[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/ext/fts5/fts5_test_mi.c

+/*
+** 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_ENABLE_FTS5
+
+#include "fts5.h"
+#include <assert.h>
+#include <string.h>
+
+typedef struct Fts5MatchinfoCtx Fts5MatchinfoCtx;
+
+#ifndef SQLITE_AMALGAMATION
+typedef unsigned int u32;
+#endif
+
+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 int fts5_api_from_db(sqlite3 *db, fts5_api **ppApi){
+  sqlite3_stmt *pStmt = 0;
+  int rc;
+
+  *ppApi = 0;
+  rc = sqlite3_prepare(db, "SELECT fts5()", -1, &pStmt, 0);
+  if( rc==SQLITE_OK ){
+    if( SQLITE_ROW==sqlite3_step(pStmt) 
+        && sizeof(fts5_api*)==sqlite3_column_bytes(pStmt, 0)
+      ){
+      memcpy(ppApi, sqlite3_column_blob(pStmt, 0), sizeof(fts5_api*));
+    }
+    rc = sqlite3_finalize(pStmt);
+  }
+
+  return rc;
+}
+
+
+/*
+** 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); 
+      iCol>=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': {
+      int iPhrase;
+      int nInt = ((p->nCol + 31) / 32) * p->nPhrase;
+      for(i=0; i<nInt; i++) aOut[i] = 0;
+
+      for(iPhrase=0; iPhrase<p->nPhrase; iPhrase++){
+        Fts5PhraseIter iter;
+        int iCol;
+        for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
+            iCol>=0; 
+            pApi->xPhraseNextColumn(pFts, &iter, &iCol)
+        ){
+          aOut[iPhrase * ((p->nCol+31)/32) + iCol/32] |= ((u32)1 << iCol%32);
+        }
+      }
+
+      break;
+    }
+
+    case 'x':
+    case 'y': {
+      int nMul = (f=='x' ? 3 : 1);
+      int iPhrase;
+
+      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)
+        ){
+          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. */
+  rc = fts5_api_from_db(db, &pApi);
+  if( rc!=SQLITE_OK ) return rc;
+
+  /* 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<2 ){
+    return SQLITE_ERROR;
+  }
+
+  /* Register the implementation of matchinfo() */
+  rc = pApi->xCreateFunction(pApi, "matchinfo", 0, fts5MatchinfoFunc, 0);
+
+  return rc;
+}
+
+#endif /* SQLITE_ENABLE_FTS5 */
+