From d508e7f1a1b8a30bb552e38134ffc66cf29e9c31 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 13 Jan 2006 01:48:59 +0000
Subject: [PATCH] Add a high-speed version of sqlite3GetVarint32 to vdbe.c for
 a 3% performance gain. (CVS 2933)

FossilOrigin-Name: a64e8251a606fb2c298d7d804f3964a9155c73c5
---
 manifest      | 14 +++++++-------
 manifest.uuid |  2 +-
 src/vacuum.c  |  3 +--
 src/vdbe.c    | 22 +++++++++++++++++++---
 4 files changed, 28 insertions(+), 13 deletions(-)

diff --git a/manifest b/manifest
index 042a61da21..5447105378 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\stests\sto\smake\ssure\s"PRAGMA\stable_info"\sworks\susing\ssqlite3_prepare16.\nTicket\s#1606.\s(CVS\s2932)
-D 2006-01-13T01:25:06
+C Add\sa\shigh-speed\sversion\sof\ssqlite3GetVarint32\sto\svdbe.c\sfor\sa\s3%\sperformance\ngain.\s(CVS\s2933)
+D 2006-01-13T01:48:59
 F Makefile.in ab3ffd8d469cef4477257169b82810030a6bb967
 F Makefile.linux-gcc aee18d8a05546dcf1888bd4547e442008a49a092
 F README 9c4e2d6706bdcc3efdd773ce752a8cdab4f90028
@@ -86,8 +86,8 @@ F src/trigger.c 694b247476d2fc0dce003af564f79e8752fc1158
 F src/update.c 261d75c702c2852d1a64274d7c414485e6f2d177
 F src/utf.c b7bffac4260177ae7f83c01d025fe0f5ed70ce71
 F src/util.c 1d751152ab36d2756deec68e576366f58b73968f
-F src/vacuum.c cd56995ecea281b3ac306ef88128ebc8a2117f84
-F src/vdbe.c 59df15f96354ddd051212499e0cf4a3392c522c1
+F src/vacuum.c 21a3c7f6f7be86bb1182fbc3df416ad702435b9e
+F src/vdbe.c f77826242cea1789990bc8ee590a30827d514475
 F src/vdbe.h 8729a4ee16ff9aeab2af9667df3cf300ff978e13
 F src/vdbeInt.h 5451cf71f229e366ac543607c0a17f36e5737ea9
 F src/vdbeapi.c afd3837cea0dec93dcb4724d073c84fa0da68e23
@@ -340,7 +340,7 @@ F www/tclsqlite.tcl bb0d1357328a42b1993d78573e587c6dcbc964b9
 F www/vdbe.tcl 87a31ace769f20d3627a64fa1fade7fed47b90d0
 F www/version3.tcl a99cf5f6d8bd4d5537584a2b342f0fb9fa601d8b
 F www/whentouse.tcl 97e2b5cd296f7d8057e11f44427dea8a4c2db513
-P 94eac140f2363c7c3df68fa6f46728abfbfee1e6
-R ba7eec4e12c4f8d86b5257326d18ba78
+P ace8ba817766f9da270cd7f06b68cc537768a8be
+R 4f16d865eb1a68e0be85977f1ba457c6
 U drh
-Z d711b0916a7e82a2a363fa2441e78363
+Z a443a150c79d39fb2ce3f4a546cc3706
diff --git a/manifest.uuid b/manifest.uuid
index 5d4fc0f463..b71a0213e7 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-ace8ba817766f9da270cd7f06b68cc537768a8be
\ No newline at end of file
+a64e8251a606fb2c298d7d804f3964a9155c73c5
\ No newline at end of file
diff --git a/src/vacuum.c b/src/vacuum.c
index 891bc9fcc6..7584554171 100644
--- a/src/vacuum.c
+++ b/src/vacuum.c
@@ -14,7 +14,7 @@
 ** Most of the code in this file may be omitted by defining the
 ** SQLITE_OMIT_VACUUM macro.
 **
-** $Id: vacuum.c,v 1.56 2006/01/11 16:10:20 danielk1977 Exp $
+** $Id: vacuum.c,v 1.57 2006/01/13 01:48:59 drh Exp $
 */
 #include "sqliteInt.h"
 #include "vdbeInt.h"
@@ -101,7 +101,6 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   Btree *pMain;           /* The database being vacuumed */
   Btree *pTemp;
   char *zSql = 0;
-  int rc2;  
   int saved_flags;       /* Saved value of the db->flags */
   Db *pDb = 0;           /* Database to detach at end of vacuum */
 
diff --git a/src/vdbe.c b/src/vdbe.c
index 9962933ba3..2837871e63 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -43,7 +43,7 @@
 ** in this file for details.  If in doubt, do not deviate from existing
 ** commenting and indentation practices when changing or adding code.
 **
-** $Id: vdbe.c,v 1.525 2006/01/12 17:20:51 drh Exp $
+** $Id: vdbe.c,v 1.526 2006/01/13 01:48:59 drh Exp $
 */
 #include "sqliteInt.h"
 #include "os.h"
@@ -101,6 +101,22 @@ int sqlite3_sort_count = 0;
 */
 #define Dynamicify(P,enc) sqlite3VdbeMemDynamicify(P)
 
+/*
+** The header of a record consists of a sequence variable-length integers.
+** These integers are almost always small and are encoded as a single byte.
+** The following macro takes advantage this fact to provide a fast decode
+** of the integers in a record header.  It is faster for the common case
+** where the integer is a single byte.  It is a little slower when the
+** integer is two or more bytes.  But overall it is faster.
+**
+** The following expressions are equivalent:
+**
+**     x = sqlite3GetVarint32( A, &B );
+**
+**     x = GetVarint( A, B );
+**
+*/
+#define GetVarint(A,B)  ((B = *(A))<=0x7f ? 1 : sqlite3GetVarint32(A, &B))
 
 /*
 ** An ephemeral string value (signified by the MEM_Ephem flag) contains
@@ -1991,7 +2007,7 @@ case OP_Column: {
         pC->aRow = 0;
       }
     }
-    idx = sqlite3GetVarint32((u8*)zData, &szHdr);
+    idx = GetVarint((u8*)zData, szHdr);
 
 
     /* The KeyFetch() or DataFetch() above are fast and will get the entire
@@ -2018,7 +2034,7 @@ case OP_Column: {
     i = 0;
     while( idx<szHdr && i<nField && offset<=payloadSize ){
       aOffset[i] = offset;
-      idx += sqlite3GetVarint32((u8*)&zData[idx], &aType[i]);
+      idx += GetVarint((u8*)&zData[idx], aType[i]);
       offset += sqlite3VdbeSerialTypeLen(aType[i]);
       i++;
     }
-- 
2.39.5