zlib

Description

API for zlib operations.

Functions
SeekableReadStream *	Common::wrapCompressedReadStream (SeekableReadStream *toBeWrapped, uint32 knownSize=0)
WriteStream *	Common::wrapCompressedWriteStream (WriteStream *toBeWrapped)

Function Documentation

wrapCompressedReadStream()

SeekableReadStream* Common::wrapCompressedReadStream	(	SeekableReadStream *	toBeWrapped,
		uint32	knownSize = 0
	)

Take an arbitrary SeekableReadStream and wrap it in a custom stream which provides transparent on-the-fly decompression. Assumes the data it retrieves from the wrapped stream to be either uncompressed or in gzip format. In the former case, the original stream is returned unmodified (and in particular, not wrapped). In the latter case the stream is returned wrapped, unless there is no ZLIB support, then NULL is returned and the old stream is destroyed.

Certain GZip-formats don't supply an easily readable length, if you still need the length carried along with the stream, and you know the decompressed length at wrap-time, then it can be supplied as knownSize here. knownSize will be ignored if the GZip-stream DOES include a length. The created stream also becomes responsible for freeing the passed stream.

It is safe to call this with a NULL parameter (in this case, NULL is returned).

Parameters

toBeWrapped	the stream to be wrapped (if it is in gzip-format)
knownSize	a supplied length of the compressed data (if not available directly)

wrapCompressedWriteStream()

WriteStream* Common::wrapCompressedWriteStream

(

WriteStream *

toBeWrapped

)

Take an arbitrary WriteStream and wrap it in a custom stream which provides transparent on-the-fly compression. The compressed data is written in the gzip format, unless ZLIB support has been disabled, in which case the given stream is returned unmodified (and in particular, not wrapped). The created stream also becomes responsible for freeing the passed stream.

It is safe to call this with a NULL parameter (in this case, NULL is returned).