Add code for the matchinfo 'longest common substring' feature.

FossilOrigin-Name: 71011a4f9baf09ec6935ad591145252bf3c286ed

ext/fts3/fts3_snippet.c

@@ -970,7 +970,123 @@ static int fts3MatchinfoSelectDoctotal(
   if( paLen ) *paLen = a;
   return SQLITE_OK;
 }
+
+typedef struct LcsIterator LcsIterator;
+struct LcsIterator {
+  Fts3Expr *pExpr;                /* Pointer to phrase expression */
+  char *pRead;                    /* Cursor used to iterate through aDoclist */
+  int iPosOffset;                 /* Tokens count up to end of this phrase */
+  int iCol;                       /* Current column number */
+  int iPos;                       /* Current position */
+};
+
+#define LCS_ITERATOR_FINISHED 0x7FFFFFFF;
+
+static int fts3MatchinfoLcsCb(
+  Fts3Expr *pExpr,                /* Phrase expression node */
+  int iPhrase,                    /* Phrase number (numbered from zero) */
+  void *pCtx                      /* Pointer to MatchInfo structure */
+){
+  LcsIterator *aIter = (LcsIterator *)pCtx;
+  aIter[iPhrase].pExpr = pExpr;
+  return SQLITE_OK;
+}
+
+static int fts3LcsIteratorAdvance(LcsIterator *pIter){
+  char *pRead = pIter->pRead;
+  sqlite3_int64 iRead;
+  int rc = 0;
+
+  pRead += sqlite3Fts3GetVarint(pRead, &iRead);
+  if( iRead==0 ){
+    pIter->iCol = LCS_ITERATOR_FINISHED;
+    rc = 1;
+  }else{
+    if( iRead==1 ){
+      pRead += sqlite3Fts3GetVarint(pRead, &iRead);
+      pIter->iCol = iRead;
+      pIter->iPos = pIter->iPosOffset;
+      pRead += sqlite3Fts3GetVarint(pRead, &iRead);
+      rc = 1;
+    }
+    pIter->iPos += (iRead-2);
+  }
+
+  pIter->pRead = pRead;
+  return rc;
+}
   
+static int fts3MatchinfoLcs(Fts3Cursor *pCsr, MatchInfo *pInfo){
+  LcsIterator *aIter;
+  int i;
+  int iCol;
+  int nToken = 0;
+
+  /* Allocate and populate the array of LcsIterator objects. The array
+  ** contains one element for each matchable phrase in the query.
+  **/
+  aIter = sqlite3_malloc(sizeof(LcsIterator) * pCsr->nPhrase);
+  if( !aIter ) return SQLITE_NOMEM;
+  memset(aIter, 0, sizeof(LcsIterator) * pCsr->nPhrase);
+  (void)fts3ExprIterate(pCsr->pExpr, fts3MatchinfoLcsCb, (void*)aIter);
+
+  for(i=0; i<pInfo->nPhrase; i++){
+    LcsIterator *pIter = &aIter[i];
+    nToken -= pIter->pExpr->pPhrase->nToken;
+    pIter->iPosOffset = nToken;
+    pIter->pRead = sqlite3Fts3FindPositions(pIter->pExpr, pCsr->iPrevId, -1);
+    if( pIter->pRead ){
+      pIter->iPos = pIter->iPosOffset;
+      fts3LcsIteratorAdvance(&aIter[i]);
+    }else{
+      pIter->iCol = LCS_ITERATOR_FINISHED;
+    }
+  }
+
+  for(iCol=0; iCol<pInfo->nCol; iCol++){
+    int nLcs = 0;
+    int nLive = 0;
+
+    for(i=0; i<pInfo->nPhrase; i++){
+      assert( aIter[i].iCol>=iCol );
+      if( aIter[i].iCol==iCol ) nLive++;
+    }
+
+    while( nLive>0 ){
+      LcsIterator *pAdv = 0;
+      int nThisLcs = 0;
+      char *aRead;
+      sqlite3_int64 iRead;
+
+      for(i=0; i<pInfo->nPhrase; i++){
+        LcsIterator *pIter = &aIter[i];
+        int nToken = pIter->pExpr->pPhrase->nToken;
+
+        if( iCol!=pIter->iCol ){  
+          nThisLcs = 0;
+          continue;
+        }
+
+        if( pAdv==0 || pIter->iPos<pAdv->iPos ){
+          pAdv = pIter;
+        }
+
+        if( nThisLcs==0 || pIter->iPos==pIter[-1].iPos ){
+          nThisLcs++;
+        }else{
+          nThisLcs = 1;
+        }
+
+        if( nThisLcs>nLcs ) nLcs = nThisLcs;
+      }
+      if( fts3LcsIteratorAdvance(pAdv) ) nLive--;
+    }
+
+    pInfo->aMatchinfo[iCol] = nLcs;
+  }
+
+  sqlite3_free(aIter);
+}
 
 static int fts3MatchinfoValues(
   Fts3Cursor *pCsr,               /* FTS3 cursor object */
@@ -1048,9 +1164,12 @@ static int fts3MatchinfoValues(
         break;
       }
 
+      case FTS3_MATCHINFO_LCS:
+        fts3MatchinfoLcs(pCsr, pInfo);
+        break;
 
-      default: 
+      default:
-        assert( zArg[i]==FTS3_MATCHINFO_LCS );
+        assert( !"this cannot happen" );
     }
 
     pInfo->aMatchinfo += fts3MatchinfoSize(pInfo, zArg[i]);

ext/fts3/fts3_write.c

@@ -328,6 +328,9 @@ int sqlite3Fts3SelectDocsize(
   return fts3SelectDocsize(pTab, SQL_SELECT_DOCSIZE, iDocid, ppStmt);
 }
 
+void sqlite3Fts3MatchinfoLcs(Fts3Expr *pExpr, u32 *aOut){
+}
+
 /*
 ** Similar to fts3SqlStmt(). Except, after binding the parameters in
 ** array apVal[] to the SQL statement identified by eStmt, the statement

manifest

@@ -1,5 +1,5 @@
-C Fix\scrashes\sthat\scan\soccur\swhen\squeries\sare\srun\son\san\sFTS4\stable\scontaining\szero\srows.
+C Add\scode\sfor\sthe\smatchinfo\s'longest\scommon\ssubstring'\sfeature.
-D 2010-11-24T15:02:23
+D 2010-11-24T19:26:19
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in e7a59672eaeb04408d1fa8501618d7501a3c5e39
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -69,11 +69,11 @@ F ext/fts3/fts3_hash.c 3c8f6387a4a7f5305588b203fa7c887d753e1f1c
 F ext/fts3/fts3_hash.h 8331fb2206c609f9fc4c4735b9ab5ad6137c88ec
 F ext/fts3/fts3_icu.c ac494aed69835008185299315403044664bda295
 F ext/fts3/fts3_porter.c 8df6f6efcc4e9e31f8bf73a4007c2e9abca1dfba
-F ext/fts3/fts3_snippet.c 967ca2d3201fd6555062c7e929bcc2b89ef8dcb8
+F ext/fts3/fts3_snippet.c be2648ff61a18af2d4a33eadbb26c0a6f06a6e26
 F ext/fts3/fts3_tokenizer.c 1301b0ee3ef414caae3257a702215925cc48cd9c
 F ext/fts3/fts3_tokenizer.h 13ffd9fcb397fec32a05ef5cd9e0fa659bf3dbd3
 F ext/fts3/fts3_tokenizer1.c 6e5cbaa588924ac578263a598e4fb9f5c9bb179d
-F ext/fts3/fts3_write.c 9b2db92b815fdd50b5531eb6db912c71feca6a70
+F ext/fts3/fts3_write.c b4e5b4c74f755a6f494dab9c131ad9bb04bab50c
 F ext/fts3/fts3speed.tcl b54caf6a18d38174f1a6e84219950d85e98bb1e9
 F ext/fts3/mkfts3amal.tcl 252ecb7fe6467854f2aa237bf2c390b74e71f100
 F ext/icu/README.txt bf8461d8cdc6b8f514c080e4e10dc3b2bbdfefa9
@@ -440,13 +440,13 @@ F test/fts3corrupt2.test 6d96efae2f8a6af3eeaf283aba437e6d0e5447ba
 F test/fts3cov.test e0fb00d8b715ddae4a94c305992dfc3ef70353d7
 F test/fts3d.test 95fb3c862cbc4297c93fceb9a635543744e9ef52
 F test/fts3defer.test d6cb0db9b5997ecf863d96ff419f83f8f2c87f4f
-F test/fts3defer2.test 548eb2ca7e6a1515a7bc151721e223be14c51f9d
+F test/fts3defer2.test da840efaedebfdd54293d04b36098e2d9872caa6
 F test/fts3e.test 1f6c6ac9cc8b772ca256e6b22aaeed50c9350851
 F test/fts3expr.test 5e745b2b6348499d9ef8d59015de3182072c564c
 F test/fts3expr2.test 18da930352e5693eaa163a3eacf96233b7290d1a
 F test/fts3fault.test 81fd40ceb12f33f9d16c5637d0f8d95d4556c456
 F test/fts3malloc.test 9c8cc3f885bb4dfc66d0460c52f68f45e4710d1b
-F test/fts3matchinfo.test 2dfdf80a927e3dc02f2e42337e5aa0b835994f6e
+F test/fts3matchinfo.test 41991bd810c6896a07c19a236ba3b489b16ba970
 F test/fts3near.test 2e318ee434d32babd27c167142e2b94ddbab4844
 F test/fts3query.test ef79d31fdb355d094baec1c1b24b60439a1fb8a2
 F test/fts3rnd.test 707533ce943f490443ce5e696236bb1675a37635
@@ -889,7 +889,7 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P ae40b34cf7c24c9601bdfb5cbe5b20f05a376ea8
+P ed61fd20adef44d0f6b2345e0205b25f3641a15e
-R bf9b07886b7dc4c93620c54d1a7703f7
+R c6aa2ef350d272455977bd9187b17fdc
 U dan
-Z c507e6c3579e8a599c5f904476d64b95
+Z a65c681ffac166b61fab0e3fae2a5af0

manifest.uuid

@@ -1 +1 @@
-ed61fd20adef44d0f6b2345e0205b25f3641a15e
+71011a4f9baf09ec6935ad591145252bf3c286ed

test/fts3defer2.test

@@ -91,6 +91,7 @@ foreach {tn sql} {
   }
 } {
   execsql $sql
+
   do_execsql_test 2.2.$tn {
     SELECT mit(matchinfo(t2, 'pcxnal')) FROM t2 WHERE t2 MATCH 'a b';
   } [list                                          \

test/fts3matchinfo.test

@@ -181,6 +181,7 @@ do_execsql_test 4.1.0 {
   INSERT INTO t4 VALUES('a b c d e', 'f g h i j');
   INSERT INTO t4 VALUES('f g h i j', 'a b c d e');
 }
+
 do_matchinfo_test 4.1.1 t4 {t4 MATCH 'a b c'} {
   p {3 3}
   c {2 2}
@@ -192,8 +193,12 @@ do_matchinfo_test 4.1.1 t4 {t4 MATCH 'a b c'} {
   l {{5 5} {5 5}}
   a {{5 5} {5 5}}
 
+  s {{3 0} {0 3}}
+
   xxxxxxxxxxxxxxxxxx - pcx - xpc - ccc - pppxpcpcx - laxnpc -
+  xpxsscplax -
 }
+
 do_matchinfo_test 4.1.2 t4 {t4 MATCH '"g h i"'} {
   p {1 1}
   c {2 2}
@@ -205,8 +210,53 @@ do_matchinfo_test 4.1.2 t4 {t4 MATCH '"g h i"'} {
   l {{5 5} {5 5}}
   a {{5 5} {5 5}}
 
+  s {{0 1} {1 0}}
+
   xxxxxxxxxxxxxxxxxx - pcx - xpc - ccc - pppxpcpcx - laxnpc -
+  sxsxs -
 }
 
+do_matchinfo_test 4.1.3 t4 {t4 MATCH 'a b'}     { s {{2 0} {0 2}} }
+do_matchinfo_test 4.1.4 t4 {t4 MATCH '"a b" c'} { s {{2 0} {0 2}} }
+do_matchinfo_test 4.1.5 t4 {t4 MATCH 'a "b c"'} { s {{2 0} {0 2}} }
+do_matchinfo_test 4.1.6 t4 {t4 MATCH 'd d'}     { s {{1 0} {0 1}} }
+
+do_execsql_test 4.2.0 {
+  CREATE VIRTUAL TABLE t5 USING fts4;
+  INSERT INTO t5 VALUES('a a a a a');
+  INSERT INTO t5 VALUES('a b a b a');
+  INSERT INTO t5 VALUES('c b c b c');
+}
+do_matchinfo_test 4.2.1 t5 {t5 MATCH 'a a'}         { s {2 1} }
+do_matchinfo_test 4.2.2 t5 {t5 MATCH 'a b'}         { s {2} }
+do_matchinfo_test 4.2.3 t5 {t5 MATCH 'a b a'}       { s {3} }
+do_matchinfo_test 4.2.4 t5 {t5 MATCH 'a a a'}       { s {3 1} }
+do_matchinfo_test 4.2.5 t5 {t5 MATCH '"a b" "a b"'} { s {2} }
+do_matchinfo_test 4.2.6 t5 {t5 MATCH 'a OR b'}      { s {1 2 1} }
+
+do_execsql_test 4.3.0 "INSERT INTO t5 VALUES('x y [string repeat {b } 50000]')";
+do_execsql_test 4.3.0 "INSERT INTO t5 VALUES('x y [string repeat {x } 50000]')";
+
+#do_matchinfo_test 4.3.1 t5 {t5 MATCH 'a a'}         { s {2 1} }
+#do_matchinfo_test 4.3.2 t5 {t5 MATCH 'a b'}         { s {2} }
+#do_matchinfo_test 4.3.3 t5 {t5 MATCH 'a b a'}       { s {3} }
+#do_matchinfo_test 4.3.4 t5 {t5 MATCH 'a a a'}       { s {3 1} }
+#do_matchinfo_test 4.3.5 t5 {t5 MATCH '"a b" "a b"'} { s {2} }
+#do_matchinfo_test 4.3.6 t5 {t5 MATCH 'a OR b'}      { s {1 2 1 1} }
+#
+#do_execsql_test 4.4.0 {
+#  UPDATE t5_segments 
+#  SET block = zeroblob(length(block)) 
+#  WHERE length(block)>10000;
+#}
+#
+#do_matchinfo_test 4.4.1 t5 {t5 MATCH 'a a'}         { s {2 1} }
+#do_matchinfo_test 4.4.2 t5 {t5 MATCH 'a b'}         { s {2} }
+#do_matchinfo_test 4.4.3 t5 {t5 MATCH 'a b a'}       { s {3} }
+#do_matchinfo_test 4.4.4 t5 {t5 MATCH 'a a a'}       { s {3 1} }
+#do_matchinfo_test 4.4.5 t5 {t5 MATCH '"a b" "a b"'} { s {2} }
+#do_matchinfo_test 4.4.6 t5 {t5 MATCH 'a OR b'}      { s {1 2 1 1} }
+
 
 finish_test
+