Rearrange fields of the BtCursor object so that it is smaller and requires less

initialization, for a small performance improvement.

FossilOrigin-Name: 0ddf5292cc0411ec6fcb7399ecf2904c899e0488404d3f65490fbe1db15efdf4

1 files changed, 4 insertions, 3 deletions

diff --git a/src/btree.c b/src/btree.c
index 168f3105f..33f584228 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -4345,7 +4345,7 @@ int sqlite3BtreeCursorSize(void){
 ** of run-time by skipping the initialization of those elements.
 */
 void sqlite3BtreeCursorZero(BtCursor *p){
-  memset(p, 0, offsetof(BtCursor, iPage));
+  memset(p, 0, offsetof(BtCursor, BTCURSOR_FIRST_UNINIT));
 }
 
 /*
@@ -4668,14 +4668,15 @@ static int accessPayload(
     */
     if( (pCur->curFlags & BTCF_ValidOvfl)==0 ){
       int nOvfl = (pCur->info.nPayload-pCur->info.nLocal+ovflSize-1)/ovflSize;
-      if( nOvfl>pCur->nOvflAlloc ){
+      if( pCur->aOverflow==0
+       || nOvfl*sizeof(Pgno) > sqlite3MallocSize(pCur->aOverflow)
+      ){
         Pgno *aNew = (Pgno*)sqlite3Realloc(
             pCur->aOverflow, nOvfl*2*sizeof(Pgno)
         );
         if( aNew==0 ){
           return SQLITE_NOMEM_BKPT;
         }else{
-          pCur->nOvflAlloc = nOvfl*2;
           pCur->aOverflow = aNew;
         }
       }