const Status ScanSelect(const string & result,
const int projCnt,
const AttrDesc projNames[],
const AttrDesc *attrDesc,
const Operator op,
const char *filter,
const int reclen)
{
Status status;
RID rid;
Record outputRec;
Record rec;
cout << "Doing HeapFileScan Selection using ScanSelect()" << endl;
InsertFileScan resultRel(result, status);
if(status != OK) return status;
char outputData[reclen];
outputRec.data = (void *)outputData;
outputRec.length = reclen;
// HeapFileScan hfs(attrDesc->relName,status);
HeapFileScan hfs(projNames->relName,status);
if(status != OK) return status;
if(filter == NULL){
if((status = hfs.startScan(0, 0, (Datatype)0, filter, op)) != OK){
return status;
}
}else{
if((status = hfs.startScan(attrDesc->attrOffset, attrDesc->attrLen, (Datatype)attrDesc->attrType, filter, op)) != OK){
return status;
}
}
while((status = hfs.scanNext(rid)) == OK){
if((status = hfs.getRecord(rec)) != OK) return status;
int outputOffset = 0;
for( int i = 0; i < projCnt; i++){
memcpy(outputData + outputOffset, (char *)rec.data + projNames[i].attrOffset, projNames[i].attrLen);
outputOffset += projNames[i].attrLen;
}
RID outRID;
if((status = resultRel.insertRecord(outputRec,outRID)) != OK){
return status;
}
}
if(status == FILEEOF) return OK;
return status;
}
void Preprocessor::applyHelpFile()
{
std::string help_file = file_directory(file_name) + file_extension(file_name) + ".help";
std::ifstream hfs(help_file);
if(!hfs.is_open())
return;
hfs.close();
std::cout << "Using HELP file: " << help_file << '.' << std::endl;
readFile(help_file);
analyseSource();
lines.clear();
source.clear();
}
const Status QU_Delete(const string & relation,
const string & attrName,
const Operator op,
const Datatype type,
const char *attrValue)
{
RID rid;
Status status;
AttrDesc attrInfo;
Record record;
// Set up a HeapFileScan
HeapFileScan hfs(relation, status);
if (status != OK) return status;
// Get attribute information
status = attrCat->getInfo(relation, attrName, attrInfo);
if (status != OK) return status;
// Start the scan with the attribute info gained above.
status = hfs.startScan(attrInfo, attrInfo.attLen, type, attrValue, op);
if (status != OK) return status;
// Find all tuples in relation
while ((status = hfs.scanNext(rid)) == OK) {
// get record
status = hfs.getRecord(record);
if (status != OK) return status;
// delete record
status = hfs.deleteRecord();
if (status != OK) return status;
}
return OK;
}
const Status ScanSelect(const string & result,
const int projCnt,
const AttrDesc projNames[],
const AttrDesc *attrDesc,
const Operator op,
const char *filter,
const int reclen)
{
cout << "Doing HeapFileScan Selection using ScanSelect()" << endl;
Status s;
Record outRec;
InsertFileScan ifs(result, s);
if(s != OK) return s;
char * outData = (char *)malloc(reclen);
if(!outData){
return INSUFMEM;
}
outRec.data = outData;
outRec.length = reclen;
HeapFileScan hfs(projNames->relName,s);
if(s != OK) return s;
if(filter == NULL)
{
if((s = hfs.startScan(0, 0, STRING, NULL, op)) != OK)
return s;
}
else
{
if((s = hfs.startScan(attrDesc->attrOffset, attrDesc->attrLen, (Datatype)attrDesc->attrType, filter, op)) != OK)
return s;
}
Record rec;
RID rid;
while((s = hfs.scanNext(rid)) == OK)
{
s = hfs.getRecord(rec);
if(s != OK) return s;
int offset = 0;
for( int i = 0; i < projCnt; i++)
{
memcpy(outData+offset, (char *)rec.data+projNames[i].attrOffset, projNames[i].attrLen);
offset+=projNames[i].attrLen;
}
s = ifs.insertRecord(outRec,rid);
if(s != OK) return s;
}
if(s == FILEEOF) s = OK;
return s;
}
