From: drh <drh@noemail.net>
Date: Wed, 20 Sep 2017 18:47:51 +0000 (+0000)
Subject: Size and performance optimization on sqlite3VdbeMemGrow().
X-Git-Tag: version-3.21.0~72
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=762dffa54ada2436128fa7d00c110467bbfc1705;p=thirdparty%2Fsqlite.git

Size and performance optimization on sqlite3VdbeMemGrow().

FossilOrigin-Name: 4b3f7eacb862fbb5b75cf50b72fb60dfbd0acb5818e9f83383a6a63c8bbeacdf
---

diff --git a/manifest b/manifest
index 9419550ac9..189711f25b 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C The\sBLOB\sreturned\sby\ssqlite3VdbeMemFromBtree()\sdoes\snot\sneed\sto\sbe\nzero-terminated.
-D 2017-09-20T18:07:50.056
+C Size\sand\sperformance\soptimization\son\ssqlite3VdbeMemGrow().
+D 2017-09-20T18:47:51.074
 F Makefile.in 4bc36d913c2e3e2d326d588d72f618ac9788b2fd4b7efda61102611a6495c3ff
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 6033b51b6aea702ea059f6ab2d47b1d3cef648695f787247dd4fb395fe60673f
@@ -532,7 +532,7 @@ F src/vdbeInt.h 1fe00770144c12c4913128f35262d11527ef3284561baaab59b947a41c08d0d9
 F src/vdbeapi.c 9c670ca0dcc1cd86373aa353b747b26fe531ca5cd4331690c611d1f03842e2a1
 F src/vdbeaux.c 3be977a032e54fe46cb1b1f3ba62158438b0cc93e091f6feca7742d20dad3203
 F src/vdbeblob.c 635a79b60340a6a14a622ea8dcb081f0a66b1ac3836870c587f232eec08c0286
-F src/vdbemem.c 4996dd14244a7757a9b8b085c03825e4b7611865e73e55df248b4f0836dcf9bf
+F src/vdbemem.c 9496f08e196c536397039783cdfda4ad2bc944d84ccad93df03e1ed3635534d6
 F src/vdbesort.c 731a09e5cb9e96b70c394c1b7cf3860fbe84acca7682e178615eb941a3a0ef2f
 F src/vdbetrace.c 48e11ebe040c6b41d146abed2602e3d00d621d7ebe4eb29b0a0f1617fd3c2f6c
 F src/vtab.c f1d5c23132fb0247af3e86146404112283ddedb6c518de0d4edc91cfb36970ef
@@ -1655,7 +1655,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 3b3e32d4cd07a1d2d1708fffa47819345ae6b39205a9f548280d499c8f481d64
-R bc412d1d9fd3e512c9d7b13d3be8fe98
+P e0af9a9040768adf8bba42a8780adeb6304bc442afb1f35d239d019db1624f40
+R 687f0aa7f9a7f38a700d64fc554d13e9
 U drh
-Z 372454472847a80abeaf6ba3b240911a
+Z 9d62175f9630fe98b6fce9be22a6837d
diff --git a/manifest.uuid b/manifest.uuid
index 05e0da2a72..cc3059d0cd 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e0af9a9040768adf8bba42a8780adeb6304bc442afb1f35d239d019db1624f40
\ No newline at end of file
+4b3f7eacb862fbb5b75cf50b72fb60dfbd0acb5818e9f83383a6a63c8bbeacdf
\ No newline at end of file
diff --git a/src/vdbemem.c b/src/vdbemem.c
index 4437de556a..403ad889cd 100644
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -155,7 +155,7 @@ SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
   assert( pMem->szMalloc==0
        || pMem->szMalloc==sqlite3DbMallocSize(pMem->db, pMem->zMalloc) );
   if( n<32 ) n = 32;
-  if( bPreserve && pMem->szMalloc>0 && pMem->z==pMem->zMalloc ){
+  if( pMem->szMalloc>0 && bPreserve && pMem->z==pMem->zMalloc ){
     pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
     bPreserve = 0;
   }else{
@@ -171,7 +171,8 @@ SQLITE_NOINLINE int sqlite3VdbeMemGrow(Mem *pMem, int n, int bPreserve){
     pMem->szMalloc = sqlite3DbMallocSize(pMem->db, pMem->zMalloc);
   }
 
-  if( bPreserve && pMem->z && ALWAYS(pMem->z!=pMem->zMalloc) ){
+  if( bPreserve && pMem->z ){
+    assert( pMem->z!=pMem->zMalloc );
     memcpy(pMem->zMalloc, pMem->z, pMem->n);
   }
   if( (pMem->flags&MEM_Dyn)!=0 ){