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Overview
Comment: | Add header comments on new routines. Rework the sqlite3Stat4Column() routine so that is (in theory) able to deal with corrupt samples. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | stat4-skipscan |
Files: | files | file ages | folders |
SHA1: |
ef5cdf949bb53a2958fa34e176b4b9ee |
User & Date: | drh 2014-06-28 16:06:44.822 |
Context
2014-06-28
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17:35 | Add further tests to skipscan5.test. (check-in: 4b8230e8fe user: dan tags: stat4-skipscan) | |
16:06 | Add header comments on new routines. Rework the sqlite3Stat4Column() routine so that is (in theory) able to deal with corrupt samples. (check-in: ef5cdf949b user: drh tags: stat4-skipscan) | |
15:26 | Fix a problem with using stat4 samples of type text when estimating the rows visited by a range-query/skip-scan loop. (check-in: dfb09db6d4 user: dan tags: stat4-skipscan) | |
Changes
Changes to src/vdbemem.c.
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1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 | FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions); FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAnalyzeTableFuncs); for(i=0; i<ArraySize(aAnalyzeTableFuncs); i++){ sqlite3FuncDefInsert(pHash, &aFunc[i]); } } static int stat4ValueFromExpr( Parse *pParse, /* Parse context */ Expr *pExpr, /* The expression to extract a value from */ u8 affinity, /* Affinity to use */ | > > > > > > > > > > > > > > > > > > | | 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 | FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions); FuncDef *aFunc = (FuncDef*)&GLOBAL(FuncDef, aAnalyzeTableFuncs); for(i=0; i<ArraySize(aAnalyzeTableFuncs); i++){ sqlite3FuncDefInsert(pHash, &aFunc[i]); } } /* ** Attempt to extract a value from pExpr and use it to construct *ppVal. ** ** If pAlloc is not NULL, then an UnpackedRecord object is created for ** pAlloc if one does not exist and the new value is added to the ** UnpackedRecord object. ** ** A value is extracted in the following cases: ** ** * (pExpr==0). In this case the value is assumed to be an SQL NULL, ** ** * The expression is a bound variable, and this is a reprepare, or ** ** * The expression is a literal value. ** ** On success, *ppVal is made to point to the extracted value. The caller ** is responsible for ensuring that the value is eventually freed. */ static int stat4ValueFromExpr( Parse *pParse, /* Parse context */ Expr *pExpr, /* The expression to extract a value from */ u8 affinity, /* Affinity to use */ struct ValueNewStat4Ctx *pAlloc,/* How to allocate space. Or NULL */ sqlite3_value **ppVal /* OUT: New value object (or NULL) */ ){ int rc = SQLITE_OK; sqlite3_value *pVal = 0; sqlite3 *db = pParse->db; /* Skip over any TK_COLLATE nodes */ |
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1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 | Expr *pExpr, /* The expression to extract a value from */ u8 affinity, /* Affinity to use */ sqlite3_value **ppVal /* OUT: New value object (or NULL) */ ){ return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal); } int sqlite3Stat4Column( sqlite3 *db, /* Database handle */ const void *pRec, /* Pointer to buffer containing record */ int nRec, /* Size of buffer pRec in bytes */ int iCol, /* Column to extract */ sqlite3_value **ppVal /* OUT: Extracted value */ ){ | > > > > > > > > < < < < < < < < | < < | | | > | | > > | > | | | > > > | > | | < > > | | > | | | | 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 | Expr *pExpr, /* The expression to extract a value from */ u8 affinity, /* Affinity to use */ sqlite3_value **ppVal /* OUT: New value object (or NULL) */ ){ return stat4ValueFromExpr(pParse, pExpr, affinity, 0, ppVal); } /* ** Extract the iCol-th column from the nRec-byte record in pRec. Write ** the column value into *ppVal. If *ppVal is initially NULL then a new ** sqlite3_value object is allocated. ** ** If *ppVal is initially NULL then the caller is responsible for ** ensuring that the value written into *ppVal is eventually freed. */ int sqlite3Stat4Column( sqlite3 *db, /* Database handle */ const void *pRec, /* Pointer to buffer containing record */ int nRec, /* Size of buffer pRec in bytes */ int iCol, /* Column to extract */ sqlite3_value **ppVal /* OUT: Extracted value */ ){ u32 t; /* a column type code */ int nHdr; /* Size of the header in the record */ int iHdr; /* Next unread header byte */ int iField; /* Next unread data byte */ int szField; /* Size of the current data field */ int i; /* Column index */ u8 *a = (u8*)pRec; /* Typecast byte array */ Mem *pMem = *ppVal; /* Write result into this Mem object */ assert( iCol>0 ); iHdr = getVarint32(a, nHdr); if( nHdr>nRec || iHdr>=nHdr ) return SQLITE_CORRUPT_BKPT; iField = nHdr; for(i=0; i<=iCol; i++){ iHdr += getVarint32(&a[iHdr], t); testcase( iHdr==nHdr ); testcase( iHdr==nHdr+1 ); if( iHdr>nHdr ) return SQLITE_CORRUPT_BKPT; szField = sqlite3VdbeSerialTypeLen(t); iField += szField; } testcase( iField==nRec ); testcase( iField==nRec+1 ); if( iField>nRec ) return SQLITE_CORRUPT_BKPT; if( pMem==0 ){ pMem = *ppVal = sqlite3ValueNew(db); if( pMem==0 ) return SQLITE_NOMEM; } sqlite3VdbeSerialGet(&a[iField-szField], t, pMem); pMem->enc = ENC(db); return SQLITE_OK; } /* ** Unless it is NULL, the argument must be an UnpackedRecord object returned ** by an earlier call to sqlite3Stat4ProbeSetValue(). This call deletes ** the object. */ |
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