org.xerial.db.heap
Class HeapPage

java.lang.Object
  org.xerial.db.heap.HeapPage

All Implemented Interfaces:

Iterable<Tuple>

public class HeapPage
extends Object
implements Iterable<Tuple>

Heap pages support sequential data appends to the database. Page Layout:

 ----------------------
 |CommonPageHeader 
 |numEntries       
 |entrySizeTotal
 | (entries: ([entry size:VariableLengthInteger, entry data ...]) )
 |  ....
 | 
 |
 | [ pointers to entries (in sorted order) ]
 ----------------------
 

Author:

leo

Constructor Summary

HeapPage(int bufferSize)

Method Summary

void	append(Tuple tuple) Appends the tuple to this heap page
int	getHeaderSize()
Iterator<Tuple>	iterator()
void	loadFrom(Buffer pageBuffer, TupleFactory tupleFactory) Loads the heap contents from the buffer
void	saveTo(Buffer pageBuffer) Marshaling the heap contents, and write them to the page buffer
void	sortTuples(TupleComparator comparator) Sort the tuple in this heap page according to the given comparator

Methods inherited from class java.lang.Object

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

Constructor Detail

HeapPage

public HeapPage(int bufferSize)

Method Detail

getHeaderSize

public int getHeaderSize()

append

public void append(Tuple tuple)
            throws DBException

Appends the tuple to this heap page

Parameters:

tuple -

Throws:

DBException - when the page has no sufficient space for this tuple

sortTuples

public void sortTuples(TupleComparator comparator)

Sort the tuple in this heap page according to the given comparator

Parameters:

comparator - TupleComparator defines total order of the tuples

loadFrom

public void loadFrom(Buffer pageBuffer,
                     TupleFactory tupleFactory)
              throws DBException

Loads the heap contents from the buffer

Parameters:

pageBuffer - the buffer

tupleFactory - factory that creates tuples from raw byte arrays

Throws:

DBException - when page type is not heap

saveTo

public void saveTo(Buffer pageBuffer)

Marshaling the heap contents, and write them to the page buffer

Parameters:

pageBuffer -

iterator

public Iterator<Tuple> iterator()

Specified by:

iterator in interface Iterable<Tuple>