Inheritance diagram for badgerdb::FileScan:

Public Member Functions
	FileScan (const std::string &name, BufMgr *bufMgr)
	~FileScan ()
void	insertRecord (const std::string &rec, RecordId &outRid)
void	deleteRecord (RecordId rid)
void	startScan (int offset, int length, Datatype type, std::string filter, Operator op)
void	endScan ()
void	scanNext (RecordId &outRid)
std::string	getRecord ()
std::string	getRandomRecord (RecordId rid)
void	gotoMark (RecordId rid)
bool	matchRec (const std::string &rec)
void	flushFile ()
void	markDirty ()
Protected Attributes
BufMgr *	bufMgr

Detailed Description

Definition at line 20 of file filescan.h.

Constructor & Destructor Documentation

badgerdb::FileScan::FileScan	(	const std::string &	name,
		BufMgr *	bufMgr
	)

Constructor.

Definition at line 16 of file filescan.cpp.

{
  try
  {
    file = new PageFile(name, false); //dont create new file
    //std::cout << "File:" << name << " opened.\n";
  }
  catch(FileNotFoundException e)
  {
    file = new PageFile(name, true);  //dont create new file
    //std::cout << "File:" << name << " created.\n";
  }

  bufMgr = bufferMgr;
  curDirtyFlag = false;
  curPage = NULL;
  filePageIter = file->begin();
}

badgerdb::FileScan::~FileScan ( )

Destructor.

Definition at line 101 of file filescan.cpp.

{
  flushFile();

  delete file;
}

Member Function Documentation

void badgerdb::FileScan::deleteRecord ( RecordId rid )

Delete a record. No need to mark the page dirty by calling markDirty().

Definition at line 79 of file filescan.cpp.

{
  Page *dPage;
  bufMgr->readPage(file, rid.page_number, dPage);
  dPage->deleteRecord(rid);
  bufMgr->unPinPage(file, rid.page_number, true);
}

void badgerdb::FileScan::endScan ( )

Reset scan parameters.

Definition at line 126 of file filescan.cpp.

{
  if (curPage != NULL)
  {
    bufMgr->unPinPage(file, (*filePageIter).page_number(), curDirtyFlag);
  }

  curPage = NULL;
  curDirtyFlag = false;
  filePageIter = file->begin();
  filter.clear();
}

void badgerdb::FileScan::flushFile ( )

Flush file from buffer manager and reset all parameters.

Definition at line 87 of file filescan.cpp.

{
  // generally must unpin last page of the scan
  if (curPage != NULL)
  {
    bufMgr->unPinPage(file, (*filePageIter).page_number(), curDirtyFlag);
    curPage = NULL;
    curDirtyFlag = false;
    filePageIter = file->begin();
  }

  bufMgr->flushFile(file);
}

std::string badgerdb::FileScan::getRandomRecord ( RecordId rid )

Read a record with RecordId rid from file.

Definition at line 226 of file filescan.cpp.

{
  // Solution Starts
  Page* page;

  bufMgr->readPage(file, rid.page_number, page);
  std::string retStr = page->getRecord(rid);
  bufMgr->unPinPage(file, rid.page_number, false);

  return retStr;
}

std::string badgerdb::FileScan::getRecord ( )

Read current record, whose RecordId was returned by last call to scanNext().

Definition at line 221 of file filescan.cpp.

{
  return *pageRecordIter;
}

void badgerdb::FileScan::gotoMark ( RecordId rid )

Point to particular record in the file so that next calls to scanNext() scan file beyond this particular record.

Definition at line 35 of file filescan.cpp.

{
  if(curPage != NULL)
  {
    bufMgr->unPinPage(file, (*filePageIter).page_number(), curDirtyFlag);
  }

  curDirtyFlag = false;
  filePageIter = file->beginAt(rid.page_number);
  bufMgr->readPage(file, rid.page_number, curPage); 
  pageRecordIter = curPage->beginAt(rid.slot_number);
}

void badgerdb::FileScan::insertRecord	(	const std::string &	rec,
		RecordId &	outRid
	)

Insert a new record in file, RecordId of inserted record returned in outRid. No need to mark the page dirty by calling markDirty().

Definition at line 48 of file filescan.cpp.

{
  Page *iPage;
  PageId iPageNo;

  for (FileIterator iter = file->begin(); iter != file->end(); ++iter)
  {
    iPageNo = iter.getCurrentPageNo();

    if(iPageNo == Page::INVALID_NUMBER)
      break;

    bufMgr->readPage(file, iPageNo, iPage);

    try
    {
      outRid = iPage->insertRecord(rec);
      bufMgr->unPinPage(file, iPageNo, true);
      return;
    }
    catch(InsufficientSpaceException &e)
    {
      bufMgr->unPinPage(file, iPageNo, false);
    }
  }

  bufMgr->allocPage(file, iPageNo, iPage);
  outRid = iPage->insertRecord(rec);
  bufMgr->unPinPage(file, iPageNo, true);
}

void badgerdb::FileScan::markDirty ( )

Mark current page being scanned in FileScan dirty.

Definition at line 287 of file filescan.cpp.

{
  curDirtyFlag = true;
}

bool badgerdb::FileScan::matchRec ( const std::string & rec )

Check if a record satisfies the scan parameters.

Definition at line 238 of file filescan.cpp.

{
  // no filtering requested
  if (filter.empty()) return true;

  // see if offset + length is beyond end of record
  // maybe this should be an error???
  if ((offset + length -1 ) >= rec.size())
    return false;

  double diff = 0;                       // < 0 if attr < fltr
  switch(type) {

    case INTEGER:
      int iattr, ifltr;                 // word-alignment problem possible
      memcpy(&iattr, rec.c_str() + offset,  length);
      memcpy(&ifltr, filter.c_str(),  length);
      //ifltr = atoi(filter.c_str());
      diff = iattr - ifltr;
      break;

    case DOUBLE:
      double fattr, ffltr;               // word-alignment problem possible
      memcpy(&fattr, rec.c_str() + offset,  length);
      memcpy(&ffltr, filter.c_str(),  length);
      //ffltr = atof(filter.c_str());
      diff = fattr - ffltr;
      break;

    case STRING:
      diff = strncmp(rec.c_str() + offset,  filter.c_str(), length);
      break;
  }

  switch(op) {
    case LT:  if (diff < 0.0) return true; break;
    case LTE: if (diff <= 0.0) return true; break;
    case EQ:  if (diff == 0.0) return true; break;
    case GTE: if (diff >= 0.0) return true; break;
    case GT:  if (diff > 0.0) return true; break;
    case NE:  if (diff != 0.0) return true; break;
    default: break;
  }

  return false;

}

void badgerdb::FileScan::scanNext ( RecordId & outRid )

Returns RecordId of next record that satisfies the scan parameters, if any.

Definition at line 139 of file filescan.cpp.

{
  std::string rec;

  if(filePageIter == file->end())
  {
    throw EndOfFileException();
  }

  // special case of the first record of the first page of the file
  if (curPage == NULL)
  {
    // need to get the first page of the file
    filePageIter = file->begin();
    if(filePageIter == file->end())
    {
      throw EndOfFileException();
    }
   
    // read the first page of the file
    bufMgr->readPage(file, (*filePageIter).page_number(), curPage); 
    curDirtyFlag = false;

    // get the first record off the page
    pageRecordIter = curPage->begin(); 

    if(pageRecordIter != curPage->end()) 
    {
      // get pointer to record
      rec = *pageRecordIter;
      if(matchRec(rec))
      {
        outRid = pageRecordIter.getCurrentRecord();
        return;
      }
    }
  }

  // Loop, looking for a record that satisfied the predicate.
  // First try and get the next record off the current page
  pageRecordIter++;

  while(1)
  {
    while (pageRecordIter == curPage->end())
    {
      // unpin the current page
      bufMgr->unPinPage(file, (*filePageIter).page_number(), curDirtyFlag);
      curPage = NULL;
      curDirtyFlag = false;

      filePageIter++;
      if (filePageIter == file->end())
      {
        curPage = NULL;
        throw EndOfFileException();
      }

      // read the next page of the file
      bufMgr->readPage(file, (*filePageIter).page_number(), curPage);

      // get the first record off the page
      pageRecordIter = curPage->begin(); 
    }

    while (pageRecordIter != curPage->end())
    {
      rec = *pageRecordIter;

      if(matchRec(rec))
      {
        // return rid of the record
        outRid = pageRecordIter.getCurrentRecord();
        return;
      }
      pageRecordIter++;
    }
  }
}

void badgerdb::FileScan::startScan	(	int	offset,
		int	length,
		Datatype	type,
		std::string	filter,
		Operator	op
	)

To set up scan parameters used by scanNext. If just want to scan all the records in the file, no need to call this, you may directly call scanNext().

Definition at line 108 of file filescan.cpp.

{
  curPage = NULL;
  curDirtyFlag = false;
  filePageIter = file->begin();

  if (filterIn.empty()) {                        // no filtering requested
    filter.clear();
    return;
  }

  offset = offsetIn;
  length = lengthIn;
  type = typeIn;
  filter = filterIn;
  op = opIn;
}

The documentation for this class was generated from the following files:

/afs/cs.wisc.edu/u/n/w/nwilliam/private/workspace/Quut/src/filescan.h
/afs/cs.wisc.edu/u/n/w/nwilliam/private/workspace/Quut/src/filescan.cpp

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation