Reorder the elements of the Mem object for a small size reduction and

performance improvement.

FossilOrigin-Name: 0be3019ed794c10de67dfd645ceea7d45815bc4b

manifest

@@ -1,5 +1,5 @@
-C Changes\sto\ssqlite3VdbeRecordUnpack()\sto\smake\sit\sslightly\ssmaller\sand\sfaster.
+C Reorder\sthe\selements\sof\sthe\sMem\sobject\sfor\sa\ssmall\ssize\sreduction\sand\nperformance\simprovement.
-D 2014-09-16T13:30:05.468
+D 2014-09-16T14:16:31.846
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in cf57f673d77606ab0f2d9627ca52a9ba1464146a
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -183,7 +183,7 @@ F src/delete.c fae81cc2eb14b75267d4f47d3cfc9ae02aae726f
 F src/expr.c 19392d98e089640c3336e65b4254cc337efef7d1
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c da985ae673efef2c712caef825a5d2edb087ead7
-F src/func.c 5d498933f6168dff80941c873805fe04dc2b766d
+F src/func.c 1629ccdd8ef3f19d7accc9d9287190489469ff81
 F src/global.c 5110fa12e09729b84eee0191c984ec4008e21937
 F src/hash.c 4263fbc955f26c2e8cdc0cf214bc42435aa4e4f5
 F src/hash.h c8f3c31722cf3277d03713909761e152a5b81094
@@ -290,11 +290,11 @@ F src/util.c 4006c01772bd8d8ac4306d523bbcee41d3e392d8
 F src/vacuum.c 59f03f92bcff57faa6a8ca256eb29ccddfb0614a
 F src/vdbe.c 9a45dcbcc967fc0cb9248c75ba245d1d47de3e78
 F src/vdbe.h c63fad052c9e7388d551e556e119c0bcf6bebdf8
-F src/vdbeInt.h b4843c35c3ba533b69d4250f550b5bacf2fb013d
+F src/vdbeInt.h 0de8705e38b5f28808e37cebb9ec6df995ac3304
-F src/vdbeapi.c 06b712d4772b318b69cd37a416deb1ff0426aa8c
+F src/vdbeapi.c 4d2aa56efa1b4a010012466bf8e97dbf179081a6
-F src/vdbeaux.c 2f284f8b052acc5b484682fbd3de35c990c2ca1c
+F src/vdbeaux.c 4d607ce804cc4ee129df5745f7b73ed472f808b6
 F src/vdbeblob.c 848238dc73e93e48432991bb5651bf87d865eca4
-F src/vdbemem.c dc36ea9fe26c25550c50085f388167086ef7d73a
+F src/vdbemem.c 4d1e1398be24f85805196c20a80699be0699a9ca
 F src/vdbesort.c a7a40ceca6325b853040ffcc363dcd49a45f201b
 F src/vdbetrace.c 16d39c1ef7d1f4a3a7464bea3b7b4bdd7849c415
 F src/vtab.c 019dbfd0406a7447c990e1f7bd1dfcdb8895697f
@@ -1198,7 +1198,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 20ed2321b09ba076e50f9fc2f42c135b25746d72
+P 8fb90da77ce0e662c1ef1ae0d854e5164494b7af
-R 052add0d7794460f3fc0b9bdb3e7879a
+R 66ed6d98b57d603d2a5f34403ecc91fe
 U drh
-Z bf1aaf6028da77cf4241e813f52ee696
+Z d53857782fade1fcfcd0d6fed6dee986

manifest.uuid

@@ -1 +1 @@
-8fb90da77ce0e662c1ef1ae0d854e5164494b7af
+0be3019ed794c10de67dfd645ceea7d45815bc4b

src/func.c

@@ -1492,6 +1492,7 @@ static void minmaxStep(
       sqlite3SkipAccumulatorLoad(context);
     }
   }else{
+    pBest->db = sqlite3_context_db_handle(context);
     sqlite3VdbeMemCopy(pBest, pArg);
   }
 }

src/vdbeInt.h

@@ -161,9 +161,6 @@ struct VdbeFrame {
 ** integer etc.) of the same value.
 */
 struct Mem {
-  sqlite3 *db;        /* The associated database connection */
-  char *z;            /* String or BLOB value */
-  double r;           /* Real value */
   union {
     i64 i;              /* Integer value used when MEM_Int is set in flags */
     int nZero;          /* Used when bit MEM_Zero is set in flags */
@@ -171,15 +168,19 @@ struct Mem {
     RowSet *pRowSet;    /* Used only when flags==MEM_RowSet */
     VdbeFrame *pFrame;  /* Used when flags==MEM_Frame */
   } u;
-  int n;              /* Number of characters in string value, excluding '\0' */
   u16 flags;          /* Some combination of MEM_Null, MEM_Str, MEM_Dyn, etc. */
   u8  enc;            /* SQLITE_UTF8, SQLITE_UTF16BE, SQLITE_UTF16LE */
+  int n;              /* Number of characters in string value, excluding '\0' */
+  double r;           /* Real value */
+  char *z;            /* String or BLOB value */
+  char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
+  /* ShallowCopy only needs to copy the information above */
+  sqlite3 *db;        /* The associated database connection */
+  void (*xDel)(void*);/* If not null, call this function to delete Mem.z */
 #ifdef SQLITE_DEBUG
   Mem *pScopyFrom;    /* This Mem is a shallow copy of pScopyFrom */
   void *pFiller;      /* So that sizeof(Mem) is a multiple of 8 */
 #endif
-  void (*xDel)(void *);  /* If not null, call this function to delete Mem.z */
-  char *zMalloc;      /* Dynamic buffer allocated by sqlite3_malloc() */
 };
 
 /* One or more of the following flags are set to indicate the validOK

src/vdbeapi.c

@@ -803,11 +803,21 @@ static const Mem *columnNullValue(void){
 #if defined(SQLITE_DEBUG) && defined(__GNUC__)
     __attribute__((aligned(8))) 
 #endif
-    = {0, "", (double)0, {0}, 0, MEM_Null, 0,
+    = {
+         .flags      = MEM_Null,
+         .enc        = 0,
+         .n          = 0,
+         .r          = (double)0,
+         .u          = {0},
+         .z          = 0,
+         .zMalloc    = 0,
+         .db         = 0,
+         .xDel       = 0,
 #ifdef SQLITE_DEBUG
-       0, 0,  /* pScopyFrom, pFiller */
+         .pScopyFrom = 0,
+         .pFiller    = 0,
 #endif
-       0, 0 };
+      };
   return &nullMem;
 }
 

src/vdbeaux.c

@@ -3303,8 +3303,9 @@ static int vdbeCompareMemString(
     int n1, n2;
     Mem c1;
     Mem c2;
-    memset(&c1, 0, sizeof(c1));
+    c1.db = c2.db = pMem1->db;
-    memset(&c2, 0, sizeof(c2));
+    c1.flags = c2.flags = 0;
+    c1.zMalloc = c2.zMalloc = 0;
     sqlite3VdbeMemShallowCopy(&c1, pMem1, MEM_Ephem);
     sqlite3VdbeMemShallowCopy(&c2, pMem2, MEM_Ephem);
     v1 = sqlite3ValueText((sqlite3_value*)&c1, pColl->enc);

src/vdbemem.c

@@ -730,6 +730,7 @@ void sqlite3VdbeMemAboutToChange(Vdbe *pVdbe, Mem *pMem){
 */
 void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
   assert( (pFrom->flags & MEM_RowSet)==0 );
+  assert( pTo->db==pFrom->db );
   VdbeMemReleaseExtern(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);
   pTo->xDel = 0;
@@ -747,6 +748,7 @@ void sqlite3VdbeMemShallowCopy(Mem *pTo, const Mem *pFrom, int srcType){
 int sqlite3VdbeMemCopy(Mem *pTo, const Mem *pFrom){
   int rc = SQLITE_OK;
 
+  assert( pTo->db==pFrom->db );
   assert( (pFrom->flags & MEM_RowSet)==0 );
   VdbeMemReleaseExtern(pTo);
   memcpy(pTo, pFrom, MEMCELLSIZE);