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 Object

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

Author:

chemit

Field Summary

Fields

Modifier and Type	Field and Description
protected long	nbLines number of lines managed by the reader

Constructor Summary

Constructors

Constructor and Description
OffsetReader()

Method Summary

Modifier and Type	Method and Description
void	close() Close the reader
protected long	createOffsets(LineReader lineReader)
protected long	createOffsets(LineReader lineReader, LineReader parent)
void	deleteOffsetFile() delete offset resources
long	getNbLines()
abstract long	getOffset(long position) Obtain an offset for a position
protected boolean	isLogEntry(String line)
protected abstract boolean	needCreate()
void	open(LineReader reader) Open the reader
protected String	readLine(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 IOException

Save the offset of the line for a given position

Parameters:

position - current line position

offset - current offset of line

Throws:

IOException - if any problem while storing

needCreate

protected abstract boolean needCreate()
                               throws IOException

Returns:

true if the reader need to create his internal datas.

Throws:

IOException - if any problme while creating

getOffset

public abstract long getOffset(long position)
                        throws 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:

IOException - todo

open

public void open(LineReader reader)
          throws IOException

Open the reader

Parameters:

reader - LineReader linked with this reader

Throws:

IOException - if any problem while opening

close

public void close()
           throws IOException

Close the reader

Throws:

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 IOException

Update the reader

Parameters:

lineReader - lineReader linked with this reader

Throws:

IOException - if any problem while updating

isLogEntry

protected boolean isLogEntry(String line)
                      throws IOException

Throws:

IOException

readLine

protected String readLine(BufferedReader reader)
                   throws IOException

read a line from reader including terminaison caracters

Parameters:

reader - reader to use

Returns:

the line with the terminaison

Throws:

IOException - if any problem while reading

createOffsets

protected long createOffsets(LineReader lineReader)
                      throws IOException

Throws:

IOException

createOffsets

protected long createOffsets(LineReader lineReader,
                             LineReader parent)
                      throws IOException

Throws:

IOException

deleteOffsetFile

public void deleteOffsetFile()

delete offset resources