relop
Class FileScan

java.lang.Object
  relop.Iterator
      relop.FileScan

public class FileScan
extends Iterator

Wrapper for heap file scan, the most basic access method. This "iterator" version takes schema into consideration and generates real tuples.

Field Summary

Fields inherited from class relop.Iterator

schema

Constructor Summary

FileScan(Schema schema, HeapFile file)
Constructs a file scan, given the schema and heap file.

Method Summary

void	close() Closes the iterator, releasing any resources (i.e.
void	explain(int depth) Gives a one-line explaination of the iterator, repeats the call on any child iterators, and increases the indent depth along the way.
RID	getLastRID() Gets the RID of the last tuple returned.
Tuple	getNext() Gets the next tuple in the iteration.
boolean	hasNext() Returns true if there are more tuples, false otherwise.
boolean	isOpen() Returns true if the iterator is open; false otherwise.
void	restart() Restarts the iterator, i.e.

Methods inherited from class relop.Iterator

execute, finalize, indent

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

FileScan

public FileScan(Schema schema,
                HeapFile file)

Constructs a file scan, given the schema and heap file.

Method Detail

explain

public void explain(int depth)

Gives a one-line explaination of the iterator, repeats the call on any child iterators, and increases the indent depth along the way.

Specified by:

explain in class Iterator

restart

public void restart()

Restarts the iterator, i.e. as if it were just constructed.

Specified by:

restart in class Iterator

isOpen

public boolean isOpen()

Returns true if the iterator is open; false otherwise.

Specified by:

isOpen in class Iterator

close

public void close()

Closes the iterator, releasing any resources (i.e. pinned pages).

Specified by:

close in class Iterator

hasNext

public boolean hasNext()

Returns true if there are more tuples, false otherwise.

Specified by:

hasNext in class Iterator

getNext

public Tuple getNext()

Gets the next tuple in the iteration.

Specified by:

getNext in class Iterator

Throws:

java.lang.IllegalStateException - if no more tuples

getLastRID

public RID getLastRID()

Gets the RID of the last tuple returned.