fr.ifremer.isisfish.logging.io
Class OffsetReader

java.lang.Object
  fr.ifremer.isisfish.logging.io.OffsetReader

Direct Known Subclasses:

FileOffsetReader, MemoryOffsetReader

public abstract class OffsetReader
extends java.lang.Object

Abstract implementation of OffsetReader giving generic algorithms to extract offsets from a LineReader.

Author:

chemit

Field Summary

protected long

nbLines number of lines managed by the reader

Constructor Summary

OffsetReader()

Method Summary

void	close() Close the reader
protected long	createOffsets(LineReader lineReader)
protected long	createOffsets(LineReader lineReader, LineReader parent)
protected long	createOffsetsForLog(LineReader lineReader)
void	deleteOffsetFile() delete offset resources
long	getNbLines()
abstract long	getOffset(long position) Obtain an offset for a position
protected boolean	isLogEntry(java.lang.String line)
protected abstract boolean	needCreate()
void	open(LineReader reader) Open the reader
protected java.lang.String	readLine(java.io.BufferedReader reader) read a line from reader including terminaison caracters
protected abstract void	storeOffset(long position, long offset) Save the offset of the line for a given position
void	update(LineReader lineReader) Update the reader

Methods inherited from class java.lang.Object

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

Field Detail

nbLines

protected long nbLines

number of lines managed by the reader

Constructor Detail

OffsetReader

public OffsetReader()

Method Detail

storeOffset

protected abstract void storeOffset(long position,
                                    long offset)
                             throws java.io.IOException

Save the offset of the line for a given position

Parameters:

position - current line position

offset - current offset of line

Throws:

java.io.IOException - if any problem while storing

needCreate

protected abstract boolean needCreate()
                               throws java.io.IOException

Returns:

true if the reader need to create his internal datas.

Throws:

java.io.IOException - if any problme while creating

getOffset

public abstract long getOffset(long position)
                        throws java.io.IOException

Obtain an offset for a position

Parameters:

position - position of the line

Returns:

the offset of the first car of the given line

Throws:

java.io.IOException - todo

open

public void open(LineReader reader)
          throws java.io.IOException

Open the reader

Parameters:

reader - LineReader linked with this reader

Throws:

java.io.IOException - if any problem while opening

close

public void close()
           throws java.io.IOException

Close the reader

Throws:

java.io.IOException - if any problem while closing

getNbLines

public long getNbLines()

Returns:

the number of lines registered in this reader

update

public void update(LineReader lineReader)
            throws java.io.IOException

Update the reader

Parameters:

lineReader - lineReader linked with this reader

Throws:

java.io.IOException - if any problem while updating

isLogEntry

protected boolean isLogEntry(java.lang.String line)
                      throws java.io.IOException

Throws:

java.io.IOException

readLine

protected java.lang.String readLine(java.io.BufferedReader reader)
                             throws java.io.IOException

read a line from reader including terminaison caracters

Parameters:

reader - reader to use

Returns:

the line with the terminaison

Throws:

java.io.IOException - if any problem while reading

createOffsets

protected long createOffsets(LineReader lineReader)
                      throws java.io.IOException

Throws:

java.io.IOException

createOffsetsForLog

protected long createOffsetsForLog(LineReader lineReader)
                            throws java.io.IOException

Throws:

java.io.IOException

createOffsets

protected long createOffsets(LineReader lineReader,
                             LineReader parent)
                      throws java.io.IOException

Throws:

java.io.IOException

deleteOffsetFile

public void deleteOffsetFile()

delete offset resources