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| 1 /* | |
| 2 ** 2011 Jan 27 | |
| 3 ** | |
| 4 ** The author disclaims copyright to this source code. In place of | |
| 5 ** a legal notice, here is a blessing: | |
| 6 ** | |
| 7 ** May you do good and not evil. | |
| 8 ** May you find forgiveness for yourself and forgive others. | |
| 9 ** May you share freely, never taking more than you give. | |
| 10 ** | |
| 11 ****************************************************************************** | |
| 12 ** | |
| 13 ** This file is not part of the production FTS code. It is only used for | |
| 14 ** testing. It contains a virtual table implementation that provides direct | |
| 15 ** access to the full-text index of an FTS table. | |
| 16 */ | |
| 17 | |
| 18 #include "fts3Int.h" | |
| 19 #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) | |
| 20 #ifdef SQLITE_TEST | |
| 21 | |
| 22 #include <string.h> | |
| 23 #include <assert.h> | |
| 24 #include <stdlib.h> | |
| 25 | |
| 26 typedef struct Fts3termTable Fts3termTable; | |
| 27 typedef struct Fts3termCursor Fts3termCursor; | |
| 28 | |
| 29 struct Fts3termTable { | |
| 30 sqlite3_vtab base; /* Base class used by SQLite core */ | |
| 31 int iIndex; /* Index for Fts3Table.aIndex[] */ | |
| 32 Fts3Table *pFts3Tab; | |
| 33 }; | |
| 34 | |
| 35 struct Fts3termCursor { | |
| 36 sqlite3_vtab_cursor base; /* Base class used by SQLite core */ | |
| 37 Fts3MultiSegReader csr; /* Must be right after "base" */ | |
| 38 Fts3SegFilter filter; | |
| 39 | |
| 40 int isEof; /* True if cursor is at EOF */ | |
| 41 char *pNext; | |
| 42 | |
| 43 sqlite3_int64 iRowid; /* Current 'rowid' value */ | |
| 44 sqlite3_int64 iDocid; /* Current 'docid' value */ | |
| 45 int iCol; /* Current 'col' value */ | |
| 46 int iPos; /* Current 'pos' value */ | |
| 47 }; | |
| 48 | |
| 49 /* | |
| 50 ** Schema of the terms table. | |
| 51 */ | |
| 52 #define FTS3_TERMS_SCHEMA "CREATE TABLE x(term, docid, col, pos)" | |
| 53 | |
| 54 /* | |
| 55 ** This function does all the work for both the xConnect and xCreate methods. | |
| 56 ** These tables have no persistent representation of their own, so xConnect | |
| 57 ** and xCreate are identical operations. | |
| 58 */ | |
| 59 static int fts3termConnectMethod( | |
| 60 sqlite3 *db, /* Database connection */ | |
| 61 void *pCtx, /* Non-zero for an fts4prefix table */ | |
| 62 int argc, /* Number of elements in argv array */ | |
| 63 const char * const *argv, /* xCreate/xConnect argument array */ | |
| 64 sqlite3_vtab **ppVtab, /* OUT: New sqlite3_vtab object */ | |
| 65 char **pzErr /* OUT: sqlite3_malloc'd error message */ | |
| 66 ){ | |
| 67 char const *zDb; /* Name of database (e.g. "main") */ | |
| 68 char const *zFts3; /* Name of fts3 table */ | |
| 69 int nDb; /* Result of strlen(zDb) */ | |
| 70 int nFts3; /* Result of strlen(zFts3) */ | |
| 71 int nByte; /* Bytes of space to allocate here */ | |
| 72 int rc; /* value returned by declare_vtab() */ | |
| 73 Fts3termTable *p; /* Virtual table object to return */ | |
| 74 int iIndex = 0; | |
| 75 | |
| 76 UNUSED_PARAMETER(pCtx); | |
| 77 if( argc==5 ){ | |
| 78 iIndex = atoi(argv[4]); | |
| 79 argc--; | |
| 80 } | |
| 81 | |
| 82 /* The user should specify a single argument - the name of an fts3 table. */ | |
| 83 if( argc!=4 ){ | |
| 84 sqlite3Fts3ErrMsg(pzErr, | |
| 85 "wrong number of arguments to fts4term constructor" | |
| 86 ); | |
| 87 return SQLITE_ERROR; | |
| 88 } | |
| 89 | |
| 90 zDb = argv[1]; | |
| 91 nDb = (int)strlen(zDb); | |
| 92 zFts3 = argv[3]; | |
| 93 nFts3 = (int)strlen(zFts3); | |
| 94 | |
| 95 rc = sqlite3_declare_vtab(db, FTS3_TERMS_SCHEMA); | |
| 96 if( rc!=SQLITE_OK ) return rc; | |
| 97 | |
| 98 nByte = sizeof(Fts3termTable) + sizeof(Fts3Table) + nDb + nFts3 + 2; | |
| 99 p = (Fts3termTable *)sqlite3_malloc(nByte); | |
| 100 if( !p ) return SQLITE_NOMEM; | |
| 101 memset(p, 0, nByte); | |
| 102 | |
| 103 p->pFts3Tab = (Fts3Table *)&p[1]; | |
| 104 p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1]; | |
| 105 p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1]; | |
| 106 p->pFts3Tab->db = db; | |
| 107 p->pFts3Tab->nIndex = iIndex+1; | |
| 108 p->iIndex = iIndex; | |
| 109 | |
| 110 memcpy((char *)p->pFts3Tab->zDb, zDb, nDb); | |
| 111 memcpy((char *)p->pFts3Tab->zName, zFts3, nFts3); | |
| 112 sqlite3Fts3Dequote((char *)p->pFts3Tab->zName); | |
| 113 | |
| 114 *ppVtab = (sqlite3_vtab *)p; | |
| 115 return SQLITE_OK; | |
| 116 } | |
| 117 | |
| 118 /* | |
| 119 ** This function does the work for both the xDisconnect and xDestroy methods. | |
| 120 ** These tables have no persistent representation of their own, so xDisconnect | |
| 121 ** and xDestroy are identical operations. | |
| 122 */ | |
| 123 static int fts3termDisconnectMethod(sqlite3_vtab *pVtab){ | |
| 124 Fts3termTable *p = (Fts3termTable *)pVtab; | |
| 125 Fts3Table *pFts3 = p->pFts3Tab; | |
| 126 int i; | |
| 127 | |
| 128 /* Free any prepared statements held */ | |
| 129 for(i=0; i<SizeofArray(pFts3->aStmt); i++){ | |
| 130 sqlite3_finalize(pFts3->aStmt[i]); | |
| 131 } | |
| 132 sqlite3_free(pFts3->zSegmentsTbl); | |
| 133 sqlite3_free(p); | |
| 134 return SQLITE_OK; | |
| 135 } | |
| 136 | |
| 137 #define FTS4AUX_EQ_CONSTRAINT 1 | |
| 138 #define FTS4AUX_GE_CONSTRAINT 2 | |
| 139 #define FTS4AUX_LE_CONSTRAINT 4 | |
| 140 | |
| 141 /* | |
| 142 ** xBestIndex - Analyze a WHERE and ORDER BY clause. | |
| 143 */ | |
| 144 static int fts3termBestIndexMethod( | |
| 145 sqlite3_vtab *pVTab, | |
| 146 sqlite3_index_info *pInfo | |
| 147 ){ | |
| 148 UNUSED_PARAMETER(pVTab); | |
| 149 | |
| 150 /* This vtab naturally does "ORDER BY term, docid, col, pos". */ | |
| 151 if( pInfo->nOrderBy ){ | |
| 152 int i; | |
| 153 for(i=0; i<pInfo->nOrderBy; i++){ | |
| 154 if( pInfo->aOrderBy[i].iColumn!=i || pInfo->aOrderBy[i].desc ) break; | |
| 155 } | |
| 156 if( i==pInfo->nOrderBy ){ | |
| 157 pInfo->orderByConsumed = 1; | |
| 158 } | |
| 159 } | |
| 160 | |
| 161 return SQLITE_OK; | |
| 162 } | |
| 163 | |
| 164 /* | |
| 165 ** xOpen - Open a cursor. | |
| 166 */ | |
| 167 static int fts3termOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){ | |
| 168 Fts3termCursor *pCsr; /* Pointer to cursor object to return */ | |
| 169 | |
| 170 UNUSED_PARAMETER(pVTab); | |
| 171 | |
| 172 pCsr = (Fts3termCursor *)sqlite3_malloc(sizeof(Fts3termCursor)); | |
| 173 if( !pCsr ) return SQLITE_NOMEM; | |
| 174 memset(pCsr, 0, sizeof(Fts3termCursor)); | |
| 175 | |
| 176 *ppCsr = (sqlite3_vtab_cursor *)pCsr; | |
| 177 return SQLITE_OK; | |
| 178 } | |
| 179 | |
| 180 /* | |
| 181 ** xClose - Close a cursor. | |
| 182 */ | |
| 183 static int fts3termCloseMethod(sqlite3_vtab_cursor *pCursor){ | |
| 184 Fts3Table *pFts3 = ((Fts3termTable *)pCursor->pVtab)->pFts3Tab; | |
| 185 Fts3termCursor *pCsr = (Fts3termCursor *)pCursor; | |
| 186 | |
| 187 sqlite3Fts3SegmentsClose(pFts3); | |
| 188 sqlite3Fts3SegReaderFinish(&pCsr->csr); | |
| 189 sqlite3_free(pCsr); | |
| 190 return SQLITE_OK; | |
| 191 } | |
| 192 | |
| 193 /* | |
| 194 ** xNext - Advance the cursor to the next row, if any. | |
| 195 */ | |
| 196 static int fts3termNextMethod(sqlite3_vtab_cursor *pCursor){ | |
| 197 Fts3termCursor *pCsr = (Fts3termCursor *)pCursor; | |
| 198 Fts3Table *pFts3 = ((Fts3termTable *)pCursor->pVtab)->pFts3Tab; | |
| 199 int rc; | |
| 200 sqlite3_int64 v; | |
| 201 | |
| 202 /* Increment our pretend rowid value. */ | |
| 203 pCsr->iRowid++; | |
| 204 | |
| 205 /* Advance to the next term in the full-text index. */ | |
| 206 if( pCsr->csr.aDoclist==0 | |
| 207 || pCsr->pNext>=&pCsr->csr.aDoclist[pCsr->csr.nDoclist-1] | |
| 208 ){ | |
| 209 rc = sqlite3Fts3SegReaderStep(pFts3, &pCsr->csr); | |
| 210 if( rc!=SQLITE_ROW ){ | |
| 211 pCsr->isEof = 1; | |
| 212 return rc; | |
| 213 } | |
| 214 | |
| 215 pCsr->iCol = 0; | |
| 216 pCsr->iPos = 0; | |
| 217 pCsr->iDocid = 0; | |
| 218 pCsr->pNext = pCsr->csr.aDoclist; | |
| 219 | |
| 220 /* Read docid */ | |
| 221 pCsr->pNext += sqlite3Fts3GetVarint(pCsr->pNext, &pCsr->iDocid); | |
| 222 } | |
| 223 | |
| 224 pCsr->pNext += sqlite3Fts3GetVarint(pCsr->pNext, &v); | |
| 225 if( v==0 ){ | |
| 226 pCsr->pNext += sqlite3Fts3GetVarint(pCsr->pNext, &v); | |
| 227 pCsr->iDocid += v; | |
| 228 pCsr->pNext += sqlite3Fts3GetVarint(pCsr->pNext, &v); | |
| 229 pCsr->iCol = 0; | |
| 230 pCsr->iPos = 0; | |
| 231 } | |
| 232 | |
| 233 if( v==1 ){ | |
| 234 pCsr->pNext += sqlite3Fts3GetVarint(pCsr->pNext, &v); | |
| 235 pCsr->iCol += (int)v; | |
| 236 pCsr->iPos = 0; | |
| 237 pCsr->pNext += sqlite3Fts3GetVarint(pCsr->pNext, &v); | |
| 238 } | |
| 239 | |
| 240 pCsr->iPos += (int)(v - 2); | |
| 241 | |
| 242 return SQLITE_OK; | |
| 243 } | |
| 244 | |
| 245 /* | |
| 246 ** xFilter - Initialize a cursor to point at the start of its data. | |
| 247 */ | |
| 248 static int fts3termFilterMethod( | |
| 249 sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */ | |
| 250 int idxNum, /* Strategy index */ | |
| 251 const char *idxStr, /* Unused */ | |
| 252 int nVal, /* Number of elements in apVal */ | |
| 253 sqlite3_value **apVal /* Arguments for the indexing scheme */ | |
| 254 ){ | |
| 255 Fts3termCursor *pCsr = (Fts3termCursor *)pCursor; | |
| 256 Fts3termTable *p = (Fts3termTable *)pCursor->pVtab; | |
| 257 Fts3Table *pFts3 = p->pFts3Tab; | |
| 258 int rc; | |
| 259 | |
| 260 UNUSED_PARAMETER(nVal); | |
| 261 UNUSED_PARAMETER(idxNum); | |
| 262 UNUSED_PARAMETER(idxStr); | |
| 263 UNUSED_PARAMETER(apVal); | |
| 264 | |
| 265 assert( idxStr==0 && idxNum==0 ); | |
| 266 | |
| 267 /* In case this cursor is being reused, close and zero it. */ | |
| 268 testcase(pCsr->filter.zTerm); | |
| 269 sqlite3Fts3SegReaderFinish(&pCsr->csr); | |
| 270 memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr); | |
| 271 | |
| 272 pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY; | |
| 273 pCsr->filter.flags |= FTS3_SEGMENT_SCAN; | |
| 274 | |
| 275 rc = sqlite3Fts3SegReaderCursor(pFts3, 0, p->iIndex, FTS3_SEGCURSOR_ALL, | |
| 276 pCsr->filter.zTerm, pCsr->filter.nTerm, 0, 1, &pCsr->csr | |
| 277 ); | |
| 278 if( rc==SQLITE_OK ){ | |
| 279 rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter); | |
| 280 } | |
| 281 if( rc==SQLITE_OK ){ | |
| 282 rc = fts3termNextMethod(pCursor); | |
| 283 } | |
| 284 return rc; | |
| 285 } | |
| 286 | |
| 287 /* | |
| 288 ** xEof - Return true if the cursor is at EOF, or false otherwise. | |
| 289 */ | |
| 290 static int fts3termEofMethod(sqlite3_vtab_cursor *pCursor){ | |
| 291 Fts3termCursor *pCsr = (Fts3termCursor *)pCursor; | |
| 292 return pCsr->isEof; | |
| 293 } | |
| 294 | |
| 295 /* | |
| 296 ** xColumn - Return a column value. | |
| 297 */ | |
| 298 static int fts3termColumnMethod( | |
| 299 sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */ | |
| 300 sqlite3_context *pCtx, /* Context for sqlite3_result_xxx() calls */ | |
| 301 int iCol /* Index of column to read value from */ | |
| 302 ){ | |
| 303 Fts3termCursor *p = (Fts3termCursor *)pCursor; | |
| 304 | |
| 305 assert( iCol>=0 && iCol<=3 ); | |
| 306 switch( iCol ){ | |
| 307 case 0: | |
| 308 sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT); | |
| 309 break; | |
| 310 case 1: | |
| 311 sqlite3_result_int64(pCtx, p->iDocid); | |
| 312 break; | |
| 313 case 2: | |
| 314 sqlite3_result_int64(pCtx, p->iCol); | |
| 315 break; | |
| 316 default: | |
| 317 sqlite3_result_int64(pCtx, p->iPos); | |
| 318 break; | |
| 319 } | |
| 320 | |
| 321 return SQLITE_OK; | |
| 322 } | |
| 323 | |
| 324 /* | |
| 325 ** xRowid - Return the current rowid for the cursor. | |
| 326 */ | |
| 327 static int fts3termRowidMethod( | |
| 328 sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */ | |
| 329 sqlite_int64 *pRowid /* OUT: Rowid value */ | |
| 330 ){ | |
| 331 Fts3termCursor *pCsr = (Fts3termCursor *)pCursor; | |
| 332 *pRowid = pCsr->iRowid; | |
| 333 return SQLITE_OK; | |
| 334 } | |
| 335 | |
| 336 /* | |
| 337 ** Register the fts3term module with database connection db. Return SQLITE_OK | |
| 338 ** if successful or an error code if sqlite3_create_module() fails. | |
| 339 */ | |
| 340 int sqlite3Fts3InitTerm(sqlite3 *db){ | |
| 341 static const sqlite3_module fts3term_module = { | |
| 342 0, /* iVersion */ | |
| 343 fts3termConnectMethod, /* xCreate */ | |
| 344 fts3termConnectMethod, /* xConnect */ | |
| 345 fts3termBestIndexMethod, /* xBestIndex */ | |
| 346 fts3termDisconnectMethod, /* xDisconnect */ | |
| 347 fts3termDisconnectMethod, /* xDestroy */ | |
| 348 fts3termOpenMethod, /* xOpen */ | |
| 349 fts3termCloseMethod, /* xClose */ | |
| 350 fts3termFilterMethod, /* xFilter */ | |
| 351 fts3termNextMethod, /* xNext */ | |
| 352 fts3termEofMethod, /* xEof */ | |
| 353 fts3termColumnMethod, /* xColumn */ | |
| 354 fts3termRowidMethod, /* xRowid */ | |
| 355 0, /* xUpdate */ | |
| 356 0, /* xBegin */ | |
| 357 0, /* xSync */ | |
| 358 0, /* xCommit */ | |
| 359 0, /* xRollback */ | |
| 360 0, /* xFindFunction */ | |
| 361 0, /* xRename */ | |
| 362 0, /* xSavepoint */ | |
| 363 0, /* xRelease */ | |
| 364 0 /* xRollbackTo */ | |
| 365 }; | |
| 366 int rc; /* Return code */ | |
| 367 | |
| 368 rc = sqlite3_create_module(db, "fts4term", &fts3term_module, 0); | |
| 369 return rc; | |
| 370 } | |
| 371 | |
| 372 #endif | |
| 373 #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */ | |
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