org.codehaus.plexus.archiver.tar

Class TarBuffer

public class TarBuffer extends Object

The TarBuffer class implements the tar archive concept of a buffered input stream. This concept goes back to the days of blocked tape drives and special io devices. In the Java universe, the only real function that this class performs is to ensure that files have the correct "block" size, or other tars will complain.

You should never have a need to access this class directly. TarBuffers are created by Tar IO Streams.

Version: $Revision: 2436 $ $Date: 2005-09-01 13:20:41 -0400 (Thu, 01 Sep 2005) $ from org.apache.ant.tools.tar.TarBuffer v1.12

Field Summary
byte[]	blockBuffer
int	blockSize
int	currBlkIdx
int	currRecIdx
boolean	debug
static int	DEFAULT_BLKSIZE
static int	DEFAULT_RCDSIZE
InputStream	inStream
OutputStream	outStream
int	recordSize
int	recsPerBlock

Constructor Summary
	TarBuffer(InputStream inStream)
	TarBuffer(InputStream inStream, int blockSize)
	TarBuffer(InputStream inStream, int blockSize, int recordSize)
	TarBuffer(OutputStream outStream)
	TarBuffer(OutputStream outStream, int blockSize)
	TarBuffer(OutputStream outStream, int blockSize, int recordSize)

Method Summary
void	close() Close the TarBuffer.
void	flushBlock() Flush the current data block if it has any data in it.
int	getBlockSize() Get the TAR Buffer's block size.
int	getCurrentBlockNum() Get the current block number, zero based.
int	getCurrentRecordNum() Get the current record number, within the current block, zero based.
int	getRecordSize() Get the TAR Buffer's record size.
void	initialize(int blockSize, int recordSize) Initialization common to all constructors.
boolean	isEOFRecord(byte[] record) Determine if an archive record indicate End of Archive.
boolean	readBlock()
byte[]	readRecord() Read a record from the input stream and return the data.
void	setDebug(boolean debug) Set the debugging flag for the buffer.
void	skipRecord() Skip over a record on the input stream.
void	writeBlock() Write a TarBuffer block to the archive.
void	writeRecord(byte[] record) Write an archive record to the archive.
void	writeRecord(byte[] buf, int offset) Write an archive record to the archive, where the record may be inside of a larger array buffer.

Field Detail

blockBuffer

private byte[] blockBuffer

blockSize

private int blockSize

currBlkIdx

private int currBlkIdx

currRecIdx

private int currRecIdx

debug

private boolean debug

DEFAULT_BLKSIZE

public static final int DEFAULT_BLKSIZE

DEFAULT_RCDSIZE

public static final int DEFAULT_RCDSIZE

inStream

private InputStream inStream

outStream

private OutputStream outStream

recordSize

private int recordSize

recsPerBlock

private int recsPerBlock

Constructor Detail

TarBuffer

public TarBuffer(InputStream inStream)

TarBuffer

public TarBuffer(InputStream inStream, int blockSize)

TarBuffer

public TarBuffer(InputStream inStream, int blockSize, int recordSize)

TarBuffer

public TarBuffer(OutputStream outStream)

TarBuffer

public TarBuffer(OutputStream outStream, int blockSize)

TarBuffer

public TarBuffer(OutputStream outStream, int blockSize, int recordSize)

Method Detail

close

public void close()

Close the TarBuffer. If this is an output buffer, also flush the current block before closing.

flushBlock

private void flushBlock()

Flush the current data block if it has any data in it.

getBlockSize

public int getBlockSize()

Get the TAR Buffer's block size. Blocks consist of multiple records.

getCurrentBlockNum

public int getCurrentBlockNum()

Get the current block number, zero based.

Returns: The current zero based block number.

getCurrentRecordNum

public int getCurrentRecordNum()

Get the current record number, within the current block, zero based. Thus, current offset = (currentBlockNum * recsPerBlk) + currentRecNum.

Returns: The current zero based record number.

getRecordSize

public int getRecordSize()

Get the TAR Buffer's record size.

initialize

private void initialize(int blockSize, int recordSize)

Initialization common to all constructors.

isEOFRecord

public boolean isEOFRecord(byte[] record)

Determine if an archive record indicate End of Archive. End of archive is indicated by a record that consists entirely of null bytes.

Parameters: record The record data to check.

readBlock

private boolean readBlock()

Returns: false if End-Of-File, else true

readRecord

public byte[] readRecord()

Read a record from the input stream and return the data.

Returns: The record data.

setDebug

public void setDebug(boolean debug)

Set the debugging flag for the buffer.

Parameters: debug If true, print debugging output.

skipRecord

public void skipRecord()

Skip over a record on the input stream.

writeBlock

private void writeBlock()

Write a TarBuffer block to the archive.

writeRecord

public void writeRecord(byte[] record)

Write an archive record to the archive.

Parameters: record The record data to write to the archive.

writeRecord

public void writeRecord(byte[] buf, int offset)

Write an archive record to the archive, where the record may be inside of a larger array buffer. The buffer must be "offset plus record size" long.

Parameters: buf The buffer containing the record data to write. offset The offset of the record data within buf.