Test that virtual table methods xBestIndex, xOpen, xFilter, xNext, xColumn, xRowid, xUpdate, xSync and xBegin can all return error messages using the sqlite3_vtab.zErrMsg variable. (CVS 5519)

FossilOrigin-Name: 007359b770f225877880b11f4c5d97bb548e38ca

src/test8.c

@@ -13,7 +13,7 @@
 ** is not included in the SQLite library.  It is used for automated
 ** testing of the SQLite library.
 **
-** $Id: test8.c,v 1.69 2008/07/28 19:34:54 drh Exp $
+** $Id: test8.c,v 1.70 2008/08/01 17:37:41 danielk1977 Exp $
 */
 #include "sqliteInt.h"
 #include "tcl.h"
@@ -44,6 +44,22 @@ typedef struct echo_cursor echo_cursor;
 ** use the named table as a backing store will fail.
 */
 
+/*
+** Errors can be provoked within the following echo virtual table methods:
+**
+**   xBestIndex   xOpen     xFilter   xNext   
+**   xColumn      xRowid    xUpdate   xSync   
+**   xBegin
+**
+** This is done by setting the global tcl variable:
+**
+**   echo_module_fail($method,$tbl)
+**
+** where $method is set to the name of the virtual table method to fail
+** (i.e. "xBestIndex") and $tbl is the name of the table being echoed (not
+** the name of the virtual table, the name of the underlying real table).
+*/
+
 /* 
 ** An echo virtual-table object.
 **
@@ -76,6 +92,18 @@ struct echo_cursor {
   sqlite3_stmt *pStmt;
 };
 
+static int simulateVtabError(echo_vtab *p, const char *zMethod){
+  const char *zErr;
+  char zVarname[128];
+  zVarname[127] = '\0';
+  snprintf(zVarname, 127, "echo_module_fail(%s,%s)", zMethod, p->zTableName);
+  zErr = Tcl_GetVar(p->interp, zVarname, TCL_GLOBAL_ONLY);
+  if( zErr ){
+    p->base.zErrMsg = sqlite3_mprintf("echo-vtab-error: %s", zErr);
+  }
+  return (zErr!=0);
+}
+
 /*
 ** Convert an SQL-style quoted string into a normal string by removing
 ** the quote characters.  The conversion is done in-place.  If the
@@ -524,6 +552,9 @@ static int echoDestroy(sqlite3_vtab *pVtab){
 */
 static int echoOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
   echo_cursor *pCur;
+  if( simulateVtabError((echo_vtab *)pVTab, "xOpen") ){
+    return SQLITE_ERROR;
+  }
   pCur = sqlite3MallocZero(sizeof(echo_cursor));
   *ppCursor = (sqlite3_vtab_cursor *)pCur;
   return (pCur ? SQLITE_OK : SQLITE_NOMEM);
@@ -557,6 +588,10 @@ static int echoNext(sqlite3_vtab_cursor *cur){
   int rc = SQLITE_OK;
   echo_cursor *pCur = (echo_cursor *)cur;
 
+  if( simulateVtabError((echo_vtab *)(cur->pVtab), "xNext") ){
+    return SQLITE_ERROR;
+  }
+
   if( pCur->pStmt ){
     rc = sqlite3_step(pCur->pStmt);
     if( rc==SQLITE_ROW ){
@@ -576,6 +611,11 @@ static int echoNext(sqlite3_vtab_cursor *cur){
 static int echoColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
   int iCol = i + 1;
   sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
+
+  if( simulateVtabError((echo_vtab *)(cur->pVtab), "xColumn") ){
+    return SQLITE_ERROR;
+  }
+
   if( !pStmt ){
     sqlite3_result_null(ctx);
   }else{
@@ -590,6 +630,11 @@ static int echoColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
 */
 static int echoRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
   sqlite3_stmt *pStmt = ((echo_cursor *)cur)->pStmt;
+
+  if( simulateVtabError((echo_vtab *)(cur->pVtab), "xRowid") ){
+    return SQLITE_ERROR;
+  }
+
   *pRowid = sqlite3_column_int64(pStmt, 0);
   return SQLITE_OK;
 }
@@ -627,6 +672,10 @@ static int echoFilter(
   echo_vtab *pVtab = (echo_vtab *)pVtabCursor->pVtab;
   sqlite3 *db = pVtab->db;
 
+  if( simulateVtabError(pVtab, "xFilter") ){
+    return SQLITE_ERROR;
+  }
+
   /* Check that idxNum matches idxStr */
   assert( idxNum==hashString(idxStr) );
 
@@ -734,12 +783,15 @@ static int echoBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   int rc = SQLITE_OK;
   int useCost = 0;
   double cost;
-
   int isIgnoreUsable = 0;
   if( Tcl_GetVar(interp, "echo_module_ignore_usable", TCL_GLOBAL_ONLY) ){
     isIgnoreUsable = 1;
   }
 
+  if( simulateVtabError(pVtab, "xBestIndex") ){
+    return SQLITE_ERROR;
+  }
+
   /* Determine the number of rows in the table and store this value in local
   ** variable nRow. The 'estimated-cost' of the scan will be the number of
   ** rows in the table for a linear scan, or the log (base 2) of the 
@@ -892,6 +944,10 @@ int echoUpdate(
   ** making any changes to a virtual table */
   assert( pVtab->inTransaction );
 
+  if( simulateVtabError(pVtab, "xUpdate") ){
+    return SQLITE_ERROR;
+  }
+
   /* If apData[0] is an integer and nData>1 then do an UPDATE */
   if( nData>1 && sqlite3_value_type(apData[0])==SQLITE_INTEGER ){
     char *zSep = " SET";
@@ -1019,6 +1075,10 @@ static int echoBegin(sqlite3_vtab *tab){
   ** a transaction */
   assert( !pVtab->inTransaction );
 
+  if( simulateVtabError(pVtab, "xBegin") ){
+    return SQLITE_ERROR;
+  }
+
   rc = echoTransactionCall(tab, "xBegin");
 
   if( rc==SQLITE_OK ){
@@ -1046,6 +1106,10 @@ static int echoSync(sqlite3_vtab *tab){
   ** transaction */
   assert( pVtab->inTransaction );
 
+  if( simulateVtabError(pVtab, "xSync") ){
+    return SQLITE_ERROR;
+  }
+
   rc = echoTransactionCall(tab, "xSync");
 
   if( rc==SQLITE_OK ){
@@ -1068,6 +1132,10 @@ static int echoCommit(sqlite3_vtab *tab){
   ** a transaction */
   assert( pVtab->inTransaction );
 
+  if( simulateVtabError(pVtab, "xCommit") ){
+    return SQLITE_ERROR;
+  }
+
   sqlite3BeginBenignMalloc();
   rc = echoTransactionCall(tab, "xCommit");
   sqlite3EndBenignMalloc();