From: dan <dan@noemail.net>
Date: Tue, 7 Jul 2015 08:29:32 +0000 (+0000)
Subject: Further optimizations for fts5 b-tree seeks.
X-Git-Tag: version-3.8.11~53
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=b2fe306a2e7bce2f50182e5bb8fb52c4bad78b65;p=thirdparty%2Fsqlite.git

Further optimizations for fts5 b-tree seeks.

FossilOrigin-Name: f37899686c032145f431f81c1072738536c61c7e
---

diff --git a/ext/fts5/fts5_index.c b/ext/fts5/fts5_index.c
index 3ba3046e36..861d300c2b 100644
--- a/ext/fts5/fts5_index.c
+++ b/ext/fts5/fts5_index.c
@@ -2133,11 +2133,32 @@ static int fts5NodeSeek(
   return iPg;
 }
 
+#define fts5IndexGetVarint32(a, iOff, nVal) {     \
+  nVal = a[iOff++];                               \
+  if( nVal & 0x80 ){                              \
+    iOff--;                                       \
+    iOff += fts5GetVarint32(&a[iOff], nVal);      \
+  }                                               \
+}
+
+#define fts5IndexSkipVarint(a, iOff) {            \
+  int iEnd = iOff+9;                              \
+  while( (a[iOff++] & 0x80) && iOff<iEnd );       \
+}
+
 /*
 ** The iterator object passed as the second argument currently contains
 ** no valid values except for the Fts5SegIter.pLeaf member variable. This
 ** function searches the leaf page for a term matching (pTerm/nTerm).
 **
+** If the specified term is found on the page, then the iterator is left
+** pointing to it. If argument bGe is zero and the term is not found,
+** the iterator is left pointing at EOF.
+**
+** If bGe is non-zero and the specified term is not found, then the
+** iterator is left pointing to the smallest term in the segment that
+** is larger than the specified term, even if this term is not on the
+** current page.
 */
 static void fts5LeafSeek(
   Fts5Index *p,                   /* Leave any error code here */
@@ -2168,12 +2189,7 @@ static void fts5LeafSeek(
     i64 rowid;
 
     /* Figure out how many new bytes are in this term */
-
-    nNew = a[iOff++];
-    if( nNew & 0x80 ){ 
-      iOff--;
-      iOff += fts5GetVarint32(&a[iOff], nNew);
-    }
+    fts5IndexGetVarint32(a, iOff, nNew);
 
     if( nKeep<nMatch ){
       goto search_failed;
@@ -2200,25 +2216,26 @@ static void fts5LeafSeek(
     iOff += nNew;
 
     /* Skip past the doclist. If the end of the page is reached, bail out. */
-    iOff += fts5GetVarint(&a[iOff], &rowid);
-    while( iOff<n ){
+    while( 1 ){
       int nPos;
 
-      iOff += fts5GetVarint32(&a[iOff], nPos);
-      iOff += (nPos / 2);
-
       /* Skip past docid delta */
-      iOff += fts5GetVarint(&a[iOff], &rowid);
-      if( rowid==0 ) break;
+      fts5IndexSkipVarint(a, iOff);
+
+      /* Skip past position list */
+      fts5IndexGetVarint32(a, iOff, nPos);
+      iOff += (nPos >> 1);
+      if( iOff>=n ) goto search_failed;
+
+      /* If this is the end of the doclist, break out of the loop */
+      if( a[iOff]==0x00 ){
+        iOff++;
+        break;
+      }
     };
-    if( iOff>=n ) goto search_failed;
 
     /* Read the nKeep field of the next term. */
-    nKeep = a[iOff++];
-    if( nKeep & 0x80 ){
-      iOff--;
-      iOff += fts5GetVarint32(&a[iOff], nKeep);
-    }
+    fts5IndexGetVarint32(a, iOff, nKeep);
   }
 
  search_failed:
diff --git a/manifest b/manifest
index 6b86af9d85..d8e9e48dae 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Speed\sup\sseek\soperations\son\sfts5\sb-tree\sstructures.
-D 2015-07-06T20:27:19.997
+C Further\soptimizations\sfor\sfts5\sb-tree\sseeks.
+D 2015-07-07T08:29:32.749
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 017bf0511d1b2dd1db5e16488fbf75a17b526cbc
 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 d81cada8367eae5e5482860ccb6ae574eee3d74a
+F ext/fts5/fts5_index.c 19f6db2a43c0126267c7fa11e3ed41105eb89e2f
 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 6d2999afbc25b9c238e4028f637c10eaaf0ec75e
-R d5f5e61506b7123fb097865134e2b1bc
+P 7b7da1eb435d321fc4283f6aa2161fa1e16f2cf3
+R 24874c7422a967bb097e1a3642b88228
 U dan
-Z 4783766915d09d11d606d5d129590086
+Z f8ef7d272cb32b051f2a236ea6d3cc77
diff --git a/manifest.uuid b/manifest.uuid
index 94b18735e0..c950998394 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-7b7da1eb435d321fc4283f6aa2161fa1e16f2cf3
\ No newline at end of file
+f37899686c032145f431f81c1072738536c61c7e
\ No newline at end of file