From: drh <drh@noemail.net>
Date: Fri, 22 Aug 2014 18:48:25 +0000 (+0000)
Subject: Performance enhancement in sqlite3PutVarint().
X-Git-Tag: version-3.8.7~170
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2f2b2b85800866c9cebde588d09706feed6462eb;p=thirdparty%2Fsqlite.git

Performance enhancement in sqlite3PutVarint().

FossilOrigin-Name: a929be551924144c9bc7aab608404d59e479abb5
---

diff --git a/manifest b/manifest
index 2ec516f887..4718b15953 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Split\sthe\ssqlite3Error()\sroutine\sinto\ssqlite3Error()\sand\nsqlite3ErrorWithMsg(),\sfor\sa\sslight\ssize\sreduction\sand\sperformance\sincrease.
-D 2014-08-22T18:00:11.621
+C Performance\senhancement\sin\ssqlite3PutVarint().
+D 2014-08-22T18:48:25.634
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5eb79e334a5de69c87740edd56af6527dd219308
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -228,7 +228,7 @@ F src/shell.c 728d2226594d356bf4fbdbdfd08538fd78fd06f3
 F src/sqlite.h.in ed9d35990c61f0388ca6405706455c4095310553
 F src/sqlite3.rc 992c9f5fb8285ae285d6be28240a7e8d3a7f2bad
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
-F src/sqliteInt.h 937869c407c61026443c879e8c90a9dff05d2d27
+F src/sqliteInt.h d8a9be2aa123a78c90ad4aba09b23e7dd3f8cc9f
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac05a5c7017d0b9f0b4bcd701228b784f987158
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -282,7 +282,7 @@ F src/tokenize.c ae45399d6252b4d736af43bee1576ce7bff86aec
 F src/trigger.c 4bddd12803275aa98f1c7ce0118fceb02b2167f6
 F src/update.c ea336ce7b8b3fc5e316ba8f082e6445babf81059
 F src/utf.c a0314e637768a030e6e84a957d0c4f6ba910cc05
-F src/util.c 524127b3c330b9f490a505ff6eb7f80dfc873a3a
+F src/util.c 068dcd26354a3898ccc64ad5c4bdb95a7a15d33a
 F src/vacuum.c 3728d74919d4fb1356f9e9a13e27773db60b7179
 F src/vdbe.c f7f4066e4d6e3858878d76ce9288ea603e12ddf6
 F src/vdbe.h c63fad052c9e7388d551e556e119c0bcf6bebdf8
@@ -290,7 +290,7 @@ F src/vdbeInt.h f5513f2b5ac1e2c5128996c7ea23add256a301df
 F src/vdbeapi.c 49b8d2943d02d276b4efef114578251a3277f47d
 F src/vdbeaux.c f7fdc59e2eefa6fc4ba7324b03ea6f8f66e98d62
 F src/vdbeblob.c 848238dc73e93e48432991bb5651bf87d865eca4
-F src/vdbemem.c d90a1e8acf8b63dc9d14cbbea12bfec6cec31394
+F src/vdbemem.c 4a64659ed8e4c3b18a9238e038145ab1bdcd146f
 F src/vdbesort.c f7f5563bf7d4695ca8f3203f3bf9de96d04ed0b3
 F src/vdbetrace.c 6f52bc0c51e144b7efdcfb2a8f771167a8816767
 F src/vtab.c 019dbfd0406a7447c990e1f7bd1dfcdb8895697f
@@ -1188,7 +1188,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P f7f2160db014f0ae11ad13c8ad70ad3444124e3e
-R 668369bbbf2d81407f36345226c5d2a9
+P cf561d1f0bb60b3d638632d20bd686dda4fa4a04
+R 892fbe852e37f91de1b9f5afa35c0502
 U drh
-Z bddb035a8072a327798c78fbe23bcf26
+Z c70614e9322ab39ef4e9fbe07eb13b05
diff --git a/manifest.uuid b/manifest.uuid
index 5842d66545..12c08a2c09 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-cf561d1f0bb60b3d638632d20bd686dda4fa4a04
\ No newline at end of file
+a929be551924144c9bc7aab608404d59e479abb5
\ No newline at end of file
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 65dd7a9279..a534c5cebc 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -3307,38 +3307,23 @@ u64 sqlite3LogEstToInt(LogEst);
 /*
 ** Routines to read and write variable-length integers.  These used to
 ** be defined locally, but now we use the varint routines in the util.c
-** file.  Code should use the MACRO forms below, as the Varint32 versions
-** are coded to assume the single byte case is already handled (which 
-** the MACRO form does).
+** file.
 */
 int sqlite3PutVarint(unsigned char*, u64);
-int sqlite3PutVarint32(unsigned char*, u32);
 u8 sqlite3GetVarint(const unsigned char *, u64 *);
 u8 sqlite3GetVarint32(const unsigned char *, u32 *);
 int sqlite3VarintLen(u64 v);
 
 /*
-** 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 macros take advantage this fact to provide a fast encode
-** and 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 = sqlite3PutVarint32( A, B );
-**
-**     x = getVarint32( A, B );
-**     x = putVarint32( A, B );
-**
+** The common case is for a varint to be a single byte.  They following
+** macros handle the common case without a procedure call, but then call
+** the procedure for larger varints.
 */
 #define getVarint32(A,B)  \
   (u8)((*(A)<(u8)0x80)?((B)=(u32)*(A)),1:sqlite3GetVarint32((A),(u32 *)&(B)))
 #define putVarint32(A,B)  \
   (u8)(((u32)(B)<(u32)0x80)?(*(A)=(unsigned char)(B)),1:\
-  sqlite3PutVarint32((A),(B)))
+  sqlite3PutVarint((A),(B)))
 #define getVarint    sqlite3GetVarint
 #define putVarint    sqlite3PutVarint
 
diff --git a/src/util.c b/src/util.c
index 1c75e4cfbe..839a4a4636 100644
--- a/src/util.c
+++ b/src/util.c
@@ -708,7 +708,7 @@ int sqlite3Atoi(const char *z){
 ** bit clear.  Except, if we get to the 9th byte, it stores the full
 ** 8 bits and is the last byte.
 */
-int sqlite3PutVarint(unsigned char *p, u64 v){
+static int SQLITE_NOINLINE putVarint64(unsigned char *p, u64 v){
   int i, j, n;
   u8 buf[10];
   if( v & (((u64)0xff000000)<<32) ){
@@ -732,28 +732,17 @@ int sqlite3PutVarint(unsigned char *p, u64 v){
   }
   return n;
 }
-
-/*
-** This routine is a faster version of sqlite3PutVarint() that only
-** works for 32-bit positive integers and which is optimized for
-** the common case of small integers.  A MACRO version, putVarint32,
-** is provided which inlines the single-byte case.  All code should use
-** the MACRO version as this function assumes the single-byte case has
-** already been handled.
-*/
-int sqlite3PutVarint32(unsigned char *p, u32 v){
-#ifndef putVarint32
-  if( (v & ~0x7f)==0 ){
-    p[0] = v;
+int sqlite3PutVarint(unsigned char *p, u64 v){
+  if( v<=0x7f ){
+    p[0] = v&0x7f;
     return 1;
   }
-#endif
-  if( (v & ~0x3fff)==0 ){
-    p[0] = (u8)((v>>7) | 0x80);
-    p[1] = (u8)(v & 0x7f);
+  if( v<=0x3fff ){
+    p[0] = ((v>>7)&0x7f)|0x80;
+    p[1] = v&0x7f;
     return 2;
   }
-  return sqlite3PutVarint(p, v);
+  return putVarint64(p,v);
 }
 
 /*
diff --git a/src/vdbemem.c b/src/vdbemem.c
index cf44aa7e2d..08cf40eaa8 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -1130,7 +1130,7 @@ static void recordFunc(
     sqlite3_result_error_nomem(context);
   }else{
     aRet[0] = nSerial+1;
-    sqlite3PutVarint(&aRet[1], iSerial);
+    putVarint32(&aRet[1], iSerial);
     sqlite3VdbeSerialPut(&aRet[1+nSerial], argv[0], iSerial);
     sqlite3_result_blob(context, aRet, nRet, SQLITE_TRANSIENT);
     sqlite3DbFree(db, aRet);