org.cdlib.xtf.util
Class CharMap

Object
  CharMap

public class CharMap
extends Object

Maintains an in-memory, one-to-one mapping from characters in one set to characters in another. The list is read from a disk file, which may be sorted or unsorted. The format of file entries should be one pair per line, separated by a bar ("|") character. The first word is considered the "key", the second is the "value". Each should be a four-digit hex number representing a Unicode code point. For speed, an in-memory cache of recently mapped words is maintained.

Field Summary

private FastCache	cache Keep a cache of lookups performed to-date
private static int	CACHE_SIZE How many recent mappings to maintain
private char[]	map The mapping of chars.
private static char	NULL_CHAR Special character to denote null list
private static int	SUPP_HASH_SIZE Size of supplimental mapping of chars... typically there are few
private IntHash	supplementalCharsMap Supplemental mapping of characters after the first

Constructor Summary

CharMap(File f)
Construct a char map by reading in a file.

CharMap(InputStream s)
Construct a char map by reading from an InputStream.

Method Summary

String	mapWord(String word) Map the characters in a word and return the mapped resulting word, or null if no mappings found.
private void	readFile(BufferedReader reader) Read in the contents of a char file.

Methods inherited from class Object

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

Field Detail

map

private char[] map

The mapping of chars.

NULL_CHAR

private static final char NULL_CHAR

Special character to denote null list

See Also:

Constant Field Values

SUPP_HASH_SIZE

private static final int SUPP_HASH_SIZE

Size of supplimental mapping of chars... typically there are few

See Also:

Constant Field Values

supplementalCharsMap

private IntHash supplementalCharsMap

Supplemental mapping of characters after the first

CACHE_SIZE

private static final int CACHE_SIZE

How many recent mappings to maintain

See Also:

Constant Field Values

cache

private FastCache cache

Keep a cache of lookups performed to-date

Constructor Detail

CharMap

public CharMap(File f)
        throws IOException

Construct a char map by reading in a file.

Throws:

IOException

CharMap

public CharMap(InputStream s)
        throws IOException

Construct a char map by reading from an InputStream.

Throws:

IOException

Method Detail

mapWord

public String mapWord(String word)

Map the characters in a word and return the mapped resulting word, or null if no mappings found.

readFile

private void readFile(BufferedReader reader)
               throws IOException

Read in the contents of a char file. The file need not be in sorted order.

Parameters:

reader - Reader to get the data from

Throws:

IOException