heap
Class HeapScan

java.lang.Object
  heap.HeapScan

All Implemented Interfaces:

GlobalConst

public class HeapScan
extends java.lang.Object
implements GlobalConst

A HeapScan object is created only through the function openScan() in the HeapFile class. It supports the getNext interface which will simply retrieve the next record in the file.

Field Summary

Fields inherited from interface global.GlobalConst

EMPTY_SLOT, FIRST_PAGEID, INVALID_PAGEID, MAX_COLSIZE, MAX_TUPSIZE, NAME_MAXLEN, PAGE_SIZE, PIN_DISKIO, PIN_MEMCPY, UNPIN_CLEAN, UNPIN_DIRTY

Method Summary

void	close() Closes the file scan, releasing any pinned pages.
byte[]	getNext(RID rid) Gets the next record in the file scan.
boolean	hasNext() Returns true if there are more records to scan, false otherwise.

Methods inherited from class java.lang.Object

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

Method Detail

close

public void close()

Closes the file scan, releasing any pinned pages.

hasNext

public boolean hasNext()

Returns true if there are more records to scan, false otherwise.

getNext

public byte[] getNext(RID rid)

Gets the next record in the file scan.

Parameters:

rid - output parameter that identifies the returned record

Throws:

java.lang.IllegalStateException - if the scan has no more elements