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sqlite/ext/fts5/fts5_expr.c
dan e0569a4aae Further test coverage improvements for fts5. 
FossilOrigin-Name: 927d9a64e13c6b768f0a15475713192fcfaaf9e7
2015-05-16 20:04:43 +00:00

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/*
** 2014 May 31
**
** 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.
**
******************************************************************************
**
*/
#ifdef SQLITE_ENABLE_FTS5
#include "fts5Int.h"
#include "fts5parse.h"
/*
** All token types in the generated fts5parse.h file are greater than 0.
*/
#define FTS5_EOF 0
typedef struct Fts5ExprTerm Fts5ExprTerm;
/*
** Functions generated by lemon from fts5parse.y.
*/
void *sqlite3Fts5ParserAlloc(void *(*mallocProc)(u64));
void sqlite3Fts5ParserFree(void*, void (*freeProc)(void*));
void sqlite3Fts5Parser(void*, int, Fts5Token, Fts5Parse*);
struct Fts5Expr {
Fts5Index *pIndex;
Fts5ExprNode *pRoot;
int bDesc; /* Iterate in descending docid order */
int nPhrase; /* Number of phrases in expression */
Fts5ExprPhrase **apExprPhrase; /* Pointers to phrase objects */
};
/*
** eType:
** Expression node type. Always one of:
**
** FTS5_AND (pLeft, pRight valid)
** FTS5_OR (pLeft, pRight valid)
** FTS5_NOT (pLeft, pRight valid)
** FTS5_STRING (pNear valid)
*/
struct Fts5ExprNode {
int eType; /* Node type */
Fts5ExprNode *pLeft; /* Left hand child node */
Fts5ExprNode *pRight; /* Right hand child node */
Fts5ExprNearset *pNear; /* For FTS5_STRING - cluster of phrases */
int bEof; /* True at EOF */
i64 iRowid; /* Current rowid */
};
/*
** An instance of the following structure represents a single search term
** or term prefix.
*/
struct Fts5ExprTerm {
int bPrefix; /* True for a prefix term */
char *zTerm; /* nul-terminated term */
Fts5IndexIter *pIter; /* Iterator for this term */
};
/*
** A phrase. One or more terms that must appear in a contiguous sequence
** within a document for it to match.
*/
struct Fts5ExprPhrase {
Fts5ExprNode *pNode; /* FTS5_STRING node this phrase is part of */
Fts5Buffer poslist; /* Current position list */
int nTerm; /* Number of entries in aTerm[] */
Fts5ExprTerm aTerm[0]; /* Terms that make up this phrase */
};
/*
** One or more phrases that must appear within a certain token distance of
** each other within each matching document.
*/
struct Fts5ExprNearset {
int nNear; /* NEAR parameter */
int iCol; /* Column to search (-1 -> all columns) */
int nPhrase; /* Number of entries in aPhrase[] array */
Fts5ExprPhrase *apPhrase[0]; /* Array of phrase pointers */
};
/*
** Parse context.
*/
struct Fts5Parse {
Fts5Config *pConfig;
char *zErr;
int rc;
int nPhrase; /* Size of apPhrase array */
Fts5ExprPhrase **apPhrase; /* Array of all phrases */
Fts5ExprNode *pExpr; /* Result of a successful parse */
};
void sqlite3Fts5ParseError(Fts5Parse *pParse, const char *zFmt, ...){
va_list ap;
va_start(ap, zFmt);
if( pParse->rc==SQLITE_OK ){
pParse->zErr = sqlite3_vmprintf(zFmt, ap);
pParse->rc = SQLITE_ERROR;
}
va_end(ap);
}
static int fts5ExprIsspace(char t){
return t==' ' || t=='\t' || t=='\n' || t=='\r';
}
static int fts5ExprIstoken(char t){
return fts5ExprIsspace(t)==0 && t!='\0'
&& t!=':' && t!='(' && t!=')'
&& t!=',' && t!='+' && t!='*';
}
/*
** Read the first token from the nul-terminated string at *pz.
*/
static int fts5ExprGetToken(
Fts5Parse *pParse,
const char **pz, /* IN/OUT: Pointer into buffer */
Fts5Token *pToken
){
const char *z = *pz;
int tok;
/* Skip past any whitespace */
while( fts5ExprIsspace(*z) ) z++;
pToken->p = z;
pToken->n = 1;
switch( *z ){
case '(': tok = FTS5_LP; break;
case ')': tok = FTS5_RP; break;
case ':': tok = FTS5_COLON; break;
case ',': tok = FTS5_COMMA; break;
case '+': tok = FTS5_PLUS; break;
case '*': tok = FTS5_STAR; break;
case '\0': tok = FTS5_EOF; break;
case '"': {
const char *z2;
tok = FTS5_STRING;
for(z2=&z[1]; 1; z2++){
if( z2[0]=='"' ){
z2++;
if( z2[0]!='"' ) break;
}
if( z2[0]=='\0' ){
sqlite3Fts5ParseError(pParse, "unterminated string");
return FTS5_EOF;
}
}
pToken->n = (z2 - z);
break;
}
default: {
const char *z2;
tok = FTS5_STRING;
for(z2=&z[1]; fts5ExprIstoken(*z2); z2++);
pToken->n = (z2 - z);
if( pToken->n==2 && memcmp(pToken->p, "OR", 2)==0 ) tok = FTS5_OR;
if( pToken->n==3 && memcmp(pToken->p, "NOT", 3)==0 ) tok = FTS5_NOT;
if( pToken->n==3 && memcmp(pToken->p, "AND", 3)==0 ) tok = FTS5_AND;
break;
}
}
*pz = &pToken->p[pToken->n];
return tok;
}
static void *fts5ParseAlloc(u64 t){ return sqlite3_malloc((int)t); }
static void fts5ParseFree(void *p){ sqlite3_free(p); }
int sqlite3Fts5ExprNew(
Fts5Config *pConfig, /* FTS5 Configuration */
const char *zExpr, /* Expression text */
Fts5Expr **ppNew,
char **pzErr
){
Fts5Parse sParse;
Fts5Token token;
const char *z = zExpr;
int t; /* Next token type */
void *pEngine;
Fts5Expr *pNew;
*ppNew = 0;
*pzErr = 0;
memset(&sParse, 0, sizeof(sParse));
pEngine = sqlite3Fts5ParserAlloc(fts5ParseAlloc);
if( pEngine==0 ){ return SQLITE_NOMEM; }
sParse.pConfig = pConfig;
do {
t = fts5ExprGetToken(&sParse, &z, &token);
sqlite3Fts5Parser(pEngine, t, token, &sParse);
}while( sParse.rc==SQLITE_OK && t!=FTS5_EOF );
sqlite3Fts5ParserFree(pEngine, fts5ParseFree);
assert( sParse.rc!=SQLITE_OK || sParse.zErr==0 );
if( sParse.rc==SQLITE_OK ){
*ppNew = pNew = sqlite3_malloc(sizeof(Fts5Expr));
if( pNew==0 ){
sParse.rc = SQLITE_NOMEM;
sqlite3Fts5ParseNodeFree(sParse.pExpr);
}else{
pNew->pRoot = sParse.pExpr;
pNew->pIndex = 0;
pNew->apExprPhrase = sParse.apPhrase;
pNew->nPhrase = sParse.nPhrase;
sParse.apPhrase = 0;
}
}
sqlite3_free(sParse.apPhrase);
*pzErr = sParse.zErr;
return sParse.rc;
}
/*
** Create a new FTS5 expression by cloning phrase iPhrase of the
** expression passed as the second argument.
*/
int sqlite3Fts5ExprPhraseExpr(
Fts5Config *pConfig,
Fts5Expr *pExpr,
int iPhrase,
Fts5Expr **ppNew
){
int rc = SQLITE_OK; /* Return code */
Fts5ExprPhrase *pOrig; /* The phrase extracted from pExpr */
Fts5ExprPhrase *pCopy; /* Copy of pOrig */
Fts5Expr *pNew = 0; /* Expression to return via *ppNew */
pOrig = pExpr->apExprPhrase[iPhrase];
pCopy = (Fts5ExprPhrase*)sqlite3Fts5MallocZero(&rc,
sizeof(Fts5ExprPhrase) + sizeof(Fts5ExprTerm) * pOrig->nTerm
);
if( pCopy ){
int i; /* Used to iterate through phrase terms */
Fts5ExprPhrase **apPhrase;
Fts5ExprNode *pNode;
Fts5ExprNearset *pNear;
pNew = (Fts5Expr*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5Expr));
apPhrase = (Fts5ExprPhrase**)sqlite3Fts5MallocZero(&rc,
sizeof(Fts5ExprPhrase*)
);
pNode = (Fts5ExprNode*)sqlite3Fts5MallocZero(&rc, sizeof(Fts5ExprNode));
pNear = (Fts5ExprNearset*)sqlite3Fts5MallocZero(&rc,
sizeof(Fts5ExprNearset) + sizeof(Fts5ExprPhrase*)
);
for(i=0; i<pOrig->nTerm; i++){
pCopy->aTerm[i].zTerm = sqlite3Fts5Strndup(&rc, pOrig->aTerm[i].zTerm,-1);
pCopy->aTerm[i].bPrefix = pOrig->aTerm[i].bPrefix;
}
if( rc==SQLITE_OK ){
/* All the allocations succeeded. Put the expression object together. */
pNew->pIndex = pExpr->pIndex;
pNew->pRoot = pNode;
pNew->nPhrase = 1;
pNew->apExprPhrase = apPhrase;
pNew->apExprPhrase[0] = pCopy;
pNode->eType = FTS5_STRING;
pNode->pNear = pNear;
pNear->iCol = -1;
pNear->nPhrase = 1;
pNear->apPhrase[0] = pCopy;
pCopy->nTerm = pOrig->nTerm;
pCopy->pNode = pNode;
}else{
/* At least one allocation failed. Free them all. */
for(i=0; i<pOrig->nTerm; i++){
sqlite3_free(pCopy->aTerm[i].zTerm);
}
sqlite3_free(pCopy);
sqlite3_free(pNear);
sqlite3_free(pNode);
sqlite3_free(apPhrase);
sqlite3_free(pNew);
pNew = 0;
}
}
*ppNew = pNew;
return rc;
}
/*
** Free the expression node object passed as the only argument.
*/
void sqlite3Fts5ParseNodeFree(Fts5ExprNode *p){
if( p ){
sqlite3Fts5ParseNodeFree(p->pLeft);
sqlite3Fts5ParseNodeFree(p->pRight);
sqlite3Fts5ParseNearsetFree(p->pNear);
sqlite3_free(p);
}
}
/*
** Free the expression object passed as the only argument.
*/
void sqlite3Fts5ExprFree(Fts5Expr *p){
if( p ){
sqlite3Fts5ParseNodeFree(p->pRoot);
sqlite3_free(p->apExprPhrase);
sqlite3_free(p);
}
}
/*
** All individual term iterators in pPhrase are guaranteed to be valid and
** pointing to the same rowid when this function is called. This function
** checks if the current rowid really is a match, and if so populates
** the pPhrase->poslist buffer accordingly. Output parameter *pbMatch
** is set to true if this is really a match, or false otherwise.
**
** SQLITE_OK is returned if an error occurs, or an SQLite error code
** otherwise. It is not considered an error code if the current rowid is
** not a match.
*/
static int fts5ExprPhraseIsMatch(
Fts5Expr *pExpr, /* Expression pPhrase belongs to */
int iCol, /* If >=0, search for matches in iCol only */
Fts5ExprPhrase *pPhrase, /* Phrase object to initialize */
int *pbMatch /* OUT: Set to true if really a match */
){
Fts5PoslistWriter writer = {0};
Fts5PoslistReader aStatic[4];
Fts5PoslistReader *aIter = aStatic;
int i;
int rc = SQLITE_OK;
fts5BufferZero(&pPhrase->poslist);
/* If the aStatic[] array is not large enough, allocate a large array
** using sqlite3_malloc(). This approach could be improved upon. */
if( pPhrase->nTerm>(sizeof(aStatic) / sizeof(aStatic[0])) ){
int nByte = sizeof(Fts5PoslistReader) * pPhrase->nTerm;
aIter = (Fts5PoslistReader*)sqlite3_malloc(nByte);
if( !aIter ) return SQLITE_NOMEM;
}
/* Initialize a term iterator for each term in the phrase */
for(i=0; i<pPhrase->nTerm; i++){
int n;
const u8 *a;
rc = sqlite3Fts5IterPoslist(pPhrase->aTerm[i].pIter, &a, &n);
if( rc || sqlite3Fts5PoslistReaderInit(iCol, a, n, &aIter[i]) ){
goto ismatch_out;
}
}
while( 1 ){
int bMatch;
i64 iPos = aIter[0].iPos;
do {
bMatch = 1;
for(i=0; i<pPhrase->nTerm; i++){
Fts5PoslistReader *pPos = &aIter[i];
i64 iAdj = iPos + i;
if( pPos->iPos!=iAdj ){
bMatch = 0;
while( pPos->iPos<iAdj ){
if( sqlite3Fts5PoslistReaderNext(pPos) ) goto ismatch_out;
}
if( pPos->iPos>iAdj ) iPos = pPos->iPos-i;
}
}
}while( bMatch==0 );
/* Append position iPos to the output */
rc = sqlite3Fts5PoslistWriterAppend(&pPhrase->poslist, &writer, iPos);
if( rc!=SQLITE_OK ) goto ismatch_out;
for(i=0; i<pPhrase->nTerm; i++){
if( sqlite3Fts5PoslistReaderNext(&aIter[i]) ) goto ismatch_out;
}
}
ismatch_out:
*pbMatch = (pPhrase->poslist.n>0);
if( aIter!=aStatic ) sqlite3_free(aIter);
return rc;
}
typedef struct Fts5LookaheadReader Fts5LookaheadReader;
struct Fts5LookaheadReader {
const u8 *a; /* Buffer containing position list */
int n; /* Size of buffer a[] in bytes */
int i; /* Current offset in position list */
i64 iPos; /* Current position */
i64 iLookahead; /* Next position */
};
#define FTS5_LOOKAHEAD_EOF (((i64)1) << 62)
static int fts5LookaheadReaderNext(Fts5LookaheadReader *p){
p->iPos = p->iLookahead;
if( sqlite3Fts5PoslistNext64(p->a, p->n, &p->i, &p->iLookahead) ){
p->iLookahead = FTS5_LOOKAHEAD_EOF;
}
return (p->iPos==FTS5_LOOKAHEAD_EOF);
}
static int fts5LookaheadReaderInit(
const u8 *a, int n, /* Buffer to read position list from */
Fts5LookaheadReader *p /* Iterator object to initialize */
){
memset(p, 0, sizeof(Fts5LookaheadReader));
p->a = a;
p->n = n;
fts5LookaheadReaderNext(p);
return fts5LookaheadReaderNext(p);
}
#if 0
static int fts5LookaheadReaderEof(Fts5LookaheadReader *p){
return (p->iPos==FTS5_LOOKAHEAD_EOF);
}
#endif
typedef struct Fts5NearTrimmer Fts5NearTrimmer;
struct Fts5NearTrimmer {
Fts5LookaheadReader reader; /* Input iterator */
Fts5PoslistWriter writer; /* Writer context */
Fts5Buffer *pOut; /* Output poslist */
};
/*
** The near-set object passed as the first argument contains more than
** one phrase. All phrases currently point to the same row. The
** Fts5ExprPhrase.poslist buffers are populated accordingly. This function
** tests if the current row contains instances of each phrase sufficiently
** close together to meet the NEAR constraint. Output variable *pbMatch
** is set to true if it does, or false otherwise.
**
** If no error occurs, SQLITE_OK is returned. Or, if an error does occur,
** an SQLite error code. If a value other than SQLITE_OK is returned, the
** final value of *pbMatch is undefined.
**
** TODO: This function should also edit the position lists associated
** with each phrase to remove any phrase instances that are not part of
** a set of intances that collectively matches the NEAR constraint.
*/
static int fts5ExprNearIsMatch(Fts5ExprNearset *pNear, int *pbMatch){
Fts5NearTrimmer aStatic[4];
Fts5NearTrimmer *a = aStatic;
Fts5ExprPhrase **apPhrase = pNear->apPhrase;
int i;
int rc = SQLITE_OK;
int bMatch;
assert( pNear->nPhrase>1 );
/* If the aStatic[] array is not large enough, allocate a large array
** using sqlite3_malloc(). This approach could be improved upon. */
if( pNear->nPhrase>(sizeof(aStatic) / sizeof(aStatic[0])) ){
int nByte = sizeof(Fts5NearTrimmer) * pNear->nPhrase;
a = (Fts5NearTrimmer*)sqlite3_malloc(nByte);
if( !a ) return SQLITE_NOMEM;
memset(a, 0, nByte);
}else{
memset(aStatic, 0, sizeof(aStatic));
}
/* Initialize a lookahead iterator for each phrase. After passing the
** buffer and buffer size to the lookaside-reader init function, zero
** the phrase poslist buffer. The new poslist for the phrase (containing
** the same entries as the original with some entries removed on account
** of the NEAR constraint) is written over the original even as it is
** being read. This is safe as the entries for the new poslist are a
** subset of the old, so it is not possible for data yet to be read to
** be overwritten. */
for(i=0; i<pNear->nPhrase; i++){
Fts5Buffer *pPoslist = &apPhrase[i]->poslist;
fts5LookaheadReaderInit(pPoslist->p, pPoslist->n, &a[i].reader);
pPoslist->n = 0;
a[i].pOut = pPoslist;
}
while( 1 ){
int iAdv;
i64 iMin;
i64 iMax;
/* This block advances the phrase iterators until they point to a set of
** entries that together comprise a match. */
iMax = a[0].reader.iPos;
do {
bMatch = 1;
for(i=0; i<pNear->nPhrase; i++){
Fts5LookaheadReader *pPos = &a[i].reader;
iMin = iMax - pNear->apPhrase[i]->nTerm - pNear->nNear;
if( pPos->iPos<iMin || pPos->iPos>iMax ){
bMatch = 0;
while( pPos->iPos<iMin ){
if( fts5LookaheadReaderNext(pPos) ) goto ismatch_out;
}
if( pPos->iPos>iMax ) iMax = pPos->iPos;
}
}
}while( bMatch==0 );
/* Add an entry to each output position list */
for(i=0; i<pNear->nPhrase; i++){
i64 iPos = a[i].reader.iPos;
Fts5PoslistWriter *pWriter = &a[i].writer;
if( a[i].pOut->n==0 || iPos!=pWriter->iPrev ){
sqlite3Fts5PoslistWriterAppend(a[i].pOut, pWriter, iPos);
}
}
iAdv = 0;
iMin = a[0].reader.iLookahead;
for(i=0; i<pNear->nPhrase; i++){
if( a[i].reader.iLookahead < iMin ){
iMin = a[i].reader.iLookahead;
iAdv = i;
}
}
if( fts5LookaheadReaderNext(&a[iAdv].reader) ) goto ismatch_out;
}
ismatch_out:
*pbMatch = (a[0].pOut->n>0);
if( a!=aStatic ) sqlite3_free(a);
return rc;
}
/*
** Advance the first term iterator in the first phrase of pNear. Set output
** variable *pbEof to true if it reaches EOF or if an error occurs.
**
** Return SQLITE_OK if successful, or an SQLite error code if an error
** occurs.
*/
static int fts5ExprNearAdvanceFirst(
Fts5Expr *pExpr, /* Expression pPhrase belongs to */
Fts5ExprNode *pNode, /* FTS5_STRING node */
int bFromValid,
i64 iFrom
){
Fts5IndexIter *pIter = pNode->pNear->apPhrase[0]->aTerm[0].pIter;
int rc;
if( bFromValid ){
rc = sqlite3Fts5IterNextFrom(pIter, iFrom);
}else{
rc = sqlite3Fts5IterNext(pIter);
}
pNode->bEof = (rc || sqlite3Fts5IterEof(pIter));
return rc;
}
/*
** Advance iterator pIter until it points to a value equal to or laster
** than the initial value of *piLast. If this means the iterator points
** to a value laster than *piLast, update *piLast to the new lastest value.
**
** If the iterator reaches EOF, set *pbEof to true before returning. If
** an error occurs, set *pRc to an error code. If either *pbEof or *pRc
** are set, return a non-zero value. Otherwise, return zero.
*/
static int fts5ExprAdvanceto(
Fts5IndexIter *pIter, /* Iterator to advance */
int bDesc, /* True if iterator is "rowid DESC" */
i64 *piLast, /* IN/OUT: Lastest rowid seen so far */
int *pRc, /* OUT: Error code */
int *pbEof /* OUT: Set to true if EOF */
){
i64 iLast = *piLast;
i64 iRowid;
iRowid = sqlite3Fts5IterRowid(pIter);
if( (bDesc==0 && iLast>iRowid) || (bDesc && iLast<iRowid) ){
int rc = sqlite3Fts5IterNextFrom(pIter, iLast);
if( rc || sqlite3Fts5IterEof(pIter) ){
*pRc = rc;
*pbEof = 1;
return 1;
}
iRowid = sqlite3Fts5IterRowid(pIter);
assert( (bDesc==0 && iRowid>=iLast) || (bDesc==1 && iRowid<=iLast) );
}
*piLast = iRowid;
return 0;
}
/*
** All individual term iterators in pNear are guaranteed to be valid when
** this function is called. This function checks if all term iterators
** point to the same rowid, and if not, advances them until they do.
** If an EOF is reached before this happens, *pbEof is set to true before
** returning.
**
** SQLITE_OK is returned if an error occurs, or an SQLite error code
** otherwise. It is not considered an error code if an iterator reaches
** EOF.
*/
static int fts5ExprNearNextRowidMatch(
Fts5Expr *pExpr, /* Expression pPhrase belongs to */
Fts5ExprNode *pNode
){
Fts5ExprNearset *pNear = pNode->pNear;
int rc = SQLITE_OK;
int i, j; /* Phrase and token index, respectively */
i64 iLast; /* Lastest rowid any iterator points to */
int bMatch; /* True if all terms are at the same rowid */
/* Initialize iLast, the "lastest" rowid any iterator points to. If the
** iterator skips through rowids in the default ascending order, this means
** the maximum rowid. Or, if the iterator is "ORDER BY rowid DESC", then it
** means the minimum rowid. */
iLast = sqlite3Fts5IterRowid(pNear->apPhrase[0]->aTerm[0].pIter);
do {
bMatch = 1;
for(i=0; i<pNear->nPhrase; i++){
Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
for(j=0; j<pPhrase->nTerm; j++){
Fts5IndexIter *pIter = pPhrase->aTerm[j].pIter;
i64 iRowid = sqlite3Fts5IterRowid(pIter);
if( iRowid!=iLast ) bMatch = 0;
if( fts5ExprAdvanceto(pIter, pExpr->bDesc, &iLast, &rc, &pNode->bEof) ){
return rc;
}
}
}
}while( bMatch==0 );
pNode->iRowid = iLast;
return rc;
}
/*
** Argument pNode points to a NEAR node. All individual term iterators
** point to valid entries (not EOF).
*
** This function tests if the term iterators currently all point to the
** same rowid, and if so, if the row matches the phrase and NEAR constraints.
** If so, the pPhrase->poslist buffers are populated and the pNode->iRowid
** variable set before returning. Or, if the current combination of
** iterators is not a match, they are advanced until they are. If one of
** the iterators reaches EOF before a match is found, *pbEof is set to
** true before returning. The final values of the pPhrase->poslist and
** iRowid fields are undefined in this case.
**
** SQLITE_OK is returned if an error occurs, or an SQLite error code
** otherwise. It is not considered an error code if an iterator reaches
** EOF.
*/
static int fts5ExprNearNextMatch(
Fts5Expr *pExpr, /* Expression that pNear is a part of */
Fts5ExprNode *pNode /* The "NEAR" node (FTS5_STRING) */
){
int rc = SQLITE_OK;
Fts5ExprNearset *pNear = pNode->pNear;
while( 1 ){
int i;
/* Advance the iterators until they all point to the same rowid */
rc = fts5ExprNearNextRowidMatch(pExpr, pNode);
if( rc!=SQLITE_OK || pNode->bEof ) break;
/* Check that each phrase in the nearset matches the current row.
** Populate the pPhrase->poslist buffers at the same time. If any
** phrase is not a match, break out of the loop early. */
for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
if( pPhrase->nTerm>1 || pNear->iCol>=0 ){
int bMatch = 0;
rc = fts5ExprPhraseIsMatch(pExpr, pNear->iCol, pPhrase, &bMatch);
if( bMatch==0 ) break;
}else{
int n;
const u8 *a;
rc = sqlite3Fts5IterPoslist(pPhrase->aTerm[0].pIter, &a, &n);
fts5BufferSet(&rc, &pPhrase->poslist, n, a);
}
}
if( rc==SQLITE_OK && i==pNear->nPhrase ){
int bMatch = 1;
if( pNear->nPhrase>1 ){
rc = fts5ExprNearIsMatch(pNear, &bMatch);
}
if( rc!=SQLITE_OK || bMatch ) break;
}
/* If control flows to here, then the current rowid is not a match.
** Advance all term iterators in all phrases to the next rowid. */
if( rc==SQLITE_OK ){
rc = fts5ExprNearAdvanceFirst(pExpr, pNode, 0, 0);
}
if( pNode->bEof || rc!=SQLITE_OK ) break;
}
return rc;
}
/*
** Initialize all term iterators in the pNear object. If any term is found
** to match no documents at all, set *pbEof to true and return immediately,
** without initializing any further iterators.
*/
static int fts5ExprNearInitAll(
Fts5Expr *pExpr,
Fts5ExprNode *pNode
){
Fts5ExprNearset *pNear = pNode->pNear;
Fts5ExprTerm *pTerm;
Fts5ExprPhrase *pPhrase;
int i, j;
int rc = SQLITE_OK;
for(i=0; rc==SQLITE_OK && i<pNear->nPhrase; i++){
pPhrase = pNear->apPhrase[i];
for(j=0; j<pPhrase->nTerm; j++){
pTerm = &pPhrase->aTerm[j];
if( pTerm->pIter ){
sqlite3Fts5IterClose(pTerm->pIter);
pTerm->pIter = 0;
}
rc = sqlite3Fts5IndexQuery(
pExpr->pIndex, pTerm->zTerm, strlen(pTerm->zTerm),
(pTerm->bPrefix ? FTS5INDEX_QUERY_PREFIX : 0) |
(pExpr->bDesc ? FTS5INDEX_QUERY_DESC : 0),
&pTerm->pIter
);
assert( rc==SQLITE_OK || pTerm->pIter==0 );
if( pTerm->pIter==0 || sqlite3Fts5IterEof(pTerm->pIter) ){
pNode->bEof = 1;
break;
}
}
}
return rc;
}
/* fts5ExprNodeNext() calls fts5ExprNodeNextMatch(). And vice-versa. */
static int fts5ExprNodeNextMatch(Fts5Expr*, Fts5ExprNode*);
static int fts5RowidCmp(
Fts5Expr *pExpr,
i64 iLhs,
i64 iRhs
){
assert( pExpr->bDesc==0 || pExpr->bDesc==1 );
if( pExpr->bDesc==0 ){
if( iLhs<iRhs ) return -1;
return (iLhs > iRhs);
}else{
if( iLhs>iRhs ) return -1;
return (iLhs < iRhs);
}
}
/*
** Compare the values currently indicated by the two nodes as follows:
**
** res = (*p1) - (*p2)
**
** Nodes that point to values that come later in the iteration order are
** considered to be larger. Nodes at EOF are the largest of all.
**
** This means that if the iteration order is ASC, then numerically larger
** rowids are considered larger. Or if it is the default DESC, numerically
** smaller rowids are larger.
*/
static int fts5NodeCompare(
Fts5Expr *pExpr,
Fts5ExprNode *p1,
Fts5ExprNode *p2
){
if( p2->bEof ) return -1;
if( p1->bEof ) return +1;
return fts5RowidCmp(pExpr, p1->iRowid, p2->iRowid);
}
/*
** Advance node iterator pNode, part of expression pExpr. If argument
** bFromValid is zero, then pNode is advanced exactly once. Or, if argument
** bFromValid is non-zero, then pNode is advanced until it is at or past
** rowid value iFrom. Whether "past" means "less than" or "greater than"
** depends on whether this is an ASC or DESC iterator.
*/
static int fts5ExprNodeNext(
Fts5Expr *pExpr,
Fts5ExprNode *pNode,
int bFromValid,
i64 iFrom
){
int rc = SQLITE_OK;
if( pNode->bEof==0 ){
switch( pNode->eType ){
case FTS5_STRING: {
rc = fts5ExprNearAdvanceFirst(pExpr, pNode, bFromValid, iFrom);
break;
};
case FTS5_AND: {
rc = fts5ExprNodeNext(pExpr, pNode->pLeft, bFromValid, iFrom);
if( rc==SQLITE_OK ){
/* todo: update (iFrom/bFromValid) here */
rc = fts5ExprNodeNext(pExpr, pNode->pRight, bFromValid, iFrom);
}
break;
}
case FTS5_OR: {
Fts5ExprNode *p1 = pNode->pLeft;
Fts5ExprNode *p2 = pNode->pRight;
int cmp = fts5NodeCompare(pExpr, p1, p2);
if( cmp<=0 || (bFromValid && fts5RowidCmp(pExpr,p1->iRowid,iFrom)<0) ){
rc = fts5ExprNodeNext(pExpr, p1, bFromValid, iFrom);
}
if( cmp>=0 || (bFromValid && fts5RowidCmp(pExpr,p2->iRowid,iFrom)<0) ){
if( rc==SQLITE_OK ){
rc = fts5ExprNodeNext(pExpr, p2, bFromValid, iFrom);
}
}
break;
}
default: assert( pNode->eType==FTS5_NOT ); {
rc = fts5ExprNodeNext(pExpr, pNode->pLeft, bFromValid, iFrom);
break;
}
}
if( rc==SQLITE_OK ){
rc = fts5ExprNodeNextMatch(pExpr, pNode);
}
}
/* Assert that if bFromValid was true, either:
**
** a) an error occurred, or
** b) the node is now at EOF, or
** c) the node is now at or past rowid iFrom.
*/
assert( bFromValid==0
|| rc!=SQLITE_OK /* a */
|| pNode->bEof /* b */
|| pNode->iRowid==iFrom || pExpr->bDesc==(pNode->iRowid<iFrom) /* c */
);
return rc;
}
static void fts5ExprSetEof(Fts5ExprNode *pNode){
if( pNode ){
pNode->bEof = 1;
fts5ExprSetEof(pNode->pLeft);
fts5ExprSetEof(pNode->pRight);
}
}
/*
** If pNode currently points to a match, this function returns SQLITE_OK
** without modifying it. Otherwise, pNode is advanced until it does point
** to a match or EOF is reached.
*/
static int fts5ExprNodeNextMatch(
Fts5Expr *pExpr, /* Expression of which pNode is a part */
Fts5ExprNode *pNode /* Expression node to test */
){
int rc = SQLITE_OK;
if( pNode->bEof==0 ){
switch( pNode->eType ){
case FTS5_STRING: {
rc = fts5ExprNearNextMatch(pExpr, pNode);
break;
}
case FTS5_AND: {
Fts5ExprNode *p1 = pNode->pLeft;
Fts5ExprNode *p2 = pNode->pRight;
while( p1->bEof==0 && p2->bEof==0 && p2->iRowid!=p1->iRowid ){
Fts5ExprNode *pAdv;
i64 iFrom;
assert( pExpr->bDesc==0 || pExpr->bDesc==1 );
if( pExpr->bDesc==(p1->iRowid > p2->iRowid) ){
pAdv = p1;
iFrom = p2->iRowid;
}else{
pAdv = p2;
iFrom = p1->iRowid;
}
rc = fts5ExprNodeNext(pExpr, pAdv, 1, iFrom);
if( rc!=SQLITE_OK ) break;
}
if( p1->bEof || p2->bEof ){
fts5ExprSetEof(pNode);
}
pNode->iRowid = p1->iRowid;
break;
}
case FTS5_OR: {
Fts5ExprNode *p1 = pNode->pLeft;
Fts5ExprNode *p2 = pNode->pRight;
Fts5ExprNode *pNext = (fts5NodeCompare(pExpr, p1, p2) > 0 ? p2 : p1);
pNode->bEof = pNext->bEof;
pNode->iRowid = pNext->iRowid;
break;
}
default: assert( pNode->eType==FTS5_NOT ); {
Fts5ExprNode *p1 = pNode->pLeft;
Fts5ExprNode *p2 = pNode->pRight;
while( rc==SQLITE_OK && p1->bEof==0 ){
int cmp = fts5NodeCompare(pExpr, p1, p2);
if( cmp>0 ){
rc = fts5ExprNodeNext(pExpr, p2, 1, p1->iRowid);
cmp = fts5NodeCompare(pExpr, p1, p2);
}
assert( rc!=SQLITE_OK || cmp<=0 );
if( rc || cmp<0 ) break;
rc = fts5ExprNodeNext(pExpr, p1, 0, 0);
}
pNode->bEof = p1->bEof;
pNode->iRowid = p1->iRowid;
break;
}
}
}
return rc;
}
/*
** Set node pNode, which is part of expression pExpr, to point to the first
** match. If there are no matches, set the Node.bEof flag to indicate EOF.
**
** Return an SQLite error code if an error occurs, or SQLITE_OK otherwise.
** It is not an error if there are no matches.
*/
static int fts5ExprNodeFirst(Fts5Expr *pExpr, Fts5ExprNode *pNode){
int rc = SQLITE_OK;
pNode->bEof = 0;
if( pNode->eType==FTS5_STRING ){
/* Initialize all term iterators in the NEAR object. */
rc = fts5ExprNearInitAll(pExpr, pNode);
/* Attempt to advance to the first match */
if( rc==SQLITE_OK && pNode->bEof==0 ){
rc = fts5ExprNearNextMatch(pExpr, pNode);
}
}else{
rc = fts5ExprNodeFirst(pExpr, pNode->pLeft);
if( rc==SQLITE_OK ){
rc = fts5ExprNodeFirst(pExpr, pNode->pRight);
}
if( rc==SQLITE_OK ){
rc = fts5ExprNodeNextMatch(pExpr, pNode);
}
}
return rc;
}
/*
** Begin iterating through the set of documents in index pIdx matched by
** the MATCH expression passed as the first argument. If the "bDesc" parameter
** is passed a non-zero value, iteration is in descending rowid order. Or,
** if it is zero, in ascending order.
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise. It
** is not considered an error if the query does not match any documents.
*/
int sqlite3Fts5ExprFirst(Fts5Expr *p, Fts5Index *pIdx, int bDesc){
int rc = SQLITE_OK;
if( p->pRoot ){
p->pIndex = pIdx;
p->bDesc = bDesc;
rc = fts5ExprNodeFirst(p, p->pRoot);
}
return rc;
}
/*
** Move to the next document
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise. It
** is not considered an error if the query does not match any documents.
*/
int sqlite3Fts5ExprNext(Fts5Expr *p){
int rc;
rc = fts5ExprNodeNext(p, p->pRoot, 0, 0);
return rc;
}
int sqlite3Fts5ExprEof(Fts5Expr *p){
return (p->pRoot==0 || p->pRoot->bEof);
}
i64 sqlite3Fts5ExprRowid(Fts5Expr *p){
return p->pRoot->iRowid;
}
static int fts5ParseStringFromToken(Fts5Token *pToken, char **pz){
int rc = SQLITE_OK;
*pz = sqlite3Fts5Strndup(&rc, pToken->p, pToken->n);
return rc;
}
/*
** Free the phrase object passed as the only argument.
*/
static void fts5ExprPhraseFree(Fts5ExprPhrase *pPhrase){
if( pPhrase ){
int i;
for(i=0; i<pPhrase->nTerm; i++){
Fts5ExprTerm *pTerm = &pPhrase->aTerm[i];
sqlite3_free(pTerm->zTerm);
if( pTerm->pIter ){
sqlite3Fts5IterClose(pTerm->pIter);
}
}
fts5BufferFree(&pPhrase->poslist);
sqlite3_free(pPhrase);
}
}
/*
** If argument pNear is NULL, then a new Fts5ExprNearset object is allocated
** and populated with pPhrase. Or, if pNear is not NULL, phrase pPhrase is
** appended to it and the results returned.
**
** If an OOM error occurs, both the pNear and pPhrase objects are freed and
** NULL returned.
*/
Fts5ExprNearset *sqlite3Fts5ParseNearset(
Fts5Parse *pParse, /* Parse context */
Fts5ExprNearset *pNear, /* Existing nearset, or NULL */
Fts5ExprPhrase *pPhrase /* Recently parsed phrase */
){
const int SZALLOC = 8;
Fts5ExprNearset *pRet = 0;
if( pParse->rc==SQLITE_OK ){
if( pPhrase==0 ){
return pNear;
}
if( pNear==0 ){
int nByte = sizeof(Fts5ExprNearset) + SZALLOC * sizeof(Fts5ExprPhrase*);
pRet = sqlite3_malloc(nByte);
if( pRet==0 ){
pParse->rc = SQLITE_NOMEM;
}else{
memset(pRet, 0, nByte);
pRet->iCol = -1;
}
}else if( (pNear->nPhrase % SZALLOC)==0 ){
int nNew = pNear->nPhrase + SZALLOC;
int nByte = sizeof(Fts5ExprNearset) + nNew * sizeof(Fts5ExprPhrase*);
pRet = (Fts5ExprNearset*)sqlite3_realloc(pNear, nByte);
if( pRet==0 ){
pParse->rc = SQLITE_NOMEM;
}
}else{
pRet = pNear;
}
}
if( pRet==0 ){
assert( pParse->rc!=SQLITE_OK );
sqlite3Fts5ParseNearsetFree(pNear);
sqlite3Fts5ParsePhraseFree(pPhrase);
}else{
pRet->apPhrase[pRet->nPhrase++] = pPhrase;
}
return pRet;
}
typedef struct TokenCtx TokenCtx;
struct TokenCtx {
Fts5ExprPhrase *pPhrase;
};
/*
** Callback for tokenizing terms used by ParseTerm().
*/
static int fts5ParseTokenize(
void *pContext, /* Pointer to Fts5InsertCtx object */
const char *pToken, /* Buffer containing token */
int nToken, /* Size of token in bytes */
int iStart, /* Start offset of token */
int iEnd /* End offset of token */
){
int rc = SQLITE_OK;
const int SZALLOC = 8;
TokenCtx *pCtx = (TokenCtx*)pContext;
Fts5ExprPhrase *pPhrase = pCtx->pPhrase;
Fts5ExprTerm *pTerm;
if( pPhrase==0 || (pPhrase->nTerm % SZALLOC)==0 ){
Fts5ExprPhrase *pNew;
int nNew = SZALLOC + (pPhrase ? pPhrase->nTerm : 0);
pNew = (Fts5ExprPhrase*)sqlite3_realloc(pPhrase,
sizeof(Fts5ExprPhrase) + sizeof(Fts5ExprTerm) * nNew
);
if( pNew==0 ) return SQLITE_NOMEM;
if( pPhrase==0 ) memset(pNew, 0, sizeof(Fts5ExprPhrase));
pCtx->pPhrase = pPhrase = pNew;
pNew->nTerm = nNew - SZALLOC;
}
pTerm = &pPhrase->aTerm[pPhrase->nTerm++];
memset(pTerm, 0, sizeof(Fts5ExprTerm));
pTerm->zTerm = sqlite3Fts5Strndup(&rc, pToken, nToken);
return rc;
}
/*
** Free the phrase object passed as the only argument.
*/
void sqlite3Fts5ParsePhraseFree(Fts5ExprPhrase *pPhrase){
fts5ExprPhraseFree(pPhrase);
}
/*
** Free the phrase object passed as the second argument.
*/
void sqlite3Fts5ParseNearsetFree(Fts5ExprNearset *pNear){
if( pNear ){
int i;
for(i=0; i<pNear->nPhrase; i++){
fts5ExprPhraseFree(pNear->apPhrase[i]);
}
sqlite3_free(pNear);
}
}
void sqlite3Fts5ParseFinished(Fts5Parse *pParse, Fts5ExprNode *p){
assert( pParse->pExpr==0 );
pParse->pExpr = p;
}
/*
** This function is called by the parser to process a string token. The
** string may or may not be quoted. In any case it is tokenized and a
** phrase object consisting of all tokens returned.
*/
Fts5ExprPhrase *sqlite3Fts5ParseTerm(
Fts5Parse *pParse, /* Parse context */
Fts5ExprPhrase *pAppend, /* Phrase to append to */
Fts5Token *pToken, /* String to tokenize */
int bPrefix /* True if there is a trailing "*" */
){
Fts5Config *pConfig = pParse->pConfig;
TokenCtx sCtx; /* Context object passed to callback */
int rc; /* Tokenize return code */
char *z = 0;
memset(&sCtx, 0, sizeof(TokenCtx));
sCtx.pPhrase = pAppend;
rc = fts5ParseStringFromToken(pToken, &z);
if( rc==SQLITE_OK ){
sqlite3Fts5Dequote(z);
rc = sqlite3Fts5Tokenize(pConfig, z, strlen(z), &sCtx, fts5ParseTokenize);
}
sqlite3_free(z);
if( rc ){
pParse->rc = rc;
fts5ExprPhraseFree(sCtx.pPhrase);
sCtx.pPhrase = 0;
}else if( sCtx.pPhrase ){
if( pAppend==0 ){
if( (pParse->nPhrase % 8)==0 ){
int nByte = sizeof(Fts5ExprPhrase*) * (pParse->nPhrase + 8);
Fts5ExprPhrase **apNew;
apNew = (Fts5ExprPhrase**)sqlite3_realloc(pParse->apPhrase, nByte);
if( apNew==0 ){
pParse->rc = SQLITE_NOMEM;
fts5ExprPhraseFree(sCtx.pPhrase);
return 0;
}
pParse->apPhrase = apNew;
}
pParse->nPhrase++;
}
pParse->apPhrase[pParse->nPhrase-1] = sCtx.pPhrase;
assert( sCtx.pPhrase->nTerm>0 );
sCtx.pPhrase->aTerm[sCtx.pPhrase->nTerm-1].bPrefix = bPrefix;
}
return sCtx.pPhrase;
}
/*
** Token pTok has appeared in a MATCH expression where the NEAR operator
** is expected. If token pTok does not contain "NEAR", store an error
** in the pParse object.
*/
void sqlite3Fts5ParseNear(Fts5Parse *pParse, Fts5Token *pTok){
if( pTok->n!=4 || memcmp("NEAR", pTok->p, 4) ){
sqlite3Fts5ParseError(
pParse, "fts5: syntax error near \"%.*s\"", pTok->n, pTok->p
);
}
}
void sqlite3Fts5ParseSetDistance(
Fts5Parse *pParse,
Fts5ExprNearset *pNear,
Fts5Token *p
){
int nNear = 0;
int i;
if( p->n ){
for(i=0; i<p->n; i++){
char c = (char)p->p[i];
if( c<'0' || c>'9' ){
sqlite3Fts5ParseError(
pParse, "expected integer, got \"%.*s\"", p->n, p->p
);
return;
}
nNear = nNear * 10 + (p->p[i] - '0');
}
}else{
nNear = FTS5_DEFAULT_NEARDIST;
}
pNear->nNear = nNear;
}
void sqlite3Fts5ParseSetColumn(
Fts5Parse *pParse,
Fts5ExprNearset *pNear,
Fts5Token *p
){
if( pParse->rc==SQLITE_OK ){
char *z = 0;
int rc = fts5ParseStringFromToken(p, &z);
if( rc==SQLITE_OK ){
Fts5Config *pConfig = pParse->pConfig;
int i;
for(i=0; i<pConfig->nCol; i++){
if( 0==sqlite3_stricmp(pConfig->azCol[i], z) ){
pNear->iCol = i;
break;
}
}
if( i==pConfig->nCol ){
sqlite3Fts5ParseError(pParse, "no such column: %s", z);
}
sqlite3_free(z);
}else{
pParse->rc = rc;
}
}
}
/*
** Allocate and return a new expression object. If anything goes wrong (i.e.
** OOM error), leave an error code in pParse and return NULL.
*/
Fts5ExprNode *sqlite3Fts5ParseNode(
Fts5Parse *pParse, /* Parse context */
int eType, /* FTS5_STRING, AND, OR or NOT */
Fts5ExprNode *pLeft, /* Left hand child expression */
Fts5ExprNode *pRight, /* Right hand child expression */
Fts5ExprNearset *pNear /* For STRING expressions, the near cluster */
){
Fts5ExprNode *pRet = 0;
if( pParse->rc==SQLITE_OK ){
assert( (eType!=FTS5_STRING && !pNear)
|| (eType==FTS5_STRING && !pLeft && !pRight)
);
if( eType==FTS5_STRING && pNear==0 ) return 0;
if( eType!=FTS5_STRING && pLeft==0 ) return pRight;
if( eType!=FTS5_STRING && pRight==0 ) return pLeft;
pRet = (Fts5ExprNode*)sqlite3_malloc(sizeof(Fts5ExprNode));
if( pRet==0 ){
pParse->rc = SQLITE_NOMEM;
}else{
memset(pRet, 0, sizeof(*pRet));
pRet->eType = eType;
pRet->pLeft = pLeft;
pRet->pRight = pRight;
pRet->pNear = pNear;
if( eType==FTS5_STRING ){
int iPhrase;
for(iPhrase=0; iPhrase<pNear->nPhrase; iPhrase++){
pNear->apPhrase[iPhrase]->pNode = pRet;
}
}
}
}
if( pRet==0 ){
assert( pParse->rc!=SQLITE_OK );
sqlite3Fts5ParseNodeFree(pLeft);
sqlite3Fts5ParseNodeFree(pRight);
sqlite3Fts5ParseNearsetFree(pNear);
}
return pRet;
}
static char *fts5ExprTermPrint(Fts5ExprTerm *pTerm){
char *zQuoted = sqlite3_malloc(strlen(pTerm->zTerm) * 2 + 3 + 2);
if( zQuoted ){
int i = 0;
char *zIn = pTerm->zTerm;
zQuoted[i++] = '"';
while( *zIn ){
if( *zIn=='"' ) zQuoted[i++] = '"';
zQuoted[i++] = *zIn++;
}
zQuoted[i++] = '"';
if( pTerm->bPrefix ){
zQuoted[i++] = ' ';
zQuoted[i++] = '*';
}
zQuoted[i++] = '\0';
}
return zQuoted;
}
static char *fts5PrintfAppend(char *zApp, const char *zFmt, ...){
char *zNew;
va_list ap;
va_start(ap, zFmt);
zNew = sqlite3_vmprintf(zFmt, ap);
va_end(ap);
if( zApp && zNew ){
char *zNew2 = sqlite3_mprintf("%s%s", zApp, zNew);
sqlite3_free(zNew);
zNew = zNew2;
}
sqlite3_free(zApp);
return zNew;
}
/*
** Compose a tcl-readable representation of expression pExpr. Return a
** pointer to a buffer containing that representation. It is the
** responsibility of the caller to at some point free the buffer using
** sqlite3_free().
*/
static char *fts5ExprPrintTcl(
Fts5Config *pConfig,
const char *zNearsetCmd,
Fts5ExprNode *pExpr
){
char *zRet = 0;
if( pExpr->eType==FTS5_STRING ){
Fts5ExprNearset *pNear = pExpr->pNear;
int i;
int iTerm;
zRet = fts5PrintfAppend(zRet, "[%s ", zNearsetCmd);
if( zRet==0 ) return 0;
if( pNear->iCol>=0 ){
zRet = fts5PrintfAppend(zRet, "-col %d ", pNear->iCol);
if( zRet==0 ) return 0;
}
if( pNear->nPhrase>1 ){
zRet = fts5PrintfAppend(zRet, "-near %d ", pNear->nNear);
if( zRet==0 ) return 0;
}
zRet = fts5PrintfAppend(zRet, "--");
if( zRet==0 ) return 0;
for(i=0; i<pNear->nPhrase; i++){
Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
zRet = fts5PrintfAppend(zRet, " {");
for(iTerm=0; zRet && iTerm<pPhrase->nTerm; iTerm++){
char *zTerm = pPhrase->aTerm[iTerm].zTerm;
zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" ", zTerm);
}
if( zRet ) zRet = fts5PrintfAppend(zRet, "}");
if( zRet==0 ) return 0;
}
zRet = fts5PrintfAppend(zRet, "]");
if( zRet==0 ) return 0;
}else{
char *zOp = 0;
char *z1 = 0;
char *z2 = 0;
switch( pExpr->eType ){
case FTS5_AND: zOp = "&&"; break;
case FTS5_NOT: zOp = "&& !"; break;
default:
assert( pExpr->eType==FTS5_OR );
zOp = "||";
break;
}
z1 = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->pLeft);
z2 = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->pRight);
if( z1 && z2 ){
int b1 = pExpr->pLeft->eType!=FTS5_STRING;
int b2 = pExpr->pRight->eType!=FTS5_STRING;
zRet = sqlite3_mprintf("%s%s%s %s %s%s%s",
b1 ? "(" : "", z1, b1 ? ")" : "",
zOp,
b2 ? "(" : "", z2, b2 ? ")" : ""
);
}
sqlite3_free(z1);
sqlite3_free(z2);
}
return zRet;
}
static char *fts5ExprPrint(Fts5Config *pConfig, Fts5ExprNode *pExpr){
char *zRet = 0;
if( pExpr->eType==FTS5_STRING ){
Fts5ExprNearset *pNear = pExpr->pNear;
int i;
int iTerm;
if( pNear->iCol>=0 ){
zRet = fts5PrintfAppend(zRet, "%s : ", pConfig->azCol[pNear->iCol]);
if( zRet==0 ) return 0;
}
if( pNear->nPhrase>1 ){
zRet = fts5PrintfAppend(zRet, "NEAR(");
if( zRet==0 ) return 0;
}
for(i=0; i<pNear->nPhrase; i++){
Fts5ExprPhrase *pPhrase = pNear->apPhrase[i];
if( i!=0 ){
zRet = fts5PrintfAppend(zRet, " ");
if( zRet==0 ) return 0;
}
for(iTerm=0; iTerm<pPhrase->nTerm; iTerm++){
char *zTerm = fts5ExprTermPrint(&pPhrase->aTerm[iTerm]);
if( zTerm ){
zRet = fts5PrintfAppend(zRet, "%s%s", iTerm==0?"":" + ", zTerm);
sqlite3_free(zTerm);
}
if( zTerm==0 || zRet==0 ){
sqlite3_free(zRet);
return 0;
}
}
}
if( pNear->nPhrase>1 ){
zRet = fts5PrintfAppend(zRet, ", %d)", pNear->nNear);
if( zRet==0 ) return 0;
}
}else{
char *zOp = 0;
char *z1 = 0;
char *z2 = 0;
switch( pExpr->eType ){
case FTS5_AND: zOp = "AND"; break;
case FTS5_NOT: zOp = "NOT"; break;
default:
assert( pExpr->eType==FTS5_OR );
zOp = "OR";
break;
}
z1 = fts5ExprPrint(pConfig, pExpr->pLeft);
z2 = fts5ExprPrint(pConfig, pExpr->pRight);
if( z1 && z2 ){
int b1 = pExpr->pLeft->eType!=FTS5_STRING;
int b2 = pExpr->pRight->eType!=FTS5_STRING;
zRet = sqlite3_mprintf("%s%s%s %s %s%s%s",
b1 ? "(" : "", z1, b1 ? ")" : "",
zOp,
b2 ? "(" : "", z2, b2 ? ")" : ""
);
}
sqlite3_free(z1);
sqlite3_free(z2);
}
return zRet;
}
/*
** The implementation of user-defined scalar functions fts5_expr() (bTcl==0)
** and fts5_expr_tcl() (bTcl!=0).
*/
static void fts5ExprFunction(
sqlite3_context *pCtx, /* Function call context */
int nArg, /* Number of args */
sqlite3_value **apVal, /* Function arguments */
int bTcl
){
Fts5Global *pGlobal = (Fts5Global*)sqlite3_user_data(pCtx);
sqlite3 *db = sqlite3_context_db_handle(pCtx);
const char *zExpr = 0;
char *zErr = 0;
Fts5Expr *pExpr = 0;
int rc;
int i;
const char **azConfig; /* Array of arguments for Fts5Config */
const char *zNearsetCmd = "nearset";
int nConfig; /* Size of azConfig[] */
Fts5Config *pConfig = 0;
int iArg = 1;
if( bTcl && nArg>1 ){
zNearsetCmd = (const char*)sqlite3_value_text(apVal[1]);
iArg = 2;
}
nConfig = 3 + (nArg-iArg);
azConfig = (const char**)sqlite3_malloc(sizeof(char*) * nConfig);
if( azConfig==0 ){
sqlite3_result_error_nomem(pCtx);
return;
}
azConfig[0] = 0;
azConfig[1] = "main";
azConfig[2] = "tbl";
for(i=3; iArg<nArg; iArg++){
azConfig[i++] = (const char*)sqlite3_value_text(apVal[iArg]);
}
zExpr = (const char*)sqlite3_value_text(apVal[0]);
rc = sqlite3Fts5ConfigParse(pGlobal, db, nConfig, azConfig, &pConfig, &zErr);
if( rc==SQLITE_OK ){
rc = sqlite3Fts5ExprNew(pConfig, zExpr, &pExpr, &zErr);
}
if( rc==SQLITE_OK ){
char *zText;
if( pExpr->pRoot==0 ){
zText = sqlite3_mprintf("");
}else if( bTcl ){
zText = fts5ExprPrintTcl(pConfig, zNearsetCmd, pExpr->pRoot);
}else{
zText = fts5ExprPrint(pConfig, pExpr->pRoot);
}
if( zText==0 ){
rc = SQLITE_NOMEM;
}else{
sqlite3_result_text(pCtx, zText, -1, SQLITE_TRANSIENT);
sqlite3_free(zText);
}
}
if( rc!=SQLITE_OK ){
if( zErr ){
sqlite3_result_error(pCtx, zErr, -1);
sqlite3_free(zErr);
}else{
sqlite3_result_error_code(pCtx, rc);
}
}
sqlite3_free(azConfig);
sqlite3Fts5ConfigFree(pConfig);
sqlite3Fts5ExprFree(pExpr);
}
static void fts5ExprFunctionHr(
sqlite3_context *pCtx, /* Function call context */
int nArg, /* Number of args */
sqlite3_value **apVal /* Function arguments */
){
fts5ExprFunction(pCtx, nArg, apVal, 0);
}
static void fts5ExprFunctionTcl(
sqlite3_context *pCtx, /* Function call context */
int nArg, /* Number of args */
sqlite3_value **apVal /* Function arguments */
){
fts5ExprFunction(pCtx, nArg, apVal, 1);
}
/*
** This is called during initialization to register the fts5_expr() scalar
** UDF with the SQLite handle passed as the only argument.
*/
int sqlite3Fts5ExprInit(Fts5Global *pGlobal, sqlite3 *db){
struct Fts5ExprFunc {
const char *z;
void (*x)(sqlite3_context*,int,sqlite3_value**);
} aFunc[] = {
{ "fts5_expr", fts5ExprFunctionHr },
{ "fts5_expr_tcl", fts5ExprFunctionTcl },
};
int i;
int rc = SQLITE_OK;
void *pCtx = (void*)pGlobal;
for(i=0; rc==SQLITE_OK && i<(sizeof(aFunc) / sizeof(aFunc[0])); i++){
struct Fts5ExprFunc *p = &aFunc[i];
rc = sqlite3_create_function(db, p->z, -1, SQLITE_UTF8, pCtx, p->x, 0, 0);
}
return rc;
}
/*
** Return the number of phrases in expression pExpr.
*/
int sqlite3Fts5ExprPhraseCount(Fts5Expr *pExpr){
return pExpr->nPhrase;
}
/*
** Return the number of terms in the iPhrase'th phrase in pExpr.
*/
int sqlite3Fts5ExprPhraseSize(Fts5Expr *pExpr, int iPhrase){
if( iPhrase<0 || iPhrase>=pExpr->nPhrase ) return 0;
return pExpr->apExprPhrase[iPhrase]->nTerm;
}
/*
** This function is used to access the current position list for phrase
** iPhrase.
*/
int sqlite3Fts5ExprPoslist(Fts5Expr *pExpr, int iPhrase, const u8 **pa){
int nRet;
Fts5ExprPhrase *pPhrase = pExpr->apExprPhrase[iPhrase];
Fts5ExprNode *pNode = pPhrase->pNode;
if( pNode->bEof==0 && pNode->iRowid==pExpr->pRoot->iRowid ){
*pa = pPhrase->poslist.p;
nRet = pPhrase->poslist.n;
}else{
*pa = 0;
nRet = 0;
}
return nRet;
}
#endif /* SQLITE_ENABLE_FTS5 */
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