Change the sqlite3VdbeMemGrow() routine so that it no longer guarantees a

minimum size of 32 bytes.  That minimum is no longer required, and without
the extra check for the minimum size, the routine runs faster.

FossilOrigin-Name: 5c499da8a4d0babc56883aa362ae124772fd9214a51169a88a5dee523d051658

diff --git a/manifest b/manifest
index 7b191284e8408ef20e3b15df8eaaa7a4b7b1478d..d01e8c1192612a98c338211fd6fa9a0eeb77f398 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Give\sthe\ssqlite3\sobject\sa\spointer\sto\sthe\scurrent\sParse\sso\sthat\sif\san\sOOM\noccurs,\sit\scan\sautomatically\sset\sthe\sParse.rc\svalue\sto\sSQLITE_NOMEM.\s\sThis\navoids\sa\sfrequent\sextra\stest\sof\sdb.mallocFailed\sin\sthe\sinnermost\sparser\sloop.
-D 2019-02-08T14:55:30.490
+C Change\sthe\ssqlite3VdbeMemGrow()\sroutine\sso\sthat\sit\sno\slonger\sguarantees\sa\nminimum\ssize\sof\s32\sbytes.\s\sThat\sminimum\sis\sno\slonger\srequired,\sand\swithout\nthe\sextra\scheck\sfor\sthe\sminimum\ssize,\sthe\sroutine\sruns\sfaster.
+D 2019-02-08T15:59:20.543
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 178d8eb6840771149cee40b322d1b3be30d330198c522c903c1b66fb5a1bfca4
@@ -591,7 +591,7 @@ F src/vdbeInt.h a76d5eed62c76bcd8de7afd3147fac1bc40c5a870582664bcd7d071ef437c37f
 F src/vdbeapi.c 57a2d794a8833f269b878dbc24e955369bdb379af6c4e93ebc5ce1a20fa3daf4
 F src/vdbeaux.c 4fa28b32452f6197dba7c8780dde11576b9a6d8ce6f35adbb69efc3e7d37fa0c
 F src/vdbeblob.c f5c70f973ea3a9e915d1693278a5f890dc78594300cf4d54e64f2b0917c94191
-F src/vdbemem.c 3173f0275cf8643a03ed02084ee56b97fc1a17a2edb5907facec504f59c3172d
+F src/vdbemem.c 8facf8d2470af0b8f5995b405b7e061435b58ac53350fddd5e5399adfa904b73
 F src/vdbesort.c 90aad5a92608f2dd771c96749beabdb562c9d881131a860a7a5bccf66dc3be7f
 F src/vdbetrace.c 79d6dbbc479267b255a7de8080eee6e729928a0ef93ed9b0bfa5618875b48392
 F src/vtab.c 2462b7d6fd72b0b916477f5ef210ee49ab58cec195483ebdac0c8c5e3ec42cab
@@ -1804,7 +1804,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 440a7cda000164d3b46109caf2e1dde80681ba9b0d94ba9be6847d2b917445cf
-R d896d8bd0769798bd0ceee3ae07599f8
+P 5c6638040b3017c6be016441422d965a3ca00dd6ae1f78cadc0b54562978f64e
+R fcc87fb69789bc1e53d9d02a501d47e6
 U drh
-Z 9fd176c740cfae5da5074aab30ee1252
+Z 16cd16f85b68b2c2cfa22d11f08d6b4d

diff --git a/manifest.uuid b/manifest.uuid
index 48f2b4598dfe7b2583fafd0c78916c1ce3a086af..837c9fcb7851fbb995bd10f8ea3c173b58ae4953 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-5c6638040b3017c6be016441422d965a3ca00dd6ae1f78cadc0b54562978f64e
\ No newline at end of file
+5c499da8a4d0babc56883aa362ae124772fd9214a51169a88a5dee523d051658
\ No newline at end of file

diff --git a/src/vdbemem.c b/src/vdbemem.c
index 5aa0ec6ca5b04507fa12b73449446d3c90cb0e85..e4cea0ff6876b8e3b27ce5b853a6cbf3d92d5589 100644 (file)
--- a/src/vdbemem.c
+++ b/src/vdbemem.c
@@ -178,8 +178,7 @@ int sqlite3VdbeChangeEncoding(Mem *pMem, int desiredEnc){
 }
 
 /*
-** Make sure pMem->z points to a writable allocation of at least 
-** min(n,32) bytes.
+** Make sure pMem->z points to a writable allocation of at least n bytes.
 **
 ** If the bPreserve argument is true, then copy of the content of
 ** pMem->z into the new allocation.  pMem must be either a string or
@@ -198,7 +197,6 @@ 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( pMem->szMalloc>0 && bPreserve && pMem->z==pMem->zMalloc ){
     pMem->z = pMem->zMalloc = sqlite3DbReallocOrFree(pMem->db, pMem->z, n);
     bPreserve = 0;