/* ** 2012 April 10 ** ** 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. ** ************************************************************************* ** ** This module implements the spellfix1 VIRTUAL TABLE that can be used ** to search a large vocabulary for close matches. See separate ** documentation files (spellfix1.wiki and editdist3.wiki) for details. */ #if SQLITE_CORE # include "sqliteInt.h" #else # include # include # include # include "sqlite3ext.h" SQLITE_EXTENSION_INIT1 #endif /* !SQLITE_CORE */ #include /* ** Character classes for ASCII characters: ** ** 0 '' Silent letters: H W ** 1 'A' Any vowel: A E I O U (Y) ** 2 'B' A bilabeal stop or fricative: B F P V ** 3 'C' Other fricatives or back stops: C G J K Q S X Z ** 4 'D' Alveolar stops: D T ** 5 'H' Letter H at the beginning of a word ** 6 'L' Glide: L ** 7 'R' Semivowel: R ** 8 'M' Nasals: M N ** 9 'W' Letter W at the beginning of a word ** 10 'Y' Letter Y at the beginning of a word. ** 11 '9' Digits: 0 1 2 3 4 5 6 7 8 9 ** 12 ' ' White space ** 13 '?' Other. */ #define CCLASS_SILENT 0 #define CCLASS_VOWEL 1 #define CCLASS_B 2 #define CCLASS_C 3 #define CCLASS_D 4 #define CCLASS_H 5 #define CCLASS_L 6 #define CCLASS_R 7 #define CCLASS_M 8 #define CCLASS_W 9 #define CCLASS_Y 10 #define CCLASS_DIGIT 11 #define CCLASS_SPACE 12 #define CCLASS_OTHER 13 /* ** The following table gives the character class for non-initial ASCII ** characters. */ static const unsigned char midClass[] = { /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE, /* */ CCLASS_SPACE, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE, /* ! */ CCLASS_OTHER, /* " */ CCLASS_OTHER, /* # */ CCLASS_OTHER, /* $ */ CCLASS_OTHER, /* % */ CCLASS_OTHER, /* & */ CCLASS_OTHER, /* ' */ CCLASS_SILENT, /* ( */ CCLASS_OTHER, /* ) */ CCLASS_OTHER, /* * */ CCLASS_OTHER, /* + */ CCLASS_OTHER, /* , */ CCLASS_OTHER, /* - */ CCLASS_OTHER, /* . */ CCLASS_OTHER, /* / */ CCLASS_OTHER, /* 0 */ CCLASS_DIGIT, /* 1 */ CCLASS_DIGIT, /* 2 */ CCLASS_DIGIT, /* 3 */ CCLASS_DIGIT, /* 4 */ CCLASS_DIGIT, /* 5 */ CCLASS_DIGIT, /* 6 */ CCLASS_DIGIT, /* 7 */ CCLASS_DIGIT, /* 8 */ CCLASS_DIGIT, /* 9 */ CCLASS_DIGIT, /* : */ CCLASS_OTHER, /* ; */ CCLASS_OTHER, /* < */ CCLASS_OTHER, /* = */ CCLASS_OTHER, /* > */ CCLASS_OTHER, /* ? */ CCLASS_OTHER, /* @ */ CCLASS_OTHER, /* A */ CCLASS_VOWEL, /* B */ CCLASS_B, /* C */ CCLASS_C, /* D */ CCLASS_D, /* E */ CCLASS_VOWEL, /* F */ CCLASS_B, /* G */ CCLASS_C, /* H */ CCLASS_SILENT, /* I */ CCLASS_VOWEL, /* J */ CCLASS_C, /* K */ CCLASS_C, /* L */ CCLASS_L, /* M */ CCLASS_M, /* N */ CCLASS_M, /* O */ CCLASS_VOWEL, /* P */ CCLASS_B, /* Q */ CCLASS_C, /* R */ CCLASS_R, /* S */ CCLASS_C, /* T */ CCLASS_D, /* U */ CCLASS_VOWEL, /* V */ CCLASS_B, /* W */ CCLASS_SILENT, /* X */ CCLASS_C, /* Y */ CCLASS_VOWEL, /* Z */ CCLASS_C, /* [ */ CCLASS_OTHER, /* \ */ CCLASS_OTHER, /* ] */ CCLASS_OTHER, /* ^ */ CCLASS_OTHER, /* _ */ CCLASS_OTHER, /* ` */ CCLASS_OTHER, /* a */ CCLASS_VOWEL, /* b */ CCLASS_B, /* c */ CCLASS_C, /* d */ CCLASS_D, /* e */ CCLASS_VOWEL, /* f */ CCLASS_B, /* g */ CCLASS_C, /* h */ CCLASS_SILENT, /* i */ CCLASS_VOWEL, /* j */ CCLASS_C, /* k */ CCLASS_C, /* l */ CCLASS_L, /* m */ CCLASS_M, /* n */ CCLASS_M, /* o */ CCLASS_VOWEL, /* p */ CCLASS_B, /* q */ CCLASS_C, /* r */ CCLASS_R, /* s */ CCLASS_C, /* t */ CCLASS_D, /* u */ CCLASS_VOWEL, /* v */ CCLASS_B, /* w */ CCLASS_SILENT, /* x */ CCLASS_C, /* y */ CCLASS_VOWEL, /* z */ CCLASS_C, /* { */ CCLASS_OTHER, /* | */ CCLASS_OTHER, /* } */ CCLASS_OTHER, /* ~ */ CCLASS_OTHER, /* */ CCLASS_OTHER, }; /* ** This tables gives the character class for ASCII characters that form the ** initial character of a word. The only difference from midClass is with ** the letters H, W, and Y. */ static const unsigned char initClass[] = { /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE, /* */ CCLASS_SPACE, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_OTHER, /* */ CCLASS_SPACE, /* ! */ CCLASS_OTHER, /* " */ CCLASS_OTHER, /* # */ CCLASS_OTHER, /* $ */ CCLASS_OTHER, /* % */ CCLASS_OTHER, /* & */ CCLASS_OTHER, /* ' */ CCLASS_OTHER, /* ( */ CCLASS_OTHER, /* ) */ CCLASS_OTHER, /* * */ CCLASS_OTHER, /* + */ CCLASS_OTHER, /* , */ CCLASS_OTHER, /* - */ CCLASS_OTHER, /* . */ CCLASS_OTHER, /* / */ CCLASS_OTHER, /* 0 */ CCLASS_DIGIT, /* 1 */ CCLASS_DIGIT, /* 2 */ CCLASS_DIGIT, /* 3 */ CCLASS_DIGIT, /* 4 */ CCLASS_DIGIT, /* 5 */ CCLASS_DIGIT, /* 6 */ CCLASS_DIGIT, /* 7 */ CCLASS_DIGIT, /* 8 */ CCLASS_DIGIT, /* 9 */ CCLASS_DIGIT, /* : */ CCLASS_OTHER, /* ; */ CCLASS_OTHER, /* < */ CCLASS_OTHER, /* = */ CCLASS_OTHER, /* > */ CCLASS_OTHER, /* ? */ CCLASS_OTHER, /* @ */ CCLASS_OTHER, /* A */ CCLASS_VOWEL, /* B */ CCLASS_B, /* C */ CCLASS_C, /* D */ CCLASS_D, /* E */ CCLASS_VOWEL, /* F */ CCLASS_B, /* G */ CCLASS_C, /* H */ CCLASS_SILENT, /* I */ CCLASS_VOWEL, /* J */ CCLASS_C, /* K */ CCLASS_C, /* L */ CCLASS_L, /* M */ CCLASS_M, /* N */ CCLASS_M, /* O */ CCLASS_VOWEL, /* P */ CCLASS_B, /* Q */ CCLASS_C, /* R */ CCLASS_R, /* S */ CCLASS_C, /* T */ CCLASS_D, /* U */ CCLASS_VOWEL, /* V */ CCLASS_B, /* W */ CCLASS_W, /* X */ CCLASS_C, /* Y */ CCLASS_Y, /* Z */ CCLASS_C, /* [ */ CCLASS_OTHER, /* \ */ CCLASS_OTHER, /* ] */ CCLASS_OTHER, /* ^ */ CCLASS_OTHER, /* _ */ CCLASS_OTHER, /* ` */ CCLASS_OTHER, /* a */ CCLASS_VOWEL, /* b */ CCLASS_B, /* c */ CCLASS_C, /* d */ CCLASS_D, /* e */ CCLASS_VOWEL, /* f */ CCLASS_B, /* g */ CCLASS_C, /* h */ CCLASS_SILENT, /* i */ CCLASS_VOWEL, /* j */ CCLASS_C, /* k */ CCLASS_C, /* l */ CCLASS_L, /* m */ CCLASS_M, /* n */ CCLASS_M, /* o */ CCLASS_VOWEL, /* p */ CCLASS_B, /* q */ CCLASS_C, /* r */ CCLASS_R, /* s */ CCLASS_C, /* t */ CCLASS_D, /* u */ CCLASS_VOWEL, /* v */ CCLASS_B, /* w */ CCLASS_W, /* x */ CCLASS_C, /* y */ CCLASS_Y, /* z */ CCLASS_C, /* { */ CCLASS_OTHER, /* | */ CCLASS_OTHER, /* } */ CCLASS_OTHER, /* ~ */ CCLASS_OTHER, /* */ CCLASS_OTHER, }; /* ** Mapping from the character class number (0-13) to a symbol for each ** character class. Note that initClass[] can be used to map the class ** symbol back into the class number. */ static const unsigned char className[] = ".ABCDHLRMWY9 ?"; /* ** Generate a "phonetic hash" from a string of ASCII characters ** in zIn[0..nIn-1]. ** ** * Map characters by character class as defined above. ** * Omit double-letters ** * Omit vowels beside R and L ** * Omit T when followed by CH ** * Omit W when followed by R ** * Omit D when followed by J or G ** * Omit K in KN or G in GN at the beginning of a word ** ** Space to hold the result is obtained from sqlite3_malloc() ** ** Return NULL if memory allocation fails. */ static unsigned char *phoneticHash(const unsigned char *zIn, int nIn){ unsigned char *zOut = sqlite3_malloc( nIn + 1 ); int i; int nOut = 0; char cPrev = 0x77; char cPrevX = 0x77; const unsigned char *aClass = initClass; if( zOut==0 ) return 0; if( nIn>2 ){ switch( zIn[0] ){ case 'g': case 'k': { if( zIn[1]=='n' ){ zIn++; nIn--; } break; } } } for(i=0; i='A' && cTo<='Z') || (cTo>='a' && cTo<='z')) ){ /* differ only in case */ return 0; } classFrom = characterClass(cPrev, cFrom); classTo = characterClass(cPrev, cTo); if( classFrom==classTo ){ /* Same character class */ return 40; } if( classFrom>=CCLASS_B && classFrom<=CCLASS_Y && classTo>=CCLASS_B && classTo<=CCLASS_Y ){ /* Convert from one consonant to another, but in a different class */ return 75; } /* Any other subsitution */ return 100; } /* ** Given two strings zA and zB which are pure ASCII, return the cost ** of transforming zA into zB. If zA ends with '*' assume that it is ** a prefix of zB and give only minimal penalty for extra characters ** on the end of zB. ** ** Smaller numbers mean a closer match. ** ** Negative values indicate an error: ** -1 One of the inputs is NULL ** -2 Non-ASCII characters on input ** -3 Unable to allocate memory ** ** If pnMatch is not NULL, then *pnMatch is set to the number of bytes ** of zB that matched the pattern in zA. If zA does not end with a '*', ** then this value is always the number of bytes in zB (i.e. strlen(zB)). ** If zA does end in a '*', then it is the number of bytes in the prefix ** of zB that was deemed to match zA. */ static int editdist1(const char *zA, const char *zB, int *pnMatch){ int nA, nB; /* Number of characters in zA[] and zB[] */ int xA, xB; /* Loop counters for zA[] and zB[] */ char cA, cB; /* Current character of zA and zB */ char cAprev, cBprev; /* Previous character of zA and zB */ char cAnext, cBnext; /* Next character in zA and zB */ int d; /* North-west cost value */ int dc = 0; /* North-west character value */ int res; /* Final result */ int *m; /* The cost matrix */ char *cx; /* Corresponding character values */ int *toFree = 0; /* Malloced space */ int mStack[60+15]; /* Stack space to use if not too much is needed */ int nMatch = 0; /* Early out if either input is NULL */ if( zA==0 || zB==0 ) return -1; /* Skip any common prefix */ while( zA[0] && zA[0]==zB[0] ){ dc = zA[0]; zA++; zB++; nMatch++; } if( pnMatch ) *pnMatch = nMatch; if( zA[0]==0 && zB[0]==0 ) return 0; #if 0 printf("A=\"%s\" B=\"%s\" dc=%c\n", zA, zB, dc?dc:' '); #endif /* Verify input strings and measure their lengths */ for(nA=0; zA[nA]; nA++){ if( zA[nA]&0x80 ) return -2; } for(nB=0; zB[nB]; nB++){ if( zB[nB]&0x80 ) return -2; } /* Special processing if either string is empty */ if( nA==0 ){ cBprev = dc; for(xB=res=0; (cB = zB[xB])!=0; xB++){ res += insertOrDeleteCost(cBprev, cB, zB[xB+1])/FINAL_INS_COST_DIV; cBprev = cB; } return res; } if( nB==0 ){ cAprev = dc; for(xA=res=0; (cA = zA[xA])!=0; xA++){ res += insertOrDeleteCost(cAprev, cA, zA[xA+1]); cAprev = cA; } return res; } /* A is a prefix of B */ if( zA[0]=='*' && zA[1]==0 ) return 0; /* Allocate and initialize the Wagner matrix */ if( nB<(sizeof(mStack)*4)/(sizeof(mStack[0])*5) ){ m = mStack; }else{ m = toFree = sqlite3_malloc( (nB+1)*5*sizeof(m[0])/4 ); if( m==0 ) return -3; } cx = (char*)&m[nB+1]; /* Compute the Wagner edit distance */ m[0] = 0; cx[0] = dc; cBprev = dc; for(xB=1; xB<=nB; xB++){ cBnext = zB[xB]; cB = zB[xB-1]; cx[xB] = cB; m[xB] = m[xB-1] + insertOrDeleteCost(cBprev, cB, cBnext); cBprev = cB; } cAprev = dc; for(xA=1; xA<=nA; xA++){ int lastA = (xA==nA); cA = zA[xA-1]; cAnext = zA[xA]; if( cA=='*' && lastA ) break; d = m[0]; dc = cx[0]; m[0] = d + insertOrDeleteCost(cAprev, cA, cAnext); cBprev = 0; for(xB=1; xB<=nB; xB++){ int totalCost, insCost, delCost, subCost, ncx; cB = zB[xB-1]; cBnext = zB[xB]; /* Cost to insert cB */ insCost = insertOrDeleteCost(cx[xB-1], cB, cBnext); if( lastA ) insCost /= FINAL_INS_COST_DIV; /* Cost to delete cA */ delCost = insertOrDeleteCost(cx[xB], cA, cBnext); /* Cost to substitute cA->cB */ subCost = substituteCost(cx[xB-1], cA, cB); /* Best cost */ totalCost = insCost + m[xB-1]; ncx = cB; if( (delCost + m[xB])nLang; i++){ EditDist3Cost *pCost, *pNext; pCost = p->a[i].pCost; while( pCost ){ pNext = pCost->pNext; sqlite3_free(pCost); pCost = pNext; } } sqlite3_free(p->a); memset(p, 0, sizeof(*p)); } static void editDist3ConfigDelete(void *pIn){ EditDist3Config *p = (EditDist3Config*)pIn; editDist3ConfigClear(p); sqlite3_free(p); } /* ** Load all edit-distance weights from a table. */ static int editDist3ConfigLoad( EditDist3Config *p, /* The edit distance configuration to load */ sqlite3 *db, /* Load from this database */ const char *zTable /* Name of the table from which to load */ ){ sqlite3_stmt *pStmt; int rc, rc2; char *zSql; int iLangPrev = -9999; EditDist3Lang *pLang = 0; zSql = sqlite3_mprintf("SELECT iLang, cFrom, cTo, iCost" " FROM \"%w\" WHERE iLang>=0 ORDER BY iLang", zTable); if( zSql==0 ) return SQLITE_NOMEM; rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); sqlite3_free(zSql); if( rc ) return rc; editDist3ConfigClear(p); while( sqlite3_step(pStmt)==SQLITE_ROW ){ int iLang = sqlite3_column_int(pStmt, 0); const char *zFrom = (const char*)sqlite3_column_text(pStmt, 1); int nFrom = zFrom ? sqlite3_column_bytes(pStmt, 1) : 0; const char *zTo = (const char*)sqlite3_column_text(pStmt, 2); int nTo = zTo ? sqlite3_column_bytes(pStmt, 2) : 0; int iCost = sqlite3_column_int(pStmt, 3); assert( zFrom!=0 || nFrom==0 ); assert( zTo!=0 || nTo==0 ); if( nFrom>100 || nTo>100 ) continue; if( iCost<0 ) continue; if( pLang==0 || iLang!=iLangPrev ){ EditDist3Lang *pNew; pNew = sqlite3_realloc(p->a, (p->nLang+1)*sizeof(p->a[0])); if( pNew==0 ){ rc = SQLITE_NOMEM; break; } p->a = pNew; pLang = &p->a[p->nLang]; p->nLang++; pLang->iLang = iLang; pLang->iInsCost = 100; pLang->iDelCost = 100; pLang->iSubCost = 150; pLang->pCost = 0; iLangPrev = iLang; } if( nFrom==1 && zFrom[0]=='?' && nTo==0 ){ pLang->iDelCost = iCost; }else if( nFrom==0 && nTo==1 && zTo[0]=='?' ){ pLang->iInsCost = iCost; }else if( nFrom==1 && nTo==1 && zFrom[0]=='?' && zTo[0]=='?' ){ pLang->iSubCost = iCost; }else{ EditDist3Cost *pCost; int nExtra = nFrom + nTo - 4; if( nExtra<0 ) nExtra = 0; pCost = sqlite3_malloc( sizeof(*pCost) + nExtra ); if( pCost==0 ){ rc = SQLITE_NOMEM; break; } pCost->nFrom = nFrom; pCost->nTo = nTo; pCost->iCost = iCost; memcpy(pCost->a, zFrom, nFrom); memcpy(pCost->a + nFrom, zTo, nTo); pCost->pNext = pLang->pCost; pLang->pCost = pCost; } } rc2 = sqlite3_finalize(pStmt); if( rc==SQLITE_OK ) rc = rc2; return rc; } /* ** Return the length (in bytes) of a utf-8 character. Or return a maximum ** of N. */ static int utf8Len(unsigned char c, int N){ int len = 1; if( c>0x7f ){ if( (c&0xe0)==0xc0 ){ len = 2; }else if( (c&0xf0)==0xe0 ){ len = 3; }else{ len = 4; } } if( len>N ) len = N; return len; } /* ** Return TRUE (non-zero) of the To side of the given cost matches ** the given string. */ static int matchTo(EditDist3Cost *p, const char *z, int n){ if( p->nTo>n ) return 0; if( memcmp(p->a+p->nFrom, z, p->nTo)!=0 ) return 0; return 1; } /* ** Return TRUE (non-zero) of the To side of the given cost matches ** the given string. */ static int matchFrom(EditDist3Cost *p, const char *z, int n){ assert( p->nFrom<=n ); if( memcmp(p->a, z, p->nFrom)!=0 ) return 0; return 1; } /* ** Return TRUE (non-zero) of the next FROM character and the next TO ** character are the same. */ static int matchFromTo( EditDist3FromString *pStr, /* Left hand string */ int n1, /* Index of comparison character on the left */ const char *z2, /* Right-handl comparison character */ int n2 /* Bytes remaining in z2[] */ ){ int b1 = pStr->a[n1].nByte; if( b1>n2 ) return 0; if( memcmp(pStr->z+n1, z2, b1)!=0 ) return 0; return 1; } /* ** Delete an EditDist3FromString objecct */ static void editDist3FromStringDelete(EditDist3FromString *p){ int i; if( p ){ for(i=0; in; i++){ sqlite3_free(p->a[i].apDel); sqlite3_free(p->a[i].apSubst); } sqlite3_free(p); } } /* ** Create a EditDist3FromString object. */ static EditDist3FromString *editDist3FromStringNew( const EditDist3Lang *pLang, const char *z, int n ){ EditDist3FromString *pStr; EditDist3Cost *p; int i; if( z==0 ) return 0; if( n<0 ) n = (int)strlen(z); pStr = sqlite3_malloc( sizeof(*pStr) + sizeof(pStr->a[0])*n + n + 1 ); if( pStr==0 ) return 0; pStr->a = (EditDist3From*)&pStr[1]; memset(pStr->a, 0, sizeof(pStr->a[0])*n); pStr->n = n; pStr->z = (char*)&pStr->a[n]; memcpy(pStr->z, z, n+1); if( n && z[n-1]=='*' ){ pStr->isPrefix = 1; n--; pStr->n--; pStr->z[n] = 0; }else{ pStr->isPrefix = 0; } for(i=0; ia[i]; memset(pFrom, 0, sizeof(*pFrom)); pFrom->nByte = utf8Len((unsigned char)z[i], n-i); for(p=pLang->pCost; p; p=p->pNext){ EditDist3Cost **apNew; if( i+p->nFrom>n ) continue; if( matchFrom(p, z+i, n-i)==0 ) continue; if( p->nTo==0 ){ apNew = sqlite3_realloc(pFrom->apDel, sizeof(*apNew)*(pFrom->nDel+1)); if( apNew==0 ) break; pFrom->apDel = apNew; apNew[pFrom->nDel++] = p; }else{ apNew = sqlite3_realloc(pFrom->apSubst, sizeof(*apNew)*(pFrom->nSubst+1)); if( apNew==0 ) break; pFrom->apSubst = apNew; apNew[pFrom->nSubst++] = p; } } if( p ){ editDist3FromStringDelete(pStr); pStr = 0; break; } } return pStr; } /* ** Update entry m[i] such that it is the minimum of its current value ** and m[j]+iCost. ** ** If the iCost is 1,000,000 or greater, then consider the cost to be ** infinite and skip the update. */ static void updateCost( unsigned int *m, int i, int j, int iCost ){ assert( iCost>=0 ); if( iCost<10000 ){ unsigned int b = m[j] + iCost; if( bpCost; p; p=p->pNext){ EditDist3Cost **apNew; if( p->nFrom>0 ) continue; if( i2+p->nTo>n2 ) continue; if( matchTo(p, z2+i2, n2-i2)==0 ) continue; a2[i2].nIns++; apNew = sqlite3_realloc(a2[i2].apIns, sizeof(*apNew)*a2[i2].nIns); if( apNew==0 ){ res = -1; /* Out of memory */ goto editDist3Abort; } a2[i2].apIns = apNew; a2[i2].apIns[a2[i2].nIns-1] = p; } } /* Prepare to compute the minimum edit distance */ szRow = f.n+1; memset(m, 0x01, (n2+1)*szRow*sizeof(m[0])); m[0] = 0; /* First fill in the top-row of the matrix with FROM deletion costs */ for(i1=0; i1iDelCost); for(k=0; knFrom, i1, p->iCost); } } /* Fill in all subsequent rows, top-to-bottom, left-to-right */ for(i2=0; i2iInsCost); for(k=0; knTo), rxp, p->iCost); } for(i1=0; i1iDelCost); for(k=0; knFrom, cxp, p->iCost); } updateCost(m, cx, cxu, pLang->iInsCost); if( matchFromTo(&f, i1, z2+i2, n2-i2) ){ updateCost(m, cx, cxd, 0); } updateCost(m, cx, cxd, pLang->iSubCost); for(k=0; knFrom+szRow*p->nTo, cxd, p->iCost); } } } } #if 0 /* Enable for debugging */ printf(" ^"); for(i1=0; i19999 ) printf(" ****"); else printf(" %4d", v); } printf("\n"); for(i2=0; i29999 ) printf(" ****"); else printf(" %4d", v); } printf("\n"); } #endif /* Free memory allocations and return the result */ res = (int)m[szRow*(n2+1)-1]; n = n2; if( f.isPrefix ){ for(i2=1; i2<=n2; i2++){ int b = m[szRow*i2-1]; if( b<=res ){ res = b; n = i2 - 1; } } } if( pnMatch ){ int nExtra = 0; for(k=0; knLang; i++){ if( pConfig->a[i].iLang==iLang ) return &pConfig->a[i]; } return &editDist3Lang; } /* ** Function: editdist3(A,B,iLang) ** editdist3(tablename) ** ** Return the cost of transforming string A into string B using edit ** weights for iLang. ** ** The second form loads edit weights into memory from a table. */ static void editDist3SqlFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ EditDist3Config *pConfig = (EditDist3Config*)sqlite3_user_data(context); sqlite3 *db = sqlite3_context_db_handle(context); int rc; if( argc==1 ){ const char *zTable = (const char*)sqlite3_value_text(argv[0]); rc = editDist3ConfigLoad(pConfig, db, zTable); if( rc ) sqlite3_result_error_code(context, rc); }else{ const char *zA = (const char*)sqlite3_value_text(argv[0]); const char *zB = (const char*)sqlite3_value_text(argv[1]); int nA = sqlite3_value_bytes(argv[0]); int nB = sqlite3_value_bytes(argv[1]); int iLang = argc==3 ? sqlite3_value_int(argv[2]) : 0; const EditDist3Lang *pLang = editDist3FindLang(pConfig, iLang); EditDist3FromString *pFrom; int dist; pFrom = editDist3FromStringNew(pLang, zA, nA); if( pFrom==0 ){ sqlite3_result_error_nomem(context); return; } dist = editDist3Core(pFrom, zB, nB, pLang, 0); editDist3FromStringDelete(pFrom); if( dist==(-1) ){ sqlite3_result_error_nomem(context); }else{ sqlite3_result_int(context, dist); } } } /* ** Register the editDist3 function with SQLite */ static int editDist3Install(sqlite3 *db){ int rc; EditDist3Config *pConfig = sqlite3_malloc( sizeof(*pConfig) ); if( pConfig==0 ) return SQLITE_NOMEM; memset(pConfig, 0, sizeof(*pConfig)); rc = sqlite3_create_function_v2(db, "editdist3", 2, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0); if( rc==SQLITE_OK ){ rc = sqlite3_create_function_v2(db, "editdist3", 3, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, 0); } if( rc==SQLITE_OK ){ rc = sqlite3_create_function_v2(db, "editdist3", 1, SQLITE_UTF8, pConfig, editDist3SqlFunc, 0, 0, editDist3ConfigDelete); }else{ sqlite3_free(pConfig); } return rc; } /* End configurable cost unicode edit distance routines ****************************************************************************** ****************************************************************************** ** Begin transliterate unicode-to-ascii implementation */ #if !SQLITE_AMALGAMATION /* ** This lookup table is used to help decode the first byte of ** a multi-byte UTF8 character. */ static const unsigned char sqlite3Utf8Trans1[] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x00, 0x01, 0x02, 0x03, 0x00, 0x01, 0x00, 0x00, }; #endif /* ** Return the value of the first UTF-8 character in the string. */ static int utf8Read(const unsigned char *z, int n, int *pSize){ int c, i; /* All callers to this routine (in the current implementation) ** always have n>0. */ if( NEVER(n==0) ){ c = i = 0; }else{ c = z[0]; i = 1; if( c>=0xc0 ){ c = sqlite3Utf8Trans1[c-0xc0]; while( i0 ){ c = utf8Read(zIn, nIn, &sz); zIn += sz; nIn -= sz; if( c<=127 ){ zOut[nOut++] = c; }else{ int xTop, xBtm, x; xTop = sizeof(translit)/sizeof(translit[0]) - 1; xBtm = 0; while( xTop>=xBtm ){ x = (xTop + xBtm)/2; if( translit[x].cFrom==c ){ zOut[nOut++] = translit[x].cTo0; if( translit[x].cTo1 ){ zOut[nOut++] = translit[x].cTo1; /* Add an extra "ch" after the "sh" for Щ and щ */ if( c==0x0429 || c== 0x0449 ){ zOut[nOut++] = 'c'; zOut[nOut++] = 'h'; } } c = 0; break; }else if( translit[x].cFrom>c ){ xTop = x-1; }else{ xBtm = x+1; } } if( c ) zOut[nOut++] = '?'; } } zOut[nOut] = 0; return zOut; } /* ** Return the number of characters in the shortest prefix of the input ** string that transliterates to an ASCII string nTrans bytes or longer. ** Or, if the transliteration of the input string is less than nTrans ** bytes in size, return the number of characters in the input string. */ static int translen_to_charlen(const char *zIn, int nIn, int nTrans){ int i, c, sz, nOut; int nChar; i = nOut = 0; for(nChar=0; i=128 ){ int xTop, xBtm, x; xTop = sizeof(translit)/sizeof(translit[0]) - 1; xBtm = 0; while( xTop>=xBtm ){ x = (xTop + xBtm)/2; if( translit[x].cFrom==c ){ if( translit[x].cTo1 ) nOut++; if( c==0x0429 || c== 0x0449 ) nOut += 2; break; }else if( translit[x].cFrom>c ){ xTop = x-1; }else{ xBtm = x+1; } } } } return nChar; } /* ** spellfix1_translit(X) ** ** Convert a string that contains non-ASCII Roman characters into ** pure ASCII. */ static void transliterateSqlFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const unsigned char *zIn = sqlite3_value_text(argv[0]); int nIn = sqlite3_value_bytes(argv[0]); unsigned char *zOut = transliterate(zIn, nIn); if( zOut==0 ){ sqlite3_result_error_nomem(context); }else{ sqlite3_result_text(context, (char*)zOut, -1, sqlite3_free); } } /* ** spellfix1_scriptcode(X) ** ** Try to determine the dominant script used by the word X and return ** its ISO 15924 numeric code. ** ** The current implementation only understands the following scripts: ** ** 215 (Latin) ** 220 (Cyrillic) ** 200 (Greek) ** ** This routine will return 998 if the input X contains characters from ** two or more of the above scripts or 999 if X contains no characters ** from any of the above scripts. */ static void scriptCodeSqlFunc( sqlite3_context *context, int argc, sqlite3_value **argv ){ const unsigned char *zIn = sqlite3_value_text(argv[0]); int nIn = sqlite3_value_bytes(argv[0]); int c, sz; int scriptMask = 0; int res; # define SCRIPT_LATIN 0x0001 # define SCRIPT_CYRILLIC 0x0002 # define SCRIPT_GREEK 0x0004 while( nIn>0 ){ c = utf8Read(zIn, nIn, &sz); zIn += sz; nIn -= sz; if( c<0x02af ){ scriptMask |= SCRIPT_LATIN; }else if( c>=0x0400 && c<=0x04ff ){ scriptMask |= SCRIPT_CYRILLIC; }else if( c>=0x0386 && c<=0x03ce ){ scriptMask |= SCRIPT_GREEK; } } switch( scriptMask ){ case 0: res = 999; break; case SCRIPT_LATIN: res = 215; break; case SCRIPT_CYRILLIC: res = 220; break; case SCRIPT_GREEK: res = 200; break; default: res = 998; break; } sqlite3_result_int(context, res); } /* End transliterate ****************************************************************************** ****************************************************************************** ** Begin spellfix1 virtual table. */ /* Maximum length of a phonehash used for querying the shadow table */ #define SPELLFIX_MX_HASH 8 /* Maximum number of hash strings to examine per query */ #define SPELLFIX_MX_RUN 1 typedef struct spellfix1_vtab spellfix1_vtab; typedef struct spellfix1_cursor spellfix1_cursor; /* Fuzzy-search virtual table object */ struct spellfix1_vtab { sqlite3_vtab base; /* Base class - must be first */ sqlite3 *db; /* Database connection */ char *zDbName; /* Name of database holding this table */ char *zTableName; /* Name of the virtual table */ char *zCostTable; /* Table holding edit-distance cost numbers */ EditDist3Config *pConfig3; /* Parsed edit distance costs */ }; /* Fuzzy-search cursor object */ struct spellfix1_cursor { sqlite3_vtab_cursor base; /* Base class - must be first */ spellfix1_vtab *pVTab; /* The table to which this cursor belongs */ char *zPattern; /* rhs of MATCH clause */ int nRow; /* Number of rows of content */ int nAlloc; /* Number of allocated rows */ int iRow; /* Current row of content */ int iLang; /* Value of the langid= constraint */ int iTop; /* Value of the top= constraint */ int iScope; /* Value of the scope= constraint */ int nSearch; /* Number of vocabulary items checked */ sqlite3_stmt *pFullScan; /* Shadow query for a full table scan */ struct spellfix1_row { /* For each row of content */ sqlite3_int64 iRowid; /* Rowid for this row */ char *zWord; /* Text for this row */ int iRank; /* Rank for this row */ int iDistance; /* Distance from pattern for this row */ int iScore; /* Score for sorting */ int iMatchlen; /* Value of matchlen column (or -1) */ char zHash[SPELLFIX_MX_HASH]; /* the phonehash used for this match */ } *a; }; /* ** Construct one or more SQL statements from the format string given ** and then evaluate those statements. The success code is written ** into *pRc. ** ** If *pRc is initially non-zero then this routine is a no-op. */ static void spellfix1DbExec( int *pRc, /* Success code */ sqlite3 *db, /* Database in which to run SQL */ const char *zFormat, /* Format string for SQL */ ... /* Arguments to the format string */ ){ va_list ap; char *zSql; if( *pRc ) return; va_start(ap, zFormat); zSql = sqlite3_vmprintf(zFormat, ap); va_end(ap); if( zSql==0 ){ *pRc = SQLITE_NOMEM; }else{ *pRc = sqlite3_exec(db, zSql, 0, 0, 0); sqlite3_free(zSql); } } /* ** xDisconnect/xDestroy method for the fuzzy-search module. */ static int spellfix1Uninit(int isDestroy, sqlite3_vtab *pVTab){ spellfix1_vtab *p = (spellfix1_vtab*)pVTab; int rc = SQLITE_OK; if( isDestroy ){ sqlite3 *db = p->db; spellfix1DbExec(&rc, db, "DROP TABLE IF EXISTS \"%w\".\"%w_vocab\"", p->zDbName, p->zTableName); } if( rc==SQLITE_OK ){ sqlite3_free(p->zTableName); editDist3ConfigDelete(p->pConfig3); sqlite3_free(p->zCostTable); sqlite3_free(p); } return rc; } static int spellfix1Disconnect(sqlite3_vtab *pVTab){ return spellfix1Uninit(0, pVTab); } static int spellfix1Destroy(sqlite3_vtab *pVTab){ return spellfix1Uninit(1, pVTab); } /* ** Make a copy of a string. Remove leading and trailing whitespace ** and dequote it. */ static char *spellfix1Dequote(const char *zIn){ char *zOut; int i, j; char c; while( isspace(zIn[0]) ) zIn++; zOut = sqlite3_mprintf("%s", zIn); if( zOut==0 ) return 0; i = (int)strlen(zOut); #if 0 /* The parser will never leave spaces at the end */ while( i>0 && isspace(zOut[i-1]) ){ i--; } #endif zOut[i] = 0; c = zOut[0]; if( c=='\'' || c=='"' ){ for(i=1, j=0; ALWAYS(zOut[i]); i++){ zOut[j++] = zOut[i]; if( zOut[i]==c ){ if( zOut[i+1]==c ){ i++; }else{ zOut[j-1] = 0; break; } } } } return zOut; } /* ** xConnect/xCreate method for the spellfix1 module. Arguments are: ** ** argv[0] -> module name ("spellfix1") ** argv[1] -> database name ** argv[2] -> table name ** argv[3].. -> optional arguments (i.e. "edit_cost_table" parameter) */ static int spellfix1Init( int isCreate, sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char **pzErr ){ spellfix1_vtab *pNew = 0; const char *zModule = argv[0]; const char *zDbName = argv[1]; const char *zTableName = argv[2]; int nDbName; int rc = SQLITE_OK; int i; nDbName = strlen(zDbName); pNew = sqlite3_malloc( sizeof(*pNew) + nDbName + 1); if( pNew==0 ){ rc = SQLITE_NOMEM; }else{ memset(pNew, 0, sizeof(*pNew)); pNew->zDbName = (char*)&pNew[1]; memcpy(pNew->zDbName, zDbName, nDbName+1); pNew->zTableName = sqlite3_mprintf("%s", zTableName); pNew->db = db; if( pNew->zTableName==0 ){ rc = SQLITE_NOMEM; }else{ rc = sqlite3_declare_vtab(db, "CREATE TABLE x(word,rank,distance,langid, " "score, matchlen, phonehash HIDDEN, " "top HIDDEN, scope HIDDEN, srchcnt HIDDEN, " "soundslike HIDDEN, command HIDDEN)" ); #define SPELLFIX_COL_WORD 0 #define SPELLFIX_COL_RANK 1 #define SPELLFIX_COL_DISTANCE 2 #define SPELLFIX_COL_LANGID 3 #define SPELLFIX_COL_SCORE 4 #define SPELLFIX_COL_MATCHLEN 5 #define SPELLFIX_COL_PHONEHASH 6 #define SPELLFIX_COL_TOP 7 #define SPELLFIX_COL_SCOPE 8 #define SPELLFIX_COL_SRCHCNT 9 #define SPELLFIX_COL_SOUNDSLIKE 10 #define SPELLFIX_COL_COMMAND 11 } if( rc==SQLITE_OK && isCreate ){ sqlite3_uint64 r; spellfix1DbExec(&rc, db, "CREATE TABLE IF NOT EXISTS \"%w\".\"%w_vocab\"(\n" " id INTEGER PRIMARY KEY,\n" " rank INT,\n" " langid INT,\n" " word TEXT,\n" " k1 TEXT,\n" " k2 TEXT\n" ");\n", zDbName, zTableName ); sqlite3_randomness(sizeof(r), &r); spellfix1DbExec(&rc, db, "CREATE INDEX IF NOT EXISTS \"%w\".\"%w_index_%llx\" " "ON \"%w_vocab\"(langid,k2);", zDbName, zModule, r, zTableName ); } for(i=3; rc==SQLITE_OK && ibase); }else{ *ppVTab = (sqlite3_vtab *)pNew; } return rc; } /* ** The xConnect and xCreate methods */ static int spellfix1Connect( sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char **pzErr ){ return spellfix1Init(0, db, pAux, argc, argv, ppVTab, pzErr); } static int spellfix1Create( sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVTab, char **pzErr ){ return spellfix1Init(1, db, pAux, argc, argv, ppVTab, pzErr); } /* ** Clear all of the content from a cursor. */ static void spellfix1ResetCursor(spellfix1_cursor *pCur){ int i; for(i=0; inRow; i++){ sqlite3_free(pCur->a[i].zWord); } pCur->nRow = 0; pCur->iRow = 0; pCur->nSearch = 0; if( pCur->pFullScan ){ sqlite3_finalize(pCur->pFullScan); pCur->pFullScan = 0; } } /* ** Resize the cursor to hold up to N rows of content */ static void spellfix1ResizeCursor(spellfix1_cursor *pCur, int N){ struct spellfix1_row *aNew; assert( N>=pCur->nRow ); aNew = sqlite3_realloc(pCur->a, sizeof(pCur->a[0])*N); if( aNew==0 && N>0 ){ spellfix1ResetCursor(pCur); sqlite3_free(pCur->a); pCur->nAlloc = 0; pCur->a = 0; }else{ pCur->nAlloc = N; pCur->a = aNew; } } /* ** Close a fuzzy-search cursor. */ static int spellfix1Close(sqlite3_vtab_cursor *cur){ spellfix1_cursor *pCur = (spellfix1_cursor *)cur; spellfix1ResetCursor(pCur); spellfix1ResizeCursor(pCur, 0); sqlite3_free(pCur->zPattern); sqlite3_free(pCur); return SQLITE_OK; } /* ** Search for terms of these forms: ** ** (A) word MATCH $str ** (B) langid == $langid ** (C) top = $top ** (D) scope = $scope ** (E) distance < $distance ** (F) distance <= $distance ** ** The plan number is a bit mask formed with these bits: ** ** 0x01 (A) is found ** 0x02 (B) is found ** 0x04 (C) is found ** 0x08 (D) is found ** 0x10 (E) is found ** 0x20 (F) is found ** ** filter.argv[*] values contains $str, $langid, $top, and $scope, ** if specified and in that order. */ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ int iPlan = 0; int iLangTerm = -1; int iTopTerm = -1; int iScopeTerm = -1; int iDistTerm = -1; int i; const struct sqlite3_index_constraint *pConstraint; pConstraint = pIdxInfo->aConstraint; for(i=0; inConstraint; i++, pConstraint++){ if( pConstraint->usable==0 ) continue; /* Terms of the form: word MATCH $str */ if( (iPlan & 1)==0 && pConstraint->iColumn==SPELLFIX_COL_WORD && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH ){ iPlan |= 1; pIdxInfo->aConstraintUsage[i].argvIndex = 1; pIdxInfo->aConstraintUsage[i].omit = 1; } /* Terms of the form: langid = $langid */ if( (iPlan & 2)==0 && pConstraint->iColumn==SPELLFIX_COL_LANGID && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){ iPlan |= 2; iLangTerm = i; } /* Terms of the form: top = $top */ if( (iPlan & 4)==0 && pConstraint->iColumn==SPELLFIX_COL_TOP && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){ iPlan |= 4; iTopTerm = i; } /* Terms of the form: scope = $scope */ if( (iPlan & 8)==0 && pConstraint->iColumn==SPELLFIX_COL_SCOPE && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){ iPlan |= 8; iScopeTerm = i; } /* Terms of the form: distance < $dist or distance <= $dist */ if( (iPlan & (16|32))==0 && pConstraint->iColumn==SPELLFIX_COL_DISTANCE && (pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT || pConstraint->op==SQLITE_INDEX_CONSTRAINT_LE) ){ iPlan |= pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ? 16 : 32; iDistTerm = i; } } if( iPlan&1 ){ int idx = 2; pIdxInfo->idxNum = iPlan; if( pIdxInfo->nOrderBy==1 && pIdxInfo->aOrderBy[0].iColumn==SPELLFIX_COL_SCORE && pIdxInfo->aOrderBy[0].desc==0 ){ pIdxInfo->orderByConsumed = 1; /* Default order by iScore */ } if( iPlan&2 ){ pIdxInfo->aConstraintUsage[iLangTerm].argvIndex = idx++; pIdxInfo->aConstraintUsage[iLangTerm].omit = 1; } if( iPlan&4 ){ pIdxInfo->aConstraintUsage[iTopTerm].argvIndex = idx++; pIdxInfo->aConstraintUsage[iTopTerm].omit = 1; } if( iPlan&8 ){ pIdxInfo->aConstraintUsage[iScopeTerm].argvIndex = idx++; pIdxInfo->aConstraintUsage[iScopeTerm].omit = 1; } if( iPlan&(16|32) ){ pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = idx++; pIdxInfo->aConstraintUsage[iDistTerm].omit = 1; } pIdxInfo->estimatedCost = (double)10000; }else{ pIdxInfo->idxNum = 0; pIdxInfo->estimatedCost = (double)10000000; } return SQLITE_OK; } /* ** Open a new fuzzy-search cursor. */ static int spellfix1Open(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){ spellfix1_vtab *p = (spellfix1_vtab*)pVTab; spellfix1_cursor *pCur; pCur = sqlite3_malloc( sizeof(*pCur) ); if( pCur==0 ) return SQLITE_NOMEM; memset(pCur, 0, sizeof(*pCur)); pCur->pVTab = p; *ppCursor = &pCur->base; return SQLITE_OK; } /* ** Adjust a distance measurement by the words rank in order to show ** preference to common words. */ static int spellfix1Score(int iDistance, int iRank){ int iLog2; for(iLog2=0; iRank>0; iLog2++, iRank>>=1){} return iDistance + 32 - iLog2; } /* ** Compare two spellfix1_row objects for sorting purposes in qsort() such ** that they sort in order of increasing distance. */ static int spellfix1RowCompare(const void *A, const void *B){ const struct spellfix1_row *a = (const struct spellfix1_row*)A; const struct spellfix1_row *b = (const struct spellfix1_row*)B; return a->iScore - b->iScore; } /* ** A structure used to pass information from spellfix1FilterForMatch() ** into spellfix1RunQuery(). */ typedef struct MatchQuery { spellfix1_cursor *pCur; /* The cursor being queried */ sqlite3_stmt *pStmt; /* shadow table query statment */ char zHash[SPELLFIX_MX_HASH]; /* The current phonehash for zPattern */ const char *zPattern; /* Transliterated input string */ int nPattern; /* Length of zPattern */ EditDist3FromString *pMatchStr3; /* Original unicode string */ EditDist3Config *pConfig3; /* Edit-distance cost coefficients */ const EditDist3Lang *pLang; /* The selected language coefficients */ int iLang; /* The language id */ int iScope; /* Default scope */ int iMaxDist; /* Maximum allowed edit distance, or -1 */ int rc; /* Error code */ int nRun; /* Number of prior runs for the same zPattern */ char azPrior[SPELLFIX_MX_RUN][SPELLFIX_MX_HASH]; /* Prior hashes */ } MatchQuery; /* ** Run a query looking for the best matches against zPattern using ** zHash as the character class seed hash. */ static void spellfix1RunQuery(MatchQuery *p, const char *zQuery, int nQuery){ const char *zK1; const char *zWord; int iDist; int iRank; int iScore; int iWorst = 0; int idx; int idxWorst = -1; int i; int iScope = p->iScope; spellfix1_cursor *pCur = p->pCur; sqlite3_stmt *pStmt = p->pStmt; char zHash1[SPELLFIX_MX_HASH]; char zHash2[SPELLFIX_MX_HASH]; char *zClass; int nClass; int rc; if( pCur->a==0 || p->rc ) return; /* Prior memory allocation failure */ zClass = (char*)phoneticHash((unsigned char*)zQuery, nQuery); if( zClass==0 ){ p->rc = SQLITE_NOMEM; return; } nClass = strlen(zClass); if( nClass>SPELLFIX_MX_HASH-2 ){ nClass = SPELLFIX_MX_HASH-2; zClass[nClass] = 0; } if( nClass<=iScope ){ if( nClass>2 ){ iScope = nClass-1; }else{ iScope = nClass; } } memcpy(zHash1, zClass, iScope); sqlite3_free(zClass); zHash1[iScope] = 0; memcpy(zHash2, zHash1, iScope); zHash2[iScope] = 'Z'; zHash2[iScope+1] = 0; #if SPELLFIX_MX_RUN>1 for(i=0; inRun; i++){ if( strcmp(p->azPrior[i], zHash1)==0 ) return; } #endif assert( p->nRunazPrior[p->nRun++], zHash1, iScope+1); if( sqlite3_bind_text(pStmt, 1, zHash1, -1, SQLITE_STATIC)==SQLITE_NOMEM || sqlite3_bind_text(pStmt, 2, zHash2, -1, SQLITE_STATIC)==SQLITE_NOMEM ){ p->rc = SQLITE_NOMEM; return; } #if SPELLFIX_MX_RUN>1 for(i=0; inRow; i++){ if( pCur->a[i].iScore>iWorst ){ iWorst = pCur->a[i].iScore; idxWorst = i; } } #endif while( sqlite3_step(pStmt)==SQLITE_ROW ){ int iMatchlen = -1; iRank = sqlite3_column_int(pStmt, 2); if( p->pMatchStr3 ){ int nWord = sqlite3_column_bytes(pStmt, 1); zWord = (const char*)sqlite3_column_text(pStmt, 1); iDist = editDist3Core(p->pMatchStr3, zWord, nWord, p->pLang, &iMatchlen); }else{ zK1 = (const char*)sqlite3_column_text(pStmt, 3); if( zK1==0 ) continue; iDist = editdist1(p->zPattern, zK1, 0); } if( iDist<0 ){ p->rc = SQLITE_NOMEM; break; } pCur->nSearch++; iScore = spellfix1Score(iDist,iRank); if( p->iMaxDist>=0 ){ if( iDist>p->iMaxDist ) continue; if( pCur->nRow>=pCur->nAlloc-1 ){ spellfix1ResizeCursor(pCur, pCur->nAlloc*2 + 10); if( pCur->a==0 ) break; } idx = pCur->nRow; }else if( pCur->nRownAlloc ){ idx = pCur->nRow; }else if( iScorea[idx].zWord); }else{ continue; } pCur->a[idx].zWord = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 1)); if( pCur->a[idx].zWord==0 ){ p->rc = SQLITE_NOMEM; break; } pCur->a[idx].iRowid = sqlite3_column_int64(pStmt, 0); pCur->a[idx].iRank = iRank; pCur->a[idx].iDistance = iDist; pCur->a[idx].iScore = iScore; pCur->a[idx].iMatchlen = iMatchlen; memcpy(pCur->a[idx].zHash, zHash1, iScope+1); if( pCur->nRownAlloc ) pCur->nRow++; if( pCur->nRow==pCur->nAlloc ){ iWorst = pCur->a[0].iScore; idxWorst = 0; for(i=1; inRow; i++){ iScore = pCur->a[i].iScore; if( iWorstrc = rc; } /* ** This version of the xFilter method work if the MATCH term is present ** and we are doing a scan. */ static int spellfix1FilterForMatch( spellfix1_cursor *pCur, int idxNum, int argc, sqlite3_value **argv ){ const unsigned char *zMatchThis; /* RHS of the MATCH operator */ EditDist3FromString *pMatchStr3 = 0; /* zMatchThis as an editdist string */ char *zPattern; /* Transliteration of zMatchThis */ int nPattern; /* Length of zPattern */ int iLimit = 20; /* Max number of rows of output */ int iScope = 3; /* Use this many characters of zClass */ int iLang = 0; /* Language code */ char *zSql; /* SQL of shadow table query */ sqlite3_stmt *pStmt = 0; /* Shadow table query */ int rc; /* Result code */ int idx = 1; /* Next available filter parameter */ spellfix1_vtab *p = pCur->pVTab; /* The virtual table that owns pCur */ MatchQuery x; /* For passing info to RunQuery() */ /* Load the cost table if we have not already done so */ if( p->zCostTable!=0 && p->pConfig3==0 ){ p->pConfig3 = sqlite3_malloc( sizeof(p->pConfig3[0]) ); if( p->pConfig3==0 ) return SQLITE_NOMEM; memset(p->pConfig3, 0, sizeof(p->pConfig3[0])); rc = editDist3ConfigLoad(p->pConfig3, p->db, p->zCostTable); if( rc ) return rc; } memset(&x, 0, sizeof(x)); x.iScope = 3; /* Default scope if none specified by "WHERE scope=N" */ x.iMaxDist = -1; /* Maximum allowed edit distance */ if( idxNum&2 ){ iLang = sqlite3_value_int(argv[idx++]); } if( idxNum&4 ){ iLimit = sqlite3_value_int(argv[idx++]); if( iLimit<1 ) iLimit = 1; } if( idxNum&8 ){ x.iScope = sqlite3_value_int(argv[idx++]); if( x.iScope<1 ) x.iScope = 1; if( x.iScope>SPELLFIX_MX_HASH-2 ) x.iScope = SPELLFIX_MX_HASH-2; } if( idxNum&(16|32) ){ x.iMaxDist = sqlite3_value_int(argv[idx++]); if( idxNum&16 ) x.iMaxDist--; if( x.iMaxDist<0 ) x.iMaxDist = 0; } spellfix1ResetCursor(pCur); spellfix1ResizeCursor(pCur, iLimit); zMatchThis = sqlite3_value_text(argv[0]); if( zMatchThis==0 ) return SQLITE_OK; if( p->pConfig3 ){ x.pLang = editDist3FindLang(p->pConfig3, iLang); pMatchStr3 = editDist3FromStringNew(x.pLang, (const char*)zMatchThis, -1); if( pMatchStr3==0 ){ x.rc = SQLITE_NOMEM; goto filter_exit; } }else{ x.pLang = 0; } zPattern = (char*)transliterate(zMatchThis, sqlite3_value_bytes(argv[0])); sqlite3_free(pCur->zPattern); pCur->zPattern = zPattern; if( zPattern==0 ){ x.rc = SQLITE_NOMEM; goto filter_exit; } nPattern = strlen(zPattern); if( zPattern[nPattern-1]=='*' ) nPattern--; zSql = sqlite3_mprintf( "SELECT id, word, rank, k1" " FROM \"%w\".\"%w_vocab\"" " WHERE langid=%d AND k2>=?1 AND k2zDbName, p->zTableName, iLang ); if( zSql==0 ){ x.rc = SQLITE_NOMEM; pStmt = 0; goto filter_exit; } rc = sqlite3_prepare_v2(p->db, zSql, -1, &pStmt, 0); sqlite3_free(zSql); pCur->iLang = iLang; x.pCur = pCur; x.pStmt = pStmt; x.zPattern = zPattern; x.nPattern = nPattern; x.pMatchStr3 = pMatchStr3; x.iLang = iLang; x.rc = rc; x.pConfig3 = p->pConfig3; if( x.rc==SQLITE_OK ){ spellfix1RunQuery(&x, zPattern, nPattern); } if( pCur->a ){ qsort(pCur->a, pCur->nRow, sizeof(pCur->a[0]), spellfix1RowCompare); pCur->iTop = iLimit; pCur->iScope = iScope; }else{ x.rc = SQLITE_NOMEM; } filter_exit: sqlite3_finalize(pStmt); editDist3FromStringDelete(pMatchStr3); return x.rc; } /* ** This version of xFilter handles a full-table scan case */ static int spellfix1FilterForFullScan( spellfix1_cursor *pCur, int idxNum, int argc, sqlite3_value **argv ){ int rc; char *zSql; spellfix1_vtab *pVTab = pCur->pVTab; spellfix1ResetCursor(pCur); zSql = sqlite3_mprintf( "SELECT word, rank, NULL, langid, id FROM \"%w\".\"%w_vocab\"", pVTab->zDbName, pVTab->zTableName); if( zSql==0 ) return SQLITE_NOMEM; rc = sqlite3_prepare_v2(pVTab->db, zSql, -1, &pCur->pFullScan, 0); sqlite3_free(zSql); pCur->nRow = pCur->iRow = 0; if( rc==SQLITE_OK ){ rc = sqlite3_step(pCur->pFullScan); if( rc==SQLITE_ROW ){ pCur->iRow = -1; rc = SQLITE_OK; } if( rc==SQLITE_DONE ){ rc = SQLITE_OK; } }else{ pCur->iRow = 0; } return rc; } /* ** Called to "rewind" a cursor back to the beginning so that ** it starts its output over again. Always called at least once ** prior to any spellfix1Column, spellfix1Rowid, or spellfix1Eof call. */ static int spellfix1Filter( sqlite3_vtab_cursor *cur, int idxNum, const char *idxStr, int argc, sqlite3_value **argv ){ spellfix1_cursor *pCur = (spellfix1_cursor *)cur; int rc; if( idxNum & 1 ){ rc = spellfix1FilterForMatch(pCur, idxNum, argc, argv); }else{ rc = spellfix1FilterForFullScan(pCur, idxNum, argc, argv); } return rc; } /* ** Advance a cursor to its next row of output */ static int spellfix1Next(sqlite3_vtab_cursor *cur){ spellfix1_cursor *pCur = (spellfix1_cursor *)cur; if( pCur->iRow < pCur->nRow ){ if( pCur->pFullScan ){ int rc = sqlite3_step(pCur->pFullScan); if( rc!=SQLITE_ROW ) pCur->iRow = pCur->nRow; }else{ pCur->iRow++; } } return SQLITE_OK; } /* ** Return TRUE if we are at the end-of-file */ static int spellfix1Eof(sqlite3_vtab_cursor *cur){ spellfix1_cursor *pCur = (spellfix1_cursor *)cur; return pCur->iRow>=pCur->nRow; } /* ** Return columns from the current row. */ static int spellfix1Column( sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i ){ spellfix1_cursor *pCur = (spellfix1_cursor*)cur; if( pCur->pFullScan ){ if( i<=SPELLFIX_COL_LANGID ){ sqlite3_result_value(ctx, sqlite3_column_value(pCur->pFullScan, i)); }else{ sqlite3_result_null(ctx); } return SQLITE_OK; } switch( i ){ case SPELLFIX_COL_WORD: { sqlite3_result_text(ctx, pCur->a[pCur->iRow].zWord, -1, SQLITE_STATIC); break; } case SPELLFIX_COL_RANK: { sqlite3_result_int(ctx, pCur->a[pCur->iRow].iRank); break; } case SPELLFIX_COL_DISTANCE: { sqlite3_result_int(ctx, pCur->a[pCur->iRow].iDistance); break; } case SPELLFIX_COL_LANGID: { sqlite3_result_int(ctx, pCur->iLang); break; } case SPELLFIX_COL_SCORE: { sqlite3_result_int(ctx, pCur->a[pCur->iRow].iScore); break; } case SPELLFIX_COL_MATCHLEN: { int iMatchlen = pCur->a[pCur->iRow].iMatchlen; if( iMatchlen<0 ){ int nPattern = strlen(pCur->zPattern); char *zWord = pCur->a[pCur->iRow].zWord; int nWord = strlen(zWord); if( nPattern>0 && pCur->zPattern[nPattern-1]=='*' ){ char *zTranslit; int res; zTranslit = (char *)transliterate((unsigned char *)zWord, nWord); if( !zTranslit ) return SQLITE_NOMEM; res = editdist1(pCur->zPattern, zTranslit, &iMatchlen); sqlite3_free(zTranslit); if( res<0 ) return SQLITE_NOMEM; iMatchlen = translen_to_charlen(zWord, nWord, iMatchlen); }else{ iMatchlen = utf8Charlen(zWord, nWord); } } sqlite3_result_int(ctx, iMatchlen); break; } case SPELLFIX_COL_PHONEHASH: { sqlite3_result_text(ctx, pCur->a[pCur->iRow].zHash, -1, SQLITE_STATIC); break; } case SPELLFIX_COL_TOP: { sqlite3_result_int(ctx, pCur->iTop); break; } case SPELLFIX_COL_SCOPE: { sqlite3_result_int(ctx, pCur->iScope); break; } case SPELLFIX_COL_SRCHCNT: { sqlite3_result_int(ctx, pCur->nSearch); break; } default: { sqlite3_result_null(ctx); break; } } return SQLITE_OK; } /* ** The rowid. */ static int spellfix1Rowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ spellfix1_cursor *pCur = (spellfix1_cursor*)cur; if( pCur->pFullScan ){ *pRowid = sqlite3_column_int64(pCur->pFullScan, 4); }else{ *pRowid = pCur->a[pCur->iRow].iRowid; } return SQLITE_OK; } /* ** The xUpdate() method. */ static int spellfix1Update( sqlite3_vtab *pVTab, int argc, sqlite3_value **argv, sqlite_int64 *pRowid ){ int rc = SQLITE_OK; sqlite3_int64 rowid, newRowid; spellfix1_vtab *p = (spellfix1_vtab*)pVTab; sqlite3 *db = p->db; if( argc==1 ){ /* A delete operation on the rowid given by argv[0] */ rowid = *pRowid = sqlite3_value_int64(argv[0]); spellfix1DbExec(&rc, db, "DELETE FROM \"%w\".\"%w_vocab\" " " WHERE id=%lld", p->zDbName, p->zTableName, rowid); }else{ const unsigned char *zWord = sqlite3_value_text(argv[SPELLFIX_COL_WORD+2]); int nWord = sqlite3_value_bytes(argv[SPELLFIX_COL_WORD+2]); int iLang = sqlite3_value_int(argv[SPELLFIX_COL_LANGID+2]); int iRank = sqlite3_value_int(argv[SPELLFIX_COL_RANK+2]); const unsigned char *zSoundslike = sqlite3_value_text(argv[SPELLFIX_COL_SOUNDSLIKE+2]); int nSoundslike = sqlite3_value_bytes(argv[SPELLFIX_COL_SOUNDSLIKE+2]); char *zK1, *zK2; int i; char c; if( zWord==0 ){ /* Inserts of the form: INSERT INTO table(command) VALUES('xyzzy'); ** cause zWord to be NULL, so we look at the "command" column to see ** what special actions to take */ const char *zCmd = (const char*)sqlite3_value_text(argv[SPELLFIX_COL_COMMAND+2]); if( zCmd==0 ){ pVTab->zErrMsg = sqlite3_mprintf("%s.word may not be NULL", p->zTableName); return SQLITE_CONSTRAINT; } if( strcmp(zCmd,"reset")==0 ){ /* Reset the edit cost table (if there is one). */ editDist3ConfigDelete(p->pConfig3); p->pConfig3 = 0; return SQLITE_OK; } pVTab->zErrMsg = sqlite3_mprintf("unknown value for %s.command: \"%w\"", p->zTableName, zCmd); return SQLITE_ERROR; } if( iRank<1 ) iRank = 1; if( zSoundslike ){ zK1 = (char*)transliterate(zSoundslike, nSoundslike); }else{ zK1 = (char*)transliterate(zWord, nWord); } if( zK1==0 ) return SQLITE_NOMEM; for(i=0; (c = zK1[i])!=0; i++){ if( c>='A' && c<='Z' ) zK1[i] += 'a' - 'A'; } zK2 = (char*)phoneticHash((const unsigned char*)zK1, i); if( zK2==0 ){ sqlite3_free(zK1); return SQLITE_NOMEM; } if( sqlite3_value_type(argv[0])==SQLITE_NULL ){ spellfix1DbExec(&rc, db, "INSERT INTO \"%w\".\"%w_vocab\"(rank,langid,word,k1,k2) " "VALUES(%d,%d,%Q,%Q,%Q)", p->zDbName, p->zTableName, iRank, iLang, zWord, zK1, zK2 ); *pRowid = sqlite3_last_insert_rowid(db); }else{ rowid = sqlite3_value_int64(argv[0]); newRowid = *pRowid = sqlite3_value_int64(argv[1]); spellfix1DbExec(&rc, db, "UPDATE \"%w\".\"%w_vocab\" SET id=%lld, rank=%d, langid=%d," " word=%Q, k1=%Q, k2=%Q WHERE id=%lld", p->zDbName, p->zTableName, newRowid, iRank, iLang, zWord, zK1, zK2, rowid ); } sqlite3_free(zK1); sqlite3_free(zK2); } return rc; } /* ** Rename the spellfix1 table. */ static int spellfix1Rename(sqlite3_vtab *pVTab, const char *zNew){ spellfix1_vtab *p = (spellfix1_vtab*)pVTab; sqlite3 *db = p->db; int rc = SQLITE_OK; char *zNewName = sqlite3_mprintf("%s", zNew); if( zNewName==0 ){ return SQLITE_NOMEM; } spellfix1DbExec(&rc, db, "ALTER TABLE \"%w\".\"%w_vocab\" RENAME TO \"%w_vocab\"", p->zDbName, p->zTableName, zNewName ); if( rc==SQLITE_OK ){ sqlite3_free(p->zTableName); p->zTableName = zNewName; }else{ sqlite3_free(zNewName); } return rc; } /* ** A virtual table module that provides fuzzy search. */ static sqlite3_module spellfix1Module = { 0, /* iVersion */ spellfix1Create, /* xCreate - handle CREATE VIRTUAL TABLE */ spellfix1Connect, /* xConnect - reconnected to an existing table */ spellfix1BestIndex, /* xBestIndex - figure out how to do a query */ spellfix1Disconnect, /* xDisconnect - close a connection */ spellfix1Destroy, /* xDestroy - handle DROP TABLE */ spellfix1Open, /* xOpen - open a cursor */ spellfix1Close, /* xClose - close a cursor */ spellfix1Filter, /* xFilter - configure scan constraints */ spellfix1Next, /* xNext - advance a cursor */ spellfix1Eof, /* xEof - check for end of scan */ spellfix1Column, /* xColumn - read data */ spellfix1Rowid, /* xRowid - read data */ spellfix1Update, /* xUpdate */ 0, /* xBegin */ 0, /* xSync */ 0, /* xCommit */ 0, /* xRollback */ 0, /* xFindMethod */ spellfix1Rename, /* xRename */ }; /* ** Register the various functions and the virtual table. */ static int spellfix1Register(sqlite3 *db){ int nErr = 0; int i; nErr += sqlite3_create_function(db, "spellfix1_translit", 1, SQLITE_UTF8, 0, transliterateSqlFunc, 0, 0); nErr += sqlite3_create_function(db, "spellfix1_editdist", 2, SQLITE_UTF8, 0, editdistSqlFunc, 0, 0); nErr += sqlite3_create_function(db, "spellfix1_phonehash", 1, SQLITE_UTF8, 0, phoneticHashSqlFunc, 0, 0); nErr += sqlite3_create_function(db, "spellfix1_scriptcode", 1, SQLITE_UTF8, 0, scriptCodeSqlFunc, 0, 0); nErr += sqlite3_create_module(db, "spellfix1", &spellfix1Module, 0); nErr += editDist3Install(db); /* Verify sanity of the translit[] table */ for(i=0; i