Refactor the sqlite3VdbeRecordCompare() routine used to compare btree records.

Create fast-track special case routines to handle the common cases more
quickly.  This gives a significant performance boost.

FossilOrigin-Name: 3325ad5bdc2f81f63b556d6f4d0589d89b142b2b

1 files changed, 14 insertions, 3 deletions

diff --git a/src/btree.c b/src/btree.c
index 4fd8e27bf..ce35afbd5 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -4547,6 +4547,7 @@ int sqlite3BtreeMovetoUnpacked(
   int *pRes                /* Write search results here */
 ){
   int rc;
+  RecordCompare xRecordCompare;
 
   assert( cursorHoldsMutex(pCur) );
   assert( sqlite3_mutex_held(pCur->pBtree->db->mutex) );
@@ -4568,6 +4569,16 @@ int sqlite3BtreeMovetoUnpacked(
     }
   }
 
+  if( pIdxKey ){
+    xRecordCompare = sqlite3VdbeFindCompare(pIdxKey);
+    assert( pIdxKey->default_rc==1 
+         || pIdxKey->default_rc==0 
+         || pIdxKey->default_rc==-1
+    );
+  }else{
+    xRecordCompare = 0; /* Not actually used.  Avoids a compiler warning. */
+  }
+
   rc = moveToRoot(pCur);
   if( rc ){
     return rc;
@@ -4652,14 +4663,14 @@ int sqlite3BtreeMovetoUnpacked(
           ** single byte varint and the record fits entirely on the main
           ** b-tree page.  */
           testcase( pCell+nCell+1==pPage->aDataEnd );
-          c = sqlite3VdbeRecordCompare(nCell, (void*)&pCell[1], pIdxKey);
+          c = xRecordCompare(nCell, (void*)&pCell[1], pIdxKey, 0);
         }else if( !(pCell[1] & 0x80) 
           && (nCell = ((nCell&0x7f)<<7) + pCell[1])<=pPage->maxLocal
         ){
           /* The record-size field is a 2 byte varint and the record 
           ** fits entirely on the main b-tree page.  */
           testcase( pCell+nCell+2==pPage->aDataEnd );
-          c = sqlite3VdbeRecordCompare(nCell, (void*)&pCell[2], pIdxKey);
+          c = xRecordCompare(nCell, (void*)&pCell[2], pIdxKey, 0);
         }else{
           /* The record flows over onto one or more overflow pages. In
           ** this case the whole cell needs to be parsed, a buffer allocated
@@ -4680,7 +4691,7 @@ int sqlite3BtreeMovetoUnpacked(
             sqlite3_free(pCellKey);
             goto moveto_finish;
           }
-          c = sqlite3VdbeRecordCompare(nCell, pCellKey, pIdxKey);
+          c = xRecordCompare(nCell, pCellKey, pIdxKey, 0);
           sqlite3_free(pCellKey);
         }
         if( c<0 ){