void xyzsql_process_delete() {
auto s = dynamic_cast<delete_stmt *>(stmt_queue.front().second);
if (s->condition_list->empty()) {
// delete all
system(("rm " + s->table_name + "/*.db").c_str());
RecordManager.createMaster(s->table_name);
auto table_info = catm.exist_relation(s->table_name);
auto cols = table_info->cols;
table_info->set_size(0);
for(auto x : *cols)
if(x->flag & (table_column::unique_attr | table_column::primary_attr))
IndexManager.createIndex(s->table_name + "/index_" + x->name + ".db", data_type_to_str(x->data_type),
x->str_len, 0, {}, {}, {});
} else {
auto table_info = catm.exist_relation(s->table_name);
int record_size = catm.calc_record_size(s->table_name);
BufferManager.newTrashCan();
// unique
condition *p = NULL, *eq = NULL;
for(auto x : *(s->condition_list)) {
if ( catm.is_indexed(x->left_attr) ) {
p = x;
if (x->op == condition::EQUALTO)
eq = x;
}
}
if ( eq != NULL || p != NULL ) {
cout << "Index used: " << p->left_attr->full_name << endl;
auto t = eq == NULL ? p->left_attr : eq->left_attr;
if (eq != NULL) p = eq;
indexIterator a;
int asdf = IndexManager.selectNode(a, base_addr + "/" + t->relation_name + "/index_" + t->attribute_name + ".db",
p->op, (p->v).to_str(catm.get_data_type(t)));
if ( asdf == 0 ) {
int b = 0, c = 0;
while (a.next(b, c) == 0) {
Record a = RecordManager.getRecord(t->relation_name, b, c, record_size);
if (calc_conditions(s->condition_list, a))
BufferManager.appendTrashCan(b, c);
}
}
} else {
indexIterator a;
int asdf = IndexManager.getStarter(a, s->table_name + "/index_" + catm.get_primary(s->table_name) + ".db");
if (asdf == 0) {
int b = 0, c = 0;
while (a.next(b, c) == 0) {
Record a = RecordManager.getRecord(s->table_name, b, c, record_size);
if (calc_conditions(s->condition_list, a))
BufferManager.appendTrashCan(b, c);
}
}
}
BufferManager.beginFetchTrash();
int blockNum, offset;
while(BufferManager.fetchTrash(blockNum, offset)) {
auto r = RecordManager.getRecord(s->table_name, blockNum, offset, record_size);
for(auto x : *(r.table_info)) {
if(x->flag & (table_column::unique_attr | table_column::primary_attr)) {
indexIterator cursor;
IndexManager.deleteNode(s->table_name + "/index_" + x->name + ".db", r.get_value(x).to_str(x->data_type));
}
}
RecordManager.deleteRecord(s->table_name, blockNum, offset, record_size);
table_info->dec_size();
}
}
cout << "records deleted." << endl;
}
