org.cdlib.xtf.util
Class DiskHashReader

Object
  DiskHashReader

public class DiskHashReader
extends Object

Provides quick access to a disk-based hash table created by a DiskHashWriter.

Author:

Martin Haye

Field Summary

(package private) static int	headerSize Size of the header we expect to find
private int	nSlots Number of hash slots in the subfile
private PackedByteBuf	slotBuf Used to decode hash slot values
private byte[]	slotBytes Buffer used to read hash slot bytes
private int	slotSize Size of each hash slot
private SubStoreReader	subfile SubStore to read the hash from

Constructor Summary

DiskHashReader(SubStoreReader subfile)
Read in the header of of the hash from the given subfile.

Method Summary

void	close() Closes the reader (and its associated subfile).
PackedByteBuf	find(String key) Locate the entry for the given string key.

Methods inherited from class Object

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

Field Detail

headerSize

static final int headerSize

Size of the header we expect to find

See Also:

Constant Field Values

subfile

private SubStoreReader subfile

SubStore to read the hash from

nSlots

private int nSlots

Number of hash slots in the subfile

slotSize

private int slotSize

Size of each hash slot

slotBytes

private byte[] slotBytes

Buffer used to read hash slot bytes

slotBuf

private PackedByteBuf slotBuf

Used to decode hash slot values

Constructor Detail

DiskHashReader

public DiskHashReader(SubStoreReader subfile)
               throws IOException

Read in the header of of the hash from the given subfile.

Parameters:

subfile - Must have been created by DiskHashWriter.outputTo()

Throws:

IOException

Method Detail

close

public void close()

Closes the reader (and its associated subfile).

find

public PackedByteBuf find(String key)
                   throws IOException

Locate the entry for the given string key. If not found, returns null.

Parameters:

key - key to look for

Throws:

IOException