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Overview
Comment: | Make sqlite_encode_binary() and sqlite_decode_binary() an official part of the library. (CVS 1295) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
786fe545560ec6c42bb0e344345031f4 |
User & Date: | drh 2004-03-14 22:12:00.000 |
Context
2004-03-14
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22:12 | Prototypes for sqlite_encode_binary() and sqlite_decode_binary() added to sqlite.h. (CVS 1296) (check-in: 359f0e787f user: drh tags: trunk) | |
22:12 | Make sqlite_encode_binary() and sqlite_decode_binary() an official part of the library. (CVS 1295) (check-in: 786fe54556 user: drh tags: trunk) | |
11:57 | Updates to the architecture document. (CVS 1294) (check-in: c661cc81b6 user: drh tags: trunk) | |
Changes
Changes to main.mk.
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68 69 70 71 72 73 74 75 76 77 78 79 80 81 | $(TOP)/src/btree.c \ $(TOP)/src/btree.h \ $(TOP)/src/btree_rb.c \ $(TOP)/src/build.c \ $(TOP)/src/copy.c \ $(TOP)/src/date.c \ $(TOP)/src/delete.c \ $(TOP)/src/expr.c \ $(TOP)/src/func.c \ $(TOP)/src/hash.c \ $(TOP)/src/hash.h \ $(TOP)/src/insert.c \ $(TOP)/src/main.c \ $(TOP)/src/os.c \ | > | 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 | $(TOP)/src/btree.c \ $(TOP)/src/btree.h \ $(TOP)/src/btree_rb.c \ $(TOP)/src/build.c \ $(TOP)/src/copy.c \ $(TOP)/src/date.c \ $(TOP)/src/delete.c \ $(TOP)/src/encode.c \ $(TOP)/src/expr.c \ $(TOP)/src/func.c \ $(TOP)/src/hash.c \ $(TOP)/src/hash.h \ $(TOP)/src/insert.c \ $(TOP)/src/main.c \ $(TOP)/src/os.c \ |
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264 265 266 267 268 269 270 271 272 273 274 275 276 277 | date.o: $(TOP)/src/date.c $(HDR) $(TCCX) -c $(TOP)/src/date.c delete.o: $(TOP)/src/delete.c $(HDR) $(TCCX) -c $(TOP)/src/delete.c expr.o: $(TOP)/src/expr.c $(HDR) $(TCCX) -c $(TOP)/src/expr.c func.o: $(TOP)/src/func.c $(HDR) $(TCCX) -c $(TOP)/src/func.c hash.o: $(TOP)/src/hash.c $(HDR) | > > > | 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 | date.o: $(TOP)/src/date.c $(HDR) $(TCCX) -c $(TOP)/src/date.c delete.o: $(TOP)/src/delete.c $(HDR) $(TCCX) -c $(TOP)/src/delete.c encode.o: $(TOP)/src/encode.c $(TCCX) -c $(TOP)/src/encode.c expr.o: $(TOP)/src/expr.c $(HDR) $(TCCX) -c $(TOP)/src/expr.c func.o: $(TOP)/src/func.c $(HDR) $(TCCX) -c $(TOP)/src/func.c hash.o: $(TOP)/src/hash.c $(HDR) |
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Changes to publish.sh.
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118 119 120 121 122 123 124 125 126 127 128 129 130 131 | sqlite_trace sqlite_compile sqlite_step sqlite_finalize sqlite_reset sqlite_bind sqlite_last_statement_changes END_OF_FILE i386-mingw32msvc-dllwrap \ --def sqlite.def -v --export-all \ --driver-name i386-mingw32msvc-gcc \ --dlltool-name i386-mingw32msvc-dlltool \ --as i386-mingw32msvc-as \ --target i386-mingw32 \ | > > | 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 | sqlite_trace sqlite_compile sqlite_step sqlite_finalize sqlite_reset sqlite_bind sqlite_last_statement_changes sqlite_encode_binary sqlite_decode_binary END_OF_FILE i386-mingw32msvc-dllwrap \ --def sqlite.def -v --export-all \ --driver-name i386-mingw32msvc-gcc \ --dlltool-name i386-mingw32msvc-dlltool \ --as i386-mingw32msvc-as \ --target i386-mingw32 \ |
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Changes to src/encode.c.
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11 12 13 14 15 16 17 | ************************************************************************* ** This file contains helper routines used to translate binary data into ** a null-terminated string (suitable for use in SQLite) and back again. ** These are convenience routines for use by people who want to store binary ** data in an SQLite database. The code in this file is not used by any other ** part of the SQLite library. ** | | > | 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | ************************************************************************* ** This file contains helper routines used to translate binary data into ** a null-terminated string (suitable for use in SQLite) and back again. ** These are convenience routines for use by people who want to store binary ** data in an SQLite database. The code in this file is not used by any other ** part of the SQLite library. ** ** $Id: encode.c,v 1.11 2004/03/14 22:12:00 drh Exp $ */ #include <string.h> #include <assert.h> /* ** How This Encoder Works ** ** The output is allowed to contain any character except 0x27 (') and ** 0x00. This is accomplished by using an escape character to encode ** 0x27 and 0x00 as a two-byte sequence. The escape character is always |
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110 111 112 113 114 115 116 117 118 119 120 121 | ** "out" must be able to hold at least 2 +(257*n)/254 bytes. ** In other words, the output will be expanded by as much as 3 ** bytes for every 254 bytes of input plus 2 bytes of fixed overhead. ** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.) ** ** The return value is the number of characters in the encoded ** string, excluding the "\000" terminator. */ int sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out){ int i, j, e, m; int cnt[256]; if( n<=0 ){ | > > > > > | | > > > > | | < < < > | | < < | | | > > > > > | 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 | ** "out" must be able to hold at least 2 +(257*n)/254 bytes. ** In other words, the output will be expanded by as much as 3 ** bytes for every 254 bytes of input plus 2 bytes of fixed overhead. ** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.) ** ** The return value is the number of characters in the encoded ** string, excluding the "\000" terminator. ** ** If out==NULL then no output is generated but the routine still returns ** the number of characters that would have been generated if out had ** not been NULL. */ int sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out){ int i, j, e, m; int cnt[256]; if( n<=0 ){ if( out ){ out[0] = 'x'; out[1] = 0; } return 1; } memset(cnt, 0, sizeof(cnt)); for(i=n-1; i>=0; i--){ cnt[in[i]]++; } m = n; for(i=1; i<256; i++){ int sum; if( i=='\'' ) continue; sum = cnt[i] + cnt[(i+1)&0xff] + cnt[(i+'\'')&0xff]; if( sum<m ){ m = sum; e = i; if( m==0 ) break; } } if( out==0 ){ return n+m+1; } out[0] = e; j = 1; for(i=0; i<n; i++){ int c = (in[i] - e)&0xff; if( c==0 || c==1 ){ out[j++] = 1; out[j++] = c+1; }else if( c=='\'' ){ out[j++] = 1; out[j++] = 3; }else{ out[j++] = c; } } out[j] = 0; assert( j==n+m+1 ); return j; } /* ** Decode the string "in" into binary data and write it into "out". ** This routine reverses the encoding created by sqlite_encode_binary(). ** The output will always be a few bytes less than the input. The number ** of bytes of output is returned. If the input is not a well-formed ** encoding, -1 is returned. ** ** The "in" and "out" parameters may point to the same buffer in order ** to decode a string in place. */ int sqlite_decode_binary(const unsigned char *in, unsigned char *out){ int i, c, e; e = *(in++); i = 0; while( (c = *(in++))!=0 ){ if( c==1 ){ c = *(in++); if( c==1 || c==2 ){ c--; }else if( c==3 ){ c = '\''; }else{ return -1; } } out[i++] = (c + e)&0xff; } return i; } #ifdef ENCODER_TEST #include <stdio.h> /* ** The subroutines above are not tested by the usual test suite. To test ** these routines, compile just this one file with a -DENCODER_TEST=1 option ** and run the result. */ int main(int argc, char **argv){ int i, j, n, m, nOut, nByteIn, nByteOut; unsigned char in[30000]; unsigned char out[33000]; nByteIn = nByteOut = 0; for(i=0; i<sizeof(in); i++){ printf("Test %d: ", i+1); n = rand() % (i+1); if( i%100==0 ){ int k; for(j=k=0; j<n; j++){ /* if( k==0 || k=='\'' ) k++; */ in[j] = k; k = (k+1)&0xff; } }else{ for(j=0; j<n; j++) in[j] = rand() & 0xff; } nByteIn += n; nOut = sqlite_encode_binary(in, n, out); nByteOut += nOut; if( nOut!=strlen(out) ){ printf(" ERROR return value is %d instead of %d\n", nOut, strlen(out)); exit(1); } if( nOut!=sqlite_encode_binary(in, n, 0) ){ printf(" ERROR actual output size disagrees with predicted size\n"); exit(1); } m = (256*n + 1262)/253; printf("size %d->%d (max %d)", n, strlen(out)+1, m); if( strlen(out)+1>m ){ printf(" ERROR output too big\n"); exit(1); } |
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240 241 242 243 244 245 246 | } if( memcmp(in, out, n)!=0 ){ printf(" ERROR decode mismatch\n"); exit(1); } printf(" OK\n"); } | | > > > | 251 252 253 254 255 256 257 258 259 260 261 262 263 | } if( memcmp(in, out, n)!=0 ){ printf(" ERROR decode mismatch\n"); exit(1); } printf(" OK\n"); } fprintf(stderr,"Finished. Total encoding: %d->%d bytes\n", nByteIn, nByteOut); fprintf(stderr,"Avg size increase: %.3f%%\n", (nByteOut-nByteIn)*100.0/(double)nByteIn); } #endif /* ENCODER_TEST */ |