% -----------------------------------------------------------------------------
\section{\class{wxZlibInputStream}}\label{wxzlibinputstream}
-This stream uncompresses all data read from it. It uses the "filtered"
-stream to get new compressed data.
+This filter stream decompresses a stream that is in zlib or gzip format.
+Note that reading the gzip format requires zlib version 1.2.1 or greater,
+(the builtin version does support gzips).
The stream is not seekable, \helpref{SeekI()}{wxinputstreamseeki} returns
{\it wxInvalidOffset}. Also \helpref{GetSize()}{wxstreambasegetsize} is
\membersection{wxZlibInputStream::wxZlibInputStream}
-\func{}{wxZlibInputStream}{\param{wxInputStream\&}{ stream}, \param{int}{ flags = 0}}
+\func{}{wxZlibInputStream}{\param{wxInputStream\&}{ stream}, \param{int}{ flags = wxZLIB\_AUTO}}
-{\it flags} should be omitted for normal usage. The flag {\it wxZLIB\_NO_HEADER}
- is needed when wxZlibInputStream is used as an 'inflate' decompressor for gzip
-or zip files.
+The {\it flags} wxZLIB\_ZLIB and wxZLIB\_GZIP specify whether the input data
+is in zlib or gzip format. If wxZLIB\_AUTO is used, then zlib will
+autodetect the stream type, this is the default.
-{\it wxZLIB\_NO_HEADER} is currently the only flag:
+If {\it flags} is wxZLIB\_NO\_HEADER, then the data is assumed to be a raw
+deflate stream without either zlib or gzip headers. This is a lower level
+mode, which is not usually used directly. It can be used to read a raw
+deflate stream embedded in a higher level protocol.
+
+%if WXWIN_COMPATIBILITY_2_4
+This version is not by default compatible with the output produced by
+the version of {\it wxZlibOutputStream} in wxWidgets 2.4.x. However,
+there is a compatibilty mode, which is switched on by passing
+wxZLIB\_24COMPATIBLE for flags. Note that in when operating in compatibilty
+mode error checking is very much reduced.
+%endif
+
+The following symbols can be use for the flags:
\begin{verbatim}
// Flags
enum {
- wxZLIB_NO_HEADER = 1 // required for use in Gzip and Zip files
-}
+#if WXWIN_COMPATIBILITY_2_4
+ wxZLIB_24COMPATIBLE = 4, // read v2.4.x data without error
+#endif
+ wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum
+ wxZLIB_ZLIB = 1, // zlib header and checksum
+ wxZLIB_GZIP = 2, // gzip header and checksum, requires zlib 1.2.1+
+ wxZLIB_AUTO = 3 // autodetect header zlib or gzip
+};
\end{verbatim}
+\membersection{wxZlibInputStream::CanHandleGZip}\label{wxzlibinputstreamcanhandlegzip}
+
+\func{static bool}{CanHandleGZip}{\void}
+
+Returns true if zlib library in use can handle gzip compressed data.
% -----------------------------------------------------------------------------
% wxZlibOutputStream
% -----------------------------------------------------------------------------
\section{\class{wxZlibOutputStream}}\label{wxzliboutputstream}
-This stream compresses all data written to it, and passes the compressed data
-to the "filtered" stream.
+This stream compresses all data written to it. The compressed output can be
+in zlib or gzip format.
+Note that writing the gzip format requires zlib version 1.2.1 or greater
+(the builtin version does support gzips).
The stream is not seekable, \helpref{SeekO()}{wxoutputstreamseeko} returns
{\it wxInvalidOffset}.
\membersection{wxZlibOutputStream::wxZlibOutputStream}
-\func{}{wxZlibOutputStream}{\param{wxOutputStream\&}{ stream}, \param{int}{ level = -1}, \param{int}{ flags = 0}}
+\func{}{wxZlibOutputStream}{\param{wxOutputStream\&}{ stream}, \param{int}{ level = -1}, \param{int}{ flags = wxZLIB\_ZLIB}}
Creates a new write-only compressed stream. {\it level} means level of
compression. It is number between 0 and 9 (including these values) where
0 means no compression and 9 best but slowest compression. -1 is default
value (currently equivalent to 6).
-{\it flags} should be omitted for normal usage. The flag {\it wxZLIB\_NO_HEADER}
- suppresses the generation of the zlib header and checksum, and is required
-when wxZlibOutputStream is used as a 'deflate' compressor for gzip or zip files.
+The {\it flags} wxZLIB\_ZLIB and wxZLIB\_GZIP specify whether the output data
+will be in zlib or gzip format. wxZLIB\_ZLIB is the default.
+
+If {\it flags} is wxZLIB\_NO\_HEADER, then a raw deflate stream is output
+without either zlib or gzip headers. This is a lower level
+mode, which is not usually used directly. It can be used to embed a raw
+deflate stream in a higher level protocol.
The following symbols can be use for the compression level and flags:
wxZ_NO_COMPRESSION = 0,
wxZ_BEST_SPEED = 1,
wxZ_BEST_COMPRESSION = 9
-}
+};
// Flags
enum {
- wxZLIB_NO_HEADER = 1 // required for use in Gzip and Zip files
-}
+ wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum
+ wxZLIB_ZLIB = 1, // zlib header and checksum
+ wxZLIB_GZIP = 2 // gzip header and checksum, requires zlib 1.2.1+
+};
\end{verbatim}
+\membersection{wxZlibOutputStream::CanHandleGZip}\label{wxoutputstreamcanhandlegzip}
+
+\func{static bool}{CanHandleGZip}{\void}
+
+Returns true if zlib library in use can handle gzip compressed data.
+
projects / wxWidgets.git / blobdiff