Top Description Fields Constructors Methods
com.ning.compress.lzf

public Class LZFCompressingInputStream

extends InputStream
Class Inheritance
Imports
java.io.IOException, .InputStream, com.ning.compress.BufferRecycler, com.ning.compress.lzf.util.ChunkEncoderFactory
Decorator InputStream implementation used for reading uncompressed data and compressing it on the fly, such that reads return compressed data. It is reverse of LZFInputStream (which instead uncompresses data).
Author
Tatu Saloranta
See Also
com.ning.compress.lzf.LZFInputStream

Field Summary

Modifier and TypeField and Description
protected int
_bufferLength

Length of the current uncompressed bytes buffer

protected int
_bufferPosition

The current position (next char to output) in the uncompressed bytes buffer.

protected boolean
_cfgFullReads

Flag that indicates whether we force full reads (reading of as many bytes as requested), or 'optimal' reads (up to as many as available, but at least one).

protected byte[]
_encodedBytes

Buffer that contains compressed data that is returned to readers.

private ChunkEncoder
_encoder

protected byte[]
_inputBuffer

Buffer in which uncompressed input is first read, before getting encoded in _encodedBytes.

protected final InputStream
_inputStream

Stream used for reading data to be compressed

protected boolean
_inputStreamClosed

Flag that indicates if we have already called 'inputStream.close()' (to avoid calling it multiple times)

protected int
_readCount

Number of bytes read from the underlying _inputStream

private final BufferRecycler
_recycler

Constructor Summary

AccessConstructor and Description
public
LZFCompressingInputStream(InputStream in)

public
LZFCompressingInputStream(final ChunkEncoder encoder, InputStream in)

public
LZFCompressingInputStream(final ChunkEncoder encoder, InputStream in, BufferRecycler bufferRecycler)

Method Summary

Modifier and TypeMethod and Description
private void
_closeInput()

public int
available()

Overrides java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected.
public void
close()

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Closes this input stream and releases any system resources associated with the stream.
public int
read()

Implements abstract java.io.InputStream.read.

Reads the next byte of data from the input stream.
public int
read(final byte[]
the buffer into which the data is read.
buffer)

Overrides java.io.InputStream.read.

Reads some number of bytes from the input stream and stores them into the buffer array b.
public int
read(final byte[]
the buffer into which the data is read.
buffer, int
the start offset in array b at which the data is written.
offset, int
the maximum number of bytes to read.
length)

Overrides java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes.
protected boolean
readyBuffer()

Fill the uncompressed bytes buffer by reading the underlying inputStream.

public void
setUseFullReads(boolean b)

Method that can be used define whether reads should be "full" or "optimal": former means that full compressed blocks are read right away as needed, optimal that only smaller chunks are read at a time, more being read as needed.

public long
skip(long
the number of bytes to be skipped.
n)

Overrides java.io.InputStream.skip.

Overridden to just skip at most a single chunk at a time
Inherited from java.io.InputStream:
markmarkSupportednullInputStreamreadAllBytesreadNBytesreadNBytesresetskipNBytestransferTo

Field Detail

_bufferLengthback to summary
protected int _bufferLength

Length of the current uncompressed bytes buffer

_bufferPositionback to summary
protected int _bufferPosition

The current position (next char to output) in the uncompressed bytes buffer.

_cfgFullReadsback to summary
protected boolean _cfgFullReads

Flag that indicates whether we force full reads (reading of as many bytes as requested), or 'optimal' reads (up to as many as available, but at least one). Default is false, meaning that 'optimal' read is used.

_encodedBytesback to summary
protected byte[] _encodedBytes

Buffer that contains compressed data that is returned to readers.

_encoderback to summary
private ChunkEncoder _encoder
_inputBufferback to summary
protected byte[] _inputBuffer

Buffer in which uncompressed input is first read, before getting encoded in _encodedBytes.

_inputStreamback to summary
protected final InputStream _inputStream

Stream used for reading data to be compressed

_inputStreamClosedback to summary
protected boolean _inputStreamClosed

Flag that indicates if we have already called 'inputStream.close()' (to avoid calling it multiple times)

_readCountback to summary
protected int _readCount

Number of bytes read from the underlying _inputStream

_recyclerback to summary
private final BufferRecycler _recycler

Constructor Detail

LZFCompressingInputStreamback to summary
public LZFCompressingInputStream(InputStream in)
LZFCompressingInputStreamback to summary
public LZFCompressingInputStream(final ChunkEncoder encoder, InputStream in)
LZFCompressingInputStreamback to summary
public LZFCompressingInputStream(final ChunkEncoder encoder, InputStream in, BufferRecycler bufferRecycler)

Method Detail

_closeInputback to summary
private void _closeInput() throws IOException
availableback to summary
public int available()

Overrides java.io.InputStream.available.

Doc from java.io.InputStream.available.

Returns an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking, which may be 0, or 0 when end of stream is detected. The read might be on the same thread or another thread. A single read or skip of this many bytes will not block, but may read or skip fewer bytes.

Note that while some implementations of InputStream will return the total number of bytes in the stream, many will not. It is never correct to use the return value of this method to allocate a buffer intended to hold all data in this stream.

A subclass's implementation of this method may choose to throw an IOException if this input stream has been closed by invoking the close() method.

Returns:int

an estimate of the number of bytes that can be read (or skipped over) from this input stream without blocking or 0 when it reaches the end of the input stream.

Annotations
@Override
closeback to summary
public void close() throws IOException

Overrides java.io.InputStream.close.

Implements java.io.Closeable.close.

Doc from java.io.InputStream.close.

Closes this input stream and releases any system resources associated with the stream.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
readback to summary
public int read() throws IOException

Implements abstract java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads the next byte of data from the input stream. The value byte is returned as an int in the range 0 to 255. If no byte is available because the end of the stream has been reached, the value -1 is returned. This method blocks until input data is available, the end of the stream is detected, or an exception is thrown.

Returns:int

the next byte of data, or -1 if the end of the stream is reached.

Annotations
@Override
Exceptions
IOException:
if an I/O error occurs.
readback to summary
public int read(final byte[] buffer) throws IOException

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads some number of bytes from the input stream and stores them into the buffer array b. The number of bytes actually read is returned as an integer. This method blocks until input data is available, end of file is detected, or an exception is thrown.

If the length of b is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at the end of the file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[0], the next one into b[1], and so on. The number of bytes read is, at most, equal to the length of b. Let k be the number of bytes actually read; these bytes will be stored in elements b[0] through b[k-1], leaving elements b[k] through b[b.length-1] unaffected.

Parameters
buffer:byte[]

the buffer into which the data is read.

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Annotations
@Override
Exceptions
IOException:
If the first byte cannot be read for any reason other than the end of the file, if the input stream has been closed, or if some other I/O error occurs.
readback to summary
public int read(final byte[] buffer, int offset, int length) throws IOException

Overrides java.io.InputStream.read.

Doc from java.io.InputStream.read.

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read. The number of bytes actually read is returned as an integer.

This method blocks until input data is available, end of file is detected, or an exception is thrown.

If len is zero, then no bytes are read and 0 is returned; otherwise, there is an attempt to read at least one byte. If no byte is available because the stream is at end of file, the value -1 is returned; otherwise, at least one byte is read and stored into b.

The first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len. Let k be the number of bytes actually read; these bytes will be stored in elements b[off] through b[off+k-1], leaving elements b[off+k] through b[off+len-1] unaffected.

In every case, elements b[0] through b[off-1] and elements b[off+len] through b[b.length-1] are unaffected.

Parameters
buffer:byte[]

the buffer into which the data is read.

offset:int

the start offset in array b at which the data is written.

length:int

the maximum number of bytes to read.

Returns:int

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Annotations
@Override
Exceptions
IOException:
If the first byte cannot be read for any reason other than end of file, or if the input stream has been closed, or if some other I/O error occurs.
readyBufferback to summary
protected boolean readyBuffer() throws IOException

Fill the uncompressed bytes buffer by reading the underlying inputStream.

setUseFullReadsback to summary
public void setUseFullReads(boolean b)

Method that can be used define whether reads should be "full" or "optimal": former means that full compressed blocks are read right away as needed, optimal that only smaller chunks are read at a time, more being read as needed.

skipback to summary
public long skip(long n) throws IOException

Overrides java.io.InputStream.skip.

Overridden to just skip at most a single chunk at a time

Parameters
n:long

Doc from java.io.InputStream.skip.

the number of bytes to be skipped.

Returns:long

Doc from java.io.InputStream.skip.

the actual number of bytes skipped which might be zero.

Annotations
@Override
Exceptions
IOException:

Doc from java.io.InputStream.skip.

if an I/O error occurs.