2034
  2035
  2036
  2037
  2038
  2039
  2040
  2041
  2042
  2043
  2044
  2045
  2046
  2047
  2048
  2049
  2050
  2051
  2052
  2053
  2054
  2055
  2056
  2057
  2058
  2059
  2060
  2061
  2062
  2063
  2064
  2065
  2066
  2067
  2068
  2069
  2070
  2071
  2072
  2073
  2074
  2075
  2076
  2077
  2078
  2079
  2080
  2081
  2082
  2083
  2084
  2085
  2086
  2087
  2088
  2089
  2090
  2091
  2092
  2093
  2094
  2095
  2096
  2097
  2098
  2099
  2100
  2101
  2102
  2103
  2104
  2105
  2106
  2107
  2108
  2109
  2110
  2111
  2112
  2113
  2114
  2115
  2116
  2117
  2118
  2119
  2120
  2121
  2122
  2123
  2124
  2125
  2126
  2127
  2128
  2129
  2130
  2131
  2132
  2133
  2134
  2135
  2136
  2137
  2138
  2139
  2140
  2141
  2142
  2143
  2144
  2145
  2146
  2147
  2148
  2149
  2150
  2151
  2152
  2153
  2154
  2155
  2156
  2157
  2158
  2159
  2160
  2161
  2162
  2163
  2164
  2165
  2166
  2167
  2168
  2169
  2170
  2171
  2172
  2173
  2174
  2175
  2176
  2177
  2178
  2179
  2180
  2181
  2182
  2183
  2184
  2185
  2186
  2187
  2188
  2189
  2190
  2191
  2192
  2193
  2194
  2195
  2196
  2197
  2198
  2199
  2200
  2201
  2202
  2203
  2204
  2205
  2206
  2207
  2208
  2209
  2210
  2211
  2212
  2213
  2214
  2215
  2216
  2217
  2218
  2219
  2220
  2221
  2222
  2223
  2224
  2225
  2226
  2227
  2228
  2229
  2230
  2231
  2232
  2233
  2234
  2235
  2236
  2237
  2238
  2239
  2240
  2241
  2242
  2243
  2244
  2245
  2246
  2247
  2248
  2249
  2250
  2251
  2252
  2253
  2254
  2255
  2256
  2257
  2258
  2259
  2260
  2261
  2262
  2263
  2264
  2265
  2266
  2267
  2268
  2269
  2270
  2271
  2272
  2273
  2274
  2275
  2276
  2277
  2278
  2279
  2280
  2281
  2282
  2283
  2284
  2285
  2286
  2287
  2288
  2289
  2290
  2291
  2292
  2293
  2294
  2295
  2296
  2297
  2298
  2299
  2300
  2301
  2302
  2303
  2304
  2305
  2306
  2307
  2308
  2309
  2310
  2311
  2312
  2313
  2314
  2315
  2316
  2317
  2318
  2319
  2320
  2321
  2322
  2323
  2324
  2325
  2326
  2327
  2328
  2329
  2330
  2331
  2332
  2333
  2334
  2335
  2336
  2337
  2338
  2339
  2340
  2341
  2342
  2343
  2344
  2345
  2346
  2347
  2348
  2349
  2350
  2351
  2352
  2353
  2354
  2355
  2356
  2357
  2358
  2359
  2360
  2361
  2362
  2363
  2364
  2365
  2366
  2367
  2368
  2369
  2370
  2371
  2372
  2373
  2374
  2375
  2376
  2377
  2378
  2379
  2380
  2381
  2382
  2383
  2384
  2385
  2386
  2387
  2388
  2389
  2390
  2391
  2392
  2393
  2394
  2395
  2396
  2397
  2398
  2399
  2400
  2401
  2402
  2403
  2404
  2405
  2406
  2407
  2408
  2409
  2410
  2411
  2412
  2413
  2414
  2415
  2416
  2417
  2418
  2419
  2420
  2421
  2422
  2423
  2424
  2425
  2426
  2427
  2428
  2429
  2430
  2431
  2432
  2433
  2434
  2435
  2436
  2437
  2438
  2439
  2440
  2441
  2442
  2443
  2444
  2445
  2446
  2447
  2448
  2449
  2450
  2451
  2452
  2453
  2454
  2455
  2456
  2457
  2458
  2459
  2460
  2461
  2462
  2463
  2464
  2465
  2466
  2467
  2468
  2469
  2470
  2471
  2472
  2473
  2474
  2475
  2476
  2477
  2478
  2479
  2480
  2481
  2482
  2483
  2484
  2485
  2486
  2487
  2488
  2489
  2490
  2491
  2492
  2493
  2494
  2495
  2496
  2497
  2498
  2499
  2500
  2501
  2502
  2503
  2504
  2505
  2506
  2507
  2508
  2509
  2510
  2511
  2512
  2513
  2514
  2515
  2516
  2517
  2518
  2519
  2520
  2521
  2522
  2523
  2524
  2525
  2526
  2527
  2528
  2529
  2530
  2531
  2532
  2533
  2534
  2535
  2536
  2537
  2538
  2539
  2540
  2541
  2542
  2543
  2544
  2545
  2546
  2547
  2548
  2549
  2550
  2551
  2552
  2553
  2554
  2555
  2556
  2557
  2558
  2559
  2560
  2561
  2562
  2563
  2564
  2565
  2566
  2567
  2568
  2569
  2570
  2571
  2572
  2573
  2574
  2575
  2576
  2577
  2578
  2579
  2580
  2581
  2582
  2583
  2584
  2585
  2586
  2587
  2588
  2589
  2590
  2591
  2592
  2593
  2594
  2595
  2596
  2597
  2598
  2599
  2600
  2601
  2602
  2603
  2604
  2605
  2606
  2607
  2608
  2609
  2610
  2611
  2612
  2613
  2614
  2615
  2616
  2617
  2618
  2619
  2620
  2621
  2622
  2623
  2624
  2625
  2626
  2627
  2628
  2629
  2630
  2631
  2632
  2633
  2634
  2635
  2636
  2637
  2638
  2639
  2640
  2641
  2642
  2643
  2644
  2645
  2646
  2647
  2648
  2649
  2650
  2651
  2652
  2653
  2654
  2655
  2656
  2657
  2658
  2659
  2660
  2661
  2662
  2663
  2664
  2665
  2666
  2667
  2668
  2669
  2670
  2671
  2672
  2673
  2674
  2675
  2676
  2677
  2678
  2679
  2680
  2681
  2682
  2683
  2684
  2685
  2686
  2687
  2688
  2689
  2690
  2691
  2692
  2693
  2694
  2695
  2696
  2697
  2698
  2699
  2700
  2701
  2702
  2703
  2704
  2705
  2706
  2707
  2708
  2709
  2710
  2711
  2712
  2713
  2714
  2715
  2716
  2717
  2718
  2719
  2720
  2721
  2722
  2723
  2724
  2725
  2726
  2727
  2728
  2729
  2730
  2731
  2732
  2733
  2734
  2735
  2736
  2737
  2738
  2739
  2740
  2741
  2742
  2743
  2744
  2745
  2746
  2747
  2748
  2749
  2750
  2751
  2752
  2753
  2754
  2755
  2756
  2757
  2758
  2759
  2760
  2761
  2762
  2763
  2764
  2765
  2766
  2767
  2768
  2769
  2770
  2771
  2772
  2773
  2774
  2775
  2776
  2777
  2778
  2779
  2780
  2781
  2782
  2783
  2784
  2785
  2786
  2787
  2788
  2789
  2790
  2791
  2792
  2793
  2794
  2795
  2796
  2797
  2798
  2799
  2800
  2801
  2802
  2803
  2804
  2805
  2806
  2807
  2808
  2809
  2810
  2811
  2812
  2813
  2814
  2815
  2816
  2817
  2818
  2819
  2820
  2821
  2822
  2823
  2824
  2825
  2826
  2827
  2828
  2829
  2830
  2831
  2832
  2833
  2834
  2835
  2836
  2837
  2838
  2839
  2840
  2841
  2842
  2843
  2844
  2845
  2846
  2847
  2848
  2849
  2850
  2851
  2852
  2853
  2854
  2855
  2856
  2857
  2858
  2859
  2860
  2861
  2862
  2863
  2864
  2865
  2866
  2867
  2868
  2869
  2870
  2871
  2872
  2873
  2874
  2875
  2876
  2877
  2878
  2879
  2880
  2881
  2882
  2883
  2884
  2885
  2886
  2887
  2888
  2889
  2890
  2891
  2892
  2893
  2894
  2895
  2896
  2897
  2898
  2899
  2900
  2901
  2902
  2903
  2904
  2905
  2906
  2907
  2908
  2909
  2910
  2911
  2912
  2913
  2914
  2915
  2916
  2917
  2918
  2919
  2920
  2921
  2922
  2923
  2924
  2925
  2926
  2927
  2928
  2929
  2930
  2931
  2932
  2933
  2934
  2935
  2936
  2937
  2938
  2939
  2940
  2941
  2942
  2943
  2944
  2945
  2946
  2947
  2948
  2949
  2950
  2951
  2952
  2953
  2954
  2955
  2956
  2957
  2958
  2959
  2960
  2961
  2962
  2963
  2964
  2965
  2966
  2967
  2968
  2969
  2970
  2971
  2972
  2973
  2974
  2975
  2976
  2977
  2978
  2979
  2980
  2981
  2982
  2983
  2984
  2985
  2986
  2987
  2988
  2989
  2990
  2991
  2992
  2993
  2994
  2995
  2996
  2997
  2998
  2999
  3000
  3001
  3002
  3003
  3004
  3005
  3006
  3007
  3008
  3009
  3010
  3011
  3012
  3013
  3014
  3015
  3016
  3017
  3018
  3019
  3020
  3021
  3022
  3023
  3024
  3025
  3026
  3027
  3028
  3029
  3030
  3031
  3032
  3033
  3034
  3035
  3036
  3037
  3038
  3039
  3040
  3041
  3042
  3043
  3044
  3045
  3046
  3047
  3048
  3049
  3050
  3051
  3052
  3053
  3054
  3055
  3056
  3057
  3058
  3059
  3060
  3061
  3062
  3063
  3064
  3065
  3066
  3067
  3068
  3069
  3070
  3071
  3072
  3073
  3074
  3075
  3076
  3077
  3078
  3079
  3080
  3081
  3082
  3083
  3084
  3085
  3086
  3087
  3088
  3089
  3090
  3091
  3092
  3093
  3094
  3095
  3096
  3097
  3098
  3099
  3100
  3101
  3102
  3103
  3104
  3105
  3106
  3107
  3108
  3109
  3110
  3111
  3112
  3113
  3114
  3115
  3116
  3117
  3118
  3119
  3120
  3121
  3122
  3123
  3124
  3125
  3126
  3127
  3128
  3129
  3130
  3131
  3132
  3133
  3134
  3135
  3136
  3137
  3138
  3139
  3140
  3141
  3142
  3143
  3144
  3145
  3146
  3147
  3148
  3149
  3150
  3151
  3152
  3153
  3154
  3155
  3156
  3157
  3158
  3159
  3160
  3161
  3162
  3163
  3164
  3165
  3166
  3167
  3168
  3169
  3170
  3171
  3172
  3173
  3174
  3175
  3176
  3177
  3178
  3179
  3180
  3181
  3182
  3183
  3184
  3185
  3186
  3187
  3188
  3189
  3190
  3191
  3192
  3193
  3194
  3195
  3196
  3197
  3198
  3199
  3200
  3201
  3202
  3203
  3204
  3205
  3206
  3207
  3208
  3209
  3210
  3211
  3212
  3213
  3214
  3215
  3216
  3217
  3218
  3219
  3220
  3221
  3222
  3223
  3224
  3225
  3226
  3227
  3228
  3229
  3230
  3231
  3232
  3233
  3234
  3235
  3236
  3237
  3238
  3239
  3240
  3241
  3242
  3243
  3244
  3245
  3246
  3247
  3248
  3249
  3250
  3251
  3252
  3253
  3254
  3255
  3256
  3257
  3258
  3259
  3260
  3261
  3262
  3263
  3264
  3265
  3266
  3267
  3268
  3269
  3270
  3271
  3272
  3273
  3274
  3275
  3276
  3277
  3278
  3279
  3280
  3281
  3282
  3283
  3284
  3285
  3286
  3287
  3288
  3289
  3290
  3291
  3292
  3293
  3294
  3295
  3296
  3297
  3298
  3299
  3300
  3301
  3302
  3303
  3304
  3305
  3306
  3307
  3308
  3309
  3310
  3311
  3312
  3313
  3314
  3315
  3316
  3317
  3318
  3319
  3320
  3321
  3322
  3323
  3324
  3325
  3326
  3327
  3328
  3329
  3330
  3331
  3332
  3333
  3334
  3335
  3336
  3337
  3338
  3339
  3340
  3341
  3342
  3343
  3344
  3345
  3346
  3347
  3348
  3349
  3350
  3351
  3352
  3353
  3354
  3355
  3356
  3357
  3358
  3359
  3360
  3361
  3362
  3363
  3364
  3365
  3366
  3367
  3368
  3369
  3370
  3371
  3372
  3373
  3374
  3375
  3376
  3377
  3378
  3379
  3380
  3381
  3382
  3383
  3384
  3385
  3386
  3387
  3388
  3389
  3390
  3391
  3392
  3393
  3394
  3395
  3396
  3397
  3398
  3399
  3400
  3401
  3402
  3403
  3404
  3405
  3406
  3407
  3408
  3409
  3410
  3411
  3412
  3413
  3414
  3415
  3416
  3417
  3418
  3419
  3420
  3421
  3422
  3423
  3424
  3425
  3426
  3427
  3428
  3429
  3430
  3431
  3432
  3433
  3434
  3435
  3436
  3437
  3438
  3439
  3440
  3441
  3442
  3443
  3444
  3445
  3446
  3447
  3448
  3449
  3450
  3451
  3452
  3453
  3454
  3455
  3456
  3457
  3458
  3459
  3460
  3461
  3462
  3463
  3464
  3465
  3466
  3467
  3468
  3469
  3470
  3471
  3472
  3473
  3474
  3475
  3476
  3477
  3478
  3479
  3480
  3481
  3482
  3483
  3484
  3485
  3486
  3487
  3488
  3489
  3490
  3491
  3492
  3493
  3494
  3495
  3496
  3497
  3498
  3499
  3500
  3501
  3502
  3503
  3504
  3505
  3506
  3507
  3508
  3509
  3510
  3511
  3512
  3513
  3514
  3515
  3516
  3517
  3518
  3519
  3520
  3521
  3522
  3523
  3524
  3525
  3526
  3527
  3528
  3529
  3530
  3531
  3532
  3533
  3534
  3535
  3536
  3537
  3538
  3539
  3540
  3541
  3542
  3543
  3544
  3545
  3546
  3547
  3548
  3549
  3550
  3551
  3552
  3553
  3554
  3555
  3556
  3557
  3558
  3559
  3560
  3561
  3562
  3563
  3564
  3565
  3566
  3567
  3568
  3569
  3570
  3571
  3572
  3573
  3574
  3575
  3576
  3577
  3578
  3579
  3580
  3581
  3582
  3583
  3584
  3585
  3586
  3587
  3588
  3589
  3590
  3591
  3592
  3593
  3594
  3595
  3596
  3597
  3598
  3599
  3600
  3601
  3602
  3603
  3604
  3605
  3606
  3607
  3608
  3609
  3610
  3611
  3612
  3613
  3614
  3615
  3616
  3617
  3618
  3619
  3620
  3621
  3622
  3623
  3624
  3625
  3626
  3627
  3628
  3629
  3630
  3631
  3632
  3633
  3634
  3635
  3636
  3637
  3638
  3639
  3640
  3641
  3642
  3643
  3644
  3645
  3646
  3647
  3648
  3649
  3650
  3651
  3652
  3653
  3654
  3655
  3656
  3657
  3658
  3659
  3660
  3661
  3662
  3663
  3664
  3665
  3666
  3667
  3668
  3669
  3670
  3671
  3672
  3673
  3674
  3675
  3676
  3677
  3678
  3679
  3680
  3681
  3682
  3683
  3684
  3685
  3686
  3687
  3688
  3689
  3690
  3691
  3692
  3693
  3694
  3695
  3696
  3697
  3698
  3699
  3700
  3701
  3702
  3703
  3704
  3705
  3706
  3707
  3708
  3709
  3710
  3711
  3712
  3713
  3714
  3715
  3716
  3717
  3718
  3719
  3720
  3721
  3722
  3723
  3724
  3725
  3726
  3727
  3728
  3729
  3730
  3731
  3732
  3733
  3734
  3735
  3736
  3737
  3738
  3739
  3740
  3741
  3742
  3743
  3744
  3745
  3746
  3747
  3748
  3749
  3750
  3751
  3752
  3753
  3754
  3755
  3756
  3757
  3758
  3759
  3760
  3761
  3762
  3763
  3764
  3765
  3766
  3767
  3768
  3769
  3770
  3771
  3772
  3773
  3774
  3775
  3776
  3777
  3778
  3779
  3780
  3781
  3782
  3783
  3784
  3785
  3786
  3787
  3788
  3789
  3790
  3791
  3792
  3793
  3794
  3795
  3796
  3797
  3798
  3799
  3800
  3801
  3802
  3803
  3804
  3805
  3806
  3807
  3808
  3809
  3810
  3811
  3812
  3813
  3814
  3815
  3816
  3817
  3818
  3819
  3820
  3821
  3822
  3823
  3824
  3825
  3826
  3827
  3828
  3829
  3830
  3831
  3832
  3833
  3834
  3835
  3836
  3837
  3838
  3839
  3840
  3841
  3842
  3843
  3844
  3845
  3846
  3847
  3848
  3849
  3850
  3851
  3852
  3853
  3854
  3855
  3856
  3857
  3858
  3859
  3860
  3861
  3862
  3863
  3864
  3865
  3866
  3867
  3868
  3869
  3870
  3871
  3872
  3873
  3874
  3875
  3876
  3877
  3878
  3879
  3880
  3881
  3882
  3883
  3884
  3885
  3886
  3887
  3888
  3889
  3890
  3891
  3892
  3893
  3894
  3895
  3896
  3897
  3898
  3899
  3900
  3901
  3902
  3903
  3904
  3905
  3906
  3907
  3908
  3909
  3910
  3911
  3912
  3913
  3914
  3915
  3916
  3917
  3918
  3919
  3920
  3921
  3922
  3923
  3924
  3925
  3926
  3927
  3928
  3929
  3930
  3931
  3932
  3933
  3934
  3935
  3936
  3937
  3938
  3939
  3940
  3941
  3942
  3943
  3944
  3945
  3946
  3947
  3948
  3949
  3950
  3951
  3952
  3953
  3954
  3955
  3956
  3957
  3958
  3959
  3960
  3961
  3962
  3963
  3964
  3965
  3966
  3967
  3968
  3969
  3970
  3971
  3972
  3973
  3974
  3975
  3976
  3977
  3978
  3979
  3980
  3981
  3982
  3983
  3984
  3985
  3986
  3987
  3988
  3989
  3990
  3991
  3992
  3993
  3994
  3995
  3996
  3997
  3998
  3999
  4000
  4001
  4002
  4003
  4004
  4005
  4006
  4007
  4008
  4009
  4010
  4011
  4012
  4013
  4014
  4015
  4016
  4017
  4018
  4019
  4020
  4021
  4022
  4023
  4024
  4025
  4026
  4027
  4028
  4029
  4030
  4031
  4032
  4033
  4034
  4035
  4036
  4037
  4038
  4039
  4040
  4041
  4042
  4043
  4044
  4045
  4046
  4047
  4048
  4049
  4050
  4051
  4052
  4053
  4054
  4055
  4056
  4057
  4058
  4059
  4060
  4061
  4062
  4063
  4064
  4065
  4066
  4067
  4068
  4069
  4070
  4071
  4072
  4073
  4074
  4075
  4076
  4077
  4078
  4079
  4080
  4081
  4082
  4083
  4084
  4085
  4086
  4087
  4088
  4089
  4090
  4091
  4092
  4093
  4094
  4095
  4096
  4097
  4098
  4099
  4100
  4101
  4102
  4103
  4104
  4105
  4106
  4107
  4108
  4109
  4110
  4111
  4112
  4113
  4114
  4115
  4116
  4117
  4118
  4119
  4120
  4121
  4122
  4123
  4124
  4125
  4126
  4127
  4128
  4129
  4130
  4131
  4132
  4133
  4134
  4135
  4136
  4137
  4138
  4139
  4140
  4141
  4142
  4143
  4144
  4145
  4146
  4147
  4148
  4149
  4150
  4151
  4152
  4153
  4154
  4155
  4156
  4157
  4158
  4159
  4160
  4161
  4162
  4163
  4164
  4165
  4166
  4167
  4168
  4169
  4170
  4171
  4172
  4173
  4174
  4175
  4176
  4177
  4178
  4179
  4180
  4181
  4182
  4183
  4184
  4185
  4186
  4187
  4188
  4189
  4190
  4191
  4192
  4193
  4194
  4195
  4196
  4197
  4198
  4199
  4200
  4201
  4202
  4203
  4204
  4205
  4206
  4207
  4208
  4209
  4210
  4211
  4212
  4213
  4214
  4215
  4216
  4217
  4218
  4219
  4220
  4221
  4222
  4223
  4224
  4225
  4226
  4227
  4228
  4229
  4230
  4231
  4232
  4233
  4234
  4235
  4236
  4237
  4238
  4239
  4240
  4241
  4242
  4243
  4244
  4245
  4246
  4247
  4248
  4249
  4250
  4251
  4252
  4253
  4254
  4255
  4256
  4257
  4258
  4259
  4260
  4261
  4262
  4263
  4264
  4265
  4266
  4267
  4268
  4269
  4270
  4271
  4272
  4273
  4274
  4275
  4276
  4277
  4278
  4279
  4280
  4281
  4282
  4283
  4284
  4285
  4286
  4287
  4288
  4289
  4290
  4291
  4292
  4293
  4294
  4295
  4296
  4297
  4298
  4299
  4300
  4301
  4302
  4303
  4304
  4305
  4306
  4307
  4308
  4309
  4310
  4311
  4312
  4313
  4314
  4315
  4316
  4317
  4318
  4319
  4320
  4321
  4322
  4323
  4324
  4325
  4326
  4327
  4328
  4329
  4330
  4331
  4332
  4333
  4334
  4335
  4336
  4337
  4338
  4339
  4340
  4341
  4342
  4343
  4344
  4345
  4346
  4347
  4348
  4349
  4350
  4351
  4352
  4353
  4354
  4355
  4356
  4357
  4358
  4359
  4360
  4361
  4362
  4363
  4364
  4365
  4366
  4367
  4368
  4369
  4370
  4371
  4372
  4373
  4374
  4375
  4376
  4377
  4378
  4379
  4380
  4381
  4382
  4383
  4384
  4385
  4386
  4387
  4388
  4389
  4390
  4391
  4392
  4393
  4394
  4395
  4396
  4397
  4398
  4399
  4400
  4401
  4402
  4403
  4404
  4405
  4406
  4407
  4408
  4409
  4410
  4411
  4412
  4413
  4414
  4415
  4416
  4417
  4418
  4419
  4420
  4421
  4422
  4423
  4424
  4425
  4426
  4427
  4428
  4429
  4430
  4431
  4432
  4433
  4434
  4435
  4436
  4437
  4438
  4439
  4440
  4441
  4442
  4443
  4444
  4445
  4446
  4447
  4448
  4449
  4450
  4451
  4452
  4453
  4454
  4455
  4456
  4457
  4458
  4459
  4460
  4461
  4462
  4463
  4464
  4465
  4466
  4467
  4468
  4469
  4470
  4471
  4472
  4473
  4474
  4475
  4476
  4477
  4478
  4479
  4480
  4481
  4482
  4483
  4484
  4485
  4486
  4487
  4488
  4489
  4490
  4491
  4492
  4493
  4494
  4495
  4496
  4497
  4498
  4499
  4500
  4501
  4502
  4503
  4504
  4505
  4506
  4507
  4508
  4509
  4510
  4511
  4512
  4513
  4514
  4515
  4516
  4517
  4518
  4519
  4520
  4521
  4522
  4523
  4524
  4525
  4526
  4527
  4528
  4529
  4530
  4531
  4532
  4533
  4534
  4535
  4536
  4537
  4538
  4539
  4540
  4541
  4542
  4543
  4544
  4545
  4546
  4547
  4548
  4549
  4550
  4551
  4552
  4553
  4554
  4555
  4556
  4557
  4558
  4559
  4560
  4561
  4562
  4563
  4564
  4565
  4566
  4567
  4568
  4569
  4570
  4571
  4572
  4573
  4574
  4575
  4576
  4577
  4578
  4579
  4580
  4581
  4582
  4583
  4584
  4585
  4586
  4587
  4588
  4589
  4590
  4591
  4592
  4593
  4594
  4595
  4596
  4597
  4598
  4599
  4600
  4601
  4602
  4603
  4604
  4605
  4606
  4607
  4608
  4609
  4610
  4611
  4612
  4613
  4614
  4615
  4616
  4617
  4618
  4619
  4620
  4621
  4622
  4623
  4624
  4625
  4626
  4627
  4628
  4629
  4630
  4631
  4632
  4633
  4634
  4635
  4636
  4637
  4638
  4639
  4640
  4641
  4642
  4643
  4644
  4645
  4646
  4647
  4648
  4649
  4650
  4651
  4652
  4653
/*
** 2001 September 15
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
*************************************************************************
** Main file for the SQLite library.  The routines in this file
** implement the programmer interface to the library.  Routines in
** other files are for internal use by SQLite and should not be
** accessed by users of the library.
*/
#include "sqliteInt.h"

#ifdef SQLITE_ENABLE_FTS3
# include "fts3.h"
#endif
#ifdef SQLITE_ENABLE_RTREE
# include "rtree.h"
#endif
#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
# include "sqliteicu.h"
#endif

/*
** This is an extension initializer that is a no-op and always
** succeeds, except that it fails if the fault-simulation is set
** to 500.
*/
static int sqlite3TestExtInit(sqlite3 *db){
  (void)db;
  return sqlite3FaultSim(500);
}


/*
** Forward declarations of external module initializer functions
** for modules that need them.
*/
#ifdef SQLITE_ENABLE_FTS1
int sqlite3Fts1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_FTS2
int sqlite3Fts2Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_FTS5
int sqlite3Fts5Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_JSON1
int sqlite3Json1Init(sqlite3*);
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
int sqlite3StmtVtabInit(sqlite3*);
#endif

/*
** An array of pointers to extension initializer functions for
** built-in extensions.
*/
static int (*const sqlite3BuiltinExtensions[])(sqlite3*) = {
#ifdef SQLITE_ENABLE_FTS1
  sqlite3Fts1Init,
#endif
#ifdef SQLITE_ENABLE_FTS2
  sqlite3Fts2Init,
#endif
#ifdef SQLITE_ENABLE_FTS3
  sqlite3Fts3Init,
#endif
#ifdef SQLITE_ENABLE_FTS5
  sqlite3Fts5Init,
#endif
#if defined(SQLITE_ENABLE_ICU) || defined(SQLITE_ENABLE_ICU_COLLATIONS)
  sqlite3IcuInit,
#endif
#ifdef SQLITE_ENABLE_RTREE
  sqlite3RtreeInit,
#endif
#ifdef SQLITE_ENABLE_DBPAGE_VTAB
  sqlite3DbpageRegister,
#endif
#ifdef SQLITE_ENABLE_DBSTAT_VTAB
  sqlite3DbstatRegister,
#endif
  sqlite3TestExtInit,
#ifdef SQLITE_ENABLE_JSON1
  sqlite3Json1Init,
#endif
#ifdef SQLITE_ENABLE_STMTVTAB
  sqlite3StmtVtabInit,
#endif
#ifdef SQLITE_ENABLE_BYTECODE_VTAB
  sqlite3VdbeBytecodeVtabInit,
#endif
};

#ifndef SQLITE_AMALGAMATION
/* IMPLEMENTATION-OF: R-46656-45156 The sqlite3_version[] string constant
** contains the text of SQLITE_VERSION macro.
*/
const char sqlite3_version[] = SQLITE_VERSION;
#endif

/* IMPLEMENTATION-OF: R-53536-42575 The sqlite3_libversion() function returns
** a pointer to the to the sqlite3_version[] string constant. 
*/
const char *sqlite3_libversion(void){ return sqlite3_version; }

/* IMPLEMENTATION-OF: R-25063-23286 The sqlite3_sourceid() function returns a
** pointer to a string constant whose value is the same as the
** SQLITE_SOURCE_ID C preprocessor macro. Except if SQLite is built using
** an edited copy of the amalgamation, then the last four characters of
** the hash might be different from SQLITE_SOURCE_ID.
*/
const char *sqlite3_sourceid(void){ return SQLITE_SOURCE_ID; }

/* IMPLEMENTATION-OF: R-35210-63508 The sqlite3_libversion_number() function
** returns an integer equal to SQLITE_VERSION_NUMBER.
*/
int sqlite3_libversion_number(void){ return SQLITE_VERSION_NUMBER; }

/* IMPLEMENTATION-OF: R-20790-14025 The sqlite3_threadsafe() function returns
** zero if and only if SQLite was compiled with mutexing code omitted due to
** the SQLITE_THREADSAFE compile-time option being set to 0.
*/
int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }

/*
** When compiling the test fixture or with debugging enabled (on Win32),
** this variable being set to non-zero will cause OSTRACE macros to emit
** extra diagnostic information.
*/
#ifdef SQLITE_HAVE_OS_TRACE
# ifndef SQLITE_DEBUG_OS_TRACE
#   define SQLITE_DEBUG_OS_TRACE 0
# endif
  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
#endif

#if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
/*
** If the following function pointer is not NULL and if
** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
** I/O active are written using this function.  These messages
** are intended for debugging activity only.
*/
SQLITE_API void (SQLITE_CDECL *sqlite3IoTrace)(const char*, ...) = 0;
#endif

/*
** If the following global variable points to a string which is the
** name of a directory, then that directory will be used to store
** temporary files.
**
** See also the "PRAGMA temp_store_directory" SQL command.
*/
char *sqlite3_temp_directory = 0;

/*
** If the following global variable points to a string which is the
** name of a directory, then that directory will be used to store
** all database files specified with a relative pathname.
**
** See also the "PRAGMA data_store_directory" SQL command.
*/
char *sqlite3_data_directory = 0;

/*
** Initialize SQLite.  
**
** This routine must be called to initialize the memory allocation,
** VFS, and mutex subsystems prior to doing any serious work with
** SQLite.  But as long as you do not compile with SQLITE_OMIT_AUTOINIT
** this routine will be called automatically by key routines such as
** sqlite3_open().  
**
** This routine is a no-op except on its very first call for the process,
** or for the first call after a call to sqlite3_shutdown.
**
** The first thread to call this routine runs the initialization to
** completion.  If subsequent threads call this routine before the first
** thread has finished the initialization process, then the subsequent
** threads must block until the first thread finishes with the initialization.
**
** The first thread might call this routine recursively.  Recursive
** calls to this routine should not block, of course.  Otherwise the
** initialization process would never complete.
**
** Let X be the first thread to enter this routine.  Let Y be some other
** thread.  Then while the initial invocation of this routine by X is
** incomplete, it is required that:
**
**    *  Calls to this routine from Y must block until the outer-most
**       call by X completes.
**
**    *  Recursive calls to this routine from thread X return immediately
**       without blocking.
*/
int sqlite3_initialize(void){
  MUTEX_LOGIC( sqlite3_mutex *pMainMtx; )      /* The main static mutex */
  int rc;                                      /* Result code */
#ifdef SQLITE_EXTRA_INIT
  int bRunExtraInit = 0;                       /* Extra initialization needed */
#endif

#ifdef SQLITE_OMIT_WSD
  rc = sqlite3_wsd_init(4096, 24);
  if( rc!=SQLITE_OK ){
    return rc;
  }
#endif

  /* If the following assert() fails on some obscure processor/compiler
  ** combination, the work-around is to set the correct pointer
  ** size at compile-time using -DSQLITE_PTRSIZE=n compile-time option */
  assert( SQLITE_PTRSIZE==sizeof(char*) );

  /* If SQLite is already completely initialized, then this call
  ** to sqlite3_initialize() should be a no-op.  But the initialization
  ** must be complete.  So isInit must not be set until the very end
  ** of this routine.
  */
  if( sqlite3GlobalConfig.isInit ){
    sqlite3MemoryBarrier();
    return SQLITE_OK;
  }

  /* Make sure the mutex subsystem is initialized.  If unable to 
  ** initialize the mutex subsystem, return early with the error.
  ** If the system is so sick that we are unable to allocate a mutex,
  ** there is not much SQLite is going to be able to do.
  **
  ** The mutex subsystem must take care of serializing its own
  ** initialization.
  */
  rc = sqlite3MutexInit();
  if( rc ) return rc;

  /* Initialize the malloc() system and the recursive pInitMutex mutex.
  ** This operation is protected by the STATIC_MAIN mutex.  Note that
  ** MutexAlloc() is called for a static mutex prior to initializing the
  ** malloc subsystem - this implies that the allocation of a static
  ** mutex must not require support from the malloc subsystem.
  */
  MUTEX_LOGIC( pMainMtx = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MAIN); )
  sqlite3_mutex_enter(pMainMtx);
  sqlite3GlobalConfig.isMutexInit = 1;
  if( !sqlite3GlobalConfig.isMallocInit ){
    rc = sqlite3MallocInit();
  }
  if( rc==SQLITE_OK ){
    sqlite3GlobalConfig.isMallocInit = 1;
    if( !sqlite3GlobalConfig.pInitMutex ){
      sqlite3GlobalConfig.pInitMutex =
           sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
      if( sqlite3GlobalConfig.bCoreMutex && !sqlite3GlobalConfig.pInitMutex ){
        rc = SQLITE_NOMEM_BKPT;
      }
    }
  }
  if( rc==SQLITE_OK ){
    sqlite3GlobalConfig.nRefInitMutex++;
  }
  sqlite3_mutex_leave(pMainMtx);

  /* If rc is not SQLITE_OK at this point, then either the malloc
  ** subsystem could not be initialized or the system failed to allocate
  ** the pInitMutex mutex. Return an error in either case.  */
  if( rc!=SQLITE_OK ){
    return rc;
  }

  /* Do the rest of the initialization under the recursive mutex so
  ** that we will be able to handle recursive calls into
  ** sqlite3_initialize().  The recursive calls normally come through
  ** sqlite3_os_init() when it invokes sqlite3_vfs_register(), but other
  ** recursive calls might also be possible.
  **
  ** IMPLEMENTATION-OF: R-00140-37445 SQLite automatically serializes calls
  ** to the xInit method, so the xInit method need not be threadsafe.
  **
  ** The following mutex is what serializes access to the appdef pcache xInit
  ** methods.  The sqlite3_pcache_methods.xInit() all is embedded in the
  ** call to sqlite3PcacheInitialize().
  */
  sqlite3_mutex_enter(sqlite3GlobalConfig.pInitMutex);
  if( sqlite3GlobalConfig.isInit==0 && sqlite3GlobalConfig.inProgress==0 ){
    sqlite3GlobalConfig.inProgress = 1;
#ifdef SQLITE_ENABLE_SQLLOG
    {
      extern void sqlite3_init_sqllog(void);
      sqlite3_init_sqllog();
    }
#endif
    memset(&sqlite3BuiltinFunctions, 0, sizeof(sqlite3BuiltinFunctions));
    sqlite3RegisterBuiltinFunctions();
    if( sqlite3GlobalConfig.isPCacheInit==0 ){
      rc = sqlite3PcacheInitialize();
    }
    if( rc==SQLITE_OK ){
      sqlite3GlobalConfig.isPCacheInit = 1;
      rc = sqlite3OsInit();
    }
#ifdef SQLITE_ENABLE_DESERIALIZE
    if( rc==SQLITE_OK ){
      rc = sqlite3MemdbInit();
    }
#endif
    if( rc==SQLITE_OK ){
      sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
          sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
      sqlite3MemoryBarrier();
      sqlite3GlobalConfig.isInit = 1;
#ifdef SQLITE_EXTRA_INIT
      bRunExtraInit = 1;
#endif
    }
    sqlite3GlobalConfig.inProgress = 0;
  }
  sqlite3_mutex_leave(sqlite3GlobalConfig.pInitMutex);

  /* Go back under the static mutex and clean up the recursive
  ** mutex to prevent a resource leak.
  */
  sqlite3_mutex_enter(pMainMtx);
  sqlite3GlobalConfig.nRefInitMutex--;
  if( sqlite3GlobalConfig.nRefInitMutex<=0 ){
    assert( sqlite3GlobalConfig.nRefInitMutex==0 );
    sqlite3_mutex_free(sqlite3GlobalConfig.pInitMutex);
    sqlite3GlobalConfig.pInitMutex = 0;
  }
  sqlite3_mutex_leave(pMainMtx);

  /* The following is just a sanity check to make sure SQLite has
  ** been compiled correctly.  It is important to run this code, but
  ** we don't want to run it too often and soak up CPU cycles for no
  ** reason.  So we run it once during initialization.
  */
#ifndef NDEBUG
#ifndef SQLITE_OMIT_FLOATING_POINT
  /* This section of code's only "output" is via assert() statements. */
  if( rc==SQLITE_OK ){
    u64 x = (((u64)1)<<63)-1;
    double y;
    assert(sizeof(x)==8);
    assert(sizeof(x)==sizeof(y));
    memcpy(&y, &x, 8);
    assert( sqlite3IsNaN(y) );
  }
#endif
#endif

  /* Do extra initialization steps requested by the SQLITE_EXTRA_INIT
  ** compile-time option.
  */
#ifdef SQLITE_EXTRA_INIT
  if( bRunExtraInit ){
    int SQLITE_EXTRA_INIT(const char*);
    rc = SQLITE_EXTRA_INIT(0);
  }
#endif

  return rc;
}

/*
** Undo the effects of sqlite3_initialize().  Must not be called while
** there are outstanding database connections or memory allocations or
** while any part of SQLite is otherwise in use in any thread.  This
** routine is not threadsafe.  But it is safe to invoke this routine
** on when SQLite is already shut down.  If SQLite is already shut down
** when this routine is invoked, then this routine is a harmless no-op.
*/
int sqlite3_shutdown(void){
#ifdef SQLITE_OMIT_WSD
  int rc = sqlite3_wsd_init(4096, 24);
  if( rc!=SQLITE_OK ){
    return rc;
  }
#endif

  if( sqlite3GlobalConfig.isInit ){
#ifdef SQLITE_EXTRA_SHUTDOWN
    void SQLITE_EXTRA_SHUTDOWN(void);
    SQLITE_EXTRA_SHUTDOWN();
#endif
    sqlite3_os_end();
    sqlite3_reset_auto_extension();
    sqlite3GlobalConfig.isInit = 0;
  }
  if( sqlite3GlobalConfig.isPCacheInit ){
    sqlite3PcacheShutdown();
    sqlite3GlobalConfig.isPCacheInit = 0;
  }
  if( sqlite3GlobalConfig.isMallocInit ){
    sqlite3MallocEnd();
    sqlite3GlobalConfig.isMallocInit = 0;

#ifndef SQLITE_OMIT_SHUTDOWN_DIRECTORIES
    /* The heap subsystem has now been shutdown and these values are supposed
    ** to be NULL or point to memory that was obtained from sqlite3_malloc(),
    ** which would rely on that heap subsystem; therefore, make sure these
    ** values cannot refer to heap memory that was just invalidated when the
    ** heap subsystem was shutdown.  This is only done if the current call to
    ** this function resulted in the heap subsystem actually being shutdown.
    */
    sqlite3_data_directory = 0;
    sqlite3_temp_directory = 0;
#endif
  }
  if( sqlite3GlobalConfig.isMutexInit ){
    sqlite3MutexEnd();
    sqlite3GlobalConfig.isMutexInit = 0;
  }

  return SQLITE_OK;
}

/*
** This API allows applications to modify the global configuration of
** the SQLite library at run-time.
**
** This routine should only be called when there are no outstanding
** database connections or memory allocations.  This routine is not
** threadsafe.  Failure to heed these warnings can lead to unpredictable
** behavior.
*/
int sqlite3_config(int op, ...){
  va_list ap;
  int rc = SQLITE_OK;

  /* sqlite3_config() shall return SQLITE_MISUSE if it is invoked while
  ** the SQLite library is in use. */
  if( sqlite3GlobalConfig.isInit ) return SQLITE_MISUSE_BKPT;

  va_start(ap, op);
  switch( op ){

    /* Mutex configuration options are only available in a threadsafe
    ** compile.
    */
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0  /* IMP: R-54466-46756 */
    case SQLITE_CONFIG_SINGLETHREAD: {
      /* EVIDENCE-OF: R-02748-19096 This option sets the threading mode to
      ** Single-thread. */
      sqlite3GlobalConfig.bCoreMutex = 0;  /* Disable mutex on core */
      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-20520-54086 */
    case SQLITE_CONFIG_MULTITHREAD: {
      /* EVIDENCE-OF: R-14374-42468 This option sets the threading mode to
      ** Multi-thread. */
      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
      sqlite3GlobalConfig.bFullMutex = 0;  /* Disable mutex on connections */
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-59593-21810 */
    case SQLITE_CONFIG_SERIALIZED: {
      /* EVIDENCE-OF: R-41220-51800 This option sets the threading mode to
      ** Serialized. */
      sqlite3GlobalConfig.bCoreMutex = 1;  /* Enable mutex on core */
      sqlite3GlobalConfig.bFullMutex = 1;  /* Enable mutex on connections */
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-63666-48755 */
    case SQLITE_CONFIG_MUTEX: {
      /* Specify an alternative mutex implementation */
      sqlite3GlobalConfig.mutex = *va_arg(ap, sqlite3_mutex_methods*);
      break;
    }
#endif
#if defined(SQLITE_THREADSAFE) && SQLITE_THREADSAFE>0 /* IMP: R-14450-37597 */
    case SQLITE_CONFIG_GETMUTEX: {
      /* Retrieve the current mutex implementation */
      *va_arg(ap, sqlite3_mutex_methods*) = sqlite3GlobalConfig.mutex;
      break;
    }
#endif

    case SQLITE_CONFIG_MALLOC: {
      /* EVIDENCE-OF: R-55594-21030 The SQLITE_CONFIG_MALLOC option takes a
      ** single argument which is a pointer to an instance of the
      ** sqlite3_mem_methods structure. The argument specifies alternative
      ** low-level memory allocation routines to be used in place of the memory
      ** allocation routines built into SQLite. */
      sqlite3GlobalConfig.m = *va_arg(ap, sqlite3_mem_methods*);
      break;
    }
    case SQLITE_CONFIG_GETMALLOC: {
      /* EVIDENCE-OF: R-51213-46414 The SQLITE_CONFIG_GETMALLOC option takes a
      ** single argument which is a pointer to an instance of the
      ** sqlite3_mem_methods structure. The sqlite3_mem_methods structure is
      ** filled with the currently defined memory allocation routines. */
      if( sqlite3GlobalConfig.m.xMalloc==0 ) sqlite3MemSetDefault();
      *va_arg(ap, sqlite3_mem_methods*) = sqlite3GlobalConfig.m;
      break;
    }
    case SQLITE_CONFIG_MEMSTATUS: {
      /* EVIDENCE-OF: R-61275-35157 The SQLITE_CONFIG_MEMSTATUS option takes
      ** single argument of type int, interpreted as a boolean, which enables
      ** or disables the collection of memory allocation statistics. */
      sqlite3GlobalConfig.bMemstat = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_SMALL_MALLOC: {
      sqlite3GlobalConfig.bSmallMalloc = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_PAGECACHE: {
      /* EVIDENCE-OF: R-18761-36601 There are three arguments to
      ** SQLITE_CONFIG_PAGECACHE: A pointer to 8-byte aligned memory (pMem),
      ** the size of each page cache line (sz), and the number of cache lines
      ** (N). */
      sqlite3GlobalConfig.pPage = va_arg(ap, void*);
      sqlite3GlobalConfig.szPage = va_arg(ap, int);
      sqlite3GlobalConfig.nPage = va_arg(ap, int);
      break;
    }
    case SQLITE_CONFIG_PCACHE_HDRSZ: {
      /* EVIDENCE-OF: R-39100-27317 The SQLITE_CONFIG_PCACHE_HDRSZ option takes
      ** a single parameter which is a pointer to an integer and writes into
      ** that integer the number of extra bytes per page required for each page
      ** in SQLITE_CONFIG_PAGECACHE. */
      *va_arg(ap, int*) = 
          sqlite3HeaderSizeBtree() +
          sqlite3HeaderSizePcache() +
          sqlite3HeaderSizePcache1();
      break;
    }

    case SQLITE_CONFIG_PCACHE: {
      /* no-op */
      break;
    }
    case SQLITE_CONFIG_GETPCACHE: {
      /* now an error */
      rc = SQLITE_ERROR;
      break;
    }

    case SQLITE_CONFIG_PCACHE2: {
      /* EVIDENCE-OF: R-63325-48378 The SQLITE_CONFIG_PCACHE2 option takes a
      ** single argument which is a pointer to an sqlite3_pcache_methods2
      ** object. This object specifies the interface to a custom page cache
      ** implementation. */
      sqlite3GlobalConfig.pcache2 = *va_arg(ap, sqlite3_pcache_methods2*);
      break;
    }
    case SQLITE_CONFIG_GETPCACHE2: {
      /* EVIDENCE-OF: R-22035-46182 The SQLITE_CONFIG_GETPCACHE2 option takes a
      ** single argument which is a pointer to an sqlite3_pcache_methods2
      ** object. SQLite copies of the current page cache implementation into
      ** that object. */
      if( sqlite3GlobalConfig.pcache2.xInit==0 ){
        sqlite3PCacheSetDefault();
      }
      *va_arg(ap, sqlite3_pcache_methods2*) = sqlite3GlobalConfig.pcache2;
      break;
    }

/* EVIDENCE-OF: R-06626-12911 The SQLITE_CONFIG_HEAP option is only
** available if SQLite is compiled with either SQLITE_ENABLE_MEMSYS3 or
** SQLITE_ENABLE_MEMSYS5 and returns SQLITE_ERROR if invoked otherwise. */
#if defined(SQLITE_ENABLE_MEMSYS3) || defined(SQLITE_ENABLE_MEMSYS5)
    case SQLITE_CONFIG_HEAP: {
      /* EVIDENCE-OF: R-19854-42126 There are three arguments to
      ** SQLITE_CONFIG_HEAP: An 8-byte aligned pointer to the memory, the
      ** number of bytes in the memory buffer, and the minimum allocation size.
      */
      sqlite3GlobalConfig.pHeap = va_arg(ap, void*);
      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
      sqlite3GlobalConfig.mnReq = va_arg(ap, int);

      if( sqlite3GlobalConfig.mnReq<1 ){
        sqlite3GlobalConfig.mnReq = 1;
      }else if( sqlite3GlobalConfig.mnReq>(1<<12) ){
        /* cap min request size at 2^12 */
        sqlite3GlobalConfig.mnReq = (1<<12);
      }

      if( sqlite3GlobalConfig.pHeap==0 ){
        /* EVIDENCE-OF: R-49920-60189 If the first pointer (the memory pointer)
        ** is NULL, then SQLite reverts to using its default memory allocator
        ** (the system malloc() implementation), undoing any prior invocation of
        ** SQLITE_CONFIG_MALLOC.
        **
        ** Setting sqlite3GlobalConfig.m to all zeros will cause malloc to
        ** revert to its default implementation when sqlite3_initialize() is run
        */
        memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
      }else{
        /* EVIDENCE-OF: R-61006-08918 If the memory pointer is not NULL then the
        ** alternative memory allocator is engaged to handle all of SQLites
        ** memory allocation needs. */
#ifdef SQLITE_ENABLE_MEMSYS3
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
#endif
#ifdef SQLITE_ENABLE_MEMSYS5
        sqlite3GlobalConfig.m = *sqlite3MemGetMemsys5();
#endif
      }
      break;
    }
#endif

    case SQLITE_CONFIG_LOOKASIDE: {
      sqlite3GlobalConfig.szLookaside = va_arg(ap, int);
      sqlite3GlobalConfig.nLookaside = va_arg(ap, int);
      break;
    }
    
    /* Record a pointer to the logger function and its first argument.
    ** The default is NULL.  Logging is disabled if the function pointer is
    ** NULL.
    */
    case SQLITE_CONFIG_LOG: {
      /* MSVC is picky about pulling func ptrs from va lists.
      ** http://support.microsoft.com/kb/47961
      ** sqlite3GlobalConfig.xLog = va_arg(ap, void(*)(void*,int,const char*));
      */
      typedef void(*LOGFUNC_t)(void*,int,const char*);
      sqlite3GlobalConfig.xLog = va_arg(ap, LOGFUNC_t);
      sqlite3GlobalConfig.pLogArg = va_arg(ap, void*);
      break;
    }

    /* EVIDENCE-OF: R-55548-33817 The compile-time setting for URI filenames
    ** can be changed at start-time using the
    ** sqlite3_config(SQLITE_CONFIG_URI,1) or
    ** sqlite3_config(SQLITE_CONFIG_URI,0) configuration calls.
    */
    case SQLITE_CONFIG_URI: {
      /* EVIDENCE-OF: R-25451-61125 The SQLITE_CONFIG_URI option takes a single
      ** argument of type int. If non-zero, then URI handling is globally
      ** enabled. If the parameter is zero, then URI handling is globally
      ** disabled. */
      sqlite3GlobalConfig.bOpenUri = va_arg(ap, int);
      break;
    }

    case SQLITE_CONFIG_COVERING_INDEX_SCAN: {
      /* EVIDENCE-OF: R-36592-02772 The SQLITE_CONFIG_COVERING_INDEX_SCAN
      ** option takes a single integer argument which is interpreted as a
      ** boolean in order to enable or disable the use of covering indices for
      ** full table scans in the query optimizer. */
      sqlite3GlobalConfig.bUseCis = va_arg(ap, int);
      break;
    }

#ifdef SQLITE_ENABLE_SQLLOG
    case SQLITE_CONFIG_SQLLOG: {
      typedef void(*SQLLOGFUNC_t)(void*, sqlite3*, const char*, int);
      sqlite3GlobalConfig.xSqllog = va_arg(ap, SQLLOGFUNC_t);
      sqlite3GlobalConfig.pSqllogArg = va_arg(ap, void *);
      break;
    }
#endif

    case SQLITE_CONFIG_MMAP_SIZE: {
      /* EVIDENCE-OF: R-58063-38258 SQLITE_CONFIG_MMAP_SIZE takes two 64-bit
      ** integer (sqlite3_int64) values that are the default mmap size limit
      ** (the default setting for PRAGMA mmap_size) and the maximum allowed
      ** mmap size limit. */
      sqlite3_int64 szMmap = va_arg(ap, sqlite3_int64);
      sqlite3_int64 mxMmap = va_arg(ap, sqlite3_int64);
      /* EVIDENCE-OF: R-53367-43190 If either argument to this option is
      ** negative, then that argument is changed to its compile-time default.
      **
      ** EVIDENCE-OF: R-34993-45031 The maximum allowed mmap size will be
      ** silently truncated if necessary so that it does not exceed the
      ** compile-time maximum mmap size set by the SQLITE_MAX_MMAP_SIZE
      ** compile-time option.
      */
      if( mxMmap<0 || mxMmap>SQLITE_MAX_MMAP_SIZE ){
        mxMmap = SQLITE_MAX_MMAP_SIZE;
      }
      if( szMmap<0 ) szMmap = SQLITE_DEFAULT_MMAP_SIZE;
      if( szMmap>mxMmap) szMmap = mxMmap;
      sqlite3GlobalConfig.mxMmap = mxMmap;
      sqlite3GlobalConfig.szMmap = szMmap;
      break;
    }

#if SQLITE_OS_WIN && defined(SQLITE_WIN32_MALLOC) /* IMP: R-04780-55815 */
    case SQLITE_CONFIG_WIN32_HEAPSIZE: {
      /* EVIDENCE-OF: R-34926-03360 SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit
      ** unsigned integer value that specifies the maximum size of the created
      ** heap. */
      sqlite3GlobalConfig.nHeap = va_arg(ap, int);
      break;
    }
#endif

    case SQLITE_CONFIG_PMASZ: {
      sqlite3GlobalConfig.szPma = va_arg(ap, unsigned int);
      break;
    }

    case SQLITE_CONFIG_STMTJRNL_SPILL: {
      sqlite3GlobalConfig.nStmtSpill = va_arg(ap, int);
      break;
    }

#ifdef SQLITE_ENABLE_SORTER_REFERENCES
    case SQLITE_CONFIG_SORTERREF_SIZE: {
      int iVal = va_arg(ap, int);
      if( iVal<0 ){
        iVal = SQLITE_DEFAULT_SORTERREF_SIZE;
      }
      sqlite3GlobalConfig.szSorterRef = (u32)iVal;
      break;
    }
#endif /* SQLITE_ENABLE_SORTER_REFERENCES */

#ifdef SQLITE_ENABLE_DESERIALIZE
    case SQLITE_CONFIG_MEMDB_MAXSIZE: {
      sqlite3GlobalConfig.mxMemdbSize = va_arg(ap, sqlite3_int64);
      break;
    }
#endif /* SQLITE_ENABLE_DESERIALIZE */

    default: {
      rc = SQLITE_ERROR;
      break;
    }
  }
  va_end(ap);
  return rc;
}

/*
** Set up the lookaside buffers for a database connection.
** Return SQLITE_OK on success.  
** If lookaside is already active, return SQLITE_BUSY.
**
** The sz parameter is the number of bytes in each lookaside slot.
** The cnt parameter is the number of slots.  If pStart is NULL the
** space for the lookaside memory is obtained from sqlite3_malloc().
** If pStart is not NULL then it is sz*cnt bytes of memory to use for
** the lookaside memory.
*/
static int setupLookaside(sqlite3 *db, void *pBuf, int sz, int cnt){
#ifndef SQLITE_OMIT_LOOKASIDE
  void *pStart;
  sqlite3_int64 szAlloc = sz*(sqlite3_int64)cnt;
  int nBig;   /* Number of full-size slots */
  int nSm;    /* Number smaller LOOKASIDE_SMALL-byte slots */
  
  if( sqlite3LookasideUsed(db,0)>0 ){
    return SQLITE_BUSY;
  }
  /* Free any existing lookaside buffer for this handle before
  ** allocating a new one so we don't have to have space for 
  ** both at the same time.
  */
  if( db->lookaside.bMalloced ){
    sqlite3_free(db->lookaside.pStart);
  }
  /* The size of a lookaside slot after ROUNDDOWN8 needs to be larger
  ** than a pointer to be useful.
  */
  sz = ROUNDDOWN8(sz);  /* IMP: R-33038-09382 */
  if( sz<=(int)sizeof(LookasideSlot*) ) sz = 0;
  if( cnt<0 ) cnt = 0;
  if( sz==0 || cnt==0 ){
    sz = 0;
    pStart = 0;
  }else if( pBuf==0 ){
    sqlite3BeginBenignMalloc();
    pStart = sqlite3Malloc( szAlloc );  /* IMP: R-61949-35727 */
    sqlite3EndBenignMalloc();
    if( pStart ) szAlloc = sqlite3MallocSize(pStart);
  }else{
    pStart = pBuf;
  }
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
  if( sz>=LOOKASIDE_SMALL*3 ){
    nBig = szAlloc/(3*LOOKASIDE_SMALL+sz);
    nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
  }else if( sz>=LOOKASIDE_SMALL*2 ){
    nBig = szAlloc/(LOOKASIDE_SMALL+sz);
    nSm = (szAlloc - sz*nBig)/LOOKASIDE_SMALL;
  }else
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
  if( sz>0 ){
    nBig = szAlloc/sz;
    nSm = 0;
  }else{
    nBig = nSm = 0;
  }
  db->lookaside.pStart = pStart;
  db->lookaside.pInit = 0;
  db->lookaside.pFree = 0;
  db->lookaside.sz = (u16)sz;
  db->lookaside.szTrue = (u16)sz;
  if( pStart ){
    int i;
    LookasideSlot *p;
    assert( sz > (int)sizeof(LookasideSlot*) );
    p = (LookasideSlot*)pStart;
    for(i=0; i<nBig; i++){
      p->pNext = db->lookaside.pInit;
      db->lookaside.pInit = p;
      p = (LookasideSlot*)&((u8*)p)[sz];
    }
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
    db->lookaside.pSmallInit = 0;
    db->lookaside.pSmallFree = 0;
    db->lookaside.pMiddle = p;
    for(i=0; i<nSm; i++){
      p->pNext = db->lookaside.pSmallInit;
      db->lookaside.pSmallInit = p;
      p = (LookasideSlot*)&((u8*)p)[LOOKASIDE_SMALL];
    }
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
    assert( ((uptr)p)<=szAlloc + (uptr)pStart );
    db->lookaside.pEnd = p;
    db->lookaside.bDisable = 0;
    db->lookaside.bMalloced = pBuf==0 ?1:0;
    db->lookaside.nSlot = nBig+nSm;
  }else{
    db->lookaside.pStart = db;
#ifndef SQLITE_OMIT_TWOSIZE_LOOKASIDE
    db->lookaside.pSmallInit = 0;
    db->lookaside.pSmallFree = 0;
    db->lookaside.pMiddle = db;
#endif /* SQLITE_OMIT_TWOSIZE_LOOKASIDE */
    db->lookaside.pEnd = db;
    db->lookaside.bDisable = 1;
    db->lookaside.sz = 0;
    db->lookaside.bMalloced = 0;
    db->lookaside.nSlot = 0;
  }
  assert( sqlite3LookasideUsed(db,0)==0 );
#endif /* SQLITE_OMIT_LOOKASIDE */
  return SQLITE_OK;
}

/*
** Return the mutex associated with a database connection.
*/
sqlite3_mutex *sqlite3_db_mutex(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->mutex;
}

/*
** Free up as much memory as we can from the given database
** connection.
*/
int sqlite3_db_release_memory(sqlite3 *db){
  int i;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  for(i=0; i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt ){
      Pager *pPager = sqlite3BtreePager(pBt);
      sqlite3PagerShrink(pPager);
    }
  }
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** Flush any dirty pages in the pager-cache for any attached database
** to disk.
*/
int sqlite3_db_cacheflush(sqlite3 *db){
  int i;
  int rc = SQLITE_OK;
  int bSeenBusy = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  for(i=0; rc==SQLITE_OK && i<db->nDb; i++){
    Btree *pBt = db->aDb[i].pBt;
    if( pBt && sqlite3BtreeTxnState(pBt)==SQLITE_TXN_WRITE ){
      Pager *pPager = sqlite3BtreePager(pBt);
      rc = sqlite3PagerFlush(pPager);
      if( rc==SQLITE_BUSY ){
        bSeenBusy = 1;
        rc = SQLITE_OK;
      }
    }
  }
  sqlite3BtreeLeaveAll(db);
  sqlite3_mutex_leave(db->mutex);
  return ((rc==SQLITE_OK && bSeenBusy) ? SQLITE_BUSY : rc);
}

/*
** Configuration settings for an individual database connection
*/
int sqlite3_db_config(sqlite3 *db, int op, ...){
  va_list ap;
  int rc;
  va_start(ap, op);
  switch( op ){
    case SQLITE_DBCONFIG_MAINDBNAME: {
      /* IMP: R-06824-28531 */
      /* IMP: R-36257-52125 */
      db->aDb[0].zDbSName = va_arg(ap,char*);
      rc = SQLITE_OK;
      break;
    }
    case SQLITE_DBCONFIG_LOOKASIDE: {
      void *pBuf = va_arg(ap, void*); /* IMP: R-26835-10964 */
      int sz = va_arg(ap, int);       /* IMP: R-47871-25994 */
      int cnt = va_arg(ap, int);      /* IMP: R-04460-53386 */
      rc = setupLookaside(db, pBuf, sz, cnt);
      break;
    }
    default: {
      static const struct {
        int op;      /* The opcode */
        u32 mask;    /* Mask of the bit in sqlite3.flags to set/clear */
      } aFlagOp[] = {
        { SQLITE_DBCONFIG_ENABLE_FKEY,           SQLITE_ForeignKeys    },
        { SQLITE_DBCONFIG_ENABLE_TRIGGER,        SQLITE_EnableTrigger  },
        { SQLITE_DBCONFIG_ENABLE_VIEW,           SQLITE_EnableView     },
        { SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER, SQLITE_Fts3Tokenizer  },
        { SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION, SQLITE_LoadExtension  },
        { SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE,      SQLITE_NoCkptOnClose  },
        { SQLITE_DBCONFIG_ENABLE_QPSG,           SQLITE_EnableQPSG     },
        { SQLITE_DBCONFIG_TRIGGER_EQP,           SQLITE_TriggerEQP     },
        { SQLITE_DBCONFIG_RESET_DATABASE,        SQLITE_ResetDatabase  },
        { SQLITE_DBCONFIG_DEFENSIVE,             SQLITE_Defensive      },
        { SQLITE_DBCONFIG_WRITABLE_SCHEMA,       SQLITE_WriteSchema|
                                                 SQLITE_NoSchemaError  },
        { SQLITE_DBCONFIG_LEGACY_ALTER_TABLE,    SQLITE_LegacyAlter    },
        { SQLITE_DBCONFIG_DQS_DDL,               SQLITE_DqsDDL         },
        { SQLITE_DBCONFIG_DQS_DML,               SQLITE_DqsDML         },
        { SQLITE_DBCONFIG_LEGACY_FILE_FORMAT,    SQLITE_LegacyFileFmt  },
        { SQLITE_DBCONFIG_TRUSTED_SCHEMA,        SQLITE_TrustedSchema  },
      };
      unsigned int i;
      rc = SQLITE_ERROR; /* IMP: R-42790-23372 */
      for(i=0; i<ArraySize(aFlagOp); i++){
        if( aFlagOp[i].op==op ){
          int onoff = va_arg(ap, int);
          int *pRes = va_arg(ap, int*);
          u64 oldFlags = db->flags;
          if( onoff>0 ){
            db->flags |= aFlagOp[i].mask;
          }else if( onoff==0 ){
            db->flags &= ~(u64)aFlagOp[i].mask;
          }
          if( oldFlags!=db->flags ){
            sqlite3ExpirePreparedStatements(db, 0);
          }
          if( pRes ){
            *pRes = (db->flags & aFlagOp[i].mask)!=0;
          }
          rc = SQLITE_OK;
          break;
        }
      }
      break;
    }
  }
  va_end(ap);
  return rc;
}

/*
** This is the default collating function named "BINARY" which is always
** available.
*/
static int binCollFunc(
  void *NotUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  int rc, n;
  UNUSED_PARAMETER(NotUsed);
  n = nKey1<nKey2 ? nKey1 : nKey2;
  /* EVIDENCE-OF: R-65033-28449 The built-in BINARY collation compares
  ** strings byte by byte using the memcmp() function from the standard C
  ** library. */
  assert( pKey1 && pKey2 );
  rc = memcmp(pKey1, pKey2, n);
  if( rc==0 ){
    rc = nKey1 - nKey2;
  }
  return rc;
}

/*
** This is the collating function named "RTRIM" which is always
** available.  Ignore trailing spaces.
*/
static int rtrimCollFunc(
  void *pUser,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  const u8 *pK1 = (const u8*)pKey1;
  const u8 *pK2 = (const u8*)pKey2;
  while( nKey1 && pK1[nKey1-1]==' ' ) nKey1--;
  while( nKey2 && pK2[nKey2-1]==' ' ) nKey2--;
  return binCollFunc(pUser, nKey1, pKey1, nKey2, pKey2);
}

/*
** Return true if CollSeq is the default built-in BINARY.
*/
int sqlite3IsBinary(const CollSeq *p){
  assert( p==0 || p->xCmp!=binCollFunc || strcmp(p->zName,"BINARY")==0 );
  return p==0 || p->xCmp==binCollFunc;
}

/*
** Another built-in collating sequence: NOCASE. 
**
** This collating sequence is intended to be used for "case independent
** comparison". SQLite's knowledge of upper and lower case equivalents
** extends only to the 26 characters used in the English language.
**
** At the moment there is only a UTF-8 implementation.
*/
static int nocaseCollatingFunc(
  void *NotUsed,
  int nKey1, const void *pKey1,
  int nKey2, const void *pKey2
){
  int r = sqlite3StrNICmp(
      (const char *)pKey1, (const char *)pKey2, (nKey1<nKey2)?nKey1:nKey2);
  UNUSED_PARAMETER(NotUsed);
  if( 0==r ){
    r = nKey1-nKey2;
  }
  return r;
}

/*
** Return the ROWID of the most recent insert
*/
sqlite_int64 sqlite3_last_insert_rowid(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->lastRowid;
}

/*
** Set the value returned by the sqlite3_last_insert_rowid() API function.
*/
void sqlite3_set_last_insert_rowid(sqlite3 *db, sqlite3_int64 iRowid){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  db->lastRowid = iRowid;
  sqlite3_mutex_leave(db->mutex);
}

/*
** Return the number of changes in the most recent call to sqlite3_exec().
*/
int sqlite3_changes(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->nChange;
}

/*
** Return the number of changes since the database handle was opened.
*/
int sqlite3_total_changes(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->nTotalChange;
}

/*
** Close all open savepoints. This function only manipulates fields of the
** database handle object, it does not close any savepoints that may be open
** at the b-tree/pager level.
*/
void sqlite3CloseSavepoints(sqlite3 *db){
  while( db->pSavepoint ){
    Savepoint *pTmp = db->pSavepoint;
    db->pSavepoint = pTmp->pNext;
    sqlite3DbFree(db, pTmp);
  }
  db->nSavepoint = 0;
  db->nStatement = 0;
  db->isTransactionSavepoint = 0;
}

/*
** Invoke the destructor function associated with FuncDef p, if any. Except,
** if this is not the last copy of the function, do not invoke it. Multiple
** copies of a single function are created when create_function() is called
** with SQLITE_ANY as the encoding.
*/
static void functionDestroy(sqlite3 *db, FuncDef *p){
  FuncDestructor *pDestructor = p->u.pDestructor;
  if( pDestructor ){
    pDestructor->nRef--;
    if( pDestructor->nRef==0 ){
      pDestructor->xDestroy(pDestructor->pUserData);
      sqlite3DbFree(db, pDestructor);
    }
  }
}

/*
** Disconnect all sqlite3_vtab objects that belong to database connection
** db. This is called when db is being closed.
*/
static void disconnectAllVtab(sqlite3 *db){
#ifndef SQLITE_OMIT_VIRTUALTABLE
  int i;
  HashElem *p;
  sqlite3BtreeEnterAll(db);
  for(i=0; i<db->nDb; i++){
    Schema *pSchema = db->aDb[i].pSchema;
    if( pSchema ){
      for(p=sqliteHashFirst(&pSchema->tblHash); p; p=sqliteHashNext(p)){
        Table *pTab = (Table *)sqliteHashData(p);
        if( IsVirtual(pTab) ) sqlite3VtabDisconnect(db, pTab);
      }
    }
  }
  for(p=sqliteHashFirst(&db->aModule); p; p=sqliteHashNext(p)){
    Module *pMod = (Module *)sqliteHashData(p);
    if( pMod->pEpoTab ){
      sqlite3VtabDisconnect(db, pMod->pEpoTab);
    }
  }
  sqlite3VtabUnlockList(db);
  sqlite3BtreeLeaveAll(db);
#else
  UNUSED_PARAMETER(db);
#endif
}

/*
** Return TRUE if database connection db has unfinalized prepared
** statements or unfinished sqlite3_backup objects.  
*/
static int connectionIsBusy(sqlite3 *db){
  int j;
  assert( sqlite3_mutex_held(db->mutex) );
  if( db->pVdbe ) return 1;
  for(j=0; j<db->nDb; j++){
    Btree *pBt = db->aDb[j].pBt;
    if( pBt && sqlite3BtreeIsInBackup(pBt) ) return 1;
  }
  return 0;
}

/*
** Close an existing SQLite database
*/
static int sqlite3Close(sqlite3 *db, int forceZombie){
  if( !db ){
    /* EVIDENCE-OF: R-63257-11740 Calling sqlite3_close() or
    ** sqlite3_close_v2() with a NULL pointer argument is a harmless no-op. */
    return SQLITE_OK;
  }
  if( !sqlite3SafetyCheckSickOrOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
  sqlite3_mutex_enter(db->mutex);
  if( db->mTrace & SQLITE_TRACE_CLOSE ){
    db->trace.xV2(SQLITE_TRACE_CLOSE, db->pTraceArg, db, 0);
  }

  /* Force xDisconnect calls on all virtual tables */
  disconnectAllVtab(db);

  /* If a transaction is open, the disconnectAllVtab() call above
  ** will not have called the xDisconnect() method on any virtual
  ** tables in the db->aVTrans[] array. The following sqlite3VtabRollback()
  ** call will do so. We need to do this before the check for active
  ** SQL statements below, as the v-table implementation may be storing
  ** some prepared statements internally.
  */
  sqlite3VtabRollback(db);

  /* Legacy behavior (sqlite3_close() behavior) is to return
  ** SQLITE_BUSY if the connection can not be closed immediately.
  */
  if( !forceZombie && connectionIsBusy(db) ){
    sqlite3ErrorWithMsg(db, SQLITE_BUSY, "unable to close due to unfinalized "
       "statements or unfinished backups");
    sqlite3_mutex_leave(db->mutex);
    return SQLITE_BUSY;
  }

#ifdef SQLITE_ENABLE_SQLLOG
  if( sqlite3GlobalConfig.xSqllog ){
    /* Closing the handle. Fourth parameter is passed the value 2. */
    sqlite3GlobalConfig.xSqllog(sqlite3GlobalConfig.pSqllogArg, db, 0, 2);
  }
#endif

  /* Convert the connection into a zombie and then close it.
  */
  db->magic = SQLITE_MAGIC_ZOMBIE;
  sqlite3LeaveMutexAndCloseZombie(db);
  return SQLITE_OK;
}

/*
** Return the transaction state for a single databse, or the maximum
** transaction state over all attached databases if zSchema is null.
*/
int sqlite3_txn_state(sqlite3 *db, const char *zSchema){
  int iDb, nDb;
  int iTxn = -1;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return -1;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( zSchema ){
    nDb = iDb = sqlite3FindDbName(db, zSchema);
    if( iDb<0 ) nDb--;
  }else{
    iDb = 0;
    nDb = db->nDb-1;
  }
  for(; iDb<=nDb; iDb++){
    Btree *pBt = db->aDb[iDb].pBt;
    int x = pBt!=0 ? sqlite3BtreeTxnState(pBt) : SQLITE_TXN_NONE;
    if( x>iTxn ) iTxn = x;
  }
  sqlite3_mutex_leave(db->mutex);
  return iTxn;
}

/*
** Two variations on the public interface for closing a database
** connection. The sqlite3_close() version returns SQLITE_BUSY and
** leaves the connection option if there are unfinalized prepared
** statements or unfinished sqlite3_backups.  The sqlite3_close_v2()
** version forces the connection to become a zombie if there are
** unclosed resources, and arranges for deallocation when the last
** prepare statement or sqlite3_backup closes.
*/
int sqlite3_close(sqlite3 *db){ return sqlite3Close(db,0); }
int sqlite3_close_v2(sqlite3 *db){ return sqlite3Close(db,1); }


/*
** Close the mutex on database connection db.
**
** Furthermore, if database connection db is a zombie (meaning that there
** has been a prior call to sqlite3_close(db) or sqlite3_close_v2(db)) and
** every sqlite3_stmt has now been finalized and every sqlite3_backup has
** finished, then free all resources.
*/
void sqlite3LeaveMutexAndCloseZombie(sqlite3 *db){
  HashElem *i;                    /* Hash table iterator */
  int j;

  /* If there are outstanding sqlite3_stmt or sqlite3_backup objects
  ** or if the connection has not yet been closed by sqlite3_close_v2(),
  ** then just leave the mutex and return.
  */
  if( db->magic!=SQLITE_MAGIC_ZOMBIE || connectionIsBusy(db) ){
    sqlite3_mutex_leave(db->mutex);
    return;
  }

  /* If we reach this point, it means that the database connection has
  ** closed all sqlite3_stmt and sqlite3_backup objects and has been
  ** passed to sqlite3_close (meaning that it is a zombie).  Therefore,
  ** go ahead and free all resources.
  */

  /* If a transaction is open, roll it back. This also ensures that if
  ** any database schemas have been modified by an uncommitted transaction
  ** they are reset. And that the required b-tree mutex is held to make
  ** the pager rollback and schema reset an atomic operation. */
  sqlite3RollbackAll(db, SQLITE_OK);

  /* Free any outstanding Savepoint structures. */
  sqlite3CloseSavepoints(db);

  /* Close all database connections */
  for(j=0; j<db->nDb; j++){
    struct Db *pDb = &db->aDb[j];
    if( pDb->pBt ){
      sqlite3BtreeClose(pDb->pBt);
      pDb->pBt = 0;
      if( j!=1 ){
        pDb->pSchema = 0;
      }
    }
  }
  /* Clear the TEMP schema separately and last */
  if( db->aDb[1].pSchema ){
    sqlite3SchemaClear(db->aDb[1].pSchema);
  }
  sqlite3VtabUnlockList(db);

  /* Free up the array of auxiliary databases */
  sqlite3CollapseDatabaseArray(db);
  assert( db->nDb<=2 );
  assert( db->aDb==db->aDbStatic );

  /* Tell the code in notify.c that the connection no longer holds any
  ** locks and does not require any further unlock-notify callbacks.
  */
  sqlite3ConnectionClosed(db);

  for(i=sqliteHashFirst(&db->aFunc); i; i=sqliteHashNext(i)){
    FuncDef *pNext, *p;
    p = sqliteHashData(i);
    do{
      functionDestroy(db, p);
      pNext = p->pNext;
      sqlite3DbFree(db, p);
      p = pNext;
    }while( p );
  }
  sqlite3HashClear(&db->aFunc);
  for(i=sqliteHashFirst(&db->aCollSeq); i; i=sqliteHashNext(i)){
    CollSeq *pColl = (CollSeq *)sqliteHashData(i);
    /* Invoke any destructors registered for collation sequence user data. */
    for(j=0; j<3; j++){
      if( pColl[j].xDel ){
        pColl[j].xDel(pColl[j].pUser);
      }
    }
    sqlite3DbFree(db, pColl);
  }
  sqlite3HashClear(&db->aCollSeq);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  for(i=sqliteHashFirst(&db->aModule); i; i=sqliteHashNext(i)){
    Module *pMod = (Module *)sqliteHashData(i);
    sqlite3VtabEponymousTableClear(db, pMod);
    sqlite3VtabModuleUnref(db, pMod);
  }
  sqlite3HashClear(&db->aModule);
#endif

  sqlite3Error(db, SQLITE_OK); /* Deallocates any cached error strings. */
  sqlite3ValueFree(db->pErr);
  sqlite3CloseExtensions(db);
#if SQLITE_USER_AUTHENTICATION
  sqlite3_free(db->auth.zAuthUser);
  sqlite3_free(db->auth.zAuthPW);
#endif

  db->magic = SQLITE_MAGIC_ERROR;

  /* The temp-database schema is allocated differently from the other schema
  ** objects (using sqliteMalloc() directly, instead of sqlite3BtreeSchema()).
  ** So it needs to be freed here. Todo: Why not roll the temp schema into
  ** the same sqliteMalloc() as the one that allocates the database 
  ** structure?
  */
  sqlite3DbFree(db, db->aDb[1].pSchema);
  sqlite3_mutex_leave(db->mutex);
  db->magic = SQLITE_MAGIC_CLOSED;
  sqlite3_mutex_free(db->mutex);
  assert( sqlite3LookasideUsed(db,0)==0 );
  if( db->lookaside.bMalloced ){
    sqlite3_free(db->lookaside.pStart);
  }
  sqlite3_free(db);
}

/*
** Rollback all database files.  If tripCode is not SQLITE_OK, then
** any write cursors are invalidated ("tripped" - as in "tripping a circuit
** breaker") and made to return tripCode if there are any further
** attempts to use that cursor.  Read cursors remain open and valid
** but are "saved" in case the table pages are moved around.
*/
void sqlite3RollbackAll(sqlite3 *db, int tripCode){
  int i;
  int inTrans = 0;
  int schemaChange;
  assert( sqlite3_mutex_held(db->mutex) );
  sqlite3BeginBenignMalloc();

  /* Obtain all b-tree mutexes before making any calls to BtreeRollback(). 
  ** This is important in case the transaction being rolled back has
  ** modified the database schema. If the b-tree mutexes are not taken
  ** here, then another shared-cache connection might sneak in between
  ** the database rollback and schema reset, which can cause false
  ** corruption reports in some cases.  */
  sqlite3BtreeEnterAll(db);
  schemaChange = (db->mDbFlags & DBFLAG_SchemaChange)!=0 && db->init.busy==0;

  for(i=0; i<db->nDb; i++){
    Btree *p = db->aDb[i].pBt;
    if( p ){
      if( sqlite3BtreeTxnState(p)==SQLITE_TXN_WRITE ){
        inTrans = 1;
      }
      sqlite3BtreeRollback(p, tripCode, !schemaChange);
    }
  }
  sqlite3VtabRollback(db);
  sqlite3EndBenignMalloc();

  if( schemaChange ){
    sqlite3ExpirePreparedStatements(db, 0);
    sqlite3ResetAllSchemasOfConnection(db);
  }
  sqlite3BtreeLeaveAll(db);

  /* Any deferred constraint violations have now been resolved. */
  db->nDeferredCons = 0;
  db->nDeferredImmCons = 0;
  db->flags &= ~(u64)SQLITE_DeferFKs;

  /* If one has been configured, invoke the rollback-hook callback */
  if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
    db->xRollbackCallback(db->pRollbackArg);
  }
}

/*
** Return a static string containing the name corresponding to the error code
** specified in the argument.
*/
#if defined(SQLITE_NEED_ERR_NAME)
const char *sqlite3ErrName(int rc){
  const char *zName = 0;
  int i, origRc = rc;
  for(i=0; i<2 && zName==0; i++, rc &= 0xff){
    switch( rc ){
      case SQLITE_OK:                 zName = "SQLITE_OK";                break;
      case SQLITE_ERROR:              zName = "SQLITE_ERROR";             break;
      case SQLITE_ERROR_SNAPSHOT:     zName = "SQLITE_ERROR_SNAPSHOT";    break;
      case SQLITE_INTERNAL:           zName = "SQLITE_INTERNAL";          break;
      case SQLITE_PERM:               zName = "SQLITE_PERM";              break;
      case SQLITE_ABORT:              zName = "SQLITE_ABORT";             break;
      case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
      case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
      case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
      case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
      case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
      case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
      case SQLITE_READONLY:           zName = "SQLITE_READONLY";          break;
      case SQLITE_READONLY_RECOVERY:  zName = "SQLITE_READONLY_RECOVERY"; break;
      case SQLITE_READONLY_CANTINIT:  zName = "SQLITE_READONLY_CANTINIT"; break;
      case SQLITE_READONLY_ROLLBACK:  zName = "SQLITE_READONLY_ROLLBACK"; break;
      case SQLITE_READONLY_DBMOVED:   zName = "SQLITE_READONLY_DBMOVED";  break;
      case SQLITE_READONLY_DIRECTORY: zName = "SQLITE_READONLY_DIRECTORY";break;
      case SQLITE_INTERRUPT:          zName = "SQLITE_INTERRUPT";         break;
      case SQLITE_IOERR:              zName = "SQLITE_IOERR";             break;
      case SQLITE_IOERR_READ:         zName = "SQLITE_IOERR_READ";        break;
      case SQLITE_IOERR_SHORT_READ:   zName = "SQLITE_IOERR_SHORT_READ";  break;
      case SQLITE_IOERR_WRITE:        zName = "SQLITE_IOERR_WRITE";       break;
      case SQLITE_IOERR_FSYNC:        zName = "SQLITE_IOERR_FSYNC";       break;
      case SQLITE_IOERR_DIR_FSYNC:    zName = "SQLITE_IOERR_DIR_FSYNC";   break;
      case SQLITE_IOERR_TRUNCATE:     zName = "SQLITE_IOERR_TRUNCATE";    break;
      case SQLITE_IOERR_FSTAT:        zName = "SQLITE_IOERR_FSTAT";       break;
      case SQLITE_IOERR_UNLOCK:       zName = "SQLITE_IOERR_UNLOCK";      break;
      case SQLITE_IOERR_RDLOCK:       zName = "SQLITE_IOERR_RDLOCK";      break;
      case SQLITE_IOERR_DELETE:       zName = "SQLITE_IOERR_DELETE";      break;
      case SQLITE_IOERR_NOMEM:        zName = "SQLITE_IOERR_NOMEM";       break;
      case SQLITE_IOERR_ACCESS:       zName = "SQLITE_IOERR_ACCESS";      break;
      case SQLITE_IOERR_CHECKRESERVEDLOCK:
                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
      case SQLITE_IOERR_LOCK:         zName = "SQLITE_IOERR_LOCK";        break;
      case SQLITE_IOERR_CLOSE:        zName = "SQLITE_IOERR_CLOSE";       break;
      case SQLITE_IOERR_DIR_CLOSE:    zName = "SQLITE_IOERR_DIR_CLOSE";   break;
      case SQLITE_IOERR_SHMOPEN:      zName = "SQLITE_IOERR_SHMOPEN";     break;
      case SQLITE_IOERR_SHMSIZE:      zName = "SQLITE_IOERR_SHMSIZE";     break;
      case SQLITE_IOERR_SHMLOCK:      zName = "SQLITE_IOERR_SHMLOCK";     break;
      case SQLITE_IOERR_SHMMAP:       zName = "SQLITE_IOERR_SHMMAP";      break;
      case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
      case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
      case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
      case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
      case SQLITE_IOERR_CONVPATH:     zName = "SQLITE_IOERR_CONVPATH";    break;
      case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
      case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
      case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
      case SQLITE_FULL:               zName = "SQLITE_FULL";              break;
      case SQLITE_CANTOPEN:           zName = "SQLITE_CANTOPEN";          break;
      case SQLITE_CANTOPEN_NOTEMPDIR: zName = "SQLITE_CANTOPEN_NOTEMPDIR";break;
      case SQLITE_CANTOPEN_ISDIR:     zName = "SQLITE_CANTOPEN_ISDIR";    break;
      case SQLITE_CANTOPEN_FULLPATH:  zName = "SQLITE_CANTOPEN_FULLPATH"; break;
      case SQLITE_CANTOPEN_CONVPATH:  zName = "SQLITE_CANTOPEN_CONVPATH"; break;
      case SQLITE_CANTOPEN_SYMLINK:   zName = "SQLITE_CANTOPEN_SYMLINK";  break;
      case SQLITE_PROTOCOL:           zName = "SQLITE_PROTOCOL";          break;
      case SQLITE_EMPTY:              zName = "SQLITE_EMPTY";             break;
      case SQLITE_SCHEMA:             zName = "SQLITE_SCHEMA";            break;
      case SQLITE_TOOBIG:             zName = "SQLITE_TOOBIG";            break;
      case SQLITE_CONSTRAINT:         zName = "SQLITE_CONSTRAINT";        break;
      case SQLITE_CONSTRAINT_UNIQUE:  zName = "SQLITE_CONSTRAINT_UNIQUE"; break;
      case SQLITE_CONSTRAINT_TRIGGER: zName = "SQLITE_CONSTRAINT_TRIGGER";break;
      case SQLITE_CONSTRAINT_FOREIGNKEY:
                                zName = "SQLITE_CONSTRAINT_FOREIGNKEY";   break;
      case SQLITE_CONSTRAINT_CHECK:   zName = "SQLITE_CONSTRAINT_CHECK";  break;
      case SQLITE_CONSTRAINT_PRIMARYKEY:
                                zName = "SQLITE_CONSTRAINT_PRIMARYKEY";   break;
      case SQLITE_CONSTRAINT_NOTNULL: zName = "SQLITE_CONSTRAINT_NOTNULL";break;
      case SQLITE_CONSTRAINT_COMMITHOOK:
                                zName = "SQLITE_CONSTRAINT_COMMITHOOK";   break;
      case SQLITE_CONSTRAINT_VTAB:    zName = "SQLITE_CONSTRAINT_VTAB";   break;
      case SQLITE_CONSTRAINT_FUNCTION:
                                zName = "SQLITE_CONSTRAINT_FUNCTION";     break;
      case SQLITE_CONSTRAINT_ROWID:   zName = "SQLITE_CONSTRAINT_ROWID";  break;
      case SQLITE_MISMATCH:           zName = "SQLITE_MISMATCH";          break;
      case SQLITE_MISUSE:             zName = "SQLITE_MISUSE";            break;
      case SQLITE_NOLFS:              zName = "SQLITE_NOLFS";             break;
      case SQLITE_AUTH:               zName = "SQLITE_AUTH";              break;
      case SQLITE_FORMAT:             zName = "SQLITE_FORMAT";            break;
      case SQLITE_RANGE:              zName = "SQLITE_RANGE";             break;
      case SQLITE_NOTADB:             zName = "SQLITE_NOTADB";            break;
      case SQLITE_ROW:                zName = "SQLITE_ROW";               break;
      case SQLITE_NOTICE:             zName = "SQLITE_NOTICE";            break;
      case SQLITE_NOTICE_RECOVER_WAL: zName = "SQLITE_NOTICE_RECOVER_WAL";break;
      case SQLITE_NOTICE_RECOVER_ROLLBACK:
                                zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
      case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
      case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
      case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
    }
  }
  if( zName==0 ){
    static char zBuf[50];
    sqlite3_snprintf(sizeof(zBuf), zBuf, "SQLITE_UNKNOWN(%d)", origRc);
    zName = zBuf;
  }
  return zName;
}
#endif

/*
** Return a static string that describes the kind of error specified in the
** argument.
*/
const char *sqlite3ErrStr(int rc){
  static const char* const aMsg[] = {
    /* SQLITE_OK          */ "not an error",
    /* SQLITE_ERROR       */ "SQL logic error",
    /* SQLITE_INTERNAL    */ 0,
    /* SQLITE_PERM        */ "access permission denied",
    /* SQLITE_ABORT       */ "query aborted",
    /* SQLITE_BUSY        */ "database is locked",
    /* SQLITE_LOCKED      */ "database table is locked",
    /* SQLITE_NOMEM       */ "out of memory",
    /* SQLITE_READONLY    */ "attempt to write a readonly database",
    /* SQLITE_INTERRUPT   */ "interrupted",
    /* SQLITE_IOERR       */ "disk I/O error",
    /* SQLITE_CORRUPT     */ "database disk image is malformed",
    /* SQLITE_NOTFOUND    */ "unknown operation",
    /* SQLITE_FULL        */ "database or disk is full",
    /* SQLITE_CANTOPEN    */ "unable to open database file",
    /* SQLITE_PROTOCOL    */ "locking protocol",
    /* SQLITE_EMPTY       */ 0,
    /* SQLITE_SCHEMA      */ "database schema has changed",
    /* SQLITE_TOOBIG      */ "string or blob too big",
    /* SQLITE_CONSTRAINT  */ "constraint failed",
    /* SQLITE_MISMATCH    */ "datatype mismatch",
    /* SQLITE_MISUSE      */ "bad parameter or other API misuse",
#ifdef SQLITE_DISABLE_LFS
    /* SQLITE_NOLFS       */ "large file support is disabled",
#else
    /* SQLITE_NOLFS       */ 0,
#endif
    /* SQLITE_AUTH        */ "authorization denied",
    /* SQLITE_FORMAT      */ 0,
    /* SQLITE_RANGE       */ "column index out of range",
    /* SQLITE_NOTADB      */ "file is not a database",
    /* SQLITE_NOTICE      */ "notification message",
    /* SQLITE_WARNING     */ "warning message",
  };
  const char *zErr = "unknown error";
  switch( rc ){
    case SQLITE_ABORT_ROLLBACK: {
      zErr = "abort due to ROLLBACK";
      break;
    }
    case SQLITE_ROW: {
      zErr = "another row available";
      break;
    }
    case SQLITE_DONE: {
      zErr = "no more rows available";
      break;
    }
    default: {
      rc &= 0xff;
      if( ALWAYS(rc>=0) && rc<ArraySize(aMsg) && aMsg[rc]!=0 ){
        zErr = aMsg[rc];
      }
      break;
    }
  }
  return zErr;
}

/*
** This routine implements a busy callback that sleeps and tries
** again until a timeout value is reached.  The timeout value is
** an integer number of milliseconds passed in as the first
** argument.
**
** Return non-zero to retry the lock.  Return zero to stop trying
** and cause SQLite to return SQLITE_BUSY.
*/
static int sqliteDefaultBusyCallback(
  void *ptr,               /* Database connection */
  int count                /* Number of times table has been busy */
){
#if SQLITE_OS_WIN || HAVE_USLEEP
  /* This case is for systems that have support for sleeping for fractions of
  ** a second.  Examples:  All windows systems, unix systems with usleep() */
  static const u8 delays[] =
     { 1, 2, 5, 10, 15, 20, 25, 25,  25,  50,  50, 100 };
  static const u8 totals[] =
     { 0, 1, 3,  8, 18, 33, 53, 78, 103, 128, 178, 228 };
# define NDELAY ArraySize(delays)
  sqlite3 *db = (sqlite3 *)ptr;
  int tmout = db->busyTimeout;
  int delay, prior;

  assert( count>=0 );
  if( count < NDELAY ){
    delay = delays[count];
    prior = totals[count];
  }else{
    delay = delays[NDELAY-1];
    prior = totals[NDELAY-1] + delay*(count-(NDELAY-1));
  }
  if( prior + delay > tmout ){
    delay = tmout - prior;
    if( delay<=0 ) return 0;
  }
  sqlite3OsSleep(db->pVfs, delay*1000);
  return 1;
#else
  /* This case for unix systems that lack usleep() support.  Sleeping
  ** must be done in increments of whole seconds */
  sqlite3 *db = (sqlite3 *)ptr;
  int tmout = ((sqlite3 *)ptr)->busyTimeout;
  if( (count+1)*1000 > tmout ){
    return 0;
  }
  sqlite3OsSleep(db->pVfs, 1000000);
  return 1;
#endif
}

/*
** Invoke the given busy handler.
**
** This routine is called when an operation failed to acquire a
** lock on VFS file pFile.
**
** If this routine returns non-zero, the lock is retried.  If it
** returns 0, the operation aborts with an SQLITE_BUSY error.
*/
int sqlite3InvokeBusyHandler(BusyHandler *p){
  int rc;
  if( p->xBusyHandler==0 || p->nBusy<0 ) return 0;
  rc = p->xBusyHandler(p->pBusyArg, p->nBusy);
  if( rc==0 ){
    p->nBusy = -1;
  }else{
    p->nBusy++;
  }
  return rc; 
}

/*
** This routine sets the busy callback for an Sqlite database to the
** given callback function with the given argument.
*/
int sqlite3_busy_handler(
  sqlite3 *db,
  int (*xBusy)(void*,int),
  void *pArg
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->busyHandler.xBusyHandler = xBusy;
  db->busyHandler.pBusyArg = pArg;
  db->busyHandler.nBusy = 0;
  db->busyTimeout = 0;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
/*
** This routine sets the progress callback for an Sqlite database to the
** given callback function with the given argument. The progress callback will
** be invoked every nOps opcodes.
*/
void sqlite3_progress_handler(
  sqlite3 *db, 
  int nOps,
  int (*xProgress)(void*), 
  void *pArg
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( nOps>0 ){
    db->xProgress = xProgress;
    db->nProgressOps = (unsigned)nOps;
    db->pProgressArg = pArg;
  }else{
    db->xProgress = 0;
    db->nProgressOps = 0;
    db->pProgressArg = 0;
  }
  sqlite3_mutex_leave(db->mutex);
}
#endif


/*
** This routine installs a default busy handler that waits for the
** specified number of milliseconds before returning 0.
*/
int sqlite3_busy_timeout(sqlite3 *db, int ms){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  if( ms>0 ){
    sqlite3_busy_handler(db, (int(*)(void*,int))sqliteDefaultBusyCallback,
                             (void*)db);
    db->busyTimeout = ms;
  }else{
    sqlite3_busy_handler(db, 0, 0);
  }
  return SQLITE_OK;
}

/*
** Cause any pending operation to stop at its earliest opportunity.
*/
void sqlite3_interrupt(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) && (db==0 || db->magic!=SQLITE_MAGIC_ZOMBIE) ){
    (void)SQLITE_MISUSE_BKPT;
    return;
  }
#endif
  AtomicStore(&db->u1.isInterrupted, 1);
}


/*
** This function is exactly the same as sqlite3_create_function(), except
** that it is designed to be called by internal code. The difference is
** that if a malloc() fails in sqlite3_create_function(), an error code
** is returned and the mallocFailed flag cleared. 
*/
int sqlite3CreateFunc(
  sqlite3 *db,
  const char *zFunctionName,
  int nArg,
  int enc,
  void *pUserData,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
  FuncDestructor *pDestructor
){
  FuncDef *p;
  int nName;
  int extraFlags;

  assert( sqlite3_mutex_held(db->mutex) );
  assert( xValue==0 || xSFunc==0 );
  if( zFunctionName==0                /* Must have a valid name */
   || (xSFunc!=0 && xFinal!=0)        /* Not both xSFunc and xFinal */
   || ((xFinal==0)!=(xStep==0))       /* Both or neither of xFinal and xStep */
   || ((xValue==0)!=(xInverse==0))    /* Both or neither of xValue, xInverse */
   || (nArg<-1 || nArg>SQLITE_MAX_FUNCTION_ARG)
   || (255<(nName = sqlite3Strlen30( zFunctionName)))
  ){
    return SQLITE_MISUSE_BKPT;
  }

  assert( SQLITE_FUNC_CONSTANT==SQLITE_DETERMINISTIC );
  assert( SQLITE_FUNC_DIRECT==SQLITE_DIRECTONLY );
  extraFlags = enc &  (SQLITE_DETERMINISTIC|SQLITE_DIRECTONLY|
                       SQLITE_SUBTYPE|SQLITE_INNOCUOUS);
  enc &= (SQLITE_FUNC_ENCMASK|SQLITE_ANY);

  /* The SQLITE_INNOCUOUS flag is the same bit as SQLITE_FUNC_UNSAFE.  But
  ** the meaning is inverted.  So flip the bit. */
  assert( SQLITE_FUNC_UNSAFE==SQLITE_INNOCUOUS );
  extraFlags ^= SQLITE_FUNC_UNSAFE;

  
#ifndef SQLITE_OMIT_UTF16
  /* If SQLITE_UTF16 is specified as the encoding type, transform this
  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
  **
  ** If SQLITE_ANY is specified, add three versions of the function
  ** to the hash table.
  */
  if( enc==SQLITE_UTF16 ){
    enc = SQLITE_UTF16NATIVE;
  }else if( enc==SQLITE_ANY ){
    int rc;
    rc = sqlite3CreateFunc(db, zFunctionName, nArg,
         (SQLITE_UTF8|extraFlags)^SQLITE_FUNC_UNSAFE,
         pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
    if( rc==SQLITE_OK ){
      rc = sqlite3CreateFunc(db, zFunctionName, nArg,
           (SQLITE_UTF16LE|extraFlags)^SQLITE_FUNC_UNSAFE,
           pUserData, xSFunc, xStep, xFinal, xValue, xInverse, pDestructor);
    }
    if( rc!=SQLITE_OK ){
      return rc;
    }
    enc = SQLITE_UTF16BE;
  }
#else
  enc = SQLITE_UTF8;
#endif
  
  /* Check if an existing function is being overridden or deleted. If so,
  ** and there are active VMs, then return SQLITE_BUSY. If a function
  ** is being overridden/deleted but there are no active VMs, allow the
  ** operation to continue but invalidate all precompiled statements.
  */
  p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 0);
  if( p && (p->funcFlags & SQLITE_FUNC_ENCMASK)==(u32)enc && p->nArg==nArg ){
    if( db->nVdbeActive ){
      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
        "unable to delete/modify user-function due to active statements");
      assert( !db->mallocFailed );
      return SQLITE_BUSY;
    }else{
      sqlite3ExpirePreparedStatements(db, 0);
    }
  }

  p = sqlite3FindFunction(db, zFunctionName, nArg, (u8)enc, 1);
  assert(p || db->mallocFailed);
  if( !p ){
    return SQLITE_NOMEM_BKPT;
  }

  /* If an older version of the function with a configured destructor is
  ** being replaced invoke the destructor function here. */
  functionDestroy(db, p);

  if( pDestructor ){
    pDestructor->nRef++;
  }
  p->u.pDestructor = pDestructor;
  p->funcFlags = (p->funcFlags & SQLITE_FUNC_ENCMASK) | extraFlags;
  testcase( p->funcFlags & SQLITE_DETERMINISTIC );
  testcase( p->funcFlags & SQLITE_DIRECTONLY );
  p->xSFunc = xSFunc ? xSFunc : xStep;
  p->xFinalize = xFinal;
  p->xValue = xValue;
  p->xInverse = xInverse;
  p->pUserData = pUserData;
  p->nArg = (u16)nArg;
  return SQLITE_OK;
}

/*
** Worker function used by utf-8 APIs that create new functions:
**
**    sqlite3_create_function()
**    sqlite3_create_function_v2()
**    sqlite3_create_window_function()
*/
static int createFunctionApi(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*),
  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
  void(*xDestroy)(void*)
){
  int rc = SQLITE_ERROR;
  FuncDestructor *pArg = 0;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( xDestroy ){
    pArg = (FuncDestructor *)sqlite3Malloc(sizeof(FuncDestructor));
    if( !pArg ){
      sqlite3OomFault(db);
      xDestroy(p);
      goto out;
    }
    pArg->nRef = 0;
    pArg->xDestroy = xDestroy;
    pArg->pUserData = p;
  }
  rc = sqlite3CreateFunc(db, zFunc, nArg, enc, p, 
      xSFunc, xStep, xFinal, xValue, xInverse, pArg
  );
  if( pArg && pArg->nRef==0 ){
    assert( rc!=SQLITE_OK );
    xDestroy(p);
    sqlite3_free(pArg);
  }

 out:
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Create new user functions.
*/
int sqlite3_create_function(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*)
){
  return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
                                    xFinal, 0, 0, 0);
}
int sqlite3_create_function_v2(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value **),
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xDestroy)(void *)
){
  return createFunctionApi(db, zFunc, nArg, enc, p, xSFunc, xStep,
                                    xFinal, 0, 0, xDestroy);
}
int sqlite3_create_window_function(
  sqlite3 *db,
  const char *zFunc,
  int nArg,
  int enc,
  void *p,
  void (*xStep)(sqlite3_context*,int,sqlite3_value **),
  void (*xFinal)(sqlite3_context*),
  void (*xValue)(sqlite3_context*),
  void (*xInverse)(sqlite3_context*,int,sqlite3_value **),
  void (*xDestroy)(void *)
){
  return createFunctionApi(db, zFunc, nArg, enc, p, 0, xStep,
                                    xFinal, xValue, xInverse, xDestroy);
}

#ifndef SQLITE_OMIT_UTF16
int sqlite3_create_function16(
  sqlite3 *db,
  const void *zFunctionName,
  int nArg,
  int eTextRep,
  void *p,
  void (*xSFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
){
  int rc;
  char *zFunc8;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zFunctionName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zFunc8 = sqlite3Utf16to8(db, zFunctionName, -1, SQLITE_UTF16NATIVE);
  rc = sqlite3CreateFunc(db, zFunc8, nArg, eTextRep, p, xSFunc,xStep,xFinal,0,0,0);
  sqlite3DbFree(db, zFunc8);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
#endif


/*
** The following is the implementation of an SQL function that always
** fails with an error message stating that the function is used in the
** wrong context.  The sqlite3_overload_function() API might construct
** SQL function that use this routine so that the functions will exist
** for name resolution but are actually overloaded by the xFindFunction
** method of virtual tables.
*/
static void sqlite3InvalidFunction(
  sqlite3_context *context,  /* The function calling context */
  int NotUsed,               /* Number of arguments to the function */
  sqlite3_value **NotUsed2   /* Value of each argument */
){
  const char *zName = (const char*)sqlite3_user_data(context);
  char *zErr;
  UNUSED_PARAMETER2(NotUsed, NotUsed2);
  zErr = sqlite3_mprintf(
      "unable to use function %s in the requested context", zName);
  sqlite3_result_error(context, zErr, -1);
  sqlite3_free(zErr);
}

/*
** Declare that a function has been overloaded by a virtual table.
**
** If the function already exists as a regular global function, then
** this routine is a no-op.  If the function does not exist, then create
** a new one that always throws a run-time error.  
**
** When virtual tables intend to provide an overloaded function, they
** should call this routine to make sure the global function exists.
** A global function must exist in order for name resolution to work
** properly.
*/
int sqlite3_overload_function(
  sqlite3 *db,
  const char *zName,
  int nArg
){
  int rc;
  char *zCopy;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 || nArg<-2 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  rc = sqlite3FindFunction(db, zName, nArg, SQLITE_UTF8, 0)!=0;
  sqlite3_mutex_leave(db->mutex);
  if( rc ) return SQLITE_OK;
  zCopy = sqlite3_mprintf(zName);
  if( zCopy==0 ) return SQLITE_NOMEM;
  return sqlite3_create_function_v2(db, zName, nArg, SQLITE_UTF8,
                           zCopy, sqlite3InvalidFunction, 0, 0, sqlite3_free);
}

#ifndef SQLITE_OMIT_TRACE
/*
** Register a trace function.  The pArg from the previously registered trace
** is returned.  
**
** A NULL trace function means that no tracing is executes.  A non-NULL
** trace is a pointer to a function that is invoked at the start of each
** SQL statement.
*/
#ifndef SQLITE_OMIT_DEPRECATED
void *sqlite3_trace(sqlite3 *db, void(*xTrace)(void*,const char*), void *pArg){
  void *pOld;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pTraceArg;
  db->mTrace = xTrace ? SQLITE_TRACE_LEGACY : 0;
  db->trace.xLegacy = xTrace;
  db->pTraceArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
#endif /* SQLITE_OMIT_DEPRECATED */

/* Register a trace callback using the version-2 interface.
*/
int sqlite3_trace_v2(
  sqlite3 *db,                               /* Trace this connection */
  unsigned mTrace,                           /* Mask of events to be traced */
  int(*xTrace)(unsigned,void*,void*,void*),  /* Callback to invoke */
  void *pArg                                 /* Context */
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( mTrace==0 ) xTrace = 0;
  if( xTrace==0 ) mTrace = 0;
  db->mTrace = mTrace;
  db->trace.xV2 = xTrace;
  db->pTraceArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_DEPRECATED
/*
** Register a profile function.  The pArg from the previously registered 
** profile function is returned.  
**
** A NULL profile function means that no profiling is executes.  A non-NULL
** profile is a pointer to a function that is invoked at the conclusion of
** each SQL statement that is run.
*/
void *sqlite3_profile(
  sqlite3 *db,
  void (*xProfile)(void*,const char*,sqlite_uint64),
  void *pArg
){
  void *pOld;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pProfileArg;
  db->xProfile = xProfile;
  db->pProfileArg = pArg;
  db->mTrace &= SQLITE_TRACE_NONLEGACY_MASK;
  if( db->xProfile ) db->mTrace |= SQLITE_TRACE_XPROFILE;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}
#endif /* SQLITE_OMIT_DEPRECATED */
#endif /* SQLITE_OMIT_TRACE */

/*
** Register a function to be invoked when a transaction commits.
** If the invoked function returns non-zero, then the commit becomes a
** rollback.
*/
void *sqlite3_commit_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  int (*xCallback)(void*),  /* Function to invoke on each commit */
  void *pArg                /* Argument to the function */
){
  void *pOld;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pOld = db->pCommitArg;
  db->xCommitCallback = xCallback;
  db->pCommitArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pOld;
}

/*
** Register a callback to be invoked each time a row is updated,
** inserted or deleted using this database connection.
*/
void *sqlite3_update_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void (*xCallback)(void*,int,char const *,char const *,sqlite_int64),
  void *pArg                /* Argument to the function */
){
  void *pRet;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pUpdateArg;
  db->xUpdateCallback = xCallback;
  db->pUpdateArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}

/*
** Register a callback to be invoked each time a transaction is rolled
** back by this database connection.
*/
void *sqlite3_rollback_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void (*xCallback)(void*), /* Callback function */
  void *pArg                /* Argument to the function */
){
  void *pRet;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pRollbackArg;
  db->xRollbackCallback = xCallback;
  db->pRollbackArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}

#ifdef SQLITE_ENABLE_PREUPDATE_HOOK
/*
** Register a callback to be invoked each time a row is updated,
** inserted or deleted using this database connection.
*/
void *sqlite3_preupdate_hook(
  sqlite3 *db,              /* Attach the hook to this database */
  void(*xCallback)(         /* Callback function */
    void*,sqlite3*,int,char const*,char const*,sqlite3_int64,sqlite3_int64),
  void *pArg                /* First callback argument */
){
  void *pRet;
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pPreUpdateArg;
  db->xPreUpdateCallback = xCallback;
  db->pPreUpdateArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
}
#endif /* SQLITE_ENABLE_PREUPDATE_HOOK */

#ifndef SQLITE_OMIT_WAL
/*
** The sqlite3_wal_hook() callback registered by sqlite3_wal_autocheckpoint().
** Invoke sqlite3_wal_checkpoint if the number of frames in the log file
** is greater than sqlite3.pWalArg cast to an integer (the value configured by
** wal_autocheckpoint()).
*/ 
int sqlite3WalDefaultHook(
  void *pClientData,     /* Argument */
  sqlite3 *db,           /* Connection */
  const char *zDb,       /* Database */
  int nFrame             /* Size of WAL */
){
  if( nFrame>=SQLITE_PTR_TO_INT(pClientData) ){
    sqlite3BeginBenignMalloc();
    sqlite3_wal_checkpoint(db, zDb);
    sqlite3EndBenignMalloc();
  }
  return SQLITE_OK;
}
#endif /* SQLITE_OMIT_WAL */

/*
** Configure an sqlite3_wal_hook() callback to automatically checkpoint
** a database after committing a transaction if there are nFrame or
** more frames in the log file. Passing zero or a negative value as the
** nFrame parameter disables automatic checkpoints entirely.
**
** The callback registered by this function replaces any existing callback
** registered using sqlite3_wal_hook(). Likewise, registering a callback
** using sqlite3_wal_hook() disables the automatic checkpoint mechanism
** configured by this function.
*/
int sqlite3_wal_autocheckpoint(sqlite3 *db, int nFrame){
#ifdef SQLITE_OMIT_WAL
  UNUSED_PARAMETER(db);
  UNUSED_PARAMETER(nFrame);
#else
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  if( nFrame>0 ){
    sqlite3_wal_hook(db, sqlite3WalDefaultHook, SQLITE_INT_TO_PTR(nFrame));
  }else{
    sqlite3_wal_hook(db, 0, 0);
  }
#endif
  return SQLITE_OK;
}

/*
** Register a callback to be invoked each time a transaction is written
** into the write-ahead-log by this database connection.
*/
void *sqlite3_wal_hook(
  sqlite3 *db,                    /* Attach the hook to this db handle */
  int(*xCallback)(void *, sqlite3*, const char*, int),
  void *pArg                      /* First argument passed to xCallback() */
){
#ifndef SQLITE_OMIT_WAL
  void *pRet;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  pRet = db->pWalArg;
  db->xWalCallback = xCallback;
  db->pWalArg = pArg;
  sqlite3_mutex_leave(db->mutex);
  return pRet;
#else
  return 0;
#endif
}

/*
** Checkpoint database zDb.
*/
int sqlite3_wal_checkpoint_v2(
  sqlite3 *db,                    /* Database handle */
  const char *zDb,                /* Name of attached database (or NULL) */
  int eMode,                      /* SQLITE_CHECKPOINT_* value */
  int *pnLog,                     /* OUT: Size of WAL log in frames */
  int *pnCkpt                     /* OUT: Total number of frames checkpointed */
){
#ifdef SQLITE_OMIT_WAL
  return SQLITE_OK;
#else
  int rc;                         /* Return code */
  int iDb = SQLITE_MAX_ATTACHED;  /* sqlite3.aDb[] index of db to checkpoint */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif

  /* Initialize the output variables to -1 in case an error occurs. */
  if( pnLog ) *pnLog = -1;
  if( pnCkpt ) *pnCkpt = -1;

  assert( SQLITE_CHECKPOINT_PASSIVE==0 );
  assert( SQLITE_CHECKPOINT_FULL==1 );
  assert( SQLITE_CHECKPOINT_RESTART==2 );
  assert( SQLITE_CHECKPOINT_TRUNCATE==3 );
  if( eMode<SQLITE_CHECKPOINT_PASSIVE || eMode>SQLITE_CHECKPOINT_TRUNCATE ){
    /* EVIDENCE-OF: R-03996-12088 The M parameter must be a valid checkpoint
    ** mode: */
    return SQLITE_MISUSE;
  }

  sqlite3_mutex_enter(db->mutex);
  if( zDb && zDb[0] ){
    iDb = sqlite3FindDbName(db, zDb);
  }
  if( iDb<0 ){
    rc = SQLITE_ERROR;
    sqlite3ErrorWithMsg(db, SQLITE_ERROR, "unknown database: %s", zDb);
  }else{
    db->busyHandler.nBusy = 0;
    rc = sqlite3Checkpoint(db, iDb, eMode, pnLog, pnCkpt);
    sqlite3Error(db, rc);
  }
  rc = sqlite3ApiExit(db, rc);

  /* If there are no active statements, clear the interrupt flag at this
  ** point.  */
  if( db->nVdbeActive==0 ){
    AtomicStore(&db->u1.isInterrupted, 0);
  }

  sqlite3_mutex_leave(db->mutex);
  return rc;
#endif
}


/*
** Checkpoint database zDb. If zDb is NULL, or if the buffer zDb points
** to contains a zero-length string, all attached databases are 
** checkpointed.
*/
int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb){
  /* EVIDENCE-OF: R-41613-20553 The sqlite3_wal_checkpoint(D,X) is equivalent to
  ** sqlite3_wal_checkpoint_v2(D,X,SQLITE_CHECKPOINT_PASSIVE,0,0). */
  return sqlite3_wal_checkpoint_v2(db,zDb,SQLITE_CHECKPOINT_PASSIVE,0,0);
}

#ifndef SQLITE_OMIT_WAL
/*
** Run a checkpoint on database iDb. This is a no-op if database iDb is
** not currently open in WAL mode.
**
** If a transaction is open on the database being checkpointed, this 
** function returns SQLITE_LOCKED and a checkpoint is not attempted. If 
** an error occurs while running the checkpoint, an SQLite error code is 
** returned (i.e. SQLITE_IOERR). Otherwise, SQLITE_OK.
**
** The mutex on database handle db should be held by the caller. The mutex
** associated with the specific b-tree being checkpointed is taken by
** this function while the checkpoint is running.
**
** If iDb is passed SQLITE_MAX_ATTACHED, then all attached databases are
** checkpointed. If an error is encountered it is returned immediately -
** no attempt is made to checkpoint any remaining databases.
**
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL, RESTART
** or TRUNCATE.
*/
int sqlite3Checkpoint(sqlite3 *db, int iDb, int eMode, int *pnLog, int *pnCkpt){
  int rc = SQLITE_OK;             /* Return code */
  int i;                          /* Used to iterate through attached dbs */
  int bBusy = 0;                  /* True if SQLITE_BUSY has been encountered */

  assert( sqlite3_mutex_held(db->mutex) );
  assert( !pnLog || *pnLog==-1 );
  assert( !pnCkpt || *pnCkpt==-1 );

  for(i=0; i<db->nDb && rc==SQLITE_OK; i++){
    if( i==iDb || iDb==SQLITE_MAX_ATTACHED ){
      rc = sqlite3BtreeCheckpoint(db->aDb[i].pBt, eMode, pnLog, pnCkpt);
      pnLog = 0;
      pnCkpt = 0;
      if( rc==SQLITE_BUSY ){
        bBusy = 1;
        rc = SQLITE_OK;
      }
    }
  }

  return (rc==SQLITE_OK && bBusy) ? SQLITE_BUSY : rc;
}
#endif /* SQLITE_OMIT_WAL */

/*
** This function returns true if main-memory should be used instead of
** a temporary file for transient pager files and statement journals.
** The value returned depends on the value of db->temp_store (runtime
** parameter) and the compile time value of SQLITE_TEMP_STORE. The
** following table describes the relationship between these two values
** and this functions return value.
**
**   SQLITE_TEMP_STORE     db->temp_store     Location of temporary database
**   -----------------     --------------     ------------------------------
**   0                     any                file      (return 0)
**   1                     1                  file      (return 0)
**   1                     2                  memory    (return 1)
**   1                     0                  file      (return 0)
**   2                     1                  file      (return 0)
**   2                     2                  memory    (return 1)
**   2                     0                  memory    (return 1)
**   3                     any                memory    (return 1)
*/
int sqlite3TempInMemory(const sqlite3 *db){
#if SQLITE_TEMP_STORE==1
  return ( db->temp_store==2 );
#endif
#if SQLITE_TEMP_STORE==2
  return ( db->temp_store!=1 );
#endif
#if SQLITE_TEMP_STORE==3
  UNUSED_PARAMETER(db);
  return 1;
#endif
#if SQLITE_TEMP_STORE<1 || SQLITE_TEMP_STORE>3
  UNUSED_PARAMETER(db);
  return 0;
#endif
}

/*
** Return UTF-8 encoded English language explanation of the most recent
** error.
*/
const char *sqlite3_errmsg(sqlite3 *db){
  const char *z;
  if( !db ){
    return sqlite3ErrStr(SQLITE_NOMEM_BKPT);
  }
  if( !sqlite3SafetyCheckSickOrOk(db) ){
    return sqlite3ErrStr(SQLITE_MISUSE_BKPT);
  }
  sqlite3_mutex_enter(db->mutex);
  if( db->mallocFailed ){
    z = sqlite3ErrStr(SQLITE_NOMEM_BKPT);
  }else{
    testcase( db->pErr==0 );
    z = db->errCode ? (char*)sqlite3_value_text(db->pErr) : 0;
    assert( !db->mallocFailed );
    if( z==0 ){
      z = sqlite3ErrStr(db->errCode);
    }
  }
  sqlite3_mutex_leave(db->mutex);
  return z;
}

#ifndef SQLITE_OMIT_UTF16
/*
** Return UTF-16 encoded English language explanation of the most recent
** error.
*/
const void *sqlite3_errmsg16(sqlite3 *db){
  static const u16 outOfMem[] = {
    'o', 'u', 't', ' ', 'o', 'f', ' ', 'm', 'e', 'm', 'o', 'r', 'y', 0
  };
  static const u16 misuse[] = {
    'b', 'a', 'd', ' ', 'p', 'a', 'r', 'a', 'm', 'e', 't', 'e', 'r', ' ',
    'o', 'r', ' ', 'o', 't', 'h', 'e', 'r', ' ', 'A', 'P', 'I', ' ',
    'm', 'i', 's', 'u', 's', 'e', 0
  };

  const void *z;
  if( !db ){
    return (void *)outOfMem;
  }
  if( !sqlite3SafetyCheckSickOrOk(db) ){
    return (void *)misuse;
  }
  sqlite3_mutex_enter(db->mutex);
  if( db->mallocFailed ){
    z = (void *)outOfMem;
  }else{
    z = sqlite3_value_text16(db->pErr);
    if( z==0 ){
      sqlite3ErrorWithMsg(db, db->errCode, sqlite3ErrStr(db->errCode));
      z = sqlite3_value_text16(db->pErr);
    }
    /* A malloc() may have failed within the call to sqlite3_value_text16()
    ** above. If this is the case, then the db->mallocFailed flag needs to
    ** be cleared before returning. Do this directly, instead of via
    ** sqlite3ApiExit(), to avoid setting the database handle error message.
    */
    sqlite3OomClear(db);
  }
  sqlite3_mutex_leave(db->mutex);
  return z;
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Return the most recent error code generated by an SQLite routine. If NULL is
** passed to this function, we assume a malloc() failed during sqlite3_open().
*/
int sqlite3_errcode(sqlite3 *db){
  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
  if( !db || db->mallocFailed ){
    return SQLITE_NOMEM_BKPT;
  }
  return db->errCode & db->errMask;
}
int sqlite3_extended_errcode(sqlite3 *db){
  if( db && !sqlite3SafetyCheckSickOrOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
  if( !db || db->mallocFailed ){
    return SQLITE_NOMEM_BKPT;
  }
  return db->errCode;
}
int sqlite3_system_errno(sqlite3 *db){
  return db ? db->iSysErrno : 0;
}  

/*
** Return a string that describes the kind of error specified in the
** argument.  For now, this simply calls the internal sqlite3ErrStr()
** function.
*/
const char *sqlite3_errstr(int rc){
  return sqlite3ErrStr(rc);
}

/*
** Create a new collating function for database "db".  The name is zName
** and the encoding is enc.
*/
static int createCollation(
  sqlite3* db,
  const char *zName, 
  u8 enc,
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*),
  void(*xDel)(void*)
){
  CollSeq *pColl;
  int enc2;
  
  assert( sqlite3_mutex_held(db->mutex) );

  /* If SQLITE_UTF16 is specified as the encoding type, transform this
  ** to one of SQLITE_UTF16LE or SQLITE_UTF16BE using the
  ** SQLITE_UTF16NATIVE macro. SQLITE_UTF16 is not used internally.
  */
  enc2 = enc;
  testcase( enc2==SQLITE_UTF16 );
  testcase( enc2==SQLITE_UTF16_ALIGNED );
  if( enc2==SQLITE_UTF16 || enc2==SQLITE_UTF16_ALIGNED ){
    enc2 = SQLITE_UTF16NATIVE;
  }
  if( enc2<SQLITE_UTF8 || enc2>SQLITE_UTF16BE ){
    return SQLITE_MISUSE_BKPT;
  }

  /* Check if this call is removing or replacing an existing collation 
  ** sequence. If so, and there are active VMs, return busy. If there
  ** are no active VMs, invalidate any pre-compiled statements.
  */
  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
  if( pColl && pColl->xCmp ){
    if( db->nVdbeActive ){
      sqlite3ErrorWithMsg(db, SQLITE_BUSY, 
        "unable to delete/modify collation sequence due to active statements");
      return SQLITE_BUSY;
    }
    sqlite3ExpirePreparedStatements(db, 0);

    /* If collation sequence pColl was created directly by a call to
    ** sqlite3_create_collation, and not generated by synthCollSeq(),
    ** then any copies made by synthCollSeq() need to be invalidated.
    ** Also, collation destructor - CollSeq.xDel() - function may need
    ** to be called.
    */ 
    if( (pColl->enc & ~SQLITE_UTF16_ALIGNED)==enc2 ){
      CollSeq *aColl = sqlite3HashFind(&db->aCollSeq, zName);
      int j;
      for(j=0; j<3; j++){
        CollSeq *p = &aColl[j];
        if( p->enc==pColl->enc ){
          if( p->xDel ){
            p->xDel(p->pUser);
          }
          p->xCmp = 0;
        }
      }
    }
  }

  pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 1);
  if( pColl==0 ) return SQLITE_NOMEM_BKPT;
  pColl->xCmp = xCompare;
  pColl->pUser = pCtx;
  pColl->xDel = xDel;
  pColl->enc = (u8)(enc2 | (enc & SQLITE_UTF16_ALIGNED));
  sqlite3Error(db, SQLITE_OK);
  return SQLITE_OK;
}


/*
** This array defines hard upper bounds on limit values.  The
** initializer must be kept in sync with the SQLITE_LIMIT_*
** #defines in sqlite3.h.
*/
static const int aHardLimit[] = {
  SQLITE_MAX_LENGTH,
  SQLITE_MAX_SQL_LENGTH,
  SQLITE_MAX_COLUMN,
  SQLITE_MAX_EXPR_DEPTH,
  SQLITE_MAX_COMPOUND_SELECT,
  SQLITE_MAX_VDBE_OP,
  SQLITE_MAX_FUNCTION_ARG,
  SQLITE_MAX_ATTACHED,
  SQLITE_MAX_LIKE_PATTERN_LENGTH,
  SQLITE_MAX_VARIABLE_NUMBER,      /* IMP: R-38091-32352 */
  SQLITE_MAX_TRIGGER_DEPTH,
  SQLITE_MAX_WORKER_THREADS,
};

/*
** Make sure the hard limits are set to reasonable values
*/
#if SQLITE_MAX_LENGTH<100
# error SQLITE_MAX_LENGTH must be at least 100
#endif
#if SQLITE_MAX_SQL_LENGTH<100
# error SQLITE_MAX_SQL_LENGTH must be at least 100
#endif
#if SQLITE_MAX_SQL_LENGTH>SQLITE_MAX_LENGTH
# error SQLITE_MAX_SQL_LENGTH must not be greater than SQLITE_MAX_LENGTH
#endif
#if SQLITE_MAX_COMPOUND_SELECT<2
# error SQLITE_MAX_COMPOUND_SELECT must be at least 2
#endif
#if SQLITE_MAX_VDBE_OP<40
# error SQLITE_MAX_VDBE_OP must be at least 40
#endif
#if SQLITE_MAX_FUNCTION_ARG<0 || SQLITE_MAX_FUNCTION_ARG>127
# error SQLITE_MAX_FUNCTION_ARG must be between 0 and 127
#endif
#if SQLITE_MAX_ATTACHED<0 || SQLITE_MAX_ATTACHED>125
# error SQLITE_MAX_ATTACHED must be between 0 and 125
#endif
#if SQLITE_MAX_LIKE_PATTERN_LENGTH<1
# error SQLITE_MAX_LIKE_PATTERN_LENGTH must be at least 1
#endif
#if SQLITE_MAX_COLUMN>32767
# error SQLITE_MAX_COLUMN must not exceed 32767
#endif
#if SQLITE_MAX_TRIGGER_DEPTH<1
# error SQLITE_MAX_TRIGGER_DEPTH must be at least 1
#endif
#if SQLITE_MAX_WORKER_THREADS<0 || SQLITE_MAX_WORKER_THREADS>50
# error SQLITE_MAX_WORKER_THREADS must be between 0 and 50
#endif


/*
** Change the value of a limit.  Report the old value.
** If an invalid limit index is supplied, report -1.
** Make no changes but still report the old value if the
** new limit is negative.
**
** A new lower limit does not shrink existing constructs.
** It merely prevents new constructs that exceed the limit
** from forming.
*/
int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
  int oldLimit;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return -1;
  }
#endif

  /* EVIDENCE-OF: R-30189-54097 For each limit category SQLITE_LIMIT_NAME
  ** there is a hard upper bound set at compile-time by a C preprocessor
  ** macro called SQLITE_MAX_NAME. (The "_LIMIT_" in the name is changed to
  ** "_MAX_".)
  */
  assert( aHardLimit[SQLITE_LIMIT_LENGTH]==SQLITE_MAX_LENGTH );
  assert( aHardLimit[SQLITE_LIMIT_SQL_LENGTH]==SQLITE_MAX_SQL_LENGTH );
  assert( aHardLimit[SQLITE_LIMIT_COLUMN]==SQLITE_MAX_COLUMN );
  assert( aHardLimit[SQLITE_LIMIT_EXPR_DEPTH]==SQLITE_MAX_EXPR_DEPTH );
  assert( aHardLimit[SQLITE_LIMIT_COMPOUND_SELECT]==SQLITE_MAX_COMPOUND_SELECT);
  assert( aHardLimit[SQLITE_LIMIT_VDBE_OP]==SQLITE_MAX_VDBE_OP );
  assert( aHardLimit[SQLITE_LIMIT_FUNCTION_ARG]==SQLITE_MAX_FUNCTION_ARG );
  assert( aHardLimit[SQLITE_LIMIT_ATTACHED]==SQLITE_MAX_ATTACHED );
  assert( aHardLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]==
                                               SQLITE_MAX_LIKE_PATTERN_LENGTH );
  assert( aHardLimit[SQLITE_LIMIT_VARIABLE_NUMBER]==SQLITE_MAX_VARIABLE_NUMBER);
  assert( aHardLimit[SQLITE_LIMIT_TRIGGER_DEPTH]==SQLITE_MAX_TRIGGER_DEPTH );
  assert( aHardLimit[SQLITE_LIMIT_WORKER_THREADS]==SQLITE_MAX_WORKER_THREADS );
  assert( SQLITE_LIMIT_WORKER_THREADS==(SQLITE_N_LIMIT-1) );


  if( limitId<0 || limitId>=SQLITE_N_LIMIT ){
    return -1;
  }
  oldLimit = db->aLimit[limitId];
  if( newLimit>=0 ){                   /* IMP: R-52476-28732 */
    if( newLimit>aHardLimit[limitId] ){
      newLimit = aHardLimit[limitId];  /* IMP: R-51463-25634 */
    }
    db->aLimit[limitId] = newLimit;
  }
  return oldLimit;                     /* IMP: R-53341-35419 */
}

/*
** This function is used to parse both URIs and non-URI filenames passed by the
** user to API functions sqlite3_open() or sqlite3_open_v2(), and for database
** URIs specified as part of ATTACH statements.
**
** The first argument to this function is the name of the VFS to use (or
** a NULL to signify the default VFS) if the URI does not contain a "vfs=xxx"
** query parameter. The second argument contains the URI (or non-URI filename)
** itself. When this function is called the *pFlags variable should contain
** the default flags to open the database handle with. The value stored in
** *pFlags may be updated before returning if the URI filename contains 
** "cache=xxx" or "mode=xxx" query parameters.
**
** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
** the VFS that should be used to open the database file. *pzFile is set to
** point to a buffer containing the name of the file to open.  The value
** stored in *pzFile is a database name acceptable to sqlite3_uri_parameter()
** and is in the same format as names created using sqlite3_create_filename().
** The caller must invoke sqlite3_free_filename() (not sqlite3_free()!) on
** the value returned in *pzFile to avoid a memory leak.
**
** If an error occurs, then an SQLite error code is returned and *pzErrMsg
** may be set to point to a buffer containing an English language error 
** message. It is the responsibility of the caller to eventually release
** this buffer by calling sqlite3_free().
*/
int sqlite3ParseUri(
  const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
  const char *zUri,               /* Nul-terminated URI to parse */
  unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
  sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
  char **pzFile,                  /* OUT: Filename component of URI */
  char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
){
  int rc = SQLITE_OK;
  unsigned int flags = *pFlags;
  const char *zVfs = zDefaultVfs;
  char *zFile;
  char c;
  int nUri = sqlite3Strlen30(zUri);

  assert( *pzErrMsg==0 );

  if( ((flags & SQLITE_OPEN_URI)             /* IMP: R-48725-32206 */
            || sqlite3GlobalConfig.bOpenUri) /* IMP: R-51689-46548 */
   && nUri>=5 && memcmp(zUri, "file:", 5)==0 /* IMP: R-57884-37496 */
  ){
    char *zOpt;
    int eState;                   /* Parser state when parsing URI */
    int iIn;                      /* Input character index */
    int iOut = 0;                 /* Output character index */
    u64 nByte = nUri+8;           /* Bytes of space to allocate */

    /* Make sure the SQLITE_OPEN_URI flag is set to indicate to the VFS xOpen 
    ** method that there may be extra parameters following the file-name.  */
    flags |= SQLITE_OPEN_URI;

    for(iIn=0; iIn<nUri; iIn++) nByte += (zUri[iIn]=='&');
    zFile = sqlite3_malloc64(nByte);
    if( !zFile ) return SQLITE_NOMEM_BKPT;

    memset(zFile, 0, 4);  /* 4-byte of 0x00 is the start of DB name marker */
    zFile += 4;

    iIn = 5;
#ifdef SQLITE_ALLOW_URI_AUTHORITY
    if( strncmp(zUri+5, "///", 3)==0 ){
      iIn = 7;
      /* The following condition causes URIs with five leading / characters
      ** like file://///host/path to be converted into UNCs like //host/path.
      ** The correct URI for that UNC has only two or four leading / characters
      ** file://host/path or file:////host/path.  But 5 leading slashes is a 
      ** common error, we are told, so we handle it as a special case. */
      if( strncmp(zUri+7, "///", 3)==0 ){ iIn++; }
    }else if( strncmp(zUri+5, "//localhost/", 12)==0 ){
      iIn = 16;
    }
#else
    /* Discard the scheme and authority segments of the URI. */
    if( zUri[5]=='/' && zUri[6]=='/' ){
      iIn = 7;
      while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
      if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
        *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 
            iIn-7, &zUri[7]);
        rc = SQLITE_ERROR;
        goto parse_uri_out;
      }
    }
#endif

    /* Copy the filename and any query parameters into the zFile buffer. 
    ** Decode %HH escape codes along the way. 
    **
    ** Within this loop, variable eState may be set to 0, 1 or 2, depending
    ** on the parsing context. As follows:
    **
    **   0: Parsing file-name.
    **   1: Parsing name section of a name=value query parameter.
    **   2: Parsing value section of a name=value query parameter.
    */
    eState = 0;
    while( (c = zUri[iIn])!=0 && c!='#' ){
      iIn++;
      if( c=='%' 
       && sqlite3Isxdigit(zUri[iIn]) 
       && sqlite3Isxdigit(zUri[iIn+1]) 
      ){
        int octet = (sqlite3HexToInt(zUri[iIn++]) << 4);
        octet += sqlite3HexToInt(zUri[iIn++]);

        assert( octet>=0 && octet<256 );
        if( octet==0 ){
#ifndef SQLITE_ENABLE_URI_00_ERROR
          /* This branch is taken when "%00" appears within the URI. In this
          ** case we ignore all text in the remainder of the path, name or
          ** value currently being parsed. So ignore the current character
          ** and skip to the next "?", "=" or "&", as appropriate. */
          while( (c = zUri[iIn])!=0 && c!='#' 
              && (eState!=0 || c!='?')
              && (eState!=1 || (c!='=' && c!='&'))
              && (eState!=2 || c!='&')
          ){
            iIn++;
          }
          continue;
#else
          /* If ENABLE_URI_00_ERROR is defined, "%00" in a URI is an error. */
          *pzErrMsg = sqlite3_mprintf("unexpected %%00 in uri");
          rc = SQLITE_ERROR;
          goto parse_uri_out;
#endif
        }
        c = octet;
      }else if( eState==1 && (c=='&' || c=='=') ){
        if( zFile[iOut-1]==0 ){
          /* An empty option name. Ignore this option altogether. */
          while( zUri[iIn] && zUri[iIn]!='#' && zUri[iIn-1]!='&' ) iIn++;
          continue;
        }
        if( c=='&' ){
          zFile[iOut++] = '\0';
        }else{
          eState = 2;
        }
        c = 0;
      }else if( (eState==0 && c=='?') || (eState==2 && c=='&') ){
        c = 0;
        eState = 1;
      }
      zFile[iOut++] = c;
    }
    if( eState==1 ) zFile[iOut++] = '\0';
    memset(zFile+iOut, 0, 4); /* end-of-options + empty journal filenames */

    /* Check if there were any options specified that should be interpreted 
    ** here. Options that are interpreted here include "vfs" and those that
    ** correspond to flags that may be passed to the sqlite3_open_v2()
    ** method. */
    zOpt = &zFile[sqlite3Strlen30(zFile)+1];
    while( zOpt[0] ){
      int nOpt = sqlite3Strlen30(zOpt);
      char *zVal = &zOpt[nOpt+1];
      int nVal = sqlite3Strlen30(zVal);

      if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
        zVfs = zVal;
      }else{
        struct OpenMode {
          const char *z;
          int mode;
        } *aMode = 0;
        char *zModeType = 0;
        int mask = 0;
        int limit = 0;

        if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
          static struct OpenMode aCacheMode[] = {
            { "shared",  SQLITE_OPEN_SHAREDCACHE },
            { "private", SQLITE_OPEN_PRIVATECACHE },
            { 0, 0 }
          };

          mask = SQLITE_OPEN_SHAREDCACHE|SQLITE_OPEN_PRIVATECACHE;
          aMode = aCacheMode;
          limit = mask;
          zModeType = "cache";
        }
        if( nOpt==4 && memcmp("mode", zOpt, 4)==0 ){
          static struct OpenMode aOpenMode[] = {
            { "ro",  SQLITE_OPEN_READONLY },
            { "rw",  SQLITE_OPEN_READWRITE }, 
            { "rwc", SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE },
            { "memory", SQLITE_OPEN_MEMORY },
            { 0, 0 }
          };

          mask = SQLITE_OPEN_READONLY | SQLITE_OPEN_READWRITE
                   | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY;
          aMode = aOpenMode;
          limit = mask & flags;
          zModeType = "access";
        }

        if( aMode ){
          int i;
          int mode = 0;
          for(i=0; aMode[i].z; i++){
            const char *z = aMode[i].z;
            if( nVal==sqlite3Strlen30(z) && 0==memcmp(zVal, z, nVal) ){
              mode = aMode[i].mode;
              break;
            }
          }
          if( mode==0 ){
            *pzErrMsg = sqlite3_mprintf("no such %s mode: %s", zModeType, zVal);
            rc = SQLITE_ERROR;
            goto parse_uri_out;
          }
          if( (mode & ~SQLITE_OPEN_MEMORY)>limit ){
            *pzErrMsg = sqlite3_mprintf("%s mode not allowed: %s",
                                        zModeType, zVal);
            rc = SQLITE_PERM;
            goto parse_uri_out;
          }
          flags = (flags & ~mask) | mode;
        }
      }

      zOpt = &zVal[nVal+1];
    }

  }else{
    zFile = sqlite3_malloc64(nUri+8);
    if( !zFile ) return SQLITE_NOMEM_BKPT;
    memset(zFile, 0, 4);
    zFile += 4;
    if( nUri ){
      memcpy(zFile, zUri, nUri);
    }
    memset(zFile+nUri, 0, 4);
    flags &= ~SQLITE_OPEN_URI;
  }

  *ppVfs = sqlite3_vfs_find(zVfs);
  if( *ppVfs==0 ){
    *pzErrMsg = sqlite3_mprintf("no such vfs: %s", zVfs);
    rc = SQLITE_ERROR;
  }
 parse_uri_out:
  if( rc!=SQLITE_OK ){
    sqlite3_free_filename(zFile);
    zFile = 0;
  }
  *pFlags = flags;
  *pzFile = zFile;
  return rc;
}

/*
** This routine does the core work of extracting URI parameters from a
** database filename for the sqlite3_uri_parameter() interface.
*/
static const char *uriParameter(const char *zFilename, const char *zParam){
  zFilename += sqlite3Strlen30(zFilename) + 1;
  while( zFilename[0] ){
    int x = strcmp(zFilename, zParam);
    zFilename += sqlite3Strlen30(zFilename) + 1;
    if( x==0 ) return zFilename;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return 0;
}



/*
** This routine does the work of opening a database on behalf of
** sqlite3_open() and sqlite3_open16(). The database filename "zFilename"  
** is UTF-8 encoded.
*/
static int openDatabase(
  const char *zFilename, /* Database filename UTF-8 encoded */
  sqlite3 **ppDb,        /* OUT: Returned database handle */
  unsigned int flags,    /* Operational flags */
  const char *zVfs       /* Name of the VFS to use */
){
  sqlite3 *db;                    /* Store allocated handle here */
  int rc;                         /* Return code */
  int isThreadsafe;               /* True for threadsafe connections */
  char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
  char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
  int i;                          /* Loop counter */

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();
  if( rc ) return rc;
#endif

  if( sqlite3GlobalConfig.bCoreMutex==0 ){
    isThreadsafe = 0;
  }else if( flags & SQLITE_OPEN_NOMUTEX ){
    isThreadsafe = 0;
  }else if( flags & SQLITE_OPEN_FULLMUTEX ){
    isThreadsafe = 1;
  }else{
    isThreadsafe = sqlite3GlobalConfig.bFullMutex;
  }

  if( flags & SQLITE_OPEN_PRIVATECACHE ){
    flags &= ~SQLITE_OPEN_SHAREDCACHE;
  }else if( sqlite3GlobalConfig.sharedCacheEnabled ){
    flags |= SQLITE_OPEN_SHAREDCACHE;
  }

  /* Remove harmful bits from the flags parameter
  **
  ** The SQLITE_OPEN_NOMUTEX and SQLITE_OPEN_FULLMUTEX flags were
  ** dealt with in the previous code block.  Besides these, the only
  ** valid input flags for sqlite3_open_v2() are SQLITE_OPEN_READONLY,
  ** SQLITE_OPEN_READWRITE, SQLITE_OPEN_CREATE, SQLITE_OPEN_SHAREDCACHE,
  ** SQLITE_OPEN_PRIVATECACHE, and some reserved bits.  Silently mask
  ** off all other flags.
  */
  flags &=  ~( SQLITE_OPEN_DELETEONCLOSE |
               SQLITE_OPEN_EXCLUSIVE |
               SQLITE_OPEN_MAIN_DB |
               SQLITE_OPEN_TEMP_DB | 
               SQLITE_OPEN_TRANSIENT_DB | 
               SQLITE_OPEN_MAIN_JOURNAL | 
               SQLITE_OPEN_TEMP_JOURNAL | 
               SQLITE_OPEN_SUBJOURNAL | 
               SQLITE_OPEN_SUPER_JOURNAL |
               SQLITE_OPEN_NOMUTEX |
               SQLITE_OPEN_FULLMUTEX |
               SQLITE_OPEN_WAL
             );

  /* Allocate the sqlite data structure */
  db = sqlite3MallocZero( sizeof(sqlite3) );
  if( db==0 ) goto opendb_out;
  if( isThreadsafe 
#ifdef SQLITE_ENABLE_MULTITHREADED_CHECKS
   || sqlite3GlobalConfig.bCoreMutex
#endif
  ){
    db->mutex = sqlite3MutexAlloc(SQLITE_MUTEX_RECURSIVE);
    if( db->mutex==0 ){
      sqlite3_free(db);
      db = 0;
      goto opendb_out;
    }
    if( isThreadsafe==0 ){
      sqlite3MutexWarnOnContention(db->mutex);
    }
  }
  sqlite3_mutex_enter(db->mutex);
  db->errMask = 0xff;
  db->nDb = 2;
  db->magic = SQLITE_MAGIC_BUSY;
  db->aDb = db->aDbStatic;
  db->lookaside.bDisable = 1;
  db->lookaside.sz = 0;

  assert( sizeof(db->aLimit)==sizeof(aHardLimit) );
  memcpy(db->aLimit, aHardLimit, sizeof(db->aLimit));
  db->aLimit[SQLITE_LIMIT_WORKER_THREADS] = SQLITE_DEFAULT_WORKER_THREADS;
  db->autoCommit = 1;
  db->nextAutovac = -1;
  db->szMmap = sqlite3GlobalConfig.szMmap;
  db->nextPagesize = 0;
  db->nMaxSorterMmap = 0x7FFFFFFF;
  db->flags |= SQLITE_ShortColNames
                 | SQLITE_EnableTrigger
                 | SQLITE_EnableView
                 | SQLITE_CacheSpill
#if !defined(SQLITE_TRUSTED_SCHEMA) || SQLITE_TRUSTED_SCHEMA+0!=0
                 | SQLITE_TrustedSchema
#endif
/* The SQLITE_DQS compile-time option determines the default settings
** for SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.
**
**    SQLITE_DQS     SQLITE_DBCONFIG_DQS_DDL    SQLITE_DBCONFIG_DQS_DML
**    ----------     -----------------------    -----------------------
**     undefined               on                          on   
**         3                   on                          on
**         2                   on                         off
**         1                  off                          on
**         0                  off                         off
**
** Legacy behavior is 3 (double-quoted string literals are allowed anywhere)
** and so that is the default.  But developers are encouranged to use
** -DSQLITE_DQS=0 (best) or -DSQLITE_DQS=1 (second choice) if possible.
*/
#if !defined(SQLITE_DQS)
# define SQLITE_DQS 3
#endif
#if (SQLITE_DQS&1)==1
                 | SQLITE_DqsDML
#endif
#if (SQLITE_DQS&2)==2
                 | SQLITE_DqsDDL
#endif

#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
                 | SQLITE_AutoIndex
#endif
#if SQLITE_DEFAULT_CKPTFULLFSYNC
                 | SQLITE_CkptFullFSync
#endif
#if SQLITE_DEFAULT_FILE_FORMAT<4
                 | SQLITE_LegacyFileFmt
#endif
#ifdef SQLITE_ENABLE_LOAD_EXTENSION
                 | SQLITE_LoadExtension
#endif
#if SQLITE_DEFAULT_RECURSIVE_TRIGGERS
                 | SQLITE_RecTriggers
#endif
#if defined(SQLITE_DEFAULT_FOREIGN_KEYS) && SQLITE_DEFAULT_FOREIGN_KEYS
                 | SQLITE_ForeignKeys
#endif
#if defined(SQLITE_REVERSE_UNORDERED_SELECTS)
                 | SQLITE_ReverseOrder
#endif
#if defined(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
                 | SQLITE_CellSizeCk
#endif
#if defined(SQLITE_ENABLE_FTS3_TOKENIZER)
                 | SQLITE_Fts3Tokenizer
#endif
#if defined(SQLITE_ENABLE_QPSG)
                 | SQLITE_EnableQPSG
#endif
#if defined(SQLITE_DEFAULT_DEFENSIVE)
                 | SQLITE_Defensive
#endif
#if defined(SQLITE_DEFAULT_LEGACY_ALTER_TABLE)
                 | SQLITE_LegacyAlter
#endif
      ;
  sqlite3HashInit(&db->aCollSeq);
#ifndef SQLITE_OMIT_VIRTUALTABLE
  sqlite3HashInit(&db->aModule);
#endif

  /* Add the default collation sequence BINARY. BINARY works for both UTF-8
  ** and UTF-16, so add a version for each to avoid any unnecessary
  ** conversions. The only error that can occur here is a malloc() failure.
  **
  ** EVIDENCE-OF: R-52786-44878 SQLite defines three built-in collating
  ** functions:
  */
  createCollation(db, sqlite3StrBINARY, SQLITE_UTF8, 0, binCollFunc, 0);
  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16BE, 0, binCollFunc, 0);
  createCollation(db, sqlite3StrBINARY, SQLITE_UTF16LE, 0, binCollFunc, 0);
  createCollation(db, "NOCASE", SQLITE_UTF8, 0, nocaseCollatingFunc, 0);
  createCollation(db, "RTRIM", SQLITE_UTF8, 0, rtrimCollFunc, 0);
  if( db->mallocFailed ){
    goto opendb_out;
  }

  /* Parse the filename/URI argument
  **
  ** Only allow sensible combinations of bits in the flags argument.  
  ** Throw an error if any non-sense combination is used.  If we
  ** do not block illegal combinations here, it could trigger
  ** assert() statements in deeper layers.  Sensible combinations
  ** are:
  **
  **  1:  SQLITE_OPEN_READONLY
  **  2:  SQLITE_OPEN_READWRITE
  **  6:  SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
  */
  db->openFlags = flags;
  assert( SQLITE_OPEN_READONLY  == 0x01 );
  assert( SQLITE_OPEN_READWRITE == 0x02 );
  assert( SQLITE_OPEN_CREATE    == 0x04 );
  testcase( (1<<(flags&7))==0x02 ); /* READONLY */
  testcase( (1<<(flags&7))==0x04 ); /* READWRITE */
  testcase( (1<<(flags&7))==0x40 ); /* READWRITE | CREATE */
  if( ((1<<(flags&7)) & 0x46)==0 ){
    rc = SQLITE_MISUSE_BKPT;  /* IMP: R-18321-05872 */
  }else{
    rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
  }
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_NOMEM ) sqlite3OomFault(db);
    sqlite3ErrorWithMsg(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
    sqlite3_free(zErrMsg);
    goto opendb_out;
  }

  /* Open the backend database driver */
  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
                        flags | SQLITE_OPEN_MAIN_DB);
  if( rc!=SQLITE_OK ){
    if( rc==SQLITE_IOERR_NOMEM ){
      rc = SQLITE_NOMEM_BKPT;
    }
    sqlite3Error(db, rc);
    goto opendb_out;
  }
  sqlite3BtreeEnter(db->aDb[0].pBt);
  db->aDb[0].pSchema = sqlite3SchemaGet(db, db->aDb[0].pBt);
  if( !db->mallocFailed ){
    sqlite3SetTextEncoding(db, SCHEMA_ENC(db));
  }
  sqlite3BtreeLeave(db->aDb[0].pBt);
  db->aDb[1].pSchema = sqlite3SchemaGet(db, 0);

  /* The default safety_level for the main database is FULL; for the temp
  ** database it is OFF. This matches the pager layer defaults.  
  */
  db->aDb[0].zDbSName = "main";
  db->aDb[0].safety_level = SQLITE_DEFAULT_SYNCHRONOUS+1;
  db->aDb[1].zDbSName = "temp";
  db->aDb[1].safety_level = PAGER_SYNCHRONOUS_OFF;

  db->magic = SQLITE_MAGIC_OPEN;
  if( db->mallocFailed ){
    goto opendb_out;
  }

  /* Register all built-in functions, but do not attempt to read the
  ** database schema yet. This is delayed until the first time the database
  ** is accessed.
  */
  sqlite3Error(db, SQLITE_OK);
  sqlite3RegisterPerConnectionBuiltinFunctions(db);
  rc = sqlite3_errcode(db);


  /* Load compiled-in extensions */
  for(i=0; rc==SQLITE_OK && i<ArraySize(sqlite3BuiltinExtensions); i++){
    rc = sqlite3BuiltinExtensions[i](db);
  }

  /* Load automatic extensions - extensions that have been registered
  ** using the sqlite3_automatic_extension() API.
  */
  if( rc==SQLITE_OK ){
    sqlite3AutoLoadExtensions(db);
    rc = sqlite3_errcode(db);
    if( rc!=SQLITE_OK ){
      goto opendb_out;
    }
  }

#ifdef SQLITE_ENABLE_INTERNAL_FUNCTIONS
  /* Testing use only!!! The -DSQLITE_ENABLE_INTERNAL_FUNCTIONS=1 compile-time
  ** option gives access to internal functions by default.  
  ** Testing use only!!! */
  db->mDbFlags |= DBFLAG_InternalFunc;
#endif

  /* -DSQLITE_DEFAULT_LOCKING_MODE=1 makes EXCLUSIVE the default locking
  ** mode.  -DSQLITE_DEFAULT_LOCKING_MODE=0 make NORMAL the default locking
  ** mode.  Doing nothing at all also makes NORMAL the default.
  */
#ifdef SQLITE_DEFAULT_LOCKING_MODE
  db->dfltLockMode = SQLITE_DEFAULT_LOCKING_MODE;
  sqlite3PagerLockingMode(sqlite3BtreePager(db->aDb[0].pBt),
                          SQLITE_DEFAULT_LOCKING_MODE);
#endif

  if( rc ) sqlite3Error(db, rc);

  /* Enable the lookaside-malloc subsystem */
  setupLookaside(db, 0, sqlite3GlobalConfig.szLookaside,
                        sqlite3GlobalConfig.nLookaside);

  sqlite3_wal_autocheckpoint(db, SQLITE_DEFAULT_WAL_AUTOCHECKPOINT);

opendb_out:
  if( db ){
    assert( db->mutex!=0 || isThreadsafe==0
           || sqlite3GlobalConfig.bFullMutex==0 );
    sqlite3_mutex_leave(db->mutex);
  }
  rc = sqlite3_errcode(db);
  assert( db!=0 || rc==SQLITE_NOMEM );
  if( rc==SQLITE_NOMEM ){
    sqlite3_close(db);
    db = 0;
  }else if( rc!=SQLITE_OK ){
    db->magic = SQLITE_MAGIC_SICK;
  }
  *ppDb = db;
#ifdef SQLITE_ENABLE_SQLLOG
  if( sqlite3GlobalConfig.xSqllog ){
    /* Opening a db handle. Fourth parameter is passed 0. */
    void *pArg = sqlite3GlobalConfig.pSqllogArg;
    sqlite3GlobalConfig.xSqllog(pArg, db, zFilename, 0);
  }
#endif
  sqlite3_free_filename(zOpen);
  return rc & 0xff;
}


/*
** Open a new database handle.
*/
int sqlite3_open(
  const char *zFilename, 
  sqlite3 **ppDb 
){
  return openDatabase(zFilename, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
}
int sqlite3_open_v2(
  const char *filename,   /* Database filename (UTF-8) */
  sqlite3 **ppDb,         /* OUT: SQLite db handle */
  int flags,              /* Flags */
  const char *zVfs        /* Name of VFS module to use */
){
  return openDatabase(filename, ppDb, (unsigned int)flags, zVfs);
}

#ifndef SQLITE_OMIT_UTF16
/*
** Open a new database handle.
*/
int sqlite3_open16(
  const void *zFilename, 
  sqlite3 **ppDb
){
  char const *zFilename8;   /* zFilename encoded in UTF-8 instead of UTF-16 */
  sqlite3_value *pVal;
  int rc;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( ppDb==0 ) return SQLITE_MISUSE_BKPT;
#endif
  *ppDb = 0;
#ifndef SQLITE_OMIT_AUTOINIT
  rc = sqlite3_initialize();
  if( rc ) return rc;
#endif
  if( zFilename==0 ) zFilename = "\000\000";
  pVal = sqlite3ValueNew(0);
  sqlite3ValueSetStr(pVal, -1, zFilename, SQLITE_UTF16NATIVE, SQLITE_STATIC);
  zFilename8 = sqlite3ValueText(pVal, SQLITE_UTF8);
  if( zFilename8 ){
    rc = openDatabase(zFilename8, ppDb,
                      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, 0);
    assert( *ppDb || rc==SQLITE_NOMEM );
    if( rc==SQLITE_OK && !DbHasProperty(*ppDb, 0, DB_SchemaLoaded) ){
      SCHEMA_ENC(*ppDb) = ENC(*ppDb) = SQLITE_UTF16NATIVE;
    }
  }else{
    rc = SQLITE_NOMEM_BKPT;
  }
  sqlite3ValueFree(pVal);

  return rc & 0xff;
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation(
  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  return sqlite3_create_collation_v2(db, zName, enc, pCtx, xCompare, 0);
}

/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation_v2(
  sqlite3* db, 
  const char *zName, 
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*),
  void(*xDel)(void*)
){
  int rc;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  rc = createCollation(db, zName, (u8)enc, pCtx, xCompare, xDel);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

#ifndef SQLITE_OMIT_UTF16
/*
** Register a new collation sequence with the database handle db.
*/
int sqlite3_create_collation16(
  sqlite3* db, 
  const void *zName,
  int enc, 
  void* pCtx,
  int(*xCompare)(void*,int,const void*,int,const void*)
){
  int rc = SQLITE_OK;
  char *zName8;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zName==0 ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  assert( !db->mallocFailed );
  zName8 = sqlite3Utf16to8(db, zName, -1, SQLITE_UTF16NATIVE);
  if( zName8 ){
    rc = createCollation(db, zName8, (u8)enc, pCtx, xCompare, 0);
    sqlite3DbFree(db, zName8);
  }
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}
#endif /* SQLITE_OMIT_UTF16 */

/*
** Register a collation sequence factory callback with the database handle
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded)(void*,sqlite3*,int eTextRep,const char*)
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->xCollNeeded = xCollNeeded;
  db->xCollNeeded16 = 0;
  db->pCollNeededArg = pCollNeededArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

#ifndef SQLITE_OMIT_UTF16
/*
** Register a collation sequence factory callback with the database handle
** db. Replace any previously installed collation sequence factory.
*/
int sqlite3_collation_needed16(
  sqlite3 *db, 
  void *pCollNeededArg, 
  void(*xCollNeeded16)(void*,sqlite3*,int eTextRep,const void*)
){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->xCollNeeded = 0;
  db->xCollNeeded16 = xCollNeeded16;
  db->pCollNeededArg = pCollNeededArg;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}
#endif /* SQLITE_OMIT_UTF16 */

#ifndef SQLITE_OMIT_DEPRECATED
/*
** This function is now an anachronism. It used to be used to recover from a
** malloc() failure, but SQLite now does this automatically.
*/
int sqlite3_global_recover(void){
  return SQLITE_OK;
}
#endif

/*
** Test to see whether or not the database connection is in autocommit
** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
** by default.  Autocommit is disabled by a BEGIN statement and reenabled
** by the next COMMIT or ROLLBACK.
*/
int sqlite3_get_autocommit(sqlite3 *db){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  return db->autoCommit;
}

/*
** The following routines are substitutes for constants SQLITE_CORRUPT,
** SQLITE_MISUSE, SQLITE_CANTOPEN, SQLITE_NOMEM and possibly other error
** constants.  They serve two purposes:
**
**   1.  Serve as a convenient place to set a breakpoint in a debugger
**       to detect when version error conditions occurs.
**
**   2.  Invoke sqlite3_log() to provide the source code location where
**       a low-level error is first detected.
*/
int sqlite3ReportError(int iErr, int lineno, const char *zType){
  sqlite3_log(iErr, "%s at line %d of [%.10s]",
              zType, lineno, 20+sqlite3_sourceid());
  return iErr;
}
int sqlite3CorruptError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_CORRUPT, lineno, "database corruption");
}
int sqlite3MisuseError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_MISUSE, lineno, "misuse");
}
int sqlite3CantopenError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_CANTOPEN, lineno, "cannot open file");
}
#if defined(SQLITE_DEBUG) || defined(SQLITE_ENABLE_CORRUPT_PGNO)
int sqlite3CorruptPgnoError(int lineno, Pgno pgno){
  char zMsg[100];
  sqlite3_snprintf(sizeof(zMsg), zMsg, "database corruption page %d", pgno);
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_CORRUPT, lineno, zMsg);
}
#endif
#ifdef SQLITE_DEBUG
int sqlite3NomemError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_NOMEM, lineno, "OOM");
}
int sqlite3IoerrnomemError(int lineno){
  testcase( sqlite3GlobalConfig.xLog!=0 );
  return sqlite3ReportError(SQLITE_IOERR_NOMEM, lineno, "I/O OOM error");
}
#endif

#ifndef SQLITE_OMIT_DEPRECATED
/*
** This is a convenience routine that makes sure that all thread-specific
** data for this thread has been deallocated.
**
** SQLite no longer uses thread-specific data so this routine is now a
** no-op.  It is retained for historical compatibility.
*/
void sqlite3_thread_cleanup(void){
}
#endif

/*
** Return meta information about a specific column of a database table.
** See comment in sqlite3.h (sqlite.h.in) for details.
*/
int sqlite3_table_column_metadata(
  sqlite3 *db,                /* Connection handle */
  const char *zDbName,        /* Database name or NULL */
  const char *zTableName,     /* Table name */
  const char *zColumnName,    /* Column name */
  char const **pzDataType,    /* OUTPUT: Declared data type */
  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
  int *pAutoinc               /* OUTPUT: True if column is auto-increment */
){
  int rc;
  char *zErrMsg = 0;
  Table *pTab = 0;
  Column *pCol = 0;
  int iCol = 0;
  char const *zDataType = 0;
  char const *zCollSeq = 0;
  int notnull = 0;
  int primarykey = 0;
  int autoinc = 0;


#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) || zTableName==0 ){
    return SQLITE_MISUSE_BKPT;
  }
#endif

  /* Ensure the database schema has been loaded */
  sqlite3_mutex_enter(db->mutex);
  sqlite3BtreeEnterAll(db);
  rc = sqlite3Init(db, &zErrMsg);
  if( SQLITE_OK!=rc ){
    goto error_out;
  }

  /* Locate the table in question */
  pTab = sqlite3FindTable(db, zTableName, zDbName);
  if( !pTab || pTab->pSelect ){
    pTab = 0;
    goto error_out;
  }

  /* Find the column for which info is requested */
  if( zColumnName==0 ){
    /* Query for existance of table only */
  }else{
    for(iCol=0; iCol<pTab->nCol; iCol++){
      pCol = &pTab->aCol[iCol];
      if( 0==sqlite3StrICmp(pCol->zName, zColumnName) ){
        break;
      }
    }
    if( iCol==pTab->nCol ){
      if( HasRowid(pTab) && sqlite3IsRowid(zColumnName) ){
        iCol = pTab->iPKey;
        pCol = iCol>=0 ? &pTab->aCol[iCol] : 0;
      }else{
        pTab = 0;
        goto error_out;
      }
    }
  }

  /* The following block stores the meta information that will be returned
  ** to the caller in local variables zDataType, zCollSeq, notnull, primarykey
  ** and autoinc. At this point there are two possibilities:
  ** 
  **     1. The specified column name was rowid", "oid" or "_rowid_" 
  **        and there is no explicitly declared IPK column. 
  **
  **     2. The table is not a view and the column name identified an 
  **        explicitly declared column. Copy meta information from *pCol.
  */ 
  if( pCol ){
    zDataType = sqlite3ColumnType(pCol,0);
    zCollSeq = pCol->zColl;
    notnull = pCol->notNull!=0;
    primarykey  = (pCol->colFlags & COLFLAG_PRIMKEY)!=0;
    autoinc = pTab->iPKey==iCol && (pTab->tabFlags & TF_Autoincrement)!=0;
  }else{
    zDataType = "INTEGER";
    primarykey = 1;
  }
  if( !zCollSeq ){
    zCollSeq = sqlite3StrBINARY;
  }

error_out:
  sqlite3BtreeLeaveAll(db);

  /* Whether the function call succeeded or failed, set the output parameters
  ** to whatever their local counterparts contain. If an error did occur,
  ** this has the effect of zeroing all output parameters.
  */
  if( pzDataType ) *pzDataType = zDataType;
  if( pzCollSeq ) *pzCollSeq = zCollSeq;
  if( pNotNull ) *pNotNull = notnull;
  if( pPrimaryKey ) *pPrimaryKey = primarykey;
  if( pAutoinc ) *pAutoinc = autoinc;

  if( SQLITE_OK==rc && !pTab ){
    sqlite3DbFree(db, zErrMsg);
    zErrMsg = sqlite3MPrintf(db, "no such table column: %s.%s", zTableName,
        zColumnName);
    rc = SQLITE_ERROR;
  }
  sqlite3ErrorWithMsg(db, rc, (zErrMsg?"%s":0), zErrMsg);
  sqlite3DbFree(db, zErrMsg);
  rc = sqlite3ApiExit(db, rc);
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Sleep for a little while.  Return the amount of time slept.
*/
int sqlite3_sleep(int ms){
  sqlite3_vfs *pVfs;
  int rc;
  pVfs = sqlite3_vfs_find(0);
  if( pVfs==0 ) return 0;

  /* This function works in milliseconds, but the underlying OsSleep() 
  ** API uses microseconds. Hence the 1000's.
  */
  rc = (sqlite3OsSleep(pVfs, 1000*ms)/1000);
  return rc;
}

/*
** Enable or disable the extended result codes.
*/
int sqlite3_extended_result_codes(sqlite3 *db, int onoff){
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  db->errMask = onoff ? 0xffffffff : 0xff;
  sqlite3_mutex_leave(db->mutex);
  return SQLITE_OK;
}

/*
** Invoke the xFileControl method on a particular database.
*/
int sqlite3_file_control(sqlite3 *db, const char *zDbName, int op, void *pArg){
  int rc = SQLITE_ERROR;
  Btree *pBtree;

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ) return SQLITE_MISUSE_BKPT;
#endif
  sqlite3_mutex_enter(db->mutex);
  pBtree = sqlite3DbNameToBtree(db, zDbName);
  if( pBtree ){
    Pager *pPager;
    sqlite3_file *fd;
    sqlite3BtreeEnter(pBtree);
    pPager = sqlite3BtreePager(pBtree);
    assert( pPager!=0 );
    fd = sqlite3PagerFile(pPager);
    assert( fd!=0 );
    if( op==SQLITE_FCNTL_FILE_POINTER ){
      *(sqlite3_file**)pArg = fd;
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_VFS_POINTER ){
      *(sqlite3_vfs**)pArg = sqlite3PagerVfs(pPager);
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_JOURNAL_POINTER ){
      *(sqlite3_file**)pArg = sqlite3PagerJrnlFile(pPager);
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_DATA_VERSION ){
      *(unsigned int*)pArg = sqlite3PagerDataVersion(pPager);
      rc = SQLITE_OK;
    }else if( op==SQLITE_FCNTL_RESERVE_BYTES ){
      int iNew = *(int*)pArg;
      *(int*)pArg = sqlite3BtreeGetRequestedReserve(pBtree);
      if( iNew>=0 && iNew<=255 ){
        sqlite3BtreeSetPageSize(pBtree, 0, iNew, 0);
      }
      rc = SQLITE_OK;
    }else{
      int nSave = db->busyHandler.nBusy;
      rc = sqlite3OsFileControl(fd, op, pArg);
      db->busyHandler.nBusy = nSave;
    }
    sqlite3BtreeLeave(pBtree);
  }
  sqlite3_mutex_leave(db->mutex);
  return rc;
}

/*
** Interface to the testing logic.
*/
int sqlite3_test_control(int op, ...){
  int rc = 0;
#ifdef SQLITE_UNTESTABLE
  UNUSED_PARAMETER(op);
#else
  va_list ap;
  va_start(ap, op);
  switch( op ){

    /*
    ** Save the current state of the PRNG.
    */
    case SQLITE_TESTCTRL_PRNG_SAVE: {
      sqlite3PrngSaveState();
      break;
    }

    /*
    ** Restore the state of the PRNG to the last state saved using
    ** PRNG_SAVE.  If PRNG_SAVE has never before been called, then
    ** this verb acts like PRNG_RESET.
    */
    case SQLITE_TESTCTRL_PRNG_RESTORE: {
      sqlite3PrngRestoreState();
      break;
    }

    /*  sqlite3_test_control(SQLITE_TESTCTRL_PRNG_SEED, int x, sqlite3 *db);
    **
    ** Control the seed for the pseudo-random number generator (PRNG) that
    ** is built into SQLite.  Cases:
    **
    **    x!=0 && db!=0       Seed the PRNG to the current value of the
    **                        schema cookie in the main database for db, or
    **                        x if the schema cookie is zero.  This case
    **                        is convenient to use with database fuzzers
    **                        as it allows the fuzzer some control over the
    **                        the PRNG seed.
    **
    **    x!=0 && db==0       Seed the PRNG to the value of x.
    **
    **    x==0 && db==0       Revert to default behavior of using the
    **                        xRandomness method on the primary VFS.
    **
    ** This test-control also resets the PRNG so that the new seed will
    ** be used for the next call to sqlite3_randomness().
    */
#ifndef SQLITE_OMIT_WSD
    case SQLITE_TESTCTRL_PRNG_SEED: {
      int x = va_arg(ap, int);
      int y;
      sqlite3 *db = va_arg(ap, sqlite3*);
      assert( db==0 || db->aDb[0].pSchema!=0 );
      if( db && (y = db->aDb[0].pSchema->schema_cookie)!=0 ){ x = y; }
      sqlite3Config.iPrngSeed = x;
      sqlite3_randomness(0,0);
      break;
    }
#endif

    /*
    **  sqlite3_test_control(BITVEC_TEST, size, program)
    **
    ** Run a test against a Bitvec object of size.  The program argument
    ** is an array of integers that defines the test.  Return -1 on a
    ** memory allocation error, 0 on success, or non-zero for an error.
    ** See the sqlite3BitvecBuiltinTest() for additional information.
    */
    case SQLITE_TESTCTRL_BITVEC_TEST: {
      int sz = va_arg(ap, int);
      int *aProg = va_arg(ap, int*);
      rc = sqlite3BitvecBuiltinTest(sz, aProg);
      break;
    }

    /*
    **  sqlite3_test_control(FAULT_INSTALL, xCallback)
    **
    ** Arrange to invoke xCallback() whenever sqlite3FaultSim() is called,
    ** if xCallback is not NULL.
    **
    ** As a test of the fault simulator mechanism itself, sqlite3FaultSim(0)
    ** is called immediately after installing the new callback and the return
    ** value from sqlite3FaultSim(0) becomes the return from
    ** sqlite3_test_control().
    */
    case SQLITE_TESTCTRL_FAULT_INSTALL: {
      /* MSVC is picky about pulling func ptrs from va lists.
      ** http://support.microsoft.com/kb/47961
      ** sqlite3GlobalConfig.xTestCallback = va_arg(ap, int(*)(int));
      */
      typedef int(*TESTCALLBACKFUNC_t)(int);
      sqlite3GlobalConfig.xTestCallback = va_arg(ap, TESTCALLBACKFUNC_t);
      rc = sqlite3FaultSim(0);
      break;
    }

    /*
    **  sqlite3_test_control(BENIGN_MALLOC_HOOKS, xBegin, xEnd)
    **
    ** Register hooks to call to indicate which malloc() failures 
    ** are benign.
    */
    case SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS: {
      typedef void (*void_function)(void);
      void_function xBenignBegin;
      void_function xBenignEnd;
      xBenignBegin = va_arg(ap, void_function);
      xBenignEnd = va_arg(ap, void_function);
      sqlite3BenignMallocHooks(xBenignBegin, xBenignEnd);
      break;
    }

    /*
    **  sqlite3_test_control(SQLITE_TESTCTRL_PENDING_BYTE, unsigned int X)
    **
    ** Set the PENDING byte to the value in the argument, if X>0.
    ** Make no changes if X==0.  Return the value of the pending byte
    ** as it existing before this routine was called.
    **
    ** IMPORTANT:  Changing the PENDING byte from 0x40000000 results in
    ** an incompatible database file format.  Changing the PENDING byte
    ** while any database connection is open results in undefined and
    ** deleterious behavior.
    */
    case SQLITE_TESTCTRL_PENDING_BYTE: {
      rc = PENDING_BYTE;
#ifndef SQLITE_OMIT_WSD
      {
        unsigned int newVal = va_arg(ap, unsigned int);
        if( newVal ) sqlite3PendingByte = newVal;
      }
#endif
      break;
    }

    /*
    **  sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, int X)
    **
    ** This action provides a run-time test to see whether or not
    ** assert() was enabled at compile-time.  If X is true and assert()
    ** is enabled, then the return value is true.  If X is true and
    ** assert() is disabled, then the return value is zero.  If X is
    ** false and assert() is enabled, then the assertion fires and the
    ** process aborts.  If X is false and assert() is disabled, then the
    ** return value is zero.
    */
    case SQLITE_TESTCTRL_ASSERT: {
      volatile int x = 0;
      assert( /*side-effects-ok*/ (x = va_arg(ap,int))!=0 );
      rc = x;
      break;
    }


    /*
    **  sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, int X)
    **
    ** This action provides a run-time test to see how the ALWAYS and
    ** NEVER macros were defined at compile-time.
    **
    ** The return value is ALWAYS(X) if X is true, or 0 if X is false.
    **
    ** The recommended test is X==2.  If the return value is 2, that means
    ** ALWAYS() and NEVER() are both no-op pass-through macros, which is the
    ** default setting.  If the return value is 1, then ALWAYS() is either
    ** hard-coded to true or else it asserts if its argument is false.
    ** The first behavior (hard-coded to true) is the case if
    ** SQLITE_TESTCTRL_ASSERT shows that assert() is disabled and the second
    ** behavior (assert if the argument to ALWAYS() is false) is the case if
    ** SQLITE_TESTCTRL_ASSERT shows that assert() is enabled.
    **
    ** The run-time test procedure might look something like this:
    **
    **    if( sqlite3_test_control(SQLITE_TESTCTRL_ALWAYS, 2)==2 ){
    **      // ALWAYS() and NEVER() are no-op pass-through macros
    **    }else if( sqlite3_test_control(SQLITE_TESTCTRL_ASSERT, 1) ){
    **      // ALWAYS(x) asserts that x is true. NEVER(x) asserts x is false.
    **    }else{
    **      // ALWAYS(x) is a constant 1.  NEVER(x) is a constant 0.
    **    }
    */
    case SQLITE_TESTCTRL_ALWAYS: {
      int x = va_arg(ap,int);
      rc = x ? ALWAYS(x) : 0;
      break;
    }

    /*
    **   sqlite3_test_control(SQLITE_TESTCTRL_BYTEORDER);
    **
    ** The integer returned reveals the byte-order of the computer on which
    ** SQLite is running:
    **
    **       1     big-endian,    determined at run-time
    **      10     little-endian, determined at run-time
    **  432101     big-endian,    determined at compile-time
    **  123410     little-endian, determined at compile-time
    */ 
    case SQLITE_TESTCTRL_BYTEORDER: {
      rc = SQLITE_BYTEORDER*100 + SQLITE_LITTLEENDIAN*10 + SQLITE_BIGENDIAN;
      break;
    }

    /*  sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS, sqlite3 *db, int N)
    **
    ** Enable or disable various optimizations for testing purposes.  The 
    ** argument N is a bitmask of optimizations to be disabled.  For normal
    ** operation N should be 0.  The idea is that a test program (like the
    ** SQL Logic Test or SLT test module) can run the same SQL multiple times
    ** with various optimizations disabled to verify that the same answer
    ** is obtained in every case.
    */
    case SQLITE_TESTCTRL_OPTIMIZATIONS: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      db->dbOptFlags = (u16)(va_arg(ap, int) & 0xffff);
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_LOCALTIME_FAULT, int onoff);
    **
    ** If parameter onoff is non-zero, subsequent calls to localtime()
    ** and its variants fail. If onoff is zero, undo this setting.
    */
    case SQLITE_TESTCTRL_LOCALTIME_FAULT: {
      sqlite3GlobalConfig.bLocaltimeFault = va_arg(ap, int);
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_INTERNAL_FUNCTIONS, sqlite3*);
    **
    ** Toggle the ability to use internal functions on or off for
    ** the database connection given in the argument.
    */
    case SQLITE_TESTCTRL_INTERNAL_FUNCTIONS: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      db->mDbFlags ^= DBFLAG_InternalFunc;
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_NEVER_CORRUPT, int);
    **
    ** Set or clear a flag that indicates that the database file is always well-
    ** formed and never corrupt.  This flag is clear by default, indicating that
    ** database files might have arbitrary corruption.  Setting the flag during
    ** testing causes certain assert() statements in the code to be activated
    ** that demonstrat invariants on well-formed database files.
    */
    case SQLITE_TESTCTRL_NEVER_CORRUPT: {
      sqlite3GlobalConfig.neverCorrupt = va_arg(ap, int);
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS, int);
    **
    ** Set or clear a flag that causes SQLite to verify that type, name,
    ** and tbl_name fields of the sqlite_schema table.  This is normally
    ** on, but it is sometimes useful to turn it off for testing.
    **
    ** 2020-07-22:  Disabling EXTRA_SCHEMA_CHECKS also disables the
    ** verification of rootpage numbers when parsing the schema.  This
    ** is useful to make it easier to reach strange internal error states
    ** during testing.  The EXTRA_SCHEMA_CHECKS setting is always enabled
    ** in production.
    */
    case SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS: {
      sqlite3GlobalConfig.bExtraSchemaChecks = va_arg(ap, int);
      break;
    }

    /* Set the threshold at which OP_Once counters reset back to zero.
    ** By default this is 0x7ffffffe (over 2 billion), but that value is
    ** too big to test in a reasonable amount of time, so this control is
    ** provided to set a small and easily reachable reset value.
    */
    case SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD: {
      sqlite3GlobalConfig.iOnceResetThreshold = va_arg(ap, int);
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_VDBE_COVERAGE, xCallback, ptr);
    **
    ** Set the VDBE coverage callback function to xCallback with context 
    ** pointer ptr.
    */
    case SQLITE_TESTCTRL_VDBE_COVERAGE: {
#ifdef SQLITE_VDBE_COVERAGE
      typedef void (*branch_callback)(void*,unsigned int,
                                      unsigned char,unsigned char);
      sqlite3GlobalConfig.xVdbeBranch = va_arg(ap,branch_callback);
      sqlite3GlobalConfig.pVdbeBranchArg = va_arg(ap,void*);
#endif
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_SORTER_MMAP, db, nMax); */
    case SQLITE_TESTCTRL_SORTER_MMAP: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      db->nMaxSorterMmap = va_arg(ap, int);
      break;
    }

    /*   sqlite3_test_control(SQLITE_TESTCTRL_ISINIT);
    **
    ** Return SQLITE_OK if SQLite has been initialized and SQLITE_ERROR if
    ** not.
    */
    case SQLITE_TESTCTRL_ISINIT: {
      if( sqlite3GlobalConfig.isInit==0 ) rc = SQLITE_ERROR;
      break;
    }

    /*  sqlite3_test_control(SQLITE_TESTCTRL_IMPOSTER, db, dbName, onOff, tnum);
    **
    ** This test control is used to create imposter tables.  "db" is a pointer
    ** to the database connection.  dbName is the database name (ex: "main" or
    ** "temp") which will receive the imposter.  "onOff" turns imposter mode on
    ** or off.  "tnum" is the root page of the b-tree to which the imposter
    ** table should connect.
    **
    ** Enable imposter mode only when the schema has already been parsed.  Then
    ** run a single CREATE TABLE statement to construct the imposter table in
    ** the parsed schema.  Then turn imposter mode back off again.
    **
    ** If onOff==0 and tnum>0 then reset the schema for all databases, causing
    ** the schema to be reparsed the next time it is needed.  This has the
    ** effect of erasing all imposter tables.
    */
    case SQLITE_TESTCTRL_IMPOSTER: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      sqlite3_mutex_enter(db->mutex);
      db->init.iDb = sqlite3FindDbName(db, va_arg(ap,const char*));
      db->init.busy = db->init.imposterTable = va_arg(ap,int);
      db->init.newTnum = va_arg(ap,int);
      if( db->init.busy==0 && db->init.newTnum>0 ){
        sqlite3ResetAllSchemasOfConnection(db);
      }
      sqlite3_mutex_leave(db->mutex);
      break;
    }

#if defined(YYCOVERAGE)
    /*  sqlite3_test_control(SQLITE_TESTCTRL_PARSER_COVERAGE, FILE *out)
    **
    ** This test control (only available when SQLite is compiled with
    ** -DYYCOVERAGE) writes a report onto "out" that shows all
    ** state/lookahead combinations in the parser state machine
    ** which are never exercised.  If any state is missed, make the
    ** return code SQLITE_ERROR.
    */
    case SQLITE_TESTCTRL_PARSER_COVERAGE: {
      FILE *out = va_arg(ap, FILE*);
      if( sqlite3ParserCoverage(out) ) rc = SQLITE_ERROR;
      break;
    }
#endif /* defined(YYCOVERAGE) */

    /*  sqlite3_test_control(SQLITE_TESTCTRL_RESULT_INTREAL, sqlite3_context*);
    **
    ** This test-control causes the most recent sqlite3_result_int64() value
    ** to be interpreted as a MEM_IntReal instead of as an MEM_Int.  Normally,
    ** MEM_IntReal values only arise during an INSERT operation of integer
    ** values into a REAL column, so they can be challenging to test.  This
    ** test-control enables us to write an intreal() SQL function that can
    ** inject an intreal() value at arbitrary places in an SQL statement,
    ** for testing purposes.
    */
    case SQLITE_TESTCTRL_RESULT_INTREAL: {
      sqlite3_context *pCtx = va_arg(ap, sqlite3_context*);
      sqlite3ResultIntReal(pCtx);
      break;
    }

    /*  sqlite3_test_control(SQLITE_TESTCTRL_SEEK_COUNT,
    **    sqlite3 *db,    // Database connection
    **    u64 *pnSeek     // Write seek count here
    **  );
    **
    ** This test-control queries the seek-counter on the "main" database
    ** file.  The seek-counter is written into *pnSeek and is then reset.
    ** The seek-count is only available if compiled with SQLITE_DEBUG.
    */
    case SQLITE_TESTCTRL_SEEK_COUNT: {
      sqlite3 *db = va_arg(ap, sqlite3*);
      u64 *pn = va_arg(ap, sqlite3_uint64*);
      *pn = sqlite3BtreeSeekCount(db->aDb->pBt);
      (void)db;  /* Silence harmless unused variable warning */
      break;
    }


  }
  va_end(ap);
#endif /* SQLITE_UNTESTABLE */
  return rc;
}

/*
** The Pager stores the Database filename, Journal filename, and WAL filename
** consecutively in memory, in that order.  The database filename is prefixed
** by four zero bytes.  Locate the start of the database filename by searching
** backwards for the first byte following four consecutive zero bytes.
**
** This only works if the filename passed in was obtained from the Pager.
*/
static const char *databaseName(const char *zName){
  while( zName[-1]!=0 || zName[-2]!=0 || zName[-3]!=0 || zName[-4]!=0 ){
    zName--;
  }
  return zName;
}

/*
** Append text z[] to the end of p[].  Return a pointer to the first
** character after then zero terminator on the new text in p[].
*/
static char *appendText(char *p, const char *z){
  size_t n = strlen(z);
  memcpy(p, z, n+1);
  return p+n+1;
}

/*
** Allocate memory to hold names for a database, journal file, WAL file,
** and query parameters.  The pointer returned is valid for use by
** sqlite3_filename_database() and sqlite3_uri_parameter() and related
** functions.
**
** Memory layout must be compatible with that generated by the pager
** and expected by sqlite3_uri_parameter() and databaseName().
*/
char *sqlite3_create_filename(
  const char *zDatabase,
  const char *zJournal,
  const char *zWal,
  int nParam,
  const char **azParam
){
  sqlite3_int64 nByte;
  int i;
  char *pResult, *p;
  nByte = strlen(zDatabase) + strlen(zJournal) + strlen(zWal) + 10;
  for(i=0; i<nParam*2; i++){
    nByte += strlen(azParam[i])+1;
  }
  pResult = p = sqlite3_malloc64( nByte );
  if( p==0 ) return 0;
  memset(p, 0, 4);
  p += 4;
  p = appendText(p, zDatabase);
  for(i=0; i<nParam*2; i++){
    p = appendText(p, azParam[i]);
  }
  *(p++) = 0;
  p = appendText(p, zJournal);
  p = appendText(p, zWal);
  *(p++) = 0;
  *(p++) = 0;
  assert( (sqlite3_int64)(p - pResult)==nByte );
  return pResult + 4;
}

/*
** Free memory obtained from sqlite3_create_filename().  It is a severe
** error to call this routine with any parameter other than a pointer
** previously obtained from sqlite3_create_filename() or a NULL pointer.
*/
void sqlite3_free_filename(char *p){
  if( p==0 ) return;
  p = (char*)databaseName(p);
  sqlite3_free(p - 4);
}


/*
** This is a utility routine, useful to VFS implementations, that checks
** to see if a database file was a URI that contained a specific query 
** parameter, and if so obtains the value of the query parameter.
**
** The zFilename argument is the filename pointer passed into the xOpen()
** method of a VFS implementation.  The zParam argument is the name of the
** query parameter we seek.  This routine returns the value of the zParam
** parameter if it exists.  If the parameter does not exist, this routine
** returns a NULL pointer.
*/
const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam){
  if( zFilename==0 || zParam==0 ) return 0;
  zFilename = databaseName(zFilename);
  return uriParameter(zFilename, zParam);
}

/*
** Return a pointer to the name of Nth query parameter of the filename.
*/
const char *sqlite3_uri_key(const char *zFilename, int N){
  if( zFilename==0 || N<0 ) return 0;
  zFilename = databaseName(zFilename);
  zFilename += sqlite3Strlen30(zFilename) + 1;
  while( zFilename[0] && (N--)>0 ){
    zFilename += sqlite3Strlen30(zFilename) + 1;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return zFilename[0] ? zFilename : 0;
}

/*
** Return a boolean value for a query parameter.
*/
int sqlite3_uri_boolean(const char *zFilename, const char *zParam, int bDflt){
  const char *z = sqlite3_uri_parameter(zFilename, zParam);
  bDflt = bDflt!=0;
  return z ? sqlite3GetBoolean(z, bDflt) : bDflt;
}

/*
** Return a 64-bit integer value for a query parameter.
*/
sqlite3_int64 sqlite3_uri_int64(
  const char *zFilename,    /* Filename as passed to xOpen */
  const char *zParam,       /* URI parameter sought */
  sqlite3_int64 bDflt       /* return if parameter is missing */
){
  const char *z = sqlite3_uri_parameter(zFilename, zParam);
  sqlite3_int64 v;
  if( z && sqlite3DecOrHexToI64(z, &v)==0 ){
    bDflt = v;
  }
  return bDflt;
}

/*
** Translate a filename that was handed to a VFS routine into the corresponding
** database, journal, or WAL file.
**
** It is an error to pass this routine a filename string that was not
** passed into the VFS from the SQLite core.  Doing so is similar to
** passing free() a pointer that was not obtained from malloc() - it is
** an error that we cannot easily detect but that will likely cause memory
** corruption.
*/
const char *sqlite3_filename_database(const char *zFilename){
  return databaseName(zFilename);
}
const char *sqlite3_filename_journal(const char *zFilename){
  zFilename = databaseName(zFilename);
  zFilename += sqlite3Strlen30(zFilename) + 1;
  while( zFilename[0] ){
    zFilename += sqlite3Strlen30(zFilename) + 1;
    zFilename += sqlite3Strlen30(zFilename) + 1;
  }
  return zFilename + 1;
}
const char *sqlite3_filename_wal(const char *zFilename){
#ifdef SQLITE_OMIT_WAL
  return 0;
#else
  zFilename = sqlite3_filename_journal(zFilename);
  zFilename += sqlite3Strlen30(zFilename) + 1;
  return zFilename;
#endif
}

/*
** Return the Btree pointer identified by zDbName.  Return NULL if not found.
*/
Btree *sqlite3DbNameToBtree(sqlite3 *db, const char *zDbName){
  int iDb = zDbName ? sqlite3FindDbName(db, zDbName) : 0;
  return iDb<0 ? 0 : db->aDb[iDb].pBt;
}

/*
** Return the filename of the database associated with a database
** connection.
*/
const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName){
  Btree *pBt;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif
  pBt = sqlite3DbNameToBtree(db, zDbName);
  return pBt ? sqlite3BtreeGetFilename(pBt) : 0;
}

/*
** Return 1 if database is read-only or 0 if read/write.  Return -1 if
** no such database exists.
*/
int sqlite3_db_readonly(sqlite3 *db, const char *zDbName){
  Btree *pBt;
#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    (void)SQLITE_MISUSE_BKPT;
    return -1;
  }
#endif
  pBt = sqlite3DbNameToBtree(db, zDbName);
  return pBt ? sqlite3BtreeIsReadonly(pBt) : -1;
}

#ifdef SQLITE_ENABLE_SNAPSHOT
/*
** Obtain a snapshot handle for the snapshot of database zDb currently 
** being read by handle db.
*/
int sqlite3_snapshot_get(
  sqlite3 *db, 
  const char *zDb,
  sqlite3_snapshot **ppSnapshot
){
  int rc = SQLITE_ERROR;
#ifndef SQLITE_OMIT_WAL

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);

  if( db->autoCommit==0 ){
    int iDb = sqlite3FindDbName(db, zDb);
    if( iDb==0 || iDb>1 ){
      Btree *pBt = db->aDb[iDb].pBt;
      if( SQLITE_TXN_WRITE!=sqlite3BtreeTxnState(pBt) ){
        rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerSnapshotGet(sqlite3BtreePager(pBt), ppSnapshot);
        }
      }
    }
  }

  sqlite3_mutex_leave(db->mutex);
#endif   /* SQLITE_OMIT_WAL */
  return rc;
}

/*
** Open a read-transaction on the snapshot idendified by pSnapshot.
*/
int sqlite3_snapshot_open(
  sqlite3 *db, 
  const char *zDb, 
  sqlite3_snapshot *pSnapshot
){
  int rc = SQLITE_ERROR;
#ifndef SQLITE_OMIT_WAL

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
#endif
  sqlite3_mutex_enter(db->mutex);
  if( db->autoCommit==0 ){
    int iDb;
    iDb = sqlite3FindDbName(db, zDb);
    if( iDb==0 || iDb>1 ){
      Btree *pBt = db->aDb[iDb].pBt;
      if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_WRITE ){
        Pager *pPager = sqlite3BtreePager(pBt);
        int bUnlock = 0;
        if( sqlite3BtreeTxnState(pBt)!=SQLITE_TXN_NONE ){
          if( db->nVdbeActive==0 ){
            rc = sqlite3PagerSnapshotCheck(pPager, pSnapshot);
            if( rc==SQLITE_OK ){
              bUnlock = 1;
              rc = sqlite3BtreeCommit(pBt);
            }
          }
        }else{
          rc = SQLITE_OK;
        }
        if( rc==SQLITE_OK ){
          rc = sqlite3PagerSnapshotOpen(pPager, pSnapshot);
        }
        if( rc==SQLITE_OK ){
          rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
          sqlite3PagerSnapshotOpen(pPager, 0);
        }
        if( bUnlock ){
          sqlite3PagerSnapshotUnlock(pPager);
        }
      }
    }
  }

  sqlite3_mutex_leave(db->mutex);
#endif   /* SQLITE_OMIT_WAL */
  return rc;
}

/*
** Recover as many snapshots as possible from the wal file associated with
** schema zDb of database db.
*/
int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb){
  int rc = SQLITE_ERROR;
  int iDb;
#ifndef SQLITE_OMIT_WAL

#ifdef SQLITE_ENABLE_API_ARMOR
  if( !sqlite3SafetyCheckOk(db) ){
    return SQLITE_MISUSE_BKPT;
  }
#endif

  sqlite3_mutex_enter(db->mutex);
  iDb = sqlite3FindDbName(db, zDb);
  if( iDb==0 || iDb>1 ){
    Btree *pBt = db->aDb[iDb].pBt;
    if( SQLITE_TXN_NONE==sqlite3BtreeTxnState(pBt) ){
      rc = sqlite3BtreeBeginTrans(pBt, 0, 0);
      if( rc==SQLITE_OK ){
        rc = sqlite3PagerSnapshotRecover(sqlite3BtreePager(pBt));
        sqlite3BtreeCommit(pBt);
      }
    }
  }
  sqlite3_mutex_leave(db->mutex);
#endif   /* SQLITE_OMIT_WAL */
  return rc;
}

/*
** Free a snapshot handle obtained from sqlite3_snapshot_get().
*/
void sqlite3_snapshot_free(sqlite3_snapshot *pSnapshot){
  sqlite3_free(pSnapshot);
}
#endif /* SQLITE_ENABLE_SNAPSHOT */

#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
/*
** Given the name of a compile-time option, return true if that option
** was used and false if not.
**
** The name can optionally begin with "SQLITE_" but the "SQLITE_" prefix
** is not required for a match.
*/
int sqlite3_compileoption_used(const char *zOptName){
  int i, n;
  int nOpt;
  const char **azCompileOpt;
 
#if SQLITE_ENABLE_API_ARMOR
  if( zOptName==0 ){
    (void)SQLITE_MISUSE_BKPT;
    return 0;
  }
#endif

  azCompileOpt = sqlite3CompileOptions(&nOpt);

  if( sqlite3StrNICmp(zOptName, "SQLITE_", 7)==0 ) zOptName += 7;
  n = sqlite3Strlen30(zOptName);

  /* Since nOpt is normally in single digits, a linear search is 
  ** adequate. No need for a binary search. */
  for(i=0; i<nOpt; i++){
    if( sqlite3StrNICmp(zOptName, azCompileOpt[i], n)==0
     && sqlite3IsIdChar((unsigned char)azCompileOpt[i][n])==0
    ){
      return 1;
    }
  }
  return 0;
}

/*
** Return the N-th compile-time option string.  If N is out of range,
** return a NULL pointer.
*/
const char *sqlite3_compileoption_get(int N){
  int nOpt;
  const char **azCompileOpt;
  azCompileOpt = sqlite3CompileOptions(&nOpt);
  if( N>=0 && N<nOpt ){
    return azCompileOpt[N];
  }
  return 0;
}
#endif /* SQLITE_OMIT_COMPILEOPTION_DIAGS */