Delete the OP_VerifySchema opcode. Enhance OP_Transaction to do the schema
version checks that OP_VerifySchema used to do.
FossilOrigin-Name: 2f3376ebf13df44e6acf27cb1f07172cd8b34033
diff --git a/src/alter.c b/src/alter.c
index 9d34b07..67070a5 100644
--- a/src/alter.c
+++ b/src/alter.c
@@ -469,7 +469,7 @@
}
#endif
- /* Begin a transaction and code the VerifyCookie for database iDb.
+ /* Begin a transaction for database iDb.
** Then modify the schema cookie (since the ALTER TABLE modifies the
** schema). Open a statement transaction if the table is a virtual
** table.
diff --git a/src/build.c b/src/build.c
index fa7364c..afd68a8 100644
--- a/src/build.c
+++ b/src/build.c
@@ -156,13 +156,14 @@
for(iDb=0, mask=1; iDb<db->nDb; mask<<=1, iDb++){
if( (mask & pParse->cookieMask)==0 ) continue;
sqlite3VdbeUsesBtree(v, iDb);
- sqlite3VdbeAddOp2(v,OP_Transaction, iDb, (mask & pParse->writeMask)!=0);
- if( db->init.busy==0 ){
- assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
- sqlite3VdbeAddOp3(v, OP_VerifyCookie,
- iDb, pParse->cookieValue[iDb],
- db->aDb[iDb].pSchema->iGeneration);
- }
+ sqlite3VdbeAddOp4Int(v,
+ OP_Transaction, /* Opcode */
+ iDb, /* P1 */
+ (mask & pParse->writeMask)!=0, /* P2 */
+ pParse->cookieValue[iDb], /* P3 */
+ db->aDb[iDb].pSchema->iGeneration /* P4 */
+ );
+ if( db->init.busy==0 ) sqlite3VdbeChangeP5(v, 1);
}
#ifndef SQLITE_OMIT_VIRTUALTABLE
for(i=0; i<pParse->nVtabLock; i++){
diff --git a/src/expr.c b/src/expr.c
index ee9d787..e417d8a 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1584,7 +1584,7 @@
pExpr = p->pEList->a[0].pExpr;
iCol = (i16)pExpr->iColumn;
- /* Code an OP_VerifyCookie and OP_TableLock for <table>. */
+ /* Code an OP_Transaction and OP_TableLock for <table>. */
iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
sqlite3CodeVerifySchema(pParse, iDb);
sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
diff --git a/src/vdbe.c b/src/vdbe.c
index 037b02f..7c8cfe1 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2946,7 +2946,7 @@
break;
}
-/* Opcode: Transaction P1 P2 * * *
+/* Opcode: Transaction P1 P2 P3 P4 P5
**
** Begin a transaction. The transaction ends when a Commit or Rollback
** opcode is encountered. Depending on the ON CONFLICT setting, the
@@ -2976,9 +2976,17 @@
** will automatically commit when the VDBE halts.
**
** If P2 is zero, then a read-lock is obtained on the database file.
+**
+** If P5!=0 then this opcode also checks the schema cookie against P3
+** and the schema generation counter against P4.
+** The cookie changes its value whenever the database schema changes.
+** This operation is used to detect when that the cookie has changed
+** and that the current process needs to reread the schema.
*/
case OP_Transaction: {
Btree *pBt;
+ int iMeta;
+ int iGen;
assert( p->bIsReader );
assert( p->readOnly==0 || pOp->p2==0 );
@@ -3022,6 +3030,35 @@
p->nStmtDefCons = db->nDeferredCons;
p->nStmtDefImmCons = db->nDeferredImmCons;
}
+
+ /* Gather the schema version number for checking */
+ sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&iMeta);
+ iGen = db->aDb[pOp->p1].pSchema->iGeneration;
+ }else{
+ iGen = iMeta = 0;
+ }
+ assert( pOp->p5==0 || pOp->p4type==P4_INT32 );
+ if( pOp->p5 && (iMeta!=pOp->p3 || iGen!=pOp->p4.i) ){
+ sqlite3DbFree(db, p->zErrMsg);
+ p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
+ /* If the schema-cookie from the database file matches the cookie
+ ** stored with the in-memory representation of the schema, do
+ ** not reload the schema from the database file.
+ **
+ ** If virtual-tables are in use, this is not just an optimization.
+ ** Often, v-tables store their data in other SQLite tables, which
+ ** are queried from within xNext() and other v-table methods using
+ ** prepared queries. If such a query is out-of-date, we do not want to
+ ** discard the database schema, as the user code implementing the
+ ** v-table would have to be ready for the sqlite3_vtab structure itself
+ ** to be invalidated whenever sqlite3_step() is called from within
+ ** a v-table method.
+ */
+ if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
+ sqlite3ResetOneSchema(db, pOp->p1);
+ }
+ p->expired = 1;
+ rc = SQLITE_SCHEMA;
}
break;
}
@@ -3096,66 +3133,6 @@
break;
}
-/* Opcode: VerifyCookie P1 P2 P3 * *
-**
-** Check the value of global database parameter number 0 (the
-** schema version) and make sure it is equal to P2 and that the
-** generation counter on the local schema parse equals P3.
-**
-** P1 is the database number which is 0 for the main database file
-** and 1 for the file holding temporary tables and some higher number
-** for auxiliary databases.
-**
-** The cookie changes its value whenever the database schema changes.
-** This operation is used to detect when that the cookie has changed
-** and that the current process needs to reread the schema.
-**
-** Either a transaction needs to have been started or an OP_Open needs
-** to be executed (to establish a read lock) before this opcode is
-** invoked.
-*/
-case OP_VerifyCookie: {
- int iMeta;
- int iGen;
- Btree *pBt;
-
- assert( pOp->p1>=0 && pOp->p1<db->nDb );
- assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
- assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
- assert( p->bIsReader );
- pBt = db->aDb[pOp->p1].pBt;
- if( pBt ){
- sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&iMeta);
- iGen = db->aDb[pOp->p1].pSchema->iGeneration;
- }else{
- iGen = iMeta = 0;
- }
- if( iMeta!=pOp->p2 || iGen!=pOp->p3 ){
- sqlite3DbFree(db, p->zErrMsg);
- p->zErrMsg = sqlite3DbStrDup(db, "database schema has changed");
- /* If the schema-cookie from the database file matches the cookie
- ** stored with the in-memory representation of the schema, do
- ** not reload the schema from the database file.
- **
- ** If virtual-tables are in use, this is not just an optimization.
- ** Often, v-tables store their data in other SQLite tables, which
- ** are queried from within xNext() and other v-table methods using
- ** prepared queries. If such a query is out-of-date, we do not want to
- ** discard the database schema, as the user code implementing the
- ** v-table would have to be ready for the sqlite3_vtab structure itself
- ** to be invalidated whenever sqlite3_step() is called from within
- ** a v-table method.
- */
- if( db->aDb[pOp->p1].pSchema->schema_cookie!=iMeta ){
- sqlite3ResetOneSchema(db, pOp->p1);
- }
-
- p->expired = 1;
- rc = SQLITE_SCHEMA;
- }
- break;
-}
-
/* Opcode: OpenRead P1 P2 P3 P4 P5
** Synopsis: root=P2 iDb=P3
**
diff --git a/src/vdbeblob.c b/src/vdbeblob.c
index 20841c4..0fbc1ad 100644
--- a/src/vdbeblob.c
+++ b/src/vdbeblob.c
@@ -134,21 +134,20 @@
** transaction.
*/
static const VdbeOpList openBlob[] = {
- {OP_Transaction, 0, 0, 0}, /* 0: Start a transaction */
- {OP_VerifyCookie, 0, 0, 0}, /* 1: Check the schema cookie */
- {OP_TableLock, 0, 0, 0}, /* 2: Acquire a read or write lock */
+ /* {OP_Transaction, 0, 0, 0}, // 0: Inserted separately */
+ {OP_TableLock, 0, 0, 0}, /* 1: Acquire a read or write lock */
/* One of the following two instructions is replaced by an OP_Noop. */
- {OP_OpenRead, 0, 0, 0}, /* 3: Open cursor 0 for reading */
- {OP_OpenWrite, 0, 0, 0}, /* 4: Open cursor 0 for read/write */
+ {OP_OpenRead, 0, 0, 0}, /* 2: Open cursor 0 for reading */
+ {OP_OpenWrite, 0, 0, 0}, /* 3: Open cursor 0 for read/write */
- {OP_Variable, 1, 1, 1}, /* 5: Push the rowid to the stack */
- {OP_NotExists, 0, 10, 1}, /* 6: Seek the cursor */
- {OP_Column, 0, 0, 1}, /* 7 */
- {OP_ResultRow, 1, 0, 0}, /* 8 */
- {OP_Goto, 0, 5, 0}, /* 9 */
- {OP_Close, 0, 0, 0}, /* 10 */
- {OP_Halt, 0, 0, 0}, /* 11 */
+ {OP_Variable, 1, 1, 1}, /* 4: Push the rowid to the stack */
+ {OP_NotExists, 0, 10, 1}, /* 5: Seek the cursor */
+ {OP_Column, 0, 0, 1}, /* 6 */
+ {OP_ResultRow, 1, 0, 0}, /* 7 */
+ {OP_Goto, 0, 4, 0}, /* 8 */
+ {OP_Close, 0, 0, 0}, /* 9 */
+ {OP_Halt, 0, 0, 0}, /* 10 */
};
int rc = SQLITE_OK;
@@ -261,36 +260,31 @@
Vdbe *v = (Vdbe *)pBlob->pStmt;
int iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+
+ sqlite3VdbeAddOp4Int(v, OP_Transaction, iDb, flags,
+ pTab->pSchema->schema_cookie,
+ pTab->pSchema->iGeneration);
+ sqlite3VdbeChangeP5(v, 1);
sqlite3VdbeAddOpList(v, sizeof(openBlob)/sizeof(VdbeOpList), openBlob);
-
- /* Configure the OP_Transaction */
- sqlite3VdbeChangeP1(v, 0, iDb);
- sqlite3VdbeChangeP2(v, 0, flags);
-
- /* Configure the OP_VerifyCookie */
- sqlite3VdbeChangeP1(v, 1, iDb);
- sqlite3VdbeChangeP2(v, 1, pTab->pSchema->schema_cookie);
- sqlite3VdbeChangeP3(v, 1, pTab->pSchema->iGeneration);
-
/* Make sure a mutex is held on the table to be accessed */
sqlite3VdbeUsesBtree(v, iDb);
/* Configure the OP_TableLock instruction */
#ifdef SQLITE_OMIT_SHARED_CACHE
- sqlite3VdbeChangeToNoop(v, 2);
+ sqlite3VdbeChangeToNoop(v, 1);
#else
- sqlite3VdbeChangeP1(v, 2, iDb);
- sqlite3VdbeChangeP2(v, 2, pTab->tnum);
- sqlite3VdbeChangeP3(v, 2, flags);
- sqlite3VdbeChangeP4(v, 2, pTab->zName, P4_TRANSIENT);
+ sqlite3VdbeChangeP1(v, 1, iDb);
+ sqlite3VdbeChangeP2(v, 1, pTab->tnum);
+ sqlite3VdbeChangeP3(v, 1, flags);
+ sqlite3VdbeChangeP4(v, 1, pTab->zName, P4_TRANSIENT);
#endif
/* Remove either the OP_OpenWrite or OpenRead. Set the P2
** parameter of the other to pTab->tnum. */
- sqlite3VdbeChangeToNoop(v, 4 - flags);
- sqlite3VdbeChangeP2(v, 3 + flags, pTab->tnum);
- sqlite3VdbeChangeP3(v, 3 + flags, iDb);
+ sqlite3VdbeChangeToNoop(v, 3 - flags);
+ sqlite3VdbeChangeP2(v, 2 + flags, pTab->tnum);
+ sqlite3VdbeChangeP3(v, 2 + flags, iDb);
/* Configure the number of columns. Configure the cursor to
** think that the table has one more column than it really
@@ -299,8 +293,8 @@
** we can invoke OP_Column to fill in the vdbe cursors type
** and offset cache without causing any IO.
*/
- sqlite3VdbeChangeP4(v, 3+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
- sqlite3VdbeChangeP2(v, 7, pTab->nCol);
+ sqlite3VdbeChangeP4(v, 2+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
+ sqlite3VdbeChangeP2(v, 6, pTab->nCol);
if( !db->mallocFailed ){
pParse->nVar = 1;
pParse->nMem = 1;