/*
** Usage: btree_clear_table ID TABLENUM
**
** Remove all entries from the given table but keep the table around.
*/
static int btree_clear_table(
void *NotUsed,
Tcl_Interp *interp, /* The TCL interpreter that invoked this command */
int argc, /* Number of arguments */
const char **argv /* Text of each argument */
){
Btree *pBt;
int iTable;
int rc;
if( argc!=3 ){
Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
" ID TABLENUM\"", 0);
return TCL_ERROR;
}
pBt = sqlite3TestTextToPtr(argv[1]);
if( Tcl_GetInt(interp, argv[2], &iTable) ) return TCL_ERROR;
sqlite3BtreeEnter(pBt);
rc = sqlite3BtreeClearTable(pBt, iTable, 0);
sqlite3BtreeLeave(pBt);
if( rc!=SQLITE_OK ){
Tcl_AppendResult(interp, errorName(rc), 0);
return TCL_ERROR;
}
return TCL_OK;
}
/*
** Reset an Agg structure. Delete all its contents.
**
** For installable aggregate functions, if the step function has been
** called, make sure the finalizer function has also been called. The
** finalizer might need to free memory that was allocated as part of its
** private context. If the finalizer has not been called yet, call it
** now.
**
** If db is NULL, then this is being called from sqliteVdbeReset(). In
** this case clean up all references to the temp-table used for
** aggregates (if it was ever opened).
**
** If db is not NULL, then this is being called from with an OP_AggReset
** opcode. Open the temp-table, if it has not already been opened and
** delete the contents of the table used for aggregate information, ready
** for the next round of aggregate processing.
*/
int sqlite3VdbeAggReset(sqlite3 *db, Agg *pAgg, KeyInfo *pKeyInfo){
int rc = 0;
BtCursor *pCsr = pAgg->pCsr;
assert( (pCsr && pAgg->nTab>0) || (!pCsr && pAgg->nTab==0)
|| sqlite3_malloc_failed );
/* If pCsr is not NULL, then the table used for aggregate information
** is open. Loop through it and free the AggElem* structure pointed at
** by each entry. If the finalizer has not been called for an AggElem,
** do that too. Finally, clear the btree table itself.
*/
if( pCsr ){
int res;
assert( pAgg->pBtree );
assert( pAgg->nTab>0 );
rc=sqlite3BtreeFirst(pCsr, &res);
while( res==0 && rc==SQLITE_OK ){
AggElem *pElem;
rc = sqlite3BtreeData(pCsr, 0, sizeof(AggElem*), (char *)&pElem);
if( res!=SQLITE_OK ){
return rc;
}
assert( pAgg->apFunc!=0 );
freeAggElem(pElem, pAgg);
rc=sqlite3BtreeNext(pCsr, &res);
}
if( rc!=SQLITE_OK ){
return rc;
}
sqlite3BtreeCloseCursor(pCsr);
sqlite3BtreeClearTable(pAgg->pBtree, pAgg->nTab);
}else{
/* The cursor may not be open because the aggregator was never used,
** or it could be that it was used but there was no GROUP BY clause.
*/
if( pAgg->pCurrent ){
freeAggElem(pAgg->pCurrent, pAgg);
}
}
/* If db is not NULL and we have not yet and we have not yet opened
** the temporary btree then do so and create the table to store aggregate
** information.
**
** If db is NULL, then close the temporary btree if it is open.
*/
if( db ){
if( !pAgg->pBtree ){
assert( pAgg->nTab==0 );
rc = sqlite3BtreeFactory(db, ":memory:", 0, TEMP_PAGES, &pAgg->pBtree);
if( rc!=SQLITE_OK ) return rc;
sqlite3BtreeBeginTrans(pAgg->pBtree, 1);
rc = sqlite3BtreeCreateTable(pAgg->pBtree, &pAgg->nTab, 0);
if( rc!=SQLITE_OK ) return rc;
}
assert( pAgg->nTab!=0 );
rc = sqlite3BtreeCursor(pAgg->pBtree, pAgg->nTab, 1,
sqlite3VdbeRecordCompare, pKeyInfo, &pAgg->pCsr);
if( rc!=SQLITE_OK ) return rc;
}else{
if( pAgg->pBtree ){
sqlite3BtreeClose(pAgg->pBtree);
pAgg->pBtree = 0;
pAgg->nTab = 0;
}
pAgg->pCsr = 0;
}
if( pAgg->apFunc ){
sqliteFree(pAgg->apFunc);
pAgg->apFunc = 0;
}
pAgg->pCurrent = 0;
pAgg->nMem = 0;
pAgg->searching = 0;
return SQLITE_OK;
}
