org.xerial.snappy

Class SnappyOutputStream

java.lang.Object

java.io.OutputStream

org.xerial.snappy.SnappyOutputStream

All Implemented Interfaces:

java.io.Closeable, java.io.Flushable, java.lang.AutoCloseable

public class SnappyOutputStream
extends java.io.OutputStream

This class implements a stream filter for writing compressed data using Snappy.

The input data is blocked into 32kb size (in default), and each block is compressed and then passed to the given OutputStream.

The output data format is:

1. snappy codec header defined in SnappyCodec (8 bytes)
2. compressed block 1 : a pair of (compressed data size [4 byte integer. Big-endian], compressed data...)
3. compressed block 2
4. ...

Note that the compressed data created by SnappyOutputStream cannot be uncompressed by Snappy.uncompress(byte[]) since the output formats of Snappy.compress(byte[]) and SnappyOutputStream are different. Use SnappyInputStream for uncompress the data generated by SnappyOutputStream.

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	inputBuffer
protected java.io.OutputStream	out
protected byte[]	outputBuffer

Constructor Summary

Constructors

Constructor and Description
SnappyOutputStream(java.io.OutputStream out)
SnappyOutputStream(java.io.OutputStream out, int blockSize)
SnappyOutputStream(java.io.OutputStream out, int blockSize, BufferAllocatorFactory bufferAllocatorFactory)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() close the stream
protected void	compressInput()
protected void	dumpOutput()
void	flush()
void	rawWrite(java.lang.Object array, int byteOffset, int byteLength) Compress the raw byte array data.
void	write(byte[] b, int off, int len)
void	write(double[] f) Compress the input array data
void	write(double[] f, int off, int len) Compress the input double array data
void	write(float[] f) Compress the input array data
void	write(float[] f, int off, int len) Compress the input float array data
void	write(int b) Writes the specified byte to this output stream.
void	write(int[] f) Compress the input array data
void	write(int[] f, int off, int len) Compress the input int array data
void	write(long[] d) Compress the input array data
void	write(long[] d, int off, int len) Compress the input long array data
void	write(short[] f) Compress the input array data
void	write(short[] f, int off, int len) Compress the input short array data

Methods inherited from class java.io.OutputStream

write

Methods inherited from class java.lang.Object

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

Field Detail

out

protected final java.io.OutputStream out

inputBuffer

protected final byte[] inputBuffer

outputBuffer

protected final byte[] outputBuffer

Constructor Detail

SnappyOutputStream

public SnappyOutputStream(java.io.OutputStream out)

SnappyOutputStream

public SnappyOutputStream(java.io.OutputStream out,
                  int blockSize)

Parameters:

out -

blockSize - byte size of the internal buffer size

Throws:

java.io.IOException

SnappyOutputStream

public SnappyOutputStream(java.io.OutputStream out,
                  int blockSize,
                  BufferAllocatorFactory bufferAllocatorFactory)

Method Detail

write

public void write(byte[] b,
         int off,
         int len)
           throws java.io.IOException

Overrides:

write in class java.io.OutputStream

Throws:

java.io.IOException

write

public void write(long[] d,
         int off,
         int len)
           throws java.io.IOException

Compress the input long array data

Parameters:

d - input array

off - offset in the array

len - the number of elements in the array to copy

Throws:

java.io.IOException

write

public void write(double[] f,
         int off,
         int len)
           throws java.io.IOException

Compress the input double array data

Parameters:

f - input array

off - offset in the array

len - the number of elements in the array to copy

Throws:

java.io.IOException

write

public void write(float[] f,
         int off,
         int len)
           throws java.io.IOException

Compress the input float array data

Parameters:

f - input array

off - offset in the array

len - the number of elements in the array to copy

Throws:

java.io.IOException

write

public void write(int[] f,
         int off,
         int len)
           throws java.io.IOException

Compress the input int array data

Parameters:

f - input array

off - offset in the array

len - the number of elements in the array to copy

Throws:

java.io.IOException

write

public void write(short[] f,
         int off,
         int len)
           throws java.io.IOException

Compress the input short array data

Parameters:

f - input array

off - offset in the array

len - the number of elements in the array to copy

Throws:

java.io.IOException

write

public void write(long[] d)
           throws java.io.IOException

Compress the input array data

Parameters:

d -

Throws:

java.io.IOException

write

public void write(double[] f)
           throws java.io.IOException

Compress the input array data

Parameters:

f -

Throws:

java.io.IOException

write

public void write(float[] f)
           throws java.io.IOException

Compress the input array data

Parameters:

f -

Throws:

java.io.IOException

write

public void write(int[] f)
           throws java.io.IOException

Compress the input array data

Parameters:

f -

Throws:

java.io.IOException

write

public void write(short[] f)
           throws java.io.IOException

Compress the input array data

Parameters:

f -

Throws:

java.io.IOException

rawWrite

public void rawWrite(java.lang.Object array,
            int byteOffset,
            int byteLength)
              throws java.io.IOException

Compress the raw byte array data.

Parameters:

array - array data of any type (e.g., byte[], float[], long[], ...)

byteOffset -

byteLength -

Throws:

java.io.IOException

write

public void write(int b)
           throws java.io.IOException

Writes the specified byte to this output stream. The general contract for write is that one byte is written to the output stream. The byte to be written is the eight low-order bits of the argument b. The 24 high-order bits of b are ignored.

Specified by:

write in class java.io.OutputStream

Throws:

java.io.IOException

flush

public void flush()
           throws java.io.IOException

Specified by:

flush in interface java.io.Flushable

Overrides:

flush in class java.io.OutputStream

Throws:

java.io.IOException

dumpOutput

protected void dumpOutput()
                   throws java.io.IOException

Throws:

java.io.IOException

compressInput

protected void compressInput()
                      throws java.io.IOException

Throws:

java.io.IOException

close

public void close()
           throws java.io.IOException

close the stream

Specified by:

close in interface java.io.Closeable

Specified by:

close in interface java.lang.AutoCloseable

Overrides:

close in class java.io.OutputStream

Throws:

java.io.IOException