Merge all recent trunk enhancements into the sessions branch.

FossilOrigin-Name: 54aaa6f29ad1bf84148c2403eed77e8311f68d66

src/vdbe.c

@@ -3245,20 +3245,6 @@ case OP_SetCookie: {       /* in3 */
 ** See also OpenRead.
 */
 case OP_ReopenIdx: {
-  VdbeCursor *pCur;
-
-  assert( pOp->p5==0 );
-  assert( pOp->p4type==P4_KEYINFO );
-  pCur = p->apCsr[pOp->p1];
-  if( pCur && pCur->pgnoRoot==(u32)pOp->p2 ){
-    assert( pCur->iDb==pOp->p3 );      /* Guaranteed by the code generator */
-    break;
-  }
-  /* If the cursor is not currently open or is open on a different
-  ** index, then fall through into OP_OpenRead to force a reopen */
-}
-case OP_OpenRead:
-case OP_OpenWrite: {
   int nField;
   KeyInfo *pKeyInfo;
   int p2;
@@ -3268,8 +3254,20 @@ case OP_OpenWrite: {
   VdbeCursor *pCur;
   Db *pDb;
 
-  assert( (pOp->p5&(OPFLAG_P2ISREG|OPFLAG_BULKCSR))==pOp->p5 );
-  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 );
+  assert( pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );
+  assert( pOp->p4type==P4_KEYINFO );
+  pCur = p->apCsr[pOp->p1];
+  if( pCur && pCur->pgnoRoot==(u32)pOp->p2 ){
+    assert( pCur->iDb==pOp->p3 );      /* Guaranteed by the code generator */
+    goto open_cursor_set_hints;
+  }
+  /* If the cursor is not currently open or is open on a different
+  ** index, then fall through into OP_OpenRead to force a reopen */
+case OP_OpenRead:
+case OP_OpenWrite:
+
+  assert( (pOp->p5&(OPFLAG_P2ISREG|OPFLAG_BULKCSR|OPFLAG_SEEKEQ))==pOp->p5 );
+  assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 || pOp->p5==OPFLAG_SEEKEQ );
   assert( p->bIsReader );
   assert( pOp->opcode==OP_OpenRead || pOp->opcode==OP_ReopenIdx
           || p->readOnly==0 );
@@ -3332,14 +3330,17 @@ case OP_OpenWrite: {
   pCur->pgnoRoot = p2;
   rc = sqlite3BtreeCursor(pX, p2, wrFlag, pKeyInfo, pCur->pCursor);
   pCur->pKeyInfo = pKeyInfo;
-  assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
-  sqlite3BtreeCursorHints(pCur->pCursor, (pOp->p5 & OPFLAG_BULKCSR));
-
   /* Set the VdbeCursor.isTable variable. Previous versions of
   ** SQLite used to check if the root-page flags were sane at this point
   ** and report database corruption if they were not, but this check has
   ** since moved into the btree layer.  */  
   pCur->isTable = pOp->p4type!=P4_KEYINFO;
+
+open_cursor_set_hints:
+  assert( OPFLAG_BULKCSR==BTREE_BULKLOAD );
+  assert( OPFLAG_SEEKEQ==BTREE_SEEK_EQ );
+  sqlite3BtreeCursorHints(pCur->pCursor,
+                          (pOp->p5 & (OPFLAG_BULKCSR|OPFLAG_SEEKEQ)));
   break;
 }
 
@@ -3600,6 +3601,22 @@ case OP_SeekGT: {       /* jump, in3 */
 #ifdef SQLITE_DEBUG
   pC->seekOp = pOp->opcode;
 #endif
+
+  /* For a cursor with the BTREE_SEEK_EQ hint, only the OP_SeekGE and
+  ** OP_SeekLE opcodes are allowed, and these must be immediately followed
+  ** by an OP_IdxGT or OP_IdxLT opcode, respectively, with the same key.
+  */
+#ifdef SQLITE_DEBUG
+  if( sqlite3BtreeCursorHasHint(pC->pCursor, BTREE_SEEK_EQ) ){
+    assert( pOp->opcode==OP_SeekGE || pOp->opcode==OP_SeekLE );
+    assert( pOp[1].opcode==OP_IdxLT || pOp[1].opcode==OP_IdxGT );
+    assert( pOp[1].p1==pOp[0].p1 );
+    assert( pOp[1].p2==pOp[0].p2 );
+    assert( pOp[1].p3==pOp[0].p3 );
+    assert( pOp[1].p4.i==pOp[0].p4.i );
+  }
+#endif
+ 
   if( pC->isTable ){
     /* The input value in P3 might be of any type: integer, real, string,
     ** blob, or NULL.  But it needs to be an integer before we can do
@@ -4989,30 +5006,15 @@ case OP_IdxGE:  {       /* jump */
 */
 case OP_Destroy: {     /* out2-prerelease */
   int iMoved;
-  int iCnt;
-  Vdbe *pVdbe;
   int iDb;
 
   assert( p->readOnly==0 );
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  iCnt = 0;
-  for(pVdbe=db->pVdbe; pVdbe; pVdbe = pVdbe->pNext){
-    if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->bIsReader 
-     && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 
-    ){
-      iCnt++;
-    }
-  }
-#else
-  iCnt = db->nVdbeRead;
-#endif
   pOut->flags = MEM_Null;
-  if( iCnt>1 ){
+  if( db->nVdbeRead > db->nVDestroy+1 ){
     rc = SQLITE_LOCKED;
     p->errorAction = OE_Abort;
   }else{
     iDb = pOp->p3;
-    assert( iCnt==1 );
     assert( DbMaskTest(p->btreeMask, iDb) );
     iMoved = 0;  /* Not needed.  Only to silence a warning. */
     rc = sqlite3BtreeDropTable(db->aDb[iDb].pBt, pOp->p1, &iMoved);
@@ -6069,13 +6071,29 @@ case OP_VBegin: {
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-/* Opcode: VCreate P1 * * P4 *
+/* Opcode: VCreate P1 P2 * * *
 **
-** P4 is the name of a virtual table in database P1. Call the xCreate method
-** for that table.
+** P2 is a register that holds the name of a virtual table in database 
+** P1. Call the xCreate method for that table.
 */
 case OP_VCreate: {
-  rc = sqlite3VtabCallCreate(db, pOp->p1, pOp->p4.z, &p->zErrMsg);
+  Mem sMem;          /* For storing the record being decoded */
+  const char *zTab;  /* Name of the virtual table */
+
+  memset(&sMem, 0, sizeof(sMem));
+  sMem.db = db;
+  /* Because P2 is always a static string, it is impossible for the
+  ** sqlite3VdbeMemCopy() to fail */
+  assert( (aMem[pOp->p2].flags & MEM_Str)!=0 );
+  assert( (aMem[pOp->p2].flags & MEM_Static)!=0 );
+  rc = sqlite3VdbeMemCopy(&sMem, &aMem[pOp->p2]);
+  assert( rc==SQLITE_OK );
+  zTab = (const char*)sqlite3_value_text(&sMem);
+  assert( zTab || db->mallocFailed );
+  if( zTab ){
+    rc = sqlite3VtabCallCreate(db, pOp->p1, zTab, &p->zErrMsg);
+  }
+  sqlite3VdbeMemRelease(&sMem);
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -6087,9 +6105,9 @@ case OP_VCreate: {
 ** of that table.
 */
 case OP_VDestroy: {
-  p->inVtabMethod = 2;
+  db->nVDestroy++;
   rc = sqlite3VtabCallDestroy(db, pOp->p1, pOp->p4.z);
-  p->inVtabMethod = 0;
+  db->nVDestroy--;
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -6105,14 +6123,17 @@ case OP_VOpen: {
   VdbeCursor *pCur;
   sqlite3_vtab_cursor *pVtabCursor;
   sqlite3_vtab *pVtab;
-  sqlite3_module *pModule;
+  const sqlite3_module *pModule;
 
   assert( p->bIsReader );
   pCur = 0;
   pVtabCursor = 0;
   pVtab = pOp->p4.pVtab->pVtab;
-  pModule = (sqlite3_module *)pVtab->pModule;
-  assert(pVtab && pModule);
+  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
+    rc = SQLITE_LOCKED;
+    break;
+  }
+  pModule = pVtab->pModule;
   rc = pModule->xOpen(pVtab, &pVtabCursor);
   sqlite3VtabImportErrmsg(p, pVtab);
   if( SQLITE_OK==rc ){
@@ -6123,6 +6144,7 @@ case OP_VOpen: {
     pCur = allocateCursor(p, pOp->p1, 0, -1, 0);
     if( pCur ){
       pCur->pVtabCursor = pVtabCursor;
+      pVtab->nRef++;
     }else{
       db->mallocFailed = 1;
       pModule->xClose(pVtabCursor);
@@ -6188,9 +6210,7 @@ case OP_VFilter: {   /* jump */
       apArg[i] = &pArgc[i+1];
     }
 
-    p->inVtabMethod = 1;
     rc = pModule->xFilter(pVtabCursor, iQuery, pOp->p4.z, nArg, apArg);
-    p->inVtabMethod = 0;
     sqlite3VtabImportErrmsg(p, pVtab);
     if( rc==SQLITE_OK ){
       res = pModule->xEof(pVtabCursor);
@@ -6280,9 +6300,7 @@ case OP_VNext: {   /* jump */
   ** data is available) and the error code returned when xColumn or
   ** some other method is next invoked on the save virtual table cursor.
   */
-  p->inVtabMethod = 1;
   rc = pModule->xNext(pCur->pVtabCursor);
-  p->inVtabMethod = 0;
   sqlite3VtabImportErrmsg(p, pVtab);
   if( rc==SQLITE_OK ){
     res = pModule->xEof(pCur->pVtabCursor);
@@ -6357,7 +6375,7 @@ case OP_VRename: {
 */
 case OP_VUpdate: {
   sqlite3_vtab *pVtab;
-  sqlite3_module *pModule;
+  const sqlite3_module *pModule;
   int nArg;
   int i;
   sqlite_int64 rowid;
@@ -6369,7 +6387,11 @@ case OP_VUpdate: {
   );
   assert( p->readOnly==0 );
   pVtab = pOp->p4.pVtab->pVtab;
-  pModule = (sqlite3_module *)pVtab->pModule;
+  if( pVtab==0 || NEVER(pVtab->pModule==0) ){
+    rc = SQLITE_LOCKED;
+    break;
+  }
+  pModule = pVtab->pModule;
   nArg = pOp->p2;
   assert( pOp->p4type==P4_VTAB );
   if( ALWAYS(pModule->xUpdate) ){