/*
** 2015 Aug 04
**
** 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 file contains test code only, it is not included in release
** versions of FTS5. It contains the implementation of an FTS5 auxiliary
** function very similar to the FTS4 function matchinfo():
**
** https://www.sqlite.org/fts3.html#matchinfo
**
** Known differences are that:
**
** 1) this function uses the FTS5 definition of "matchable phrase", which
** excludes any phrases that are part of an expression sub-tree that
** does not match the current row. This comes up for MATCH queries
** such as:
**
** "a OR (b AND c)"
**
** In FTS4, if a single row contains instances of tokens "a" and "c",
** but not "b", all instances of "c" are considered matches. In FTS5,
** they are not (as the "b AND c" sub-tree does not match the current
** row.
**
** 2) For the values returned by 'x' that apply to all rows of the table,
** NEAR constraints are not considered. But for the number of hits in
** the current row, they are.
**
** This file exports a single function that may be called to register the
** matchinfo() implementation with a database handle:
**
** int sqlite3Fts5TestRegisterMatchinfo(sqlite3 *db);
*/
#ifdef SQLITE_TEST
#ifdef SQLITE_ENABLE_FTS5
#include "fts5.h"
#include <tcl.h>
#include <assert.h>
#include <string.h>
typedef struct Fts5MatchinfoCtx Fts5MatchinfoCtx;
typedef unsigned int u32;
struct Fts5MatchinfoCtx {
int nCol; /* Number of cols in FTS5 table */
int nPhrase; /* Number of phrases in FTS5 query */
char *zArg; /* nul-term'd copy of 2nd arg */
int nRet; /* Number of elements in aRet[] */
u32 *aRet; /* Array of 32-bit unsigned ints to return */
};
/*
** Return a pointer to the fts5_api pointer for database connection db.
** If an error occurs, return NULL and leave an error in the database
** handle (accessible using sqlite3_errcode()/errmsg()).
*/
static fts5_api *fts5_api_from_db(sqlite3 *db){
fts5_api *pRet = 0;
sqlite3_stmt *pStmt = 0;
if( SQLITE_OK==sqlite3_prepare(db, "SELECT fts5()", -1, &pStmt, 0)
&& SQLITE_ROW==sqlite3_step(pStmt)
&& sizeof(pRet)==sqlite3_column_bytes(pStmt, 0)
){
memcpy(&pRet, sqlite3_column_blob(pStmt, 0), sizeof(pRet));
}
sqlite3_finalize(pStmt);
return pRet;
}
/*
** Argument f should be a flag accepted by matchinfo() (a valid character
** in the string passed as the second argument). If it is not, -1 is
** returned. Otherwise, if f is a valid matchinfo flag, the value returned
** is the number of 32-bit integers added to the output array if the
** table has nCol columns and the query nPhrase phrases.
*/
static int fts5MatchinfoFlagsize(int nCol, int nPhrase, char f){
int ret = -1;
switch( f ){
case 'p': ret = 1; break;
case 'c': ret = 1; break;
case 'x': ret = 3 * nCol * nPhrase; break;
case 'y': ret = nCol * nPhrase; break;
case 'b': ret = ((nCol + 31) / 32) * nPhrase; break;
case 'n': ret = 1; break;
case 'a': ret = nCol; break;
case 'l': ret = nCol; break;
case 's': ret = nCol; break;
}
return ret;
}
static int fts5MatchinfoIter(
const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
Fts5Context *pFts, /* First arg to pass to pApi functions */
Fts5MatchinfoCtx *p,
int(*x)(const Fts5ExtensionApi*,Fts5Context*,Fts5MatchinfoCtx*,char,u32*)
){
int i;
int n = 0;
int rc = SQLITE_OK;
char f;
for(i=0; (f = p->zArg[i]); i++){
rc = x(pApi, pFts, p, f, &p->aRet[n]);
if( rc!=SQLITE_OK ) break;
n += fts5MatchinfoFlagsize(p->nCol, p->nPhrase, f);
}
return rc;
}
static int fts5MatchinfoXCb(
const Fts5ExtensionApi *pApi,
Fts5Context *pFts,
void *pUserData
){
Fts5PhraseIter iter;
int iCol, iOff;
u32 *aOut = (u32*)pUserData;
int iPrev = -1;
for(pApi->xPhraseFirst(pFts, 0, &iter, &iCol, &iOff);
iOff>=0;
pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
){
aOut[iCol*3+1]++;
if( iCol!=iPrev ) aOut[iCol*3 + 2]++;
iPrev = iCol;
}
return SQLITE_OK;
}
static int fts5MatchinfoGlobalCb(
const Fts5ExtensionApi *pApi,
Fts5Context *pFts,
Fts5MatchinfoCtx *p,
char f,
u32 *aOut
){
int rc = SQLITE_OK;
switch( f ){
case 'p':
aOut[0] = p->nPhrase;
break;
case 'c':
aOut[0] = p->nCol;
break;
case 'x': {
int i;
for(i=0; i<p->nPhrase && rc==SQLITE_OK; i++){
void *pPtr = (void*)&aOut[i * p->nCol * 3];
rc = pApi->xQueryPhrase(pFts, i, pPtr, fts5MatchinfoXCb);
}
break;
}
case 'n': {
sqlite3_int64 nRow;
rc = pApi->xRowCount(pFts, &nRow);
aOut[0] = (u32)nRow;
break;
}
case 'a': {
sqlite3_int64 nRow = 0;
rc = pApi->xRowCount(pFts, &nRow);
if( nRow==0 ){
memset(aOut, 0, sizeof(u32) * p->nCol);
}else{
int i;
for(i=0; rc==SQLITE_OK && i<p->nCol; i++){
sqlite3_int64 nToken;
rc = pApi->xColumnTotalSize(pFts, i, &nToken);
if( rc==SQLITE_OK){
aOut[i] = (u32)((2*nToken + nRow) / (2*nRow));
}
}
}
break;
}
}
return rc;
}
static int fts5MatchinfoLocalCb(
const Fts5ExtensionApi *pApi,
Fts5Context *pFts,
Fts5MatchinfoCtx *p,
char f,
u32 *aOut
){
int i;
int rc = SQLITE_OK;
switch( f ){
case 'b':
case 'x':
case 'y': {
int nMul = (f=='x' ? 3 : 1);
int iPhrase;
if( f=='b' ){
int nInt = ((p->nCol + 31) / 32) * p->nPhrase;
for(i=0; i<nInt; i++) aOut[i] = 0;
}else{
for(i=0; i<(p->nCol*p->nPhrase); i++) aOut[i*nMul] = 0;
}
for(iPhrase=0; iPhrase<p->nPhrase; iPhrase++){
Fts5PhraseIter iter;
int iOff, iCol;
for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
iOff>=0;
pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
){
if( f=='b' ){
aOut[iPhrase * ((p->nCol+31)/32) + iCol/32] |= ((u32)1 << iCol%32);
}else{
aOut[nMul * (iCol + iPhrase * p->nCol)]++;
}
}
}
break;
}
case 'l': {
for(i=0; rc==SQLITE_OK && i<p->nCol; i++){
int nToken;
rc = pApi->xColumnSize(pFts, i, &nToken);
aOut[i] = (u32)nToken;
}
break;
}
case 's': {
int nInst;
memset(aOut, 0, sizeof(u32) * p->nCol);
rc = pApi->xInstCount(pFts, &nInst);
for(i=0; rc==SQLITE_OK && i<nInst; i++){
int iPhrase, iOff, iCol = 0;
int iNextPhrase;
int iNextOff;
u32 nSeq = 1;
int j;
rc = pApi->xInst(pFts, i, &iPhrase, &iCol, &iOff);
iNextPhrase = iPhrase+1;
iNextOff = iOff+pApi->xPhraseSize(pFts, 0);
for(j=i+1; rc==SQLITE_OK && j<nInst; j++){
int ip, ic, io;
rc = pApi->xInst(pFts, j, &ip, &ic, &io);
if( ic!=iCol || io>iNextOff ) break;
if( ip==iNextPhrase && io==iNextOff ){
nSeq++;
iNextPhrase = ip+1;
iNextOff = io + pApi->xPhraseSize(pFts, ip);
}
}
if( nSeq>aOut[iCol] ) aOut[iCol] = nSeq;
}
break;
}
}
return rc;
}
static Fts5MatchinfoCtx *fts5MatchinfoNew(
const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
Fts5Context *pFts, /* First arg to pass to pApi functions */
sqlite3_context *pCtx, /* Context for returning error message */
const char *zArg /* Matchinfo flag string */
){
Fts5MatchinfoCtx *p;
int nCol;
int nPhrase;
int i;
int nInt;
int nByte;
int rc;
nCol = pApi->xColumnCount(pFts);
nPhrase = pApi->xPhraseCount(pFts);
nInt = 0;
for(i=0; zArg[i]; i++){
int n = fts5MatchinfoFlagsize(nCol, nPhrase, zArg[i]);
if( n<0 ){
char *zErr = sqlite3_mprintf("unrecognized matchinfo flag: %c", zArg[i]);
sqlite3_result_error(pCtx, zErr, -1);
sqlite3_free(zErr);
return 0;
}
nInt += n;
}
nByte = sizeof(Fts5MatchinfoCtx) /* The struct itself */
+ sizeof(u32) * nInt /* The p->aRet[] array */
+ (i+1); /* The p->zArg string */
p = (Fts5MatchinfoCtx*)sqlite3_malloc(nByte);
if( p==0 ){
sqlite3_result_error_nomem(pCtx);
return 0;
}
memset(p, 0, nByte);
p->nCol = nCol;
p->nPhrase = nPhrase;
p->aRet = (u32*)&p[1];
p->nRet = nInt;
p->zArg = (char*)&p->aRet[nInt];
memcpy(p->zArg, zArg, i);
rc = fts5MatchinfoIter(pApi, pFts, p, fts5MatchinfoGlobalCb);
if( rc!=SQLITE_OK ){
sqlite3_result_error_code(pCtx, rc);
sqlite3_free(p);
p = 0;
}
return p;
}
static void fts5MatchinfoFunc(
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 *zArg;
Fts5MatchinfoCtx *p;
int rc = SQLITE_OK;
if( nVal>0 ){
zArg = (const char*)sqlite3_value_text(apVal[0]);
}else{
zArg = "pcx";
}
p = (Fts5MatchinfoCtx*)pApi->xGetAuxdata(pFts, 0);
if( p==0 || sqlite3_stricmp(zArg, p->zArg) ){
p = fts5MatchinfoNew(pApi, pFts, pCtx, zArg);
if( p==0 ){
rc = SQLITE_NOMEM;
}else{
rc = pApi->xSetAuxdata(pFts, p, sqlite3_free);
}
}
if( rc==SQLITE_OK ){
rc = fts5MatchinfoIter(pApi, pFts, p, fts5MatchinfoLocalCb);
}
if( rc!=SQLITE_OK ){
sqlite3_result_error_code(pCtx, rc);
}else{
/* No errors has occured, so return a copy of the array of integers. */
int nByte = p->nRet * sizeof(u32);
sqlite3_result_blob(pCtx, (void*)p->aRet, nByte, SQLITE_TRANSIENT);
}
}
int sqlite3Fts5TestRegisterMatchinfo(sqlite3 *db){
int rc; /* Return code */
fts5_api *pApi; /* FTS5 API functions */
/* Extract the FTS5 API pointer from the database handle. The
** fts5_api_from_db() function above is copied verbatim from the
** FTS5 documentation. Refer there for details. */
pApi = fts5_api_from_db(db);
/* If fts5_api_from_db() returns NULL, then either FTS5 is not registered
** with this database handle, or an error (OOM perhaps?) has occurred.
**
** Also check that the fts5_api object is version 2 or newer.
*/
if( pApi==0 || pApi->iVersion<1 ){
return SQLITE_ERROR;
}
/* Register the implementation of matchinfo() */
rc = pApi->xCreateFunction(pApi, "matchinfo", 0, fts5MatchinfoFunc, 0);
return rc;
}
#endif /* SQLITE_ENABLE_FTS5 */
#endif /* SQLITE_TEST */