Rework the Fts5MultiSegIter structure a bit to make it more efficient.

FossilOrigin-Name: 0778825d0ec9315c70659fae8d0640b209049dd8

ext/fts5/fts5_index.c

@@ -436,15 +436,6 @@ struct Fts5CResult {
   u8 bTermEq;                     /* True if the terms are equal */
 };
 
-struct Fts5MultiSegIter {
-  int nSeg;                       /* Size of aSeg[] array */
-  int bRev;                       /* True to iterate in reverse order */
-  int bSkipEmpty;                 /* True to skip deleted entries */
-  int bEof;                       /* True at EOF */
-  Fts5SegIter *aSeg;              /* Array of segment iterators */
-  Fts5CResult *aFirst;            /* Current merge state (see above) */
-};
-
 /*
 ** Object for iterating through a single segment, visiting each term/docid
 ** pair in the segment.
@@ -519,6 +510,16 @@ struct Fts5SegIter {
 #define FTS5_SEGITER_REVERSE 0x02
 
 
+struct Fts5MultiSegIter {
+  int nSeg;                       /* Size of aSeg[] array */
+  int bRev;                       /* True to iterate in reverse order */
+  int bSkipEmpty;                 /* True to skip deleted entries */
+  int bEof;                       /* True at EOF */
+  Fts5CResult *aFirst;            /* Current merge state (see above) */
+  Fts5SegIter aSeg[1];            /* Array of segment iterators */
+};
+
+
 /*
 ** Object for iterating through the conents of a single internal node in 
 ** memory.
@@ -2444,7 +2445,7 @@ static int fts5MultiIterAdvanceRowid(
   Fts5SegIter *pNew = &pIter->aSeg[iChanged];
   Fts5SegIter *pOther = &pIter->aSeg[iChanged ^ 0x0001];
 
-  for(i=(pIter->nSeg+iChanged)/2; p->rc==SQLITE_OK; i=i/2){
+  for(i=(pIter->nSeg+iChanged)/2; 1; i=i/2){
     Fts5CResult *pRes = &pIter->aFirst[i];
 
     assert( pNew->pLeaf );
@@ -2522,12 +2523,11 @@ static Fts5MultiSegIter *fts5MultiIterAlloc(
   for(nSlot=2; nSlot<nSeg; nSlot=nSlot*2);
   pNew = fts5IdxMalloc(p, 
       sizeof(Fts5MultiSegIter) +          /* pNew */
-      sizeof(Fts5SegIter) * nSlot +       /* pNew->aSeg[] */
+      sizeof(Fts5SegIter) * (nSlot-1) +   /* pNew->aSeg[] */
       sizeof(Fts5CResult) * nSlot         /* pNew->aFirst[] */
   );
   if( pNew ){
     pNew->nSeg = nSlot;
-    pNew->aSeg = (Fts5SegIter*)&pNew[1];
     pNew->aFirst = (Fts5CResult*)&pNew->aSeg[nSlot];
   }
   return pNew;

manifest

@@ -1,5 +1,5 @@
-C Speed\sup\seof\schecks\son\sfts5\scursors.
-D 2015-07-03T19:13:56.700
+C Rework\sthe\sFts5MultiSegIter\sstructure\sa\sbit\sto\smake\sit\smore\sefficient.
+D 2015-07-03T20:47:18.417
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 78db7e3b643002849258892ab2a9df10c24ee63d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -112,7 +112,7 @@ F ext/fts5/fts5_buffer.c 80f9ba4431848cb857e3d2158f5280093dcd8015
 F ext/fts5/fts5_config.c b2456e9625bca41c51d54c363e369c6356895c90
 F ext/fts5/fts5_expr.c d2e148345639c5a5583e0daa39a639bf298ae6a7
 F ext/fts5/fts5_hash.c 219f4edd72e5cf95b19c33f1058809a18fad5229
-F ext/fts5/fts5_index.c 84c8aa1c226898b781f2cbe90040a57ddc4a4259
+F ext/fts5/fts5_index.c 50f137bc97ae8c28ea555e156a01a155601cf0ff
 F ext/fts5/fts5_main.c 37b0055cb4036c4b4bb4eb36e30ebd1c21c63939
 F ext/fts5/fts5_storage.c 4cae85b5287b159d9d98174a4e70adf872b0930a
 F ext/fts5/fts5_tcl.c 85eb4e0d0fefa9420b78151496ad4599a1783e20
@@ -1364,7 +1364,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 48bd54594752d5be3337f12c72f28d2080cb630b
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 030f60a7ba171650ce8c0ac32dc166eab80aca32
-R 2a024a904d5b19f97eab1afbe90fa7a1
+P 3df4af5d8c28863783b0bc867abfbe31cc96f1b9
+R bd4f50649100a2ce39bd3db1b7c2671b
 U dan
-Z 8ac5a178ca95670b120c3cf4b40c3d86
+Z 0da0ca80bc4a2dfa97d128394464cd4d

manifest.uuid

@@ -1 +1 @@
-3df4af5d8c28863783b0bc867abfbe31cc96f1b9
+0778825d0ec9315c70659fae8d0640b209049dd8