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Experimental changes to fts3 function matchinfo().

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FossilOrigin-Name: 9cf0f2b76bc68c168e3fa861b7235f384db21d38
This commit is contained in:
dan
2010-11-23 19:16:47 +00:00
parent 15eac4e48a
commit 1e66e40eb9
9 changed files with 361 additions and 84 deletions
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331
ext/fts3/fts3_snippet.c
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@ -17,6 +17,22 @@
#include <string.h>
#include <assert.h>
/*
** Characters that may appear in the second argument to matchinfo().
*/
#define FTS3_MATCHINFO_NPHRASE 'p' /* 1 value */
#define FTS3_MATCHINFO_NCOL 'c' /* 1 value */
#define FTS3_MATCHINFO_NDOC 'n' /* 1 value */
#define FTS3_MATCHINFO_AVGLENGTH 'a' /* nCol values */
#define FTS3_MATCHINFO_LENGTH 'l' /* nCol values */
#define FTS3_MATCHINFO_LCS 's' /* nCol values */
#define FTS3_MATCHINFO_HITS 'x' /* 3*nCol*nPhrase values */
/*
** The default value for the second argument to matchinfo().
*/
#define FTS3_MATCHINFO_DEFAULT "pcx"
/*
** Used as an fts3ExprIterate() context when loading phrase doclists to
@ -70,6 +86,8 @@ typedef struct MatchInfo MatchInfo;
struct MatchInfo {
Fts3Cursor *pCursor; /* FTS3 Cursor */
int nCol; /* Number of columns in table */
int nPhrase; /* Number of matchable phrases in query */
sqlite3_int64 nDoc; /* Number of docs in database */
u32 *aMatchinfo; /* Pre-allocated buffer */
};
@ -783,10 +801,26 @@ static void fts3LoadColumnlistCounts(char **pp, u32 *aOut, int isGlobal){
/*
** fts3ExprIterate() callback used to collect the "global" matchinfo stats
** for a single query. The "global" stats are those elements of the matchinfo
** array that are constant for all rows returned by the current query.
** for a single query.
**
** fts3ExprIterate() callback to load the 'global' elements of a
** FTS3_MATCHINFO_HITS matchinfo array. The global stats are those elements
** of the matchinfo array that are constant for all rows returned by the
** current query.
**
** Argument pCtx is actually a pointer to a struct of type MatchInfo. This
** function populates Matchinfo.aMatchinfo[] as follows:
**
** for(iCol=0; iCol<nCol; iCol++){
** aMatchinfo[3*iPhrase*nCol + 3*iCol + 1] = X;
** aMatchinfo[3*iPhrase*nCol + 3*iCol + 2] = Y;
** }
**
** where X is the number of matches for phrase iPhrase is column iCol of all
** rows of the table. Y is the number of rows for which column iCol contains
** at least one instance of phrase iPhrase.
*/
static int fts3ExprGlobalMatchinfoCb(
static int fts3ExprGlobalHitsCb(
Fts3Expr *pExpr, /* Phrase expression node */
int iPhrase, /* Phrase number (numbered from zero) */
void *pCtx /* Pointer to MatchInfo structure */
@ -796,7 +830,7 @@ static int fts3ExprGlobalMatchinfoCb(
char *pIter;
char *pEnd;
char *pFree = 0;
const int iStart = 2 + (iPhrase * p->nCol * 3) + 1;
u32 *aOut = &p->aMatchinfo[3*iPhrase*p->nCol];
assert( pExpr->isLoaded );
assert( pExpr->eType==FTSQUERY_PHRASE );
@ -814,10 +848,10 @@ static int fts3ExprGlobalMatchinfoCb(
pIter = pFree;
pEnd = &pFree[nFree];
}else{
int nDoc = p->aMatchinfo[2 + 3*p->nCol*p->aMatchinfo[0]];
for(ii=0; ii<p->nCol; ii++){
p->aMatchinfo[iStart + ii*3] = nDoc;
p->aMatchinfo[iStart + ii*3 + 1] = nDoc;
int iCol; /* Column index */
for(iCol=0; iCol<p->nCol; iCol++){
aOut[iCol*3 + 1] = (u32)p->nDoc;
aOut[iCol*3 + 2] = (u32)p->nDoc;
}
return SQLITE_OK;
}
@ -829,7 +863,7 @@ static int fts3ExprGlobalMatchinfoCb(
/* Fill in the global hit count matrix row for this phrase. */
while( pIter<pEnd ){
while( *pIter++ & 0x80 ); /* Skip past docid. */
fts3LoadColumnlistCounts(&pIter, &p->aMatchinfo[iStart], 1);
fts3LoadColumnlistCounts(&pIter, &aOut[1], 1);
}
sqlite3_free(pFree);
@ -837,11 +871,11 @@ static int fts3ExprGlobalMatchinfoCb(
}
/*
** fts3ExprIterate() callback used to collect the "local" matchinfo stats
** for a single query. The "local" stats are those elements of the matchinfo
** fts3ExprIterate() callback used to collect the "local" part of the
** FTS3_MATCHINFO_HITS array. The local stats are those elements of the
** array that are different for each row returned by the query.
*/
static int fts3ExprLocalMatchinfoCb(
static int fts3ExprLocalHitsCb(
Fts3Expr *pExpr, /* Phrase expression node */
int iPhrase, /* Phrase number */
void *pCtx /* Pointer to MatchInfo structure */
@ -850,7 +884,7 @@ static int fts3ExprLocalMatchinfoCb(
if( pExpr->aDoclist ){
char *pCsr;
int iStart = 2 + (iPhrase * p->nCol * 3);
int iStart = iPhrase * p->nCol * 3;
int i;
for(i=0; i<p->nCol; i++) p->aMatchinfo[iStart+i*3] = 0;
@ -864,66 +898,230 @@ static int fts3ExprLocalMatchinfoCb(
return SQLITE_OK;
}
static int fts3MatchinfoCheck(
Fts3Table *pTab,
char cArg,
char **pzErr
){
if( cArg==FTS3_MATCHINFO_NPHRASE
|| cArg==FTS3_MATCHINFO_NCOL
|| cArg==FTS3_MATCHINFO_NDOC && pTab->bHasStat
|| cArg==FTS3_MATCHINFO_AVGLENGTH && pTab->bHasStat
|| cArg==FTS3_MATCHINFO_LENGTH && pTab->bHasDocsize
|| cArg==FTS3_MATCHINFO_LCS
|| cArg==FTS3_MATCHINFO_HITS
){
return SQLITE_OK;
}
*pzErr = sqlite3_mprintf("unrecognized matchinfo request: %c", cArg);
return SQLITE_ERROR;
}
static int fts3MatchinfoSize(MatchInfo *pInfo, char cArg){
int nVal; /* Number of integers output by cArg */
switch( cArg ){
case FTS3_MATCHINFO_NDOC:
case FTS3_MATCHINFO_NPHRASE:
case FTS3_MATCHINFO_NCOL:
nVal = 1;
break;
case FTS3_MATCHINFO_AVGLENGTH:
case FTS3_MATCHINFO_LENGTH:
case FTS3_MATCHINFO_LCS:
nVal = pInfo->nCol;
break;
case FTS3_MATCHINFO_HITS:
nVal = pInfo->nCol * pInfo->nPhrase * 3;
break;
}
return nVal;
}
static int fts3MatchinfoSelectDoctotal(
Fts3Table *pTab,
sqlite3_stmt **ppStmt,
sqlite3_int64 *pnDoc,
const char **paLen
){
sqlite3_stmt *pStmt;
const char *a;
sqlite3_int64 nDoc;
if( !*ppStmt ){
int rc = sqlite3Fts3SelectDoctotal(pTab, ppStmt);
if( rc!=SQLITE_OK ) return rc;
}
pStmt = *ppStmt;
a = sqlite3_column_blob(pStmt, 0);
a += sqlite3Fts3GetVarint(a, &nDoc);
*pnDoc = (u32)nDoc;
if( paLen ) *paLen = a;
return SQLITE_OK;
}
static int fts3MatchinfoValues(
Fts3Cursor *pCsr, /* FTS3 cursor object */
int bGlobal, /* True to grab the global stats */
MatchInfo *pInfo, /* Matchinfo context object */
const char *zArg /* Matchinfo format string */
){
int rc = SQLITE_OK;
int i;
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
sqlite3_stmt *pSelect = 0;
for(i=0; zArg[i]; i++){
switch( zArg[i] ){
case FTS3_MATCHINFO_NPHRASE:
if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nPhrase;
break;
case FTS3_MATCHINFO_NCOL:
if( bGlobal ) pInfo->aMatchinfo[0] = pInfo->nCol;
break;
case FTS3_MATCHINFO_NDOC:
if( bGlobal ){
sqlite3_int64 nDoc;
rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, 0);
pInfo->aMatchinfo[0] = (u32)nDoc;
}
break;
case FTS3_MATCHINFO_AVGLENGTH:
if( bGlobal ){
sqlite3_int64 nDoc; /* Number of rows in table */
const char *a; /* Aggregate column length array */
rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &nDoc, &a);
if( rc==SQLITE_OK ){
int iCol;
for(iCol=0; iCol<pInfo->nCol; iCol++){
sqlite3_int64 nToken;
a += sqlite3Fts3GetVarint(a, &nToken);
pInfo->aMatchinfo[iCol] = ((u32)(nToken&0xffffffff)+nDoc/2)/nDoc;
}
}
}
break;
case FTS3_MATCHINFO_LENGTH: {
sqlite3_stmt *pSelectDocsize = 0;
rc = sqlite3Fts3SelectDocsize(pTab, pCsr->iPrevId, &pSelectDocsize);
if( rc==SQLITE_OK ){
int iCol;
const char *a = sqlite3_column_blob(pSelectDocsize, 0);
for(iCol=0; iCol<pInfo->nCol; iCol++){
sqlite3_int64 nToken;
a += sqlite3Fts3GetVarint(a, &nToken);
pInfo->aMatchinfo[iCol] = (u32)nToken;
}
}
sqlite3_reset(pSelectDocsize);
break;
}
case FTS3_MATCHINFO_HITS: {
Fts3Expr *pExpr = pCsr->pExpr;
if( bGlobal ){
if( pCsr->pDeferred ){
rc = fts3MatchinfoSelectDoctotal(pTab, &pSelect, &pInfo->nDoc, 0);
}
(void)fts3ExprIterate(pExpr, fts3ExprGlobalHitsCb,(void*)pInfo);
}
(void)fts3ExprIterate(pExpr, fts3ExprLocalHitsCb,(void*)pInfo);
break;
}
default:
assert( zArg[i]==FTS3_MATCHINFO_LCS );
}
pInfo->aMatchinfo += fts3MatchinfoSize(pInfo, zArg[i]);
}
sqlite3_reset(pSelect);
return rc;
}
/*
** Populate pCsr->aMatchinfo[] with data for the current row. The
** 'matchinfo' data is an array of 32-bit unsigned integers (C type u32).
*/
static int fts3GetMatchinfo(Fts3Cursor *pCsr){
static int fts3GetMatchinfo(
Fts3Cursor *pCsr, /* FTS3 Cursor object */
const char *zArg /* Second argument to matchinfo() function */
){
MatchInfo sInfo;
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
int rc = SQLITE_OK;
int bGlobal = 0; /* Collect 'global' stats as well as local */
memset(&sInfo, 0, sizeof(MatchInfo));
sInfo.pCursor = pCsr;
sInfo.nCol = pTab->nColumn;
/* If there is cached matchinfo() data, but the format string for the
** cache does not match the format string for this request, discard
** the cached data. */
if( pCsr->zMatchinfo && strcmp(pCsr->zMatchinfo, zArg) ){
assert( pCsr->aMatchinfo );
sqlite3_free(pCsr->aMatchinfo);
pCsr->zMatchinfo = 0;
pCsr->aMatchinfo = 0;
}
/* If Fts3Cursor.aMatchinfo[] is NULL, then this is the first time the
** matchinfo function has been called for this query. In this case
** allocate the array used to accumulate the matchinfo data and
** initialize those elements that are constant for every row.
*/
if( pCsr->aMatchinfo==0 ){
/* If Fts3Cursor.aMatchinfo[] is NULL, then this is the first time the
** matchinfo function has been called for this query. In this case
** allocate the array used to accumulate the matchinfo data and
** initialize those elements that are constant for every row.
*/
int nPhrase; /* Number of phrases */
int nMatchinfo; /* Number of u32 elements in match-info */
int nMatchinfo = 0; /* Number of u32 elements in match-info */
int nArg; /* Bytes in zArg */
int i; /* Used to iterate through zArg */
/* Load doclists for each phrase in the query. */
rc = fts3ExprLoadDoclists(pCsr, &nPhrase, 0);
if( rc!=SQLITE_OK ){
return rc;
}
nMatchinfo = 2 + 3*sInfo.nCol*nPhrase;
if( pTab->bHasDocsize ){
nMatchinfo += 1 + 2*pTab->nColumn;
rc = fts3ExprLoadDoclists(pCsr, &pCsr->nPhrase, 0);
if( rc!=SQLITE_OK ) return rc;
sInfo.nPhrase = pCsr->nPhrase;
for(i=0; zArg[i]; i++){
nMatchinfo += fts3MatchinfoSize(&sInfo, zArg[i]);
}
sInfo.aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo);
if( !sInfo.aMatchinfo ){
return SQLITE_NOMEM;
}
memset(sInfo.aMatchinfo, 0, sizeof(u32)*nMatchinfo);
/* Allocate space for Fts3Cursor.aMatchinfo[] and Fts3Cursor.zMatchinfo. */
nArg = strlen(zArg);
pCsr->aMatchinfo = (u32 *)sqlite3_malloc(sizeof(u32)*nMatchinfo + nArg + 1);
if( !pCsr->aMatchinfo ) return SQLITE_NOMEM;
/* First element of match-info is the number of phrases in the query */
sInfo.aMatchinfo[0] = nPhrase;
sInfo.aMatchinfo[1] = sInfo.nCol;
if( pTab->bHasDocsize ){
int ofst = 2 + 3*sInfo.aMatchinfo[0]*sInfo.aMatchinfo[1];
rc = sqlite3Fts3MatchinfoDocsizeGlobal(pCsr, &sInfo.aMatchinfo[ofst]);
}
(void)fts3ExprIterate(pCsr->pExpr, fts3ExprGlobalMatchinfoCb,(void*)&sInfo);
pCsr->aMatchinfo = sInfo.aMatchinfo;
pCsr->zMatchinfo = (char *)&pCsr->aMatchinfo[nMatchinfo];
pCsr->nMatchinfo = nMatchinfo;
memcpy(pCsr->zMatchinfo, zArg, nArg+1);
memset(pCsr->aMatchinfo, 0, sizeof(u32)*nMatchinfo);
pCsr->isMatchinfoNeeded = 1;
bGlobal = 1;
}
sInfo.aMatchinfo = pCsr->aMatchinfo;
sInfo.nPhrase = pCsr->nPhrase;
if( rc==SQLITE_OK && pCsr->isMatchinfoNeeded ){
(void)fts3ExprIterate(pCsr->pExpr, fts3ExprLocalMatchinfoCb, (void*)&sInfo);
if( pTab->bHasDocsize ){
int ofst = 2 + 3*sInfo.aMatchinfo[0]*sInfo.aMatchinfo[1];
rc = sqlite3Fts3MatchinfoDocsizeLocal(pCsr, &sInfo.aMatchinfo[ofst]);
}
rc = fts3MatchinfoValues(pCsr, bGlobal, &sInfo, zArg);
pCsr->isMatchinfoNeeded = 0;
}
return SQLITE_OK;
return rc;
}
/*
@ -1211,22 +1409,43 @@ void sqlite3Fts3Offsets(
/*
** Implementation of matchinfo() function.
*/
void sqlite3Fts3Matchinfo(sqlite3_context *pContext, Fts3Cursor *pCsr){
void sqlite3Fts3Matchinfo(
sqlite3_context *pContext, /* Function call context */
Fts3Cursor *pCsr, /* FTS3 table cursor */
const char *zArg /* Second arg to matchinfo() function */
){
Fts3Table *pTab = (Fts3Table *)pCsr->base.pVtab;
int rc;
int i;
const char *zFormat;
if( zArg ){
for(i=0; zArg[i]; i++){
char *zErr = 0;
if( fts3MatchinfoCheck(pTab, zArg[i], &zErr) ){
sqlite3_result_error(pContext, zErr, -1);
sqlite3_free(zErr);
return;
}
}
zFormat = zArg;
}else{
zFormat = FTS3_MATCHINFO_DEFAULT;
}
if( !pCsr->pExpr ){
sqlite3_result_blob(pContext, "", 0, SQLITE_STATIC);
return;
}
rc = fts3GetMatchinfo(pCsr);
sqlite3Fts3SegmentsClose((Fts3Table *)pCsr->base.pVtab );
/* Retrieve matchinfo() data. */
rc = fts3GetMatchinfo(pCsr, zFormat);
sqlite3Fts3SegmentsClose(pTab);
if( rc!=SQLITE_OK ){
sqlite3_result_error_code(pContext, rc);
}else{
Fts3Table *pTab = (Fts3Table*)pCsr->base.pVtab;
int n = sizeof(u32)*(2+pCsr->aMatchinfo[0]*pCsr->aMatchinfo[1]*3);
if( pTab->bHasDocsize ){
n += sizeof(u32)*(1 + 2*pTab->nColumn);
}
int n = pCsr->nMatchinfo * sizeof(u32);
sqlite3_result_blob(pContext, pCsr->aMatchinfo, n, SQLITE_TRANSIENT);
}
}