Module kala.compress.archivers.dump

Package kala.compress.archivers.dump

Class TapeInputStream

java.lang.Object

java.io.InputStream

java.io.FilterInputStream

kala.compress.archivers.dump.TapeInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

final class TapeInputStream
extends FilterInputStream

Filter stream that mimics a physical tape drive capable of compressing the data stream.

Field Summary

Fields

Modifier and Type	Field	Description
private byte[]	blockBuffer
private int	blockSize
private long	bytesRead
private int	currBlkIdx
private boolean	isCompressed
private int	readOffset
private static final int	RECORD_SIZE

Fields inherited from class java.io.FilterInputStream

in

Constructor Summary

Constructors

Constructor	Description
TapeInputStream(InputStream in)	Constructs a new instance.

Method Summary

Modifier and Type	Method	Description
int	available()
void	close()	Close the input stream.
long	getBytesRead()	Gets number of bytes read.
byte[]	peek()	Peek at the next record from the input stream and return the data.
int	read()
int	read(byte[] b, int off, int len)
private void	readBlock(boolean decompress)	Read next block.
private void	readFully(byte[] b, int off, int len)	Read buffer
private byte[]	readRange(int len)
byte[]	readRecord()	Read a record from the input stream and return the data.
void	resetBlockSize(int recsPerBlock, boolean isCompressed)	Sets the DumpArchive Buffer's block size.
long	skip(long len)	Skip bytes.

Methods inherited from class java.io.FilterInputStream

mark, markSupported, read, reset

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class java.lang.Object

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

Field Details

RECORD_SIZE

private static final int RECORD_SIZE

See Also:

• Constant Field Values

blockBuffer

private byte[] blockBuffer

currBlkIdx

private int currBlkIdx

blockSize

private int blockSize

readOffset

private int readOffset

isCompressed

private boolean isCompressed

bytesRead

private long bytesRead

Constructor Details

TapeInputStream

TapeInputStream(InputStream in)

Constructs a new instance.

Parameters:

in - the underlying input stream.

Method Details

available

public int available()
              throws IOException

Overrides:

available in class FilterInputStream

Throws:

IOException

See Also:

• InputStream.available()

close

public void close()
           throws IOException

Close the input stream.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class FilterInputStream

Throws:

IOException - on error

getBytesRead

public long getBytesRead()

Gets number of bytes read.

Returns:

number of bytes read.

peek

public byte[] peek()
            throws IOException

Peek at the next record from the input stream and return the data.

Returns:

The record data.

Throws:

IOException - on error

read

public int read()
         throws IOException

Overrides:

read in class FilterInputStream

Throws:

IOException

See Also:

• InputStream.read()

read

public int read(byte[] b,
 int off,
 int len)
         throws IOException

reads the full given length unless EOF is reached.

Overrides:

read in class FilterInputStream

Parameters:

len - length to read, must be a multiple of the stream's record size

Throws:

IOException

readBlock

private void readBlock(boolean decompress)
                throws IOException

Read next block. All decompression is handled here.

Parameters:

decompress - if false the buffer will not be decompressed. This is an optimization for longer seeks.

Throws:

IOException

readFully

private void readFully(byte[] b,
 int off,
 int len)
                throws IOException

Read buffer

Throws:

IOException

readRange

private byte[] readRange(int len)
                  throws IOException

Throws:

IOException

readRecord

public byte[] readRecord()
                  throws IOException

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

Returns:

The record data.

Throws:

IOException - on error

resetBlockSize

public void resetBlockSize(int recsPerBlock,
 boolean isCompressed)
                    throws IOException

Sets the DumpArchive Buffer's block size. We need to sync the block size with the dump archive's actual block size since compression is handled at the block level.

Parameters:

recsPerBlock - records per block

isCompressed - true if the archive is compressed

Throws:

IOException - more than one block has been read

IOException - there was an error reading additional blocks.

IOException - recsPerBlock is smaller than 1

skip

public long skip(long len)
          throws IOException

Skip bytes. Same as read but without the arraycopy.

skips the full given length unless EOF is reached.

Overrides:

skip in class FilterInputStream

Parameters:

len - length to read, must be a multiple of the stream's record size

Throws:

IOException