OLBzlibOutStream Class Reference
[Streams]

A stream for bzlib compression. More...

#import <ObjectiveLib/BzlibOutStream.h>

Inheritance diagram for OLBzlibOutStream:

[legend]List of all members.

Public Member Functions
(void)	- close
	Close the stream.
(void)	- freeStreamResources
	Free the stream's resources.
(unsigned)	- writeBytes:count:
	Write a sequence of bytes to the stream.
Initializers and Deallocators
(id)	- initWithOutStream:
	Initialize the compression stream.
(id)	- initWithOutStream:blockSize:
	Initialize the compression stream.
(id)	- initWithOutStream:blockSize:bufferSize:
	Initialize the compression stream.
Static Public Member Functions
(id)	+ streamWithOutStream:
	Create and return a new compression stream.
(id)	+ streamWithOutStream:blockSize:
	Create and return a new compression stream.
Protected Attributes
uint8_t *	buffer
	The buffer required by bzlib.
unsigned	bufferSize
	The size of the zlib buffer.
void *	bzstream
	The opaque data type used by bzlib to represent the stream.

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Detailed Description

A stream for bzlib compression.

This is a concrete layered stream that compresses all data written using the library bzlib. The bzlib library is very similar to the zlib compression library, except that it compresses much better and usually more slowly than zlib.

Note:

Data written through OLBzlibOutStream is suitable for reading using the command-line tool bzip2.

See also:

OLBzlibInStream, OLZlibOutStream

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Member Function Documentation

- (void) close

Close the stream.

After receiving this message the stream will no longer be available for writing.

Exceptions:

OLInputOutputException

if there is an error closing the stream

Reimplemented from OLLayeredOutStream.

- (void) freeStreamResources

Free the stream's resources.

This secondary freeing method is necessary to allow the reference count to be properly manipulated from within the normal free (OLReferenceCountedStream) method.

Note:

All sublcasses that allocate resources must implement this method to free those resources and call [super freeStreamResources].

Reimplemented from OLLayeredOutStream.

- (id) initWithOutStream:

(OLOutStream *)

underStream

Initialize the compression stream.

The stream uses a block size of 9 and a buffer size of 1,024. The given out stream underStream is the next lower stream in the stream stack.

Exceptions:

OLInputOutputException

if the stream cannot be created for compression

Parameters:

underStream

the next lower stream in the stack

Returns:

a reference to this stream

Reimplemented from OLLayeredOutStream.

- (id) initWithOutStream:		(OLOutStream *)	underStream
blockSize:		(int)	block

Initialize the compression stream.

The stream uses the given block size and a buffer size of 1,024. The given out stream underStream is the next lower stream in the stream stack.

Precondition:

The indicated block must be in the range [1,9].

Exceptions:

OLInputOutputException

if the stream cannot be created for compression

Parameters:

	underStream	the next lower stream in the stack
	block	the block size which must be in the range [1,9]

Returns:

a reference to this stream

- (id) initWithOutStream:		(OLOutStream *)	underStream
blockSize:		(int)	block
bufferSize:		(unsigned)	size

Initialize the compression stream.

The stream uses the given block size and buffer size. The given out stream underStream is the next lower stream in the stream stack.

Precondition:

The indicated block must be in the range [1,9].

Exceptions:

OLInputOutputException

if the stream cannot be created for compression

Parameters:

	underStream	the next lower stream in the stack
	block	the block size which must be in the range [1,9]
	size	the buffer size

Returns:

a reference to this stream

+ (id) streamWithOutStream:

(OLOutStream *)

underStream

Create and return a new compression stream.

The stream uses a block size of 9 and a buffer size of 1,024. The given out stream underStream is the next lower stream in the stream stack.

Note:

If OpenStep is present the returned object will be autoreleased before being returned.

Exceptions:

OLInputOutputException

if the stream cannot be created for compression

Parameters:

underStream

the next lower stream in the stack

Returns:

a reference to the newly created stream

+ (id) streamWithOutStream:		(OLOutStream *)	underStream
blockSize:		(int)	block

Create and return a new compression stream.

The stream uses the given block size and a buffer size of 1,024. The given out stream underStream is the next lower stream in the stream stack.

Precondition:

The indicated block must be in the range [1,9].

Note:

If OpenStep is present the returned object will be autoreleased before being returned.

Exceptions:

	OLInvalidArgumentException	if the block size is not in the range [1,9]
	OLInputOutputException	if the stream cannot be created for compression

Parameters:

	underStream	the next lower stream in the stack
	block	the block size which must be in the range [1,9]

Returns:

a reference to the newly created stream

- (unsigned) writeBytes:		(const uint8_t *)	bytes
count:		(unsigned)	num

Write a sequence of bytes to the stream.

Compress up to num bytes and return the number actually written.

Exceptions:

OLInputOutputException

if there is an error writing to the stream

Parameters:

	bytes	the bytes to write
	num	the number of bytes to write

Returns:

the number of bytes written

Reimplemented from OLLayeredOutStream.

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Member Data Documentation

- (uint8_t*) buffer [protected]

The buffer required by bzlib.

- (unsigned) bufferSize [protected]

The size of the zlib buffer.

- (void*) bzstream [protected]

The opaque data type used by bzlib to represent the stream.

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The documentation for this class was generated from the following file:

• BzlibOutStream.h

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Generated Sun Apr 22 15:18:21 2007, © 2004-2007 Will Mason