From: drh <>
Date: Fri, 25 Feb 2022 20:11:59 +0000 (+0000)
Subject: Revise the initialization processing for OP_Column to make it about
X-Git-Tag: version-3.39.0~366
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fc56950337825789486227a2f4ce8655d670b420;p=thirdparty%2Fsqlite.git

Revise the initialization processing for OP_Column to make it about
1.8 million cycles faster.

FossilOrigin-Name: 3b7259ebd5b9b1f75577521c4d0d96f5503d302a513b20a0b17dbe8c3823dd33
---

diff --git a/manifest b/manifest
index 42a39fbdc4..892f8fb779 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sthe\sOP_NullRow\sdocumentation\sso\sthat\sit\saccurately\sdescribes\swhat\sit\nactually\sdoes\sfor\sa\spseudo-cursor.
-D 2022-02-25T18:51:09.169
+C Revise\sthe\sinitialization\sprocessing\sfor\sOP_Column\sto\smake\sit\sabout\n1.8\smillion\scycles\sfaster.
+D 2022-02-25T20:11:59.160
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -624,11 +624,11 @@ F src/upsert.c 8789047a8f0a601ea42fa0256d1ba3190c13746b6ba940fe2d25643a7e991937
 F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
 F src/util.c 602fe229f32a96ceccae4f40824129669582096f7c355f53dbac156c9fecef23
 F src/vacuum.c 6c38ddc52f0619865c91dae9c441d4d48bf3040d7dc1bc5b22da1e45547ed0b3
-F src/vdbe.c 5299556464a6a947611334db56adbf20d2b345c1cff7d74f666008c349f0410c
+F src/vdbe.c e3947ae70531c7e26fdca3da379bcb1aaad349dc1daad9841a11dd78f40e4705
 F src/vdbe.h a1d0e3b934e835e73edd146f2e7c4eadb711b5c9875c18159a57483fd78e550e
-F src/vdbeInt.h b45599a2b59f1ce042512ab6786b0b82a8cf3002f6b0fa60b4834e2cd3ac61d8
+F src/vdbeInt.h de2348c1643c1ac5bf0932452cbb708f52f52d8b4e29b667abdcfd4bacbf6aa6
 F src/vdbeapi.c 8863ffb5a7bac42fe9a68aaa3526ee29fc18fb02a9b27188b756de41e33856e9
-F src/vdbeaux.c 3aa7ec0f53156760e9b42557122c61f90efddba5d9d173d076b3b8826b1b23bb
+F src/vdbeaux.c 1dc2bdd377baf4e3602e02ca33d241944f04bda2e724526437018f143f9e75f3
 F src/vdbeblob.c 5e61ce31aca17db8fb60395407457a8c1c7fb471dde405e0cd675974611dcfcd
 F src/vdbemem.c 7737f0b1c480a32b057849c804d2f21d5389649bb8be80f77ad75df700adc9a1
 F src/vdbesort.c 43756031ca7430f7aec3ef904824a7883c4ede783e51f280d99b9b65c0796e35
@@ -1944,8 +1944,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 54f49f65ac943263a1622b1efe519c8a61f30f23694fd4fec89ad2bf0e17b473
-R 84b7b86c0cda7b37ea1827afa5aef02e
+P 4e269902094e8f9d852e5fc852e473167048fdeb9034f1fb1436f6df205de926
+R 8636bb1bb599a232ab53a80eb27f1dd2
 U drh
-Z ad486a9d2be85a263d9516418548523a
+Z 2c3c6e68626da40fc12f58f70cf79dcd
 # Remove this line to create a well-formed Fossil manifest.
diff --git a/manifest.uuid b/manifest.uuid
index 05dec89be9..45a49d23f0 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-4e269902094e8f9d852e5fc852e473167048fdeb9034f1fb1436f6df205de926
\ No newline at end of file
+3b7259ebd5b9b1f75577521c4d0d96f5503d302a513b20a0b17dbe8c3823dd33
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index f6c350a9b5..d1e54b8f9e 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2659,7 +2659,7 @@ case OP_Offset: {          /* out3 */
 case OP_Column: {
   u32 p2;            /* column number to retrieve */
   VdbeCursor *pC;    /* The VDBE cursor */
-  BtCursor *pCrsr;   /* The BTree cursor */
+  BtCursor *pCrsr;   /* The B-Tree cursor corresponding to pC */
   u32 *aOffset;      /* aOffset[i] is offset to start of data for i-th column */
   int len;           /* The length of the serialized data for the column */
   int i;             /* Loop counter */
@@ -2673,19 +2673,11 @@ case OP_Column: {
   Mem *pReg;         /* PseudoTable input register */
 
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
+  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
   pC = p->apCsr[pOp->p1];
-  assert( pC!=0 );
   p2 = (u32)pOp->p2;
 
-  /* If the cursor cache is stale (meaning it is not currently point at
-  ** the correct row) then bring it up-to-date by doing the necessary 
-  ** B-Tree seek. */
-  rc = sqlite3VdbeCursorMoveto(&pC, &p2);
-  if( rc ) goto abort_due_to_error;
-
-  assert( pOp->p3>0 && pOp->p3<=(p->nMem+1 - p->nCursor) );
-  pDest = &aMem[pOp->p3];
-  memAboutToChange(p, pDest);
+op_column_restart:
   assert( pC!=0 );
   assert( p2<(u32)pC->nField );
   aOffset = pC->aOffset;
@@ -2706,11 +2698,28 @@ case OP_Column: {
         pC->payloadSize = pC->szRow = pReg->n;
         pC->aRow = (u8*)pReg->z;
       }else{
+        pDest = &aMem[pOp->p3];
+        memAboutToChange(p, pDest);
         sqlite3VdbeMemSetNull(pDest);
         goto op_column_out;
       }
     }else{
       pCrsr = pC->uc.pCursor;
+      if( pC->deferredMoveto ){
+        u32 iMap;
+        assert( !pC->isEphemeral );
+        if( pC->ub.aAltMap && (iMap = pC->ub.aAltMap[1+p2])>0  ){
+          pC = pC->pAltCursor;
+          p2 = iMap - 1;
+          goto op_column_restart;
+        }
+        rc = sqlite3VdbeFinishMoveto(pC);
+        if( rc ) goto abort_due_to_error;
+      }else if( sqlite3BtreeCursorHasMoved(pCrsr) ){
+        rc = sqlite3VdbeHandleMovedCursor(pC);
+        if( rc ) goto abort_due_to_error;
+        goto op_column_restart;
+      }
       assert( pC->eCurType==CURTYPE_BTREE );
       assert( pCrsr );
       assert( sqlite3BtreeCursorIsValid(pCrsr) );
@@ -2766,6 +2775,10 @@ case OP_Column: {
       testcase( aOffset[0]==0 );
       goto op_column_read_header;
     }
+  }else if( sqlite3BtreeCursorHasMoved(pC->uc.pCursor) ){
+    rc = sqlite3VdbeHandleMovedCursor(pC);
+    if( rc ) goto abort_due_to_error;
+    goto op_column_restart;
   }
 
   /* Make sure at least the first p2+1 entries of the header have been
@@ -2834,6 +2847,8 @@ case OP_Column: {
     ** columns.  So the result will be either the default value or a NULL.
     */
     if( pC->nHdrParsed<=p2 ){
+      pDest = &aMem[pOp->p3];
+      memAboutToChange(p, pDest);
       if( pOp->p4type==P4_MEM ){
         sqlite3VdbeMemShallowCopy(pDest, pOp->p4.pMem, MEM_Static);
       }else{
@@ -2851,6 +2866,8 @@ case OP_Column: {
   */
   assert( p2<pC->nHdrParsed );
   assert( rc==SQLITE_OK );
+  pDest = &aMem[pOp->p3];
+  memAboutToChange(p, pDest);
   assert( sqlite3VdbeCheckMemInvariants(pDest) );
   if( VdbeMemDynamic(pDest) ){
     sqlite3VdbeMemSetNull(pDest);
@@ -6197,6 +6214,7 @@ case OP_IdxRowid: {           /* out2 */
       pTabCur->nullRow = 0;
       pTabCur->movetoTarget = rowid;
       pTabCur->deferredMoveto = 1;
+      pTabCur->cacheStatus = CACHE_STALE;
       assert( pOp->p4type==P4_INTARRAY || pOp->p4.ai==0 );
       assert( !pTabCur->isEphemeral );
       pTabCur->ub.aAltMap = pOp->p4.ai;
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index f02b37c6a2..cc5fd604d5 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -506,8 +506,8 @@ struct ValueList {
 void sqlite3VdbeError(Vdbe*, const char *, ...);
 void sqlite3VdbeFreeCursor(Vdbe *, VdbeCursor*);
 void sqliteVdbePopStack(Vdbe*,int);
+int SQLITE_NOINLINE sqlite3VdbeHandleMovedCursor(VdbeCursor *p);
 int SQLITE_NOINLINE sqlite3VdbeFinishMoveto(VdbeCursor*);
-int sqlite3VdbeCursorMoveto(VdbeCursor**, u32*);
 int sqlite3VdbeCursorRestore(VdbeCursor*);
 u32 sqlite3VdbeSerialTypeLen(u32);
 u8 sqlite3VdbeOneByteSerialTypeLen(u8);
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index bcfe63130f..35044127ac 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -3505,7 +3505,7 @@ int SQLITE_NOINLINE sqlite3VdbeFinishMoveto(VdbeCursor *p){
 ** is supposed to be pointing.  If the row was deleted out from under the
 ** cursor, set the cursor to point to a NULL row.
 */
-static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
+int SQLITE_NOINLINE sqlite3VdbeHandleMovedCursor(VdbeCursor *p){
   int isDifferentRow, rc;
   assert( p->eCurType==CURTYPE_BTREE );
   assert( p->uc.pCursor!=0 );
@@ -3523,39 +3523,7 @@ static int SQLITE_NOINLINE handleMovedCursor(VdbeCursor *p){
 int sqlite3VdbeCursorRestore(VdbeCursor *p){
   assert( p->eCurType==CURTYPE_BTREE );
   if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
-    return handleMovedCursor(p);
-  }
-  return SQLITE_OK;
-}
-
-/*
-** Make sure the cursor p is ready to read or write the row to which it
-** was last positioned.  Return an error code if an OOM fault or I/O error
-** prevents us from positioning the cursor to its correct position.
-**
-** If a MoveTo operation is pending on the given cursor, then do that
-** MoveTo now.  If no move is pending, check to see if the row has been
-** deleted out from under the cursor and if it has, mark the row as
-** a NULL row.
-**
-** If the cursor is already pointing to the correct row and that row has
-** not been deleted out from under the cursor, then this routine is a no-op.
-*/
-int sqlite3VdbeCursorMoveto(VdbeCursor **pp, u32 *piCol){
-  VdbeCursor *p = *pp;
-  assert( p->eCurType==CURTYPE_BTREE || p->eCurType==CURTYPE_PSEUDO );
-  if( p->deferredMoveto ){
-    u32 iMap;
-    assert( !p->isEphemeral );
-    if( p->ub.aAltMap && (iMap = p->ub.aAltMap[1+*piCol])>0 && !p->nullRow ){
-      *pp = p->pAltCursor;
-      *piCol = iMap - 1;
-      return SQLITE_OK;
-    }
-    return sqlite3VdbeFinishMoveto(p);
-  }
-  if( sqlite3BtreeCursorHasMoved(p->uc.pCursor) ){
-    return handleMovedCursor(p);
+    return sqlite3VdbeHandleMovedCursor(p);
   }
   return SQLITE_OK;
 }