/*
** This function is called from within the echo-modules xCreate and
** xConnect methods. The argc and argv arguments are copies of those
** passed to the calling method. This function is responsible for
** calling sqlite3_declare_vtab() to declare the schema of the virtual
** table being created or connected.
**
** If the constructor was passed just one argument, i.e.:
**
** CREATE TABLE t1 AS echo(t2);
**
** Then t2 is assumed to be the name of a *real* database table. The
** schema of the virtual table is declared by passing a copy of the
** CREATE TABLE statement for the real table to sqlite3_declare_vtab().
** Hence, the virtual table should have exactly the same column names and
** types as the real table.
*/
static int echoDeclareVtab(
echo_vtab pVtab,
sqlite3 db
)
{
int rc = SQLITE_OK;
if ( pVtab.zTableName != null )
{
sqlite3_stmt pStmt = null;
rc = sqlite3_prepare( db,
"SELECT sql FROM sqlite_master WHERE type = 'table' AND name = ?",
-1, ref pStmt, 0 );
if ( rc == SQLITE_OK )
{
sqlite3_bind_text( pStmt, 1, pVtab.zTableName, -1, null );
if ( sqlite3_step( pStmt ) == SQLITE_ROW )
{
int rc2;
string zCreateTable = (string)sqlite3_column_text( pStmt, 0 );
rc = sqlite3_declare_vtab( db, zCreateTable );
rc2 = sqlite3_finalize( pStmt );
if ( rc == SQLITE_OK )
{
rc = rc2;
}
}
else
{
rc = sqlite3_finalize( pStmt );
if ( rc == SQLITE_OK )
{
rc = SQLITE_ERROR;
}
}
if ( rc == SQLITE_OK )
{
rc = getColumnNames( db, pVtab.zTableName, out pVtab.aCol, out pVtab.nCol );
}
if ( rc == SQLITE_OK )
{
rc = getIndexArray( db, pVtab.zTableName, pVtab.nCol, ref pVtab.aIndex );
}
}
}
return rc;
}
/*
** This function is called to do the work of the xConnect() method -
** to allocate the required in-memory structures for a newly connected
** virtual table.
*/
static int echoConstructor(
sqlite3 db,
object pAux,
int argc, string[] argv,
out sqlite3_vtab ppVtab,
out string pzErr
)
{
int rc;
int i;
echo_vtab pVtab;
pzErr = "";
/* Allocate the sqlite3_vtab/echo_vtab structure itself */
pVtab = new echo_vtab();//sqlite3MallocZero( sizeof(*pVtab) );
//if( null==pVtab ){
// return SQLITE_NOMEM;
//}
pVtab.interp = ( (EchoModule)pAux ).interp;
pVtab.db = db;
/* Allocate echo_vtab.zThis */
pVtab.zThis = sqlite3_mprintf( "%s", argv[2] );
//if( null==pVtab.zThis ){
// object obj = ppVtab;
// echoDestructor( ref obj );
// obj = null;
// return SQLITE_NOMEM;
//}
/* Allocate echo_vtab.zTableName */
if ( argc > 3 )
{
pVtab.zTableName = sqlite3_mprintf( "%s", argv[3] );
dequoteString( ref pVtab.zTableName );
if ( !String.IsNullOrEmpty( pVtab.zTableName ) && pVtab.zTableName[0] == '*' )
{
string z = sqlite3_mprintf( "%s%s", argv[2], ( pVtab.zTableName.Substring(1) ) );
//sqlite3_free(pVtab.zTableName);
pVtab.zTableName = z;
pVtab.isPattern = 1;
}
//if( null==pVtab.zTableName ){
// object obj = ppVtab;
// echoDestructor( ref obj );
// obj = null;
// return SQLITE_NOMEM;
//}
}
/* Log the arguments to this function to Tcl var ::echo_module */
for ( i = 0; i < argc; i++ )
{
appendToEchoModule( pVtab.interp, argv[i] );
}
/* Invoke sqlite3_declare_vtab and set up other members of the echo_vtab
** structure. If an error occurs, delete the sqlite3_vtab structure and
** return an error code.
*/
rc = echoDeclareVtab( pVtab, db );
if ( rc != SQLITE_OK )
{
//object obj = ppVtab;
//echoDestructor( ref obj );
//obj = null;
ppVtab = null;
return rc;
}
/* Success. Set ppVtab and return */
ppVtab = pVtab;//.base;
return SQLITE_OK;
}
static int simulateVtabError( echo_vtab p, string zMethod )
{
string zErr;
StringBuilder zVarname = new StringBuilder( 128 );
//zVarname[127] = '\0';
sqlite3_snprintf( 127, zVarname, "echo_module_fail(%s,%s)", zMethod, p.zTableName );
zErr = TCL.Tcl_GetVar( p.interp, zVarname.ToString(), (TCL.VarFlag)TCL.TCL_GLOBAL_ONLY ).ToString();
if ( zErr != "" )
{
p.zErrMsg = sqlite3_mprintf( "echo-vtab-error: %s", zErr );
}
return ( zErr != "" ? 1 : 0 );
}
