swishej
Class IndexFile

java.lang.Object
  |
  +--swishej.IndexFile

class IndexFile

extends java.lang.Object

Representation of SWISH-E index file

Field Summary

(package private) FileHash	fh Table to remember file information.
(package private) java.util.Hashtable	fn Table of file names.
(package private) java.lang.String	header Index file header.
(package private) static java.lang.String	ifheader SWISH-E file header.
(package private) static java.lang.String	indexchars File offset mapping.
(package private) int	maxfilenum Highest short file number of index.
(package private) MetaHash	mh Table of meta words.
(package private) int[]	offsets Table of file offsets.
(package private) Reader	rd Reference for reading index from file or URL.
(package private) StopHash	sh Table of stop words.
(package private) boolean	stemming Indicator for word stemming.
(package private) static java.lang.String	stheader Line marking word stemming info.
(package private) boolean	valid Indicator for index' validity.

Constructor Summary

(package private)

IndexFile(Reader rd) Creates and reads index file representation.

Method Summary

(package private) int	decodefilenum(int num) Decode short file number from given result number.
(package private) java.lang.String[]	dumpWords(java.lang.String initial) Dump keywords given initial into String array.
(package private) boolean	findWord(java.lang.String word) Lookup word and position index pointer accordingly.
(package private) ResultList	getfileinfo(java.lang.String word, int meta) Lookup word and make ResultList of it
(package private) void	getIndexFilenum() Determine number of files in index
(package private) java.lang.String	getmatchword(java.lang.String prefix, boolean first) Match words against given prefix
(package private) java.lang.String	lookupfile(int filenum) Lookup file given result number and return file description
(package private) void	readFileOffsets() Read file long numbers (= offsets) from index into file table
(package private) void	readMetaNames() Read meta words from index
(package private) void	readOffsets() Read offsets right after file header
(package private) void	readStopwords() Read stop words from index into stop word table
(package private) static char	toLowerCase(char ch) Own toLowerCase static method, does NOT convert non-ASCII characters to lower case.
(package private) static java.lang.String	toLowerCase(java.lang.String string) Own toLowerCase static method, does NOT convert non-ASCII characters to lower case.

Methods inherited from class java.lang.Object

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

Field Detail

indexchars

static java.lang.String indexchars

File offset mapping.

ifheader

static final java.lang.String ifheader

SWISH-E file header.

stheader

static final java.lang.String stheader

Line marking word stemming info.

rd

Reader rd

Reference for reading index from file or URL.

offsets

int[] offsets

Table of file offsets.

maxfilenum

int maxfilenum

Highest short file number of index.

valid

boolean valid

Indicator for index' validity.

stemming

boolean stemming

Indicator for word stemming.

fh

FileHash fh

Table to remember file information.

sh

StopHash sh

Table of stop words.

mh

MetaHash mh

Table of meta words.

fn

java.util.Hashtable fn

Table of file names.

header

java.lang.String header

Index file header.

Constructor Detail

IndexFile

IndexFile(Reader rd)
    throws java.io.IOException

Creates and reads index file representation.

Parameters:

rd - Reader for reading file or URL.

Throws:

java.io.IOException - if file is invalid or unreadable

Method Detail

toLowerCase

static java.lang.String toLowerCase(java.lang.String string)

Own toLowerCase static method, does NOT convert non-ASCII characters to lower case.

Parameters:

string - string to be converted

Returns:

string with all ASCII characters recoded to lower case

toLowerCase

static char toLowerCase(char ch)

Own toLowerCase static method, does NOT convert non-ASCII characters to lower case.

Parameters:

ch - character to be converted

Returns:

character recoded to lower case if ASCII

readOffsets

void readOffsets()
           throws java.io.IOException

Read offsets right after file header

Throws:

java.io.IOException - on read error

getIndexFilenum

void getIndexFilenum()
               throws java.io.IOException

Determine number of files in index

Throws:

java.io.IOException - on read error

readStopwords

void readStopwords()
             throws java.io.IOException

Read stop words from index into stop word table

Throws:

java.io.IOException - on read error

readFileOffsets

void readFileOffsets()
               throws java.io.IOException

Read file long numbers (= offsets) from index into file table

Throws:

java.io.IOException - on read error

readMetaNames

void readMetaNames()
             throws java.io.IOException

Read meta words from index

Throws:

java.io.IOException - on read error

decodefilenum

int decodefilenum(int num)

Decode short file number from given result number.

Parameters:

num - number from search result

Returns:

short file number

lookupfile

java.lang.String lookupfile(int filenum)

Lookup file given result number and return file description

Parameters:

num - number from search result

Returns:

File information or null.

findWord

boolean findWord(java.lang.String word)

Lookup word and position index pointer accordingly.

Parameters:

word - word to be found

Returns:

true if word found, false otherwise

getfileinfo

ResultList getfileinfo(java.lang.String word,
                       int meta)

Lookup word and make ResultList of it

Parameters:

word - word to be found

meta - meta number to be considered

Returns:

new ResultList or null if not found

getmatchword

java.lang.String getmatchword(java.lang.String prefix,
                              boolean first)

Match words against given prefix

Parameters:

prefix - word prefix

first - true for first match

Returns:

word or null if not found

dumpWords

java.lang.String[] dumpWords(java.lang.String initial)

Dump keywords given initial into String array.

Parameters:

initial - String giving the initial character

Returns:

String[] containing words or null