static RC RollBackUpdate(SM_DbHandle &db, Event &event, RID &rid)
{
RC rc;
printf("QL: Undoing update.\n");
RM_FileHandle *pTableHandle;
if ((rc = db.FindTableHandle(event.tableName.c_str(), pTableHandle)))
return rc;
RM_Record record;
if ((rc = pTableHandle->GetRec(rid, record)))
return rc;
char *data;
if ((rc = record.GetData(data)))
return rc;
SM_Attribute *pAttr;
if ((rc = db.FindAttribute(event.tableName.c_str(), event.attrName.c_str(), pAttr)))
return rc;
// If indexed, remove the old entry.
IX_IndexHandle *pIndexHandle;
if (pAttr->hasIndex) {
if ((rc = db.FindIndexHandle(event.tableName.c_str(), event.attrName.c_str(), pIndexHandle)))
return rc;
if ((rc = pIndexHandle->DeleteEntry(data + pAttr->attrOffset, rid)))
return rc;
}
// Restore the record.
int recordSize = pTableHandle->header.recordSize;
memcpy(data, event.record, recordSize);
// Update the record.
if ((rc = pTableHandle->UpdateRec(record)))
return rc;
// If indexed, insert the new entry.
if (pAttr->hasIndex) {
if ((rc = pIndexHandle->InsertEntry(data + pAttr->attrOffset, rid)))
return rc;
}
return 0;
}
RC QL_Manager::FindRecords(const char *relName, vector<RM_Record> &records){
RC rc;
RM_FileHandle *rh;
IX_IndexHandle *ih;
if (rc = db.FindTableHandle(relName, rh))
return rc;
RM_FileScan rmscan;
IX_IndexScan ixscan;
vector<RM_Record> v_now;
v_now.clear();
bool flagAll = true;
if (rmp.nConditions) {
for (int i = 0; i < rmp.nConditions; i++)
if (rmp.conditions[i].bRhsIsValue) {
if (strcmp(relName, rmp.conditions[i].lhsAttr.relName) != 0)
continue;
vector<RM_Record> v_tmp;
v_tmp.clear();
char *attrName = rmp.conditions[i].lhsAttr.attrName;
SM_Attribute *smAttr;
if (rc = db.FindAttribute(relName, attrName, smAttr))
return rc;
AttrType attrType = smAttr->attrType;
int attrLength = smAttr->attrLength;
int attrOffset = smAttr->attrOffset;
int attrNumber = smAttr->number;
CompOp op = rmp.conditions[i].op;
void *data = rmp.conditions[i].rhsValue.data;
if (smAttr->hasIndex && isCmpOp(op)) {
if (rc = db.FindIndexHandle(relName, attrName, ih))
return rc;
ixscan.OpenScan(*ih, op, data);
RID rid;
RM_Record rec;
v_tmp.clear();
while (1) {
rc = ixscan.GetNextEntry(rid);
if (rc != 0 && rc != IX_EOF)
return rc;
if (rc == IX_EOF) break;
if (rc = rh->GetRec(rid, rec))
return rc;
v_tmp.push_back(rec);
}
ixscan.CloseScan();
} else {
if (op == IS_OP || op == IS_NOT_OP) {
int number = smAttr->number;
int nullBitmap = rh->header.recordSize - sizeof(int);
if ((rc = rmscan.OpenScan(*rh, NOTYPE, 4, nullBitmap, 0, op, &number)))
return rc;
} else {
if (rc = rmscan.OpenScan(*rh, attrType, attrLength, attrOffset, attrNumber, op, data))
return rc;
}
v_tmp.clear();
RM_Record rec;
while (rmscan.GetNextRec(rec) != RM_ERR_EOF) {
v_tmp.push_back(rec);
}
if (rc = rmscan.CloseScan())
return rc;
}
if (rc = MergeAnd(v_now, v_tmp, flagAll))
return rc;
flagAll = false;
}
}
//cout << "before flagAll\n";
if (flagAll) {
int t = 0;
if (rc = rmscan.OpenScan(*rh, INT, 4, 0, 0, NO_OP, &t, NO_HINT))
return rc;
//cout << "after open scan\n";
RM_Record rec;
v_now.clear();
while (rmscan.GetNextRec(rec) != RM_ERR_EOF)
v_now.push_back(rec);
if (rc = rmscan.CloseScan())
return rc;
}
//cout << "after flagAll\n";
records.clear();
records.assign(v_now.begin(), v_now.end());
return 0;
}