org.archive.wayback.util.flatfile
Class FlatFile

java.lang.Object
  org.archive.wayback.util.flatfile.FlatFile

Direct Known Subclasses:

CachedFile, CDXIndex

public class FlatFile
extends Object

Subclass of File, which allows binary searching, returning Iterators that allow scanning forwards and backwards thru the (sorted) file starting from a particular prefix.

Version:

$Date: 2010-09-29 05:28:38 +0700 (Wed, 29 Sep 2010) $, $Revision: 3262 $

Author:

brad

Field Summary

protected File

file

Constructor Summary

FlatFile()

FlatFile(File parent, String child)

FlatFile(String path)

Method Summary

long	findKeyOffset(RandomAccessFile fh, String key) Binary search thru RandomAccessFile argument to locate the first line prefixed by key argument.
long	findKeyOffsetLT(RandomAccessFile fh, String key)
long	getLastMatchOffset()
String	getPath()
CloseableIterator<String>	getRecordIterator(String prefix)
CloseableIterator<String>	getRecordIteratorLT(String prefix)
ReverseRecordIterator	getReverseRecordIterator(String prefix)
CloseableIterator<String>	getSequentialIterator()
static void	main(String[] args)
void	setPath(String path)
void	store(Iterator<String> itr)

Methods inherited from class java.lang.Object

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

Field Detail

file

protected File file

Constructor Detail

FlatFile

public FlatFile()

FlatFile

public FlatFile(File parent,
                String child)

Parameters:

parent -

child -

FlatFile

public FlatFile(String path)

Parameters:

path -

Method Detail

setPath

public void setPath(String path)

Parameters:

path - to set

getPath

public String getPath()

Returns:

current String path, or null if none has been set

findKeyOffset

public long findKeyOffset(RandomAccessFile fh,
                          String key)
                   throws IOException

Binary search thru RandomAccessFile argument to locate the first line prefixed by key argument. As a side effect, the RandomAccessFile's position is also set to the start of the first matching line.

Parameters:

fh -

key -

Returns:

long offset where first record prefixed with key is found

Throws:

IOException

findKeyOffsetLT

public long findKeyOffsetLT(RandomAccessFile fh,
                            String key)
                     throws IOException

Throws:

IOException

getLastMatchOffset

public long getLastMatchOffset()

Returns:

Returns the lastMatchOffset.

getSequentialIterator

public CloseableIterator<String> getSequentialIterator()
                                                throws IOException

Returns:

Iterator returning one String object for each line in the file.

Throws:

IOException

getRecordIterator

public CloseableIterator<String> getRecordIterator(String prefix)
                                            throws IOException

Parameters:

prefix -

Returns:

Iterator for records beggining with key

Throws:

IOException

getRecordIteratorLT

public CloseableIterator<String> getRecordIteratorLT(String prefix)
                                              throws IOException

Throws:

IOException

getReverseRecordIterator

public ReverseRecordIterator getReverseRecordIterator(String prefix)
                                               throws IOException

Parameters:

prefix -

Returns:

ReverseRecordIterator positioned to return the first line BEFORE prefix at the first call to readPrevLine().

Throws:

IOException

store

public void store(Iterator<String> itr)
           throws IOException

Throws:

IOException

main

public static void main(String[] args)

Parameters:

args -