4c68a10264
1. CanHandleGZip static method 2. code cleanup 3. 2.4 compatibility mode git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@26713 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
142 lines
4.8 KiB
TeX
142 lines
4.8 KiB
TeX
% -----------------------------------------------------------------------------
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% wxZlibInputStream
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% -----------------------------------------------------------------------------
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\section{\class{wxZlibInputStream}}\label{wxzlibinputstream}
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This filter stream decompresses a stream that is in zlib or gzip format.
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Note that reading the gzip format requires zlib version 1.2.1 or greater,
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(the builtin version does support gzips).
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The stream is not seekable, \helpref{SeekI()}{wxinputstreamseeki} returns
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{\it wxInvalidOffset}. Also \helpref{GetSize()}{wxstreambasegetsize} is
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not supported, it always returns $0$.
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\wxheading{Derived from}
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\helpref{wxFilterInputStream}{wxfilterinputstream}
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\wxheading{Include files}
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<wx/zstream.h>
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\wxheading{See also}
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\helpref{wxInputStream}{wxinputstream},
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\helpref{wxZlibOutputStream}{wxzliboutputstream}.
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\latexignore{\rtfignore{\wxheading{Members}}}
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\membersection{wxZlibInputStream::wxZlibInputStream}
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\func{}{wxZlibInputStream}{\param{wxInputStream\&}{ stream}, \param{int}{ flags = wxZLIB\_AUTO}}
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The {\it flags} wxZLIB\_ZLIB and wxZLIB\_GZIP specify whether the input data
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is in zlib or gzip format. If wxZLIB\_AUTO is used, then zlib will
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autodetect the stream type, this is the default.
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If {\it flags} is wxZLIB\_NO\_HEADER, then the data is assumed to be a raw
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deflate stream without either zlib or gzip headers. This is a lower level
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mode, which is not usually used directly. It can be used to read a raw
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deflate stream embedded in a higher level protocol.
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%if WXWIN_COMPATIBILITY_2_4
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This version is not by default compatible with the output produced by
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the version of {\it wxZlibOutputStream} in wxWidgets 2.4.x. However,
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there is a compatibilty mode, which is switched on by passing
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wxZLIB\_24COMPATIBLE for flags. Note that in when operating in compatibilty
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mode error checking is very much reduced.
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%endif
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The following symbols can be use for the flags:
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\begin{verbatim}
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// Flags
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enum {
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#if WXWIN_COMPATIBILITY_2_4
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wxZLIB_24COMPATIBLE = 4, // read v2.4.x data without error
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#endif
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wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum
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wxZLIB_ZLIB = 1, // zlib header and checksum
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wxZLIB_GZIP = 2, // gzip header and checksum, requires zlib 1.2.1+
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wxZLIB_AUTO = 3 // autodetect header zlib or gzip
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};
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\end{verbatim}
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\membersection{wxZlibInputStream::CanHandleGZip}\label{wxzlibinputstreamcanhandlegzip}
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\func{static bool}{CanHandleGZip}{\void}
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Returns true if zlib library in use can handle gzip compressed data.
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% -----------------------------------------------------------------------------
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% wxZlibOutputStream
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% -----------------------------------------------------------------------------
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\section{\class{wxZlibOutputStream}}\label{wxzliboutputstream}
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This stream compresses all data written to it. The compressed output can be
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in zlib or gzip format.
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Note that writing the gzip format requires zlib version 1.2.1 or greater
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(the builtin version does support gzips).
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The stream is not seekable, \helpref{SeekO()}{wxoutputstreamseeko} returns
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{\it wxInvalidOffset}.
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\wxheading{Derived from}
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\helpref{wxFilterOutputStream}{wxfilteroutputstream}
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\wxheading{Include files}
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<wx/zstream.h>
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\wxheading{See also}
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\helpref{wxOutputStream}{wxoutputstream},
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\helpref{wxZlibInputStream}{wxzlibinputstream}
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\latexignore{\rtfignore{\wxheading{Members}}}
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\membersection{wxZlibOutputStream::wxZlibOutputStream}
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\func{}{wxZlibOutputStream}{\param{wxOutputStream\&}{ stream}, \param{int}{ level = -1}, \param{int}{ flags = wxZLIB\_ZLIB}}
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Creates a new write-only compressed stream. {\it level} means level of
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compression. It is number between 0 and 9 (including these values) where
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0 means no compression and 9 best but slowest compression. -1 is default
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value (currently equivalent to 6).
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The {\it flags} wxZLIB\_ZLIB and wxZLIB\_GZIP specify whether the output data
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will be in zlib or gzip format. wxZLIB\_ZLIB is the default.
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If {\it flags} is wxZLIB\_NO\_HEADER, then a raw deflate stream is output
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without either zlib or gzip headers. This is a lower level
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mode, which is not usually used directly. It can be used to embed a raw
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deflate stream in a higher level protocol.
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The following symbols can be use for the compression level and flags:
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\begin{verbatim}
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// Compression level
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enum {
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wxZ_DEFAULT_COMPRESSION = -1,
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wxZ_NO_COMPRESSION = 0,
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wxZ_BEST_SPEED = 1,
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wxZ_BEST_COMPRESSION = 9
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};
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// Flags
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enum {
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wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum
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wxZLIB_ZLIB = 1, // zlib header and checksum
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wxZLIB_GZIP = 2 // gzip header and checksum, requires zlib 1.2.1+
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};
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\end{verbatim}
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\membersection{wxZlibOutputStream::CanHandleGZip}\label{wxoutputstreamcanhandlegzip}
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\func{static bool}{CanHandleGZip}{\void}
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Returns true if zlib library in use can handle gzip compressed data.
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