Module kala.compress.archivers.zip

Package kala.compress.archivers.zip

Class StreamCompressor

java.lang.Object

kala.compress.archivers.zip.StreamCompressor

All Implemented Interfaces:

java.io.Closeable, java.lang.AutoCloseable

Direct Known Subclasses:

StreamCompressor.DataOutputCompressor, StreamCompressor.OutputStreamCompressor, StreamCompressor.ScatterGatherBackingStoreCompressor, StreamCompressor.SeekableByteChannelCompressor

public abstract class StreamCompressor
extends java.lang.Object
implements java.io.Closeable

Encapsulates a Deflater and crc calculator, handling multiple types of output streams. Currently ZipEntry.DEFLATED and ZipEntry.STORED are the only supported compression methods.

Since:

1.10

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private static class	StreamCompressor.DataOutputCompressor
private static class	StreamCompressor.OutputStreamCompressor
private static class	StreamCompressor.ScatterGatherBackingStoreCompressor
private static class	StreamCompressor.SeekableByteChannelCompressor

Field Summary

Fields

Modifier and Type	Field	Description
private static int	BUFFER_SIZE
private java.util.zip.CRC32	crc
private java.util.zip.Deflater	deflater
private static int	DEFLATER_BLOCK_SIZE	Apparently Deflater.setInput gets slowed down a lot on Sun JVMs when it gets handed a huge buffer.
private byte[]	outputBuffer
private byte[]	readerBuf
private long	sourcePayloadLength
private long	totalWrittenToOutputStream
private long	writtenToOutputStreamForLastEntry

Constructor Summary

Constructors

Constructor	Description
StreamCompressor(java.util.zip.Deflater deflater)

Method Summary

Modifier and Type	Method	Description
void	close()
static StreamCompressor	create(int compressionLevel, ScatterGatherBackingStore bs)	Creates a stream compressor with the given compression level.
(package private) static StreamCompressor	create(java.io.DataOutput os, java.util.zip.Deflater deflater)	Creates a stream compressor with the given compression level.
(package private) static StreamCompressor	create(java.io.OutputStream os)	Creates a stream compressor with the default compression level.
(package private) static StreamCompressor	create(java.io.OutputStream os, java.util.zip.Deflater deflater)	Creates a stream compressor with the given compression level.
(package private) static StreamCompressor	create(java.nio.channels.SeekableByteChannel os, java.util.zip.Deflater deflater)	Creates a stream compressor with the given compression level.
static StreamCompressor	create(ScatterGatherBackingStore bs)	Creates a stream compressor with the default compression level.
(package private) void	deflate()
void	deflate(java.io.InputStream source, int method)	Deflates the given source using the supplied compression method
private void	deflateUntilInputIsNeeded()
(package private) void	flushDeflater()
long	getBytesRead()	Gets the number of bytes read from the source stream
long	getBytesWrittenForLastEntry()	Gets the number of bytes written to the output for the last entry
long	getCrc32()	Gets the crc32 of the last deflated file
long	getTotalBytesWritten()	Gets the total number of bytes written to the output for all files
(package private) void	reset()
(package private) long	write(byte[] b, int offset, int length, int method)	Writes bytes to ZIP entry.
void	writeCounted(byte[] data)
void	writeCounted(byte[] data, int offset, int length)
private void	writeDeflated(byte[] b, int offset, int length)
protected abstract void	writeOut(byte[] data, int offset, int length)

Methods inherited from class java.lang.Object

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

Field Detail

DEFLATER_BLOCK_SIZE

private static final int DEFLATER_BLOCK_SIZE

Apparently Deflater.setInput gets slowed down a lot on Sun JVMs when it gets handed a huge buffer. See https://issues.apache.org/bugzilla/show_bug.cgi?id=45396 Using a buffer size of 8192 bytes proved to be a good compromise

See Also:

Constant Field Values

BUFFER_SIZE

private static final int BUFFER_SIZE

See Also:

Constant Field Values

deflater

private final java.util.zip.Deflater deflater

crc

private final java.util.zip.CRC32 crc

writtenToOutputStreamForLastEntry

private long writtenToOutputStreamForLastEntry

sourcePayloadLength

private long sourcePayloadLength

totalWrittenToOutputStream

private long totalWrittenToOutputStream

outputBuffer

private final byte[] outputBuffer

readerBuf

private final byte[] readerBuf

Constructor Detail

StreamCompressor

StreamCompressor(java.util.zip.Deflater deflater)

Method Detail

create

static StreamCompressor create(java.io.DataOutput os,
                               java.util.zip.Deflater deflater)

Creates a stream compressor with the given compression level.

Parameters:

os - The DataOutput to receive output

deflater - The deflater to use for the compressor

Returns:

A stream compressor

create

public static StreamCompressor create(int compressionLevel,
                                      ScatterGatherBackingStore bs)

Creates a stream compressor with the given compression level.

Parameters:

compressionLevel - The Deflater compression level

bs - The ScatterGatherBackingStore to receive output

Returns:

A stream compressor

create

static StreamCompressor create(java.io.OutputStream os)

Creates a stream compressor with the default compression level.

Parameters:

os - The stream to receive output

Returns:

A stream compressor

create

static StreamCompressor create(java.io.OutputStream os,
                               java.util.zip.Deflater deflater)

Creates a stream compressor with the given compression level.

Parameters:

os - The stream to receive output

deflater - The deflater to use

Returns:

A stream compressor

create

public static StreamCompressor create(ScatterGatherBackingStore bs)

Creates a stream compressor with the default compression level.

Parameters:

bs - The ScatterGatherBackingStore to receive output

Returns:

A stream compressor

create

static StreamCompressor create(java.nio.channels.SeekableByteChannel os,
                               java.util.zip.Deflater deflater)

Creates a stream compressor with the given compression level.

Parameters:

os - The SeekableByteChannel to receive output

deflater - The deflater to use for the compressor

Returns:

A stream compressor

Since:

1.13

close

public void close()
           throws java.io.IOException

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable

Throws:

java.io.IOException

deflate

void deflate()
      throws java.io.IOException

Throws:

java.io.IOException

deflate

public void deflate(java.io.InputStream source,
                    int method)
             throws java.io.IOException

Deflates the given source using the supplied compression method

Parameters:

source - The source to compress

method - The #ZipArchiveEntry compression method

Throws:

java.io.IOException - When failures happen

deflateUntilInputIsNeeded

private void deflateUntilInputIsNeeded()
                                throws java.io.IOException

Throws:

java.io.IOException

flushDeflater

void flushDeflater()
            throws java.io.IOException

Throws:

java.io.IOException

getBytesRead

public long getBytesRead()

Gets the number of bytes read from the source stream

Returns:

The number of bytes read, never negative

getBytesWrittenForLastEntry

public long getBytesWrittenForLastEntry()

Gets the number of bytes written to the output for the last entry

Returns:

The number of bytes, never negative

getCrc32

public long getCrc32()

Gets the crc32 of the last deflated file

Returns:

the crc32

getTotalBytesWritten

public long getTotalBytesWritten()

Gets the total number of bytes written to the output for all files

Returns:

The number of bytes, never negative

reset

void reset()

write

long write(byte[] b,
           int offset,
           int length,
           int method)
    throws java.io.IOException

Writes bytes to ZIP entry.

Parameters:

b - the byte array to write

offset - the start position to write from

length - the number of bytes to write

method - the comrpession method to use

Returns:

the number of bytes written to the stream this time

Throws:

java.io.IOException - on error

writeCounted

public void writeCounted(byte[] data)
                  throws java.io.IOException

Throws:

java.io.IOException

writeCounted

public void writeCounted(byte[] data,
                         int offset,
                         int length)
                  throws java.io.IOException

Throws:

java.io.IOException

writeDeflated

private void writeDeflated(byte[] b,
                           int offset,
                           int length)
                    throws java.io.IOException

Throws:

java.io.IOException

writeOut

protected abstract void writeOut(byte[] data,
                                 int offset,
                                 int length)
                          throws java.io.IOException

Throws:

java.io.IOException