| /* |
| ** 2011 Jan 27 |
| ** |
| ** 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. |
| ** |
| ****************************************************************************** |
| ** |
| */ |
| #include "fts3Int.h" |
| #if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) |
| |
| #include <string.h> |
| #include <assert.h> |
| |
| typedef struct Fts3auxTable Fts3auxTable; |
| typedef struct Fts3auxCursor Fts3auxCursor; |
| |
| struct Fts3auxTable { |
| sqlite3_vtab base; /* Base class used by SQLite core */ |
| Fts3Table *pFts3Tab; |
| }; |
| |
| struct Fts3auxCursor { |
| sqlite3_vtab_cursor base; /* Base class used by SQLite core */ |
| Fts3MultiSegReader csr; /* Must be right after "base" */ |
| Fts3SegFilter filter; |
| char *zStop; |
| int nStop; /* Byte-length of string zStop */ |
| int iLangid; /* Language id to query */ |
| int isEof; /* True if cursor is at EOF */ |
| sqlite3_int64 iRowid; /* Current rowid */ |
| |
| int iCol; /* Current value of 'col' column */ |
| int nStat; /* Size of aStat[] array */ |
| struct Fts3auxColstats { |
| sqlite3_int64 nDoc; /* 'documents' values for current csr row */ |
| sqlite3_int64 nOcc; /* 'occurrences' values for current csr row */ |
| } *aStat; |
| }; |
| |
| /* |
| ** Schema of the terms table. |
| */ |
| #define FTS3_AUX_SCHEMA \ |
| "CREATE TABLE x(term, col, documents, occurrences, languageid HIDDEN)" |
| |
| /* |
| ** This function does all the work for both the xConnect and xCreate methods. |
| ** These tables have no persistent representation of their own, so xConnect |
| ** and xCreate are identical operations. |
| */ |
| static int fts3auxConnectMethod( |
| sqlite3 *db, /* Database connection */ |
| void *pUnused, /* Unused */ |
| int argc, /* Number of elements in argv array */ |
| const char * const *argv, /* xCreate/xConnect argument array */ |
| sqlite3_vtab **ppVtab, /* OUT: New sqlite3_vtab object */ |
| char **pzErr /* OUT: sqlite3_malloc'd error message */ |
| ){ |
| char const *zDb; /* Name of database (e.g. "main") */ |
| char const *zFts3; /* Name of fts3 table */ |
| int nDb; /* Result of strlen(zDb) */ |
| int nFts3; /* Result of strlen(zFts3) */ |
| sqlite3_int64 nByte; /* Bytes of space to allocate here */ |
| int rc; /* value returned by declare_vtab() */ |
| Fts3auxTable *p; /* Virtual table object to return */ |
| |
| UNUSED_PARAMETER(pUnused); |
| |
| /* The user should invoke this in one of two forms: |
| ** |
| ** CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table); |
| ** CREATE VIRTUAL TABLE xxx USING fts4aux(fts4-table-db, fts4-table); |
| */ |
| if( argc!=4 && argc!=5 ) goto bad_args; |
| |
| zDb = argv[1]; |
| nDb = (int)strlen(zDb); |
| if( argc==5 ){ |
| if( nDb==4 && 0==sqlite3_strnicmp("temp", zDb, 4) ){ |
| zDb = argv[3]; |
| nDb = (int)strlen(zDb); |
| zFts3 = argv[4]; |
| }else{ |
| goto bad_args; |
| } |
| }else{ |
| zFts3 = argv[3]; |
| } |
| nFts3 = (int)strlen(zFts3); |
| |
| rc = sqlite3_declare_vtab(db, FTS3_AUX_SCHEMA); |
| if( rc!=SQLITE_OK ) return rc; |
| |
| nByte = sizeof(Fts3auxTable) + sizeof(Fts3Table) + nDb + nFts3 + 2; |
| p = (Fts3auxTable *)sqlite3_malloc64(nByte); |
| if( !p ) return SQLITE_NOMEM; |
| memset(p, 0, nByte); |
| |
| p->pFts3Tab = (Fts3Table *)&p[1]; |
| p->pFts3Tab->zDb = (char *)&p->pFts3Tab[1]; |
| p->pFts3Tab->zName = &p->pFts3Tab->zDb[nDb+1]; |
| p->pFts3Tab->db = db; |
| p->pFts3Tab->nIndex = 1; |
| |
| memcpy((char *)p->pFts3Tab->zDb, zDb, nDb); |
| memcpy((char *)p->pFts3Tab->zName, zFts3, nFts3); |
| sqlite3Fts3Dequote((char *)p->pFts3Tab->zName); |
| |
| *ppVtab = (sqlite3_vtab *)p; |
| return SQLITE_OK; |
| |
| bad_args: |
| sqlite3Fts3ErrMsg(pzErr, "invalid arguments to fts4aux constructor"); |
| return SQLITE_ERROR; |
| } |
| |
| /* |
| ** This function does the work for both the xDisconnect and xDestroy methods. |
| ** These tables have no persistent representation of their own, so xDisconnect |
| ** and xDestroy are identical operations. |
| */ |
| static int fts3auxDisconnectMethod(sqlite3_vtab *pVtab){ |
| Fts3auxTable *p = (Fts3auxTable *)pVtab; |
| Fts3Table *pFts3 = p->pFts3Tab; |
| int i; |
| |
| /* Free any prepared statements held */ |
| for(i=0; i<SizeofArray(pFts3->aStmt); i++){ |
| sqlite3_finalize(pFts3->aStmt[i]); |
| } |
| sqlite3_free(pFts3->zSegmentsTbl); |
| sqlite3_free(p); |
| return SQLITE_OK; |
| } |
| |
| #define FTS4AUX_EQ_CONSTRAINT 1 |
| #define FTS4AUX_GE_CONSTRAINT 2 |
| #define FTS4AUX_LE_CONSTRAINT 4 |
| |
| /* |
| ** xBestIndex - Analyze a WHERE and ORDER BY clause. |
| */ |
| static int fts3auxBestIndexMethod( |
| sqlite3_vtab *pVTab, |
| sqlite3_index_info *pInfo |
| ){ |
| int i; |
| int iEq = -1; |
| int iGe = -1; |
| int iLe = -1; |
| int iLangid = -1; |
| int iNext = 1; /* Next free argvIndex value */ |
| |
| UNUSED_PARAMETER(pVTab); |
| |
| /* This vtab delivers always results in "ORDER BY term ASC" order. */ |
| if( pInfo->nOrderBy==1 |
| && pInfo->aOrderBy[0].iColumn==0 |
| && pInfo->aOrderBy[0].desc==0 |
| ){ |
| pInfo->orderByConsumed = 1; |
| } |
| |
| /* Search for equality and range constraints on the "term" column. |
| ** And equality constraints on the hidden "languageid" column. */ |
| for(i=0; i<pInfo->nConstraint; i++){ |
| if( pInfo->aConstraint[i].usable ){ |
| int op = pInfo->aConstraint[i].op; |
| int iCol = pInfo->aConstraint[i].iColumn; |
| |
| if( iCol==0 ){ |
| if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iEq = i; |
| if( op==SQLITE_INDEX_CONSTRAINT_LT ) iLe = i; |
| if( op==SQLITE_INDEX_CONSTRAINT_LE ) iLe = i; |
| if( op==SQLITE_INDEX_CONSTRAINT_GT ) iGe = i; |
| if( op==SQLITE_INDEX_CONSTRAINT_GE ) iGe = i; |
| } |
| if( iCol==4 ){ |
| if( op==SQLITE_INDEX_CONSTRAINT_EQ ) iLangid = i; |
| } |
| } |
| } |
| |
| if( iEq>=0 ){ |
| pInfo->idxNum = FTS4AUX_EQ_CONSTRAINT; |
| pInfo->aConstraintUsage[iEq].argvIndex = iNext++; |
| pInfo->estimatedCost = 5; |
| }else{ |
| pInfo->idxNum = 0; |
| pInfo->estimatedCost = 20000; |
| if( iGe>=0 ){ |
| pInfo->idxNum += FTS4AUX_GE_CONSTRAINT; |
| pInfo->aConstraintUsage[iGe].argvIndex = iNext++; |
| pInfo->estimatedCost /= 2; |
| } |
| if( iLe>=0 ){ |
| pInfo->idxNum += FTS4AUX_LE_CONSTRAINT; |
| pInfo->aConstraintUsage[iLe].argvIndex = iNext++; |
| pInfo->estimatedCost /= 2; |
| } |
| } |
| if( iLangid>=0 ){ |
| pInfo->aConstraintUsage[iLangid].argvIndex = iNext++; |
| pInfo->estimatedCost--; |
| } |
| |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** xOpen - Open a cursor. |
| */ |
| static int fts3auxOpenMethod(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCsr){ |
| Fts3auxCursor *pCsr; /* Pointer to cursor object to return */ |
| |
| UNUSED_PARAMETER(pVTab); |
| |
| pCsr = (Fts3auxCursor *)sqlite3_malloc(sizeof(Fts3auxCursor)); |
| if( !pCsr ) return SQLITE_NOMEM; |
| memset(pCsr, 0, sizeof(Fts3auxCursor)); |
| |
| *ppCsr = (sqlite3_vtab_cursor *)pCsr; |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** xClose - Close a cursor. |
| */ |
| static int fts3auxCloseMethod(sqlite3_vtab_cursor *pCursor){ |
| Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab; |
| Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor; |
| |
| sqlite3Fts3SegmentsClose(pFts3); |
| sqlite3Fts3SegReaderFinish(&pCsr->csr); |
| sqlite3_free((void *)pCsr->filter.zTerm); |
| sqlite3_free(pCsr->zStop); |
| sqlite3_free(pCsr->aStat); |
| sqlite3_free(pCsr); |
| return SQLITE_OK; |
| } |
| |
| static int fts3auxGrowStatArray(Fts3auxCursor *pCsr, int nSize){ |
| if( nSize>pCsr->nStat ){ |
| struct Fts3auxColstats *aNew; |
| aNew = (struct Fts3auxColstats *)sqlite3_realloc64(pCsr->aStat, |
| sizeof(struct Fts3auxColstats) * nSize |
| ); |
| if( aNew==0 ) return SQLITE_NOMEM; |
| memset(&aNew[pCsr->nStat], 0, |
| sizeof(struct Fts3auxColstats) * (nSize - pCsr->nStat) |
| ); |
| pCsr->aStat = aNew; |
| pCsr->nStat = nSize; |
| } |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** xNext - Advance the cursor to the next row, if any. |
| */ |
| static int fts3auxNextMethod(sqlite3_vtab_cursor *pCursor){ |
| Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor; |
| Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab; |
| int rc; |
| |
| /* Increment our pretend rowid value. */ |
| pCsr->iRowid++; |
| |
| for(pCsr->iCol++; pCsr->iCol<pCsr->nStat; pCsr->iCol++){ |
| if( pCsr->aStat[pCsr->iCol].nDoc>0 ) return SQLITE_OK; |
| } |
| |
| rc = sqlite3Fts3SegReaderStep(pFts3, &pCsr->csr); |
| if( rc==SQLITE_ROW ){ |
| int i = 0; |
| int nDoclist = pCsr->csr.nDoclist; |
| char *aDoclist = pCsr->csr.aDoclist; |
| int iCol; |
| |
| int eState = 0; |
| |
| if( pCsr->zStop ){ |
| int n = (pCsr->nStop<pCsr->csr.nTerm) ? pCsr->nStop : pCsr->csr.nTerm; |
| int mc = memcmp(pCsr->zStop, pCsr->csr.zTerm, n); |
| if( mc<0 || (mc==0 && pCsr->csr.nTerm>pCsr->nStop) ){ |
| pCsr->isEof = 1; |
| return SQLITE_OK; |
| } |
| } |
| |
| if( fts3auxGrowStatArray(pCsr, 2) ) return SQLITE_NOMEM; |
| memset(pCsr->aStat, 0, sizeof(struct Fts3auxColstats) * pCsr->nStat); |
| iCol = 0; |
| rc = SQLITE_OK; |
| |
| while( i<nDoclist ){ |
| sqlite3_int64 v = 0; |
| |
| i += sqlite3Fts3GetVarint(&aDoclist[i], &v); |
| switch( eState ){ |
| /* State 0. In this state the integer just read was a docid. */ |
| case 0: |
| pCsr->aStat[0].nDoc++; |
| eState = 1; |
| iCol = 0; |
| break; |
| |
| /* State 1. In this state we are expecting either a 1, indicating |
| ** that the following integer will be a column number, or the |
| ** start of a position list for column 0. |
| ** |
| ** The only difference between state 1 and state 2 is that if the |
| ** integer encountered in state 1 is not 0 or 1, then we need to |
| ** increment the column 0 "nDoc" count for this term. |
| */ |
| case 1: |
| assert( iCol==0 ); |
| if( v>1 ){ |
| pCsr->aStat[1].nDoc++; |
| } |
| eState = 2; |
| /* fall through */ |
| |
| case 2: |
| if( v==0 ){ /* 0x00. Next integer will be a docid. */ |
| eState = 0; |
| }else if( v==1 ){ /* 0x01. Next integer will be a column number. */ |
| eState = 3; |
| }else{ /* 2 or greater. A position. */ |
| pCsr->aStat[iCol+1].nOcc++; |
| pCsr->aStat[0].nOcc++; |
| } |
| break; |
| |
| /* State 3. The integer just read is a column number. */ |
| default: assert( eState==3 ); |
| iCol = (int)v; |
| if( iCol<1 ){ |
| rc = SQLITE_CORRUPT_VTAB; |
| break; |
| } |
| if( fts3auxGrowStatArray(pCsr, iCol+2) ) return SQLITE_NOMEM; |
| pCsr->aStat[iCol+1].nDoc++; |
| eState = 2; |
| break; |
| } |
| } |
| |
| pCsr->iCol = 0; |
| }else{ |
| pCsr->isEof = 1; |
| } |
| return rc; |
| } |
| |
| /* |
| ** xFilter - Initialize a cursor to point at the start of its data. |
| */ |
| static int fts3auxFilterMethod( |
| sqlite3_vtab_cursor *pCursor, /* The cursor used for this query */ |
| int idxNum, /* Strategy index */ |
| const char *idxStr, /* Unused */ |
| int nVal, /* Number of elements in apVal */ |
| sqlite3_value **apVal /* Arguments for the indexing scheme */ |
| ){ |
| Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor; |
| Fts3Table *pFts3 = ((Fts3auxTable *)pCursor->pVtab)->pFts3Tab; |
| int rc; |
| int isScan = 0; |
| int iLangVal = 0; /* Language id to query */ |
| |
| int iEq = -1; /* Index of term=? value in apVal */ |
| int iGe = -1; /* Index of term>=? value in apVal */ |
| int iLe = -1; /* Index of term<=? value in apVal */ |
| int iLangid = -1; /* Index of languageid=? value in apVal */ |
| int iNext = 0; |
| |
| UNUSED_PARAMETER(nVal); |
| UNUSED_PARAMETER(idxStr); |
| |
| assert( idxStr==0 ); |
| assert( idxNum==FTS4AUX_EQ_CONSTRAINT || idxNum==0 |
| || idxNum==FTS4AUX_LE_CONSTRAINT || idxNum==FTS4AUX_GE_CONSTRAINT |
| || idxNum==(FTS4AUX_LE_CONSTRAINT|FTS4AUX_GE_CONSTRAINT) |
| ); |
| |
| if( idxNum==FTS4AUX_EQ_CONSTRAINT ){ |
| iEq = iNext++; |
| }else{ |
| isScan = 1; |
| if( idxNum & FTS4AUX_GE_CONSTRAINT ){ |
| iGe = iNext++; |
| } |
| if( idxNum & FTS4AUX_LE_CONSTRAINT ){ |
| iLe = iNext++; |
| } |
| } |
| if( iNext<nVal ){ |
| iLangid = iNext++; |
| } |
| |
| /* In case this cursor is being reused, close and zero it. */ |
| testcase(pCsr->filter.zTerm); |
| sqlite3Fts3SegReaderFinish(&pCsr->csr); |
| sqlite3_free((void *)pCsr->filter.zTerm); |
| sqlite3_free(pCsr->aStat); |
| sqlite3_free(pCsr->zStop); |
| memset(&pCsr->csr, 0, ((u8*)&pCsr[1]) - (u8*)&pCsr->csr); |
| |
| pCsr->filter.flags = FTS3_SEGMENT_REQUIRE_POS|FTS3_SEGMENT_IGNORE_EMPTY; |
| if( isScan ) pCsr->filter.flags |= FTS3_SEGMENT_SCAN; |
| |
| if( iEq>=0 || iGe>=0 ){ |
| const unsigned char *zStr = sqlite3_value_text(apVal[0]); |
| assert( (iEq==0 && iGe==-1) || (iEq==-1 && iGe==0) ); |
| if( zStr ){ |
| pCsr->filter.zTerm = sqlite3_mprintf("%s", zStr); |
| if( pCsr->filter.zTerm==0 ) return SQLITE_NOMEM; |
| pCsr->filter.nTerm = (int)strlen(pCsr->filter.zTerm); |
| } |
| } |
| |
| if( iLe>=0 ){ |
| pCsr->zStop = sqlite3_mprintf("%s", sqlite3_value_text(apVal[iLe])); |
| if( pCsr->zStop==0 ) return SQLITE_NOMEM; |
| pCsr->nStop = (int)strlen(pCsr->zStop); |
| } |
| |
| if( iLangid>=0 ){ |
| iLangVal = sqlite3_value_int(apVal[iLangid]); |
| |
| /* If the user specified a negative value for the languageid, use zero |
| ** instead. This works, as the "languageid=?" constraint will also |
| ** be tested by the VDBE layer. The test will always be false (since |
| ** this module will not return a row with a negative languageid), and |
| ** so the overall query will return zero rows. */ |
| if( iLangVal<0 ) iLangVal = 0; |
| } |
| pCsr->iLangid = iLangVal; |
| |
| rc = sqlite3Fts3SegReaderCursor(pFts3, iLangVal, 0, FTS3_SEGCURSOR_ALL, |
| pCsr->filter.zTerm, pCsr->filter.nTerm, 0, isScan, &pCsr->csr |
| ); |
| if( rc==SQLITE_OK ){ |
| rc = sqlite3Fts3SegReaderStart(pFts3, &pCsr->csr, &pCsr->filter); |
| } |
| |
| if( rc==SQLITE_OK ) rc = fts3auxNextMethod(pCursor); |
| return rc; |
| } |
| |
| /* |
| ** xEof - Return true if the cursor is at EOF, or false otherwise. |
| */ |
| static int fts3auxEofMethod(sqlite3_vtab_cursor *pCursor){ |
| Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor; |
| return pCsr->isEof; |
| } |
| |
| /* |
| ** xColumn - Return a column value. |
| */ |
| static int fts3auxColumnMethod( |
| sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */ |
| sqlite3_context *pCtx, /* Context for sqlite3_result_xxx() calls */ |
| int iCol /* Index of column to read value from */ |
| ){ |
| Fts3auxCursor *p = (Fts3auxCursor *)pCursor; |
| |
| assert( p->isEof==0 ); |
| switch( iCol ){ |
| case 0: /* term */ |
| sqlite3_result_text(pCtx, p->csr.zTerm, p->csr.nTerm, SQLITE_TRANSIENT); |
| break; |
| |
| case 1: /* col */ |
| if( p->iCol ){ |
| sqlite3_result_int(pCtx, p->iCol-1); |
| }else{ |
| sqlite3_result_text(pCtx, "*", -1, SQLITE_STATIC); |
| } |
| break; |
| |
| case 2: /* documents */ |
| sqlite3_result_int64(pCtx, p->aStat[p->iCol].nDoc); |
| break; |
| |
| case 3: /* occurrences */ |
| sqlite3_result_int64(pCtx, p->aStat[p->iCol].nOcc); |
| break; |
| |
| default: /* languageid */ |
| assert( iCol==4 ); |
| sqlite3_result_int(pCtx, p->iLangid); |
| break; |
| } |
| |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** xRowid - Return the current rowid for the cursor. |
| */ |
| static int fts3auxRowidMethod( |
| sqlite3_vtab_cursor *pCursor, /* Cursor to retrieve value from */ |
| sqlite_int64 *pRowid /* OUT: Rowid value */ |
| ){ |
| Fts3auxCursor *pCsr = (Fts3auxCursor *)pCursor; |
| *pRowid = pCsr->iRowid; |
| return SQLITE_OK; |
| } |
| |
| /* |
| ** Register the fts3aux module with database connection db. Return SQLITE_OK |
| ** if successful or an error code if sqlite3_create_module() fails. |
| */ |
| int sqlite3Fts3InitAux(sqlite3 *db){ |
| static const sqlite3_module fts3aux_module = { |
| 0, /* iVersion */ |
| fts3auxConnectMethod, /* xCreate */ |
| fts3auxConnectMethod, /* xConnect */ |
| fts3auxBestIndexMethod, /* xBestIndex */ |
| fts3auxDisconnectMethod, /* xDisconnect */ |
| fts3auxDisconnectMethod, /* xDestroy */ |
| fts3auxOpenMethod, /* xOpen */ |
| fts3auxCloseMethod, /* xClose */ |
| fts3auxFilterMethod, /* xFilter */ |
| fts3auxNextMethod, /* xNext */ |
| fts3auxEofMethod, /* xEof */ |
| fts3auxColumnMethod, /* xColumn */ |
| fts3auxRowidMethod, /* xRowid */ |
| 0, /* xUpdate */ |
| 0, /* xBegin */ |
| 0, /* xSync */ |
| 0, /* xCommit */ |
| 0, /* xRollback */ |
| 0, /* xFindFunction */ |
| 0, /* xRename */ |
| 0, /* xSavepoint */ |
| 0, /* xRelease */ |
| 0, /* xRollbackTo */ |
| 0, /* xShadowName */ |
| 0 /* xIntegrity */ |
| }; |
| int rc; /* Return code */ |
| |
| rc = sqlite3_create_module(db, "fts4aux", &fts3aux_module, 0); |
| return rc; |
| } |
| |
| #endif /* !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_FTS3) */ |