#include "fts5Int.h"
#include <math.h>
-/*************************************************************************
-** Start of highlight() implementation.
+/*
+** Object used to iterate through all "coalesced phrase instances" in
+** a single column of the current row. If the phrase instances in the
+** column being considered do not overlap, this object simply iterates
+** through them. Or, if they do overlap (share one or more tokens in
+** common), each set of overlapping instances is treated as a single
+** match. See documentation for the highlight() auxiliary function for
+** details.
+**
+** Usage is:
+**
+** for(rc = fts5CInstIterNext(pApi, pFts, iCol, &iter);
+** (rc==SQLITE_OK && 0==fts5CInstIterEof(&iter);
+** rc = fts5CInstIterNext(&iter)
+** ){
+** printf("instance starts at %d, ends at %d\n", iter.iStart, iter.iEnd);
+** }
+**
*/
-typedef struct HighlightContext HighlightContext;
-struct HighlightContext {
+typedef struct CInstIter CInstIter;
+struct CInstIter {
const Fts5ExtensionApi *pApi; /* API offered by current FTS version */
Fts5Context *pFts; /* First arg to pass to pApi functions */
+ int iCol; /* Column to search */
+ int iInst; /* Next phrase instance index */
int nInst; /* Total number of phrase instances */
- int iInst; /* Current phrase instance index */
- int iStart; /* First token of current phrase */
- int iEnd; /* Last token of current phrase */
+ /* Output variables */
+ int iStart; /* First token in coalesced phrase instance */
+ int iEnd; /* Last token in coalesced phrase instance */
+};
+
+/*
+** Return non-zero if the iterator is at EOF, or zero otherwise.
+*/
+static int fts5CInstIterEof(CInstIter *pIter){
+ return (pIter->iStart < 0);
+}
+
+/*
+** Advance the iterator to the next coalesced phrase instance. Return
+** an SQLite error code if an error occurs, or SQLITE_OK otherwise.
+*/
+static int fts5CInstIterNext(CInstIter *pIter){
+ int rc = SQLITE_OK;
+ pIter->iStart = -1;
+ pIter->iEnd = -1;
+
+ while( rc==SQLITE_OK && pIter->iInst<pIter->nInst ){
+ int ip; int ic; int io;
+ rc = pIter->pApi->xInst(pIter->pFts, pIter->iInst, &ip, &ic, &io);
+ if( rc==SQLITE_OK ){
+ if( ic==pIter->iCol ){
+ int iEnd = io - 1 + pIter->pApi->xPhraseSize(pIter->pFts, ip);
+ if( pIter->iStart<0 ){
+ pIter->iStart = io;
+ pIter->iEnd = iEnd;
+ }else if( io<=pIter->iEnd ){
+ if( iEnd>pIter->iEnd ) pIter->iEnd = iEnd;
+ }else{
+ break;
+ }
+ }
+ pIter->iInst++;
+ }
+ }
+
+ return rc;
+}
+
+/*
+** Initialize the iterator object indicated by the final parameter to
+** iterate through coalesced phrase instances in column iCol.
+*/
+static int fts5CInstIterInit(
+ const Fts5ExtensionApi *pApi,
+ Fts5Context *pFts,
+ int iCol,
+ CInstIter *pIter
+){
+ int rc;
+
+ memset(pIter, 0, sizeof(CInstIter));
+ pIter->pApi = pApi;
+ pIter->pFts = pFts;
+ pIter->iCol = iCol;
+ rc = pApi->xInstCount(pFts, &pIter->nInst);
+
+ if( rc==SQLITE_OK ){
+ rc = fts5CInstIterNext(pIter);
+ }
+
+ return rc;
+}
+
+
+
+/*************************************************************************
+** Start of highlight() implementation.
+*/
+typedef struct HighlightContext HighlightContext;
+struct HighlightContext {
+ CInstIter iter; /* Coalesced Instance Iterator */
+ int iRangeStart;
+ int iRangeEnd;
const char *zOpen; /* Opening highlight */
const char *zClose; /* Closing highlight */
- int iCol; /* Column to read from */
-
const char *zIn; /* Input text */
int nIn; /* Size of input text in bytes */
int iOff; /* Current offset within zIn[] */
** Append text to the HighlightContext output string - p->zOut. Argument
** z points to a buffer containing n bytes of text to append. If n is
** negative, everything up until the first '\0' is appended to the output.
+**
+** If *pRc is set to any value other than SQLITE_OK when this function is
+** called, it is a no-op. If an error (i.e. an OOM condition) is encountered,
+** *pRc is set to an error code before returning.
*/
static void fts5HighlightAppend(
int *pRc,
}
}
+/*
+** Tokenizer callback used by implementation of highlight() function.
+*/
static int fts5HighlightCb(
void *pContext, /* Pointer to HighlightContext object */
const char *pToken, /* Buffer containing token */
HighlightContext *p = (HighlightContext*)pContext;
int rc = SQLITE_OK;
- if( iPos==p->iStart ){
+ if( p->iRangeEnd>0 ){
+ if( iPos<p->iRangeStart || iPos>p->iRangeEnd ) return SQLITE_OK;
+ if( iPos==p->iRangeStart ) p->iOff = iStartOff;
+ }
+
+ if( iPos==p->iter.iStart ){
fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iStartOff - p->iOff);
fts5HighlightAppend(&rc, p, p->zOpen, -1);
p->iOff = iStartOff;
}
- if( iPos==p->iEnd ){
- int bClose = 1;
- for(p->iInst++; rc==SQLITE_OK && p->iInst<p->nInst; p->iInst++){
- int iP, iPCol, iOff;
- rc = p->pApi->xInst(p->pFts, p->iInst, &iP, &iPCol, &iOff);
- if( iPCol!=p->iCol ){
- p->iStart = p->iEnd = -1;
- }else{
- int iEnd = iOff - 1 + p->pApi->xPhraseSize(p->pFts, iP);
- if( iEnd<=p->iEnd ) continue;
- if( iOff<=p->iEnd ) bClose = 0;
- p->iStart = iOff;
- p->iEnd = iEnd;
- }
- break;
+ if( iPos==p->iter.iEnd ){
+ if( p->iRangeEnd && p->iter.iStart<p->iRangeStart ){
+ fts5HighlightAppend(&rc, p, p->zOpen, -1);
+ }
+ fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
+ fts5HighlightAppend(&rc, p, p->zClose, -1);
+ p->iOff = iEndOff;
+ if( rc==SQLITE_OK ){
+ rc = fts5CInstIterNext(&p->iter);
}
+ }
- if( bClose ){
- fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
+ if( p->iRangeEnd>0 && iPos==p->iRangeEnd ){
+ fts5HighlightAppend(&rc, p, &p->zIn[p->iOff], iEndOff - p->iOff);
+ p->iOff = iEndOff;
+ if( iPos<p->iter.iEnd ){
fts5HighlightAppend(&rc, p, p->zClose, -1);
- p->iOff = iEndOff;
}
}
return rc;
}
+/*
+** Implementation of highlight() function.
+*/
static void fts5HighlightFunction(
const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
Fts5Context *pFts, /* First arg to pass to pApi functions */
){
HighlightContext ctx;
int rc;
+ int iCol;
if( nVal!=3 ){
const char *zErr = "wrong number of arguments to function highlight()";
return;
}
+ iCol = sqlite3_value_int(apVal[0]);
memset(&ctx, 0, sizeof(HighlightContext));
- ctx.iCol = sqlite3_value_int(apVal[0]);
ctx.zOpen = (const char*)sqlite3_value_text(apVal[1]);
ctx.zClose = (const char*)sqlite3_value_text(apVal[2]);
- ctx.pApi = pApi;
- ctx.pFts = pFts;
- rc = pApi->xColumnText(pFts, ctx.iCol, &ctx.zIn, &ctx.nIn);
- if( rc==SQLITE_OK ) rc = pApi->xInstCount(pFts, &ctx.nInst);
-
- /* Find the first phrase instance in the right column. */
- ctx.iStart = -1;
- ctx.iEnd = -1;
- for( ; ctx.iInst<ctx.nInst && rc==SQLITE_OK; ctx.iInst++){
- int iP, iPCol, iOff;
- rc = pApi->xInst(pFts, ctx.iInst, &iP, &iPCol, &iOff);
- if( iPCol==ctx.iCol ){
- ctx.iStart = iOff;
- ctx.iEnd = iOff - 1 + pApi->xPhraseSize(pFts, iP);
- break;
- }
+ rc = pApi->xColumnText(pFts, iCol, &ctx.zIn, &ctx.nIn);
+
+ if( rc==SQLITE_OK ){
+ rc = fts5CInstIterInit(pApi, pFts, iCol, &ctx.iter);
}
if( rc==SQLITE_OK ){
/*
**************************************************************************/
-typedef struct SnipPhrase SnipPhrase;
-typedef struct SnipIter SnipIter;
-typedef struct SnippetCtx SnippetCtx;
-
-struct SnipPhrase {
- u64 mask; /* Current mask */
- int nToken; /* Tokens in this phrase */
- int i; /* Current offset in phrase poslist */
- i64 iPos; /* Next position in phrase (-ve -> EOF) */
-};
-
-struct SnipIter {
- i64 iLast; /* Last token position of current snippet */
- int nScore; /* Score of current snippet */
-
- const Fts5ExtensionApi *pApi;
- Fts5Context *pFts;
- u64 szmask; /* Mask used to on SnipPhrase.mask */
- int nPhrase; /* Number of phrases */
- SnipPhrase aPhrase[0]; /* Array of size nPhrase */
-};
-
-struct SnippetCtx {
- int iFirst; /* Offset of first token to record */
- int nToken; /* Size of aiStart[] and aiEnd[] arrays */
- int iSeen; /* Set to largest offset seen */
- int *aiStart;
- int *aiEnd;
-};
-
-static int fts5SnippetCallback(
- void *pContext, /* Pointer to Fts5Buffer 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 iPos /* Position offset of token */
-){
- int rc = SQLITE_OK;
- SnippetCtx *pCtx = (SnippetCtx*)pContext;
- int iOff = iPos - pCtx->iFirst;
-
- if( iOff>=0 ){
- if( iOff < pCtx->nToken ){
- pCtx->aiStart[iOff] = iStart;
- pCtx->aiEnd[iOff] = iEnd;
- }
- pCtx->iSeen = iPos;
- if( iOff>=pCtx->nToken ) rc = SQLITE_DONE;
- }
- return rc;
-}
-
-/*
-** Set pIter->nScore to the score for the current entry.
-*/
-static void fts5SnippetCalculateScore(SnipIter *pIter){
- int i;
- int nScore = 0;
- assert( pIter->iLast>=0 );
-
- for(i=0; i<pIter->nPhrase; i++){
- SnipPhrase *p = &pIter->aPhrase[i];
- u64 mask = p->mask;
- if( mask ){
- u64 j;
- nScore += 1000;
- for(j=1; j & pIter->szmask; j<<=1){
- if( mask & j ) nScore++;
- }
- }
- }
-
- pIter->nScore = nScore;
-}
-
-/*
-** Allocate a new snippet iter.
-*/
-static int fts5SnipIterNew(
+static void fts5SnippetFunction(
const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
Fts5Context *pFts, /* First arg to pass to pApi functions */
- int nToken, /* Number of tokens in snippets */
- SnipIter **ppIter /* OUT: New object */
+ sqlite3_context *pCtx, /* Context for returning result/error */
+ int nVal, /* Number of values in apVal[] array */
+ sqlite3_value **apVal /* Array of trailing arguments */
){
- int i; /* Counter variable */
- SnipIter *pIter; /* New iterator object */
- int nByte; /* Bytes of space to allocate */
+ HighlightContext ctx;
+ int rc = SQLITE_OK; /* Return code */
+ int iCol; /* 1st argument to snippet() */
+ const char *zEllips; /* 4th argument to snippet() */
+ int nToken; /* 5th argument to snippet() */
+ int nInst; /* Number of instance matches this row */
+ int i; /* Used to iterate through instances */
int nPhrase; /* Number of phrases in query */
-
- *ppIter = 0;
- nPhrase = pApi->xPhraseCount(pFts);
- nByte = sizeof(SnipIter) + nPhrase * sizeof(SnipPhrase);
- pIter = (SnipIter*)sqlite3_malloc(nByte);
- if( pIter==0 ) return SQLITE_NOMEM;
- memset(pIter, 0, nByte);
-
- pIter->nPhrase = nPhrase;
- pIter->pApi = pApi;
- pIter->pFts = pFts;
- pIter->szmask = ((u64)1 << nToken) - 1;
- assert( nToken<=63 );
-
- for(i=0; i<nPhrase; i++){
- pIter->aPhrase[i].nToken = pApi->xPhraseSize(pFts, i);
- }
-
- *ppIter = pIter;
- return SQLITE_OK;
-}
-
-/*
-** Set the iterator to point to the first candidate snippet.
-*/
-static void fts5SnipIterFirst(SnipIter *pIter){
- const Fts5ExtensionApi *pApi = pIter->pApi;
- Fts5Context *pFts = pIter->pFts;
- int i; /* Used to iterate through phrases */
- SnipPhrase *pMin = 0; /* Phrase with first match */
-
- memset(pIter->aPhrase, 0, sizeof(SnipPhrase) * pIter->nPhrase);
-
- for(i=0; i<pIter->nPhrase; i++){
- SnipPhrase *p = &pIter->aPhrase[i];
- p->nToken = pApi->xPhraseSize(pFts, i);
- pApi->xPoslist(pFts, i, &p->i, &p->iPos);
- if( p->iPos>=0 && (pMin==0 || p->iPos<pMin->iPos) ){
- pMin = p;
- }
+ unsigned char *aSeen; /* Array of "seen instance" flags */
+ int iBestCol; /* Column containing best snippet */
+ int iBestStart = 0; /* First token of best snippet */
+ int iBestLast = nToken; /* Last token of best snippet */
+ int nBestScore = 0; /* Score of best snippet */
+ int nColSize; /* Total size of iBestCol in tokens */
+
+ if( nVal!=5 ){
+ const char *zErr = "wrong number of arguments to function snippet()";
+ sqlite3_result_error(pCtx, zErr, -1);
+ return;
}
- assert( pMin );
- pIter->iLast = pMin->iPos + pMin->nToken - 1;
- pMin->mask = 0x01;
- pApi->xPoslist(pFts, pMin - pIter->aPhrase, &pMin->i, &pMin->iPos);
- fts5SnippetCalculateScore(pIter);
-}
+ memset(&ctx, 0, sizeof(HighlightContext));
+ rc = pApi->xColumnText(pFts, iCol, &ctx.zIn, &ctx.nIn);
-/*
-** Advance the snippet iterator to the next candidate snippet.
-*/
-static void fts5SnipIterNext(SnipIter *pIter){
- const Fts5ExtensionApi *pApi = pIter->pApi;
- Fts5Context *pFts = pIter->pFts;
- int nPhrase = pIter->nPhrase;
- int i; /* Used to iterate through phrases */
- SnipPhrase *pMin = 0;
+ iCol = sqlite3_value_int(apVal[0]);
+ ctx.zOpen = (const char*)sqlite3_value_text(apVal[1]);
+ ctx.zClose = (const char*)sqlite3_value_text(apVal[2]);
+ zEllips = (const char*)sqlite3_value_text(apVal[3]);
+ nToken = sqlite3_value_int(apVal[4]);
- for(i=0; i<nPhrase; i++){
- SnipPhrase *p = &pIter->aPhrase[i];
- if( p->iPos>=0 && (pMin==0 || p->iPos<pMin->iPos) ) pMin = p;
+ iBestCol = (iCol>=0 ? iCol : 0);
+ nPhrase = pApi->xPhraseCount(pFts);
+ aSeen = sqlite3_malloc(nPhrase);
+ if( aSeen==0 ){
+ rc = SQLITE_NOMEM;
}
- if( pMin==0 ){
- /* pMin==0 indicates that the SnipIter is at EOF. */
- pIter->iLast = -1;
- }else{
- i64 nShift = pMin->iPos - pIter->iLast;
- assert( nShift>=0 );
- for(i=0; i<nPhrase; i++){
- SnipPhrase *p = &pIter->aPhrase[i];
- if( nShift>=63 ){
- p->mask = 0;
- }else{
- p->mask = p->mask << (int)nShift;
- p->mask &= pIter->szmask;
+ if( rc==SQLITE_OK ){
+ rc = pApi->xInstCount(pFts, &nInst);
+ }
+ for(i=0; rc==SQLITE_OK && i<nInst; i++){
+ int ip, iSnippetCol, iStart;
+ memset(aSeen, 0, nPhrase);
+ rc = pApi->xInst(pFts, i, &ip, &iSnippetCol, &iStart);
+ if( rc==SQLITE_OK && (iCol<0 || iSnippetCol==iCol) ){
+ int nScore = 1000;
+ int iLast = iStart - 1 + pApi->xPhraseSize(pFts, ip);
+ int j;
+ aSeen[ip] = 1;
+
+ for(j=i+1; rc==SQLITE_OK && j<nInst; j++){
+ int ic; int io; int iFinal;
+ rc = pApi->xInst(pFts, j, &ip, &ic, &io);
+ iFinal = io + pApi->xPhraseSize(pFts, ip) - 1;
+ if( rc==SQLITE_OK && ic==iSnippetCol && iLast<iStart+nToken ){
+ nScore += aSeen[ip] ? 1000 : 1;
+ aSeen[ip] = 1;
+ if( iFinal>iLast ) iLast = iFinal;
+ }
}
- }
- pIter->iLast = pMin->iPos;
- pMin->mask |= 0x01;
- fts5SnippetCalculateScore(pIter);
- pApi->xPoslist(pFts, pMin - pIter->aPhrase, &pMin->i, &pMin->iPos);
+ if( rc==SQLITE_OK && nScore>nBestScore ){
+ iBestCol = iSnippetCol;
+ iBestStart = iStart;
+ iBestLast = iLast;
+ nBestScore = nScore;
+ }
+ }
}
-}
-static void fts5SnipIterFree(SnipIter *pIter){
- if( pIter ){
- sqlite3_free(pIter);
+ if( rc==SQLITE_OK ){
+ rc = pApi->xColumnSize(pFts, iBestCol, &nColSize);
}
-}
-
-static int fts5SnippetText(
- const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
- Fts5Context *pFts, /* First arg to pass to pApi functions */
- SnipIter *pIter, /* Snippet to write to buffer */
- int nToken, /* Size of desired snippet in tokens */
- const char *zStart,
- const char *zFinal,
- const char *zEllip,
- Fts5Buffer *pBuf /* Write output to this buffer */
-){
- SnippetCtx ctx;
- int i;
- u64 all = 0;
- const char *zCol; /* Column text to extract snippet from */
- int nCol; /* Size of column text in bytes */
- int rc;
- int nShift;
-
- rc = pApi->xColumnText(pFts, FTS5_POS2COLUMN(pIter->iLast), &zCol, &nCol);
- if( rc!=SQLITE_OK ) return rc;
-
- /* At this point pIter->iLast is the offset of the last token in the
- ** proposed snippet. However, in all cases pIter->iLast contains the
- ** final token of one of the phrases. This makes the snippet look
- ** unbalanced. For example:
- **
- ** "...x x x x x <b>term</b>..."
- **
- ** It is better to increase iLast a little so that the snippet looks
- ** more like:
- **
- ** "...x x x <b>term</b> y y..."
- **
- ** The problem is that there is no easy way to discover whether or not
- ** how many tokens are present in the column following "term".
- */
-
- /* Set variable nShift to the number of tokens by which the snippet
- ** should be shifted, assuming there are sufficient tokens to the right
- ** of iLast in the column value. */
- for(i=0; i<pIter->nPhrase; i++){
- int iToken;
- for(iToken=0; iToken<pIter->aPhrase[i].nToken; iToken++){
- all |= (pIter->aPhrase[i].mask << iToken);
- }
+ if( rc==SQLITE_OK ){
+ rc = pApi->xColumnText(pFts, iBestCol, &ctx.zIn, &ctx.nIn);
}
- for(i=nToken-1; i>=0; i--){
- if( all & ((u64)1 << i) ) break;
+ if( rc==SQLITE_OK ){
+ rc = fts5CInstIterInit(pApi, pFts, iBestCol, &ctx.iter);
}
- assert( i>=0 );
- nShift = (nToken - i) / 2;
- memset(&ctx, 0, sizeof(SnippetCtx));
- ctx.nToken = nToken + nShift;
- ctx.iFirst = FTS5_POS2OFFSET(pIter->iLast) - nToken + 1;
- if( ctx.iFirst<0 ){
- nShift += ctx.iFirst;
- if( nShift<0 ) nShift = 0;
- ctx.iFirst = 0;
+ if( (iBestStart+nToken-1)>iBestLast ){
+ iBestStart -= (iBestStart+nToken-1-iBestLast) / 2;
}
- ctx.aiStart = (int*)sqlite3_malloc(sizeof(int) * ctx.nToken * 2);
- if( ctx.aiStart==0 ) return SQLITE_NOMEM;
- ctx.aiEnd = &ctx.aiStart[ctx.nToken];
-
- rc = pApi->xTokenize(pFts, zCol, nCol, (void*)&ctx, fts5SnippetCallback);
- if( rc==SQLITE_OK ){
- int i1; /* First token from input to include */
- int i2; /* Last token from input to include */
-
- int iPrint;
- int iMatchto;
- int iLast;
-
- int *aiStart = ctx.aiStart - ctx.iFirst;
- int *aiEnd = ctx.aiEnd - ctx.iFirst;
-
- /* Ideally we want to start the snippet with token (ctx.iFirst + nShift).
- ** However, this is only possible if there are sufficient tokens within
- ** the column. This block sets variables i1 and i2 to the first and last
- ** input tokens to include in the snippet. */
- if( (ctx.iFirst + nShift + nToken)<=ctx.iSeen ){
- i1 = ctx.iFirst + nShift;
- i2 = i1 + nToken - 1;
- }else{
- i2 = ctx.iSeen;
- i1 = ctx.iSeen - nToken + 1;
- assert( i1>=0 || ctx.iFirst==0 );
- if( i1<0 ) i1 = 0;
- }
-
- /* If required, append the preceding ellipsis. */
- if( i1>0 ) sqlite3Fts5BufferAppendPrintf(&rc, pBuf, "%s", zEllip);
-
- iLast = FTS5_POS2OFFSET(pIter->iLast);
- iPrint = i1;
- iMatchto = -1;
-
- for(i=i1; i<=i2; i++){
-
- /* Check if this is the first token of any phrase match. */
- int ip;
- for(ip=0; ip<pIter->nPhrase; ip++){
- SnipPhrase *pPhrase = &pIter->aPhrase[ip];
- u64 m = (1 << (iLast - i - pPhrase->nToken + 1));
-
- if( i<=iLast && (pPhrase->mask & m) ){
- if( iMatchto<0 ){
- sqlite3Fts5BufferAppendPrintf(&rc, pBuf, "%.*s%s",
- aiStart[i] - aiStart[iPrint],
- &zCol[aiStart[iPrint]],
- zStart
- );
- iPrint = i;
- }
- if( i>iMatchto ) iMatchto = i + pPhrase->nToken - 1;
- }
- }
-
- if( i==iMatchto ){
- sqlite3Fts5BufferAppendPrintf(&rc, pBuf, "%.*s%s",
- aiEnd[i] - aiStart[iPrint],
- &zCol[aiStart[iPrint]],
- zFinal
- );
- iMatchto = -1;
- iPrint = i+1;
-
- if( i<i2 ){
- sqlite3Fts5BufferAppendPrintf(&rc, pBuf, "%.*s",
- aiStart[i+1] - aiEnd[i],
- &zCol[aiEnd[i]]
- );
- }
- }
- }
-
- if( iPrint<=i2 ){
- sqlite3Fts5BufferAppendPrintf(&rc, pBuf, "%.*s",
- aiEnd[i2] - aiStart[iPrint],
- &zCol[aiStart[iPrint]]
- );
- if( iMatchto>=0 ){
- sqlite3Fts5BufferAppendString(&rc, pBuf, zFinal);
- }
- }
-
- /* If required, append the trailing ellipsis. */
- if( i2<ctx.iSeen ) sqlite3Fts5BufferAppendString(&rc, pBuf, zEllip);
+ if( iBestStart+nToken>nColSize ){
+ iBestStart = nColSize - nToken;
}
+ if( iBestStart<0 ) iBestStart = 0;
- sqlite3_free(ctx.aiStart);
- return rc;
-}
-
-/*
-** A default snippet() implementation. This is compatible with the FTS3
-** snippet() function.
-*/
-static void fts5SnippetFunction(
- const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
- Fts5Context *pFts, /* First arg to pass to pApi functions */
- sqlite3_context *pCtx, /* Context for returning result/error */
- int nVal, /* Number of values in apVal[] array */
- sqlite3_value **apVal /* Array of trailing arguments */
-){
- const char *zStart = "<b>";
- const char *zFinal = "</b>";
- const char *zEllip = "<b>...</b>";
- int nToken = -15;
- int nAbs;
- int rc;
- SnipIter *pIter = 0;
+ ctx.iRangeStart = iBestStart;
+ ctx.iRangeEnd = iBestStart + nToken - 1;
- if( nVal>=1 ) zStart = (const char*)sqlite3_value_text(apVal[0]);
- if( nVal>=2 ) zFinal = (const char*)sqlite3_value_text(apVal[1]);
- if( nVal>=3 ) zEllip = (const char*)sqlite3_value_text(apVal[2]);
- if( nVal>=4 ){
- nToken = sqlite3_value_int(apVal[3]);
- if( nToken==0 ) nToken = -15;
+ if( iBestStart>0 ){
+ fts5HighlightAppend(&rc, &ctx, zEllips, -1);
}
- nAbs = nToken * (nToken<0 ? -1 : 1);
-
- rc = fts5SnipIterNew(pApi, pFts, nAbs, &pIter);
if( rc==SQLITE_OK ){
- Fts5Buffer buf; /* Result buffer */
- int nBestScore = 0; /* Score of best snippet found */
-
- for(fts5SnipIterFirst(pIter);
- pIter->iLast>=0;
- fts5SnipIterNext(pIter)
- ){
- if( pIter->nScore>nBestScore ) nBestScore = pIter->nScore;
- }
- for(fts5SnipIterFirst(pIter);
- pIter->iLast>=0;
- fts5SnipIterNext(pIter)
- ){
- if( pIter->nScore==nBestScore ) break;
- }
-
- memset(&buf, 0, sizeof(Fts5Buffer));
- rc = fts5SnippetText(pApi, pFts, pIter, nAbs, zStart, zFinal, zEllip, &buf);
- if( rc==SQLITE_OK ){
- sqlite3_result_text(pCtx, (const char*)buf.p, buf.n, SQLITE_TRANSIENT);
- }
- sqlite3_free(buf.p);
+ rc = pApi->xTokenize(pFts, ctx.zIn, ctx.nIn, (void*)&ctx, fts5HighlightCb);
+ }
+ if( ctx.iRangeEnd>=(nColSize-1) ){
+ fts5HighlightAppend(&rc, &ctx, &ctx.zIn[ctx.iOff], ctx.nIn - ctx.iOff);
+ }else{
+ fts5HighlightAppend(&rc, &ctx, zEllips, -1);
}
- fts5SnipIterFree(pIter);
- if( rc!=SQLITE_OK ){
+ if( rc==SQLITE_OK ){
+ sqlite3_result_text(pCtx, (const char*)ctx.zOut, -1, SQLITE_TRANSIENT);
+ }else{
sqlite3_result_error_code(pCtx, rc);
}
+ sqlite3_free(ctx.zOut);
+ sqlite3_free(aSeen);
}
+/************************************************************************/
+
/*
** Context object passed by fts5GatherTotals() to xQueryPhrase callback
projects / thirdparty / sqlite.git / commitdiff
