From 4c68a10264347cc04b1a6634000595f160792231 Mon Sep 17 00:00:00 2001 From: =?utf8?q?V=C3=A1clav=20Slav=C3=ADk?= Date: Sun, 11 Apr 2004 19:34:56 +0000 Subject: [PATCH 1/1] improvements to zlib streams (patch 929416): 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 --- docs/changes.txt | 3 + docs/latex/wx/strmzlib.tex | 55 ++++++++++--- include/wx/zstream.h | 23 ++++-- src/common/zstream.cpp | 161 +++++++++++++++++++++++++------------ 4 files changed, 172 insertions(+), 70 deletions(-) diff --git a/docs/changes.txt b/docs/changes.txt index 6dd0708c9b..1ab41e7a4f 100644 --- a/docs/changes.txt +++ b/docs/changes.txt @@ -42,6 +42,9 @@ INCOMPATIBLE CHANGES SINCE 2.4.x - wxTaskBarIcon objects must now be destroyed before the application can exit. Previously, the application terminated if there were no top level windows; now it terminates if there are no top level windows or taskbar icons left. +- wxZlibInputStream is not by default compatible with the output of the + 2.4.x version of wxZlibOutputStream. However, there is a compatibilty mode, + switched on by passing wxZLIB_24COMPATIBLE to the constructor. wxTaskBarIcon must be explicitly destroyed now, otherwise the application won't exit even though there are no top level windows diff --git a/docs/latex/wx/strmzlib.tex b/docs/latex/wx/strmzlib.tex index d563a50640..46945e16ad 100644 --- a/docs/latex/wx/strmzlib.tex +++ b/docs/latex/wx/strmzlib.tex @@ -4,7 +4,8 @@ \section{\class{wxZlibInputStream}}\label{wxzlibinputstream} This filter stream decompresses a stream that is in zlib or gzip format. -Note that reading the gzip format requires zlib version 1.2.0 greater. +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 @@ -27,25 +28,45 @@ not supported, it always returns $0$. \membersection{wxZlibInputStream::wxZlibInputStream} -\func{}{wxZlibInputStream}{\param{wxInputStream\&}{ stream}, \param{int}{ flags = wxZLIB\_ZLIB | wxZLIB\_GZIP}} +\func{}{wxZlibInputStream}{\param{wxInputStream\&}{ stream}, \param{int}{ flags = wxZLIB\_AUTO}} The {\it flags} wxZLIB\_ZLIB and wxZLIB\_GZIP specify whether the input data -is in zlib or gzip format. If both are used, bitwise ored, then zlib will +is in zlib or gzip format. If wxZLIB\_AUTO is used, then zlib will autodetect the stream type, this is the default. -If {\it flags} is zero, then the data is assumed to be a raw deflate stream -without either zlib or gzip headers. + +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 = 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+ +#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 @@ -54,7 +75,8 @@ enum { 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 1.2.0 greater. +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}. @@ -86,8 +108,11 @@ value (currently equivalent to 6). 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 zero, then a raw deflate stream is output without either -zlib or gzip headers. + +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: @@ -104,7 +129,13 @@ enum { enum { 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+ + 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. + diff --git a/include/wx/zstream.h b/include/wx/zstream.h index de88e07b56..748abd7b47 100644 --- a/include/wx/zstream.h +++ b/include/wx/zstream.h @@ -31,19 +31,25 @@ enum { // Flags enum { - 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+ +#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 }; class WXDLLIMPEXP_BASE wxZlibInputStream: public wxFilterInputStream { public: - wxZlibInputStream(wxInputStream& stream, int flags = wxZLIB_ZLIB | wxZLIB_GZIP); + wxZlibInputStream(wxInputStream& stream, int flags = wxZLIB_AUTO); virtual ~wxZlibInputStream(); char Peek() { return wxInputStream::Peek(); } size_t GetSize() const { return wxInputStream::GetSize(); } + static bool CanHandleGZip(); + protected: size_t OnSysRead(void *buffer, size_t size); off_t OnSysTell() const { return m_pos; } @@ -53,8 +59,11 @@ class WXDLLIMPEXP_BASE wxZlibInputStream: public wxFilterInputStream { unsigned char *m_z_buffer; struct z_stream_s *m_inflate; off_t m_pos; +#if WXWIN_COMPATIBILITY_2_4 + bool m_24compatibilty; +#endif - DECLARE_NO_COPY_CLASS(wxZlibInputStream) + DECLARE_NO_COPY_CLASS(wxZlibInputStream) }; class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream { @@ -65,6 +74,8 @@ class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream { void Sync() { DoFlush(false); } size_t GetSize() const { return (size_t)m_pos; } + static bool CanHandleGZip(); + protected: size_t OnSysWrite(const void *buffer, size_t size); off_t OnSysTell() const { return m_pos; } @@ -77,7 +88,7 @@ class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream { struct z_stream_s *m_deflate; off_t m_pos; - DECLARE_NO_COPY_CLASS(wxZlibOutputStream) + DECLARE_NO_COPY_CLASS(wxZlibOutputStream) }; #endif diff --git a/src/common/zstream.cpp b/src/common/zstream.cpp index 5372d21481..09d616bab2 100644 --- a/src/common/zstream.cpp +++ b/src/common/zstream.cpp @@ -38,7 +38,9 @@ #endif enum { - ZSTREAM_BUFFER_SIZE = 16384 + ZSTREAM_BUFFER_SIZE = 16384, + ZSTREAM_GZIP = 0x10, // gzip header + ZSTREAM_AUTO = 0x20 // auto detect between gzip and zlib }; ////////////////////// @@ -53,25 +55,43 @@ wxZlibInputStream::wxZlibInputStream(wxInputStream& stream, int flags) m_z_size = ZSTREAM_BUFFER_SIZE; m_pos = 0; +#if WXWIN_COMPATIBILITY_2_4 + // treat compatibilty mode as auto + m_24compatibilty = flags == wxZLIB_24COMPATIBLE; + if (m_24compatibilty) + flags = wxZLIB_AUTO; +#endif + + // if gzip is asked for but not supported... + if ((flags == wxZLIB_GZIP || flags == wxZLIB_AUTO) && !CanHandleGZip()) { + if (flags == wxZLIB_AUTO) { + // an error will come later if the input turns out not to be a zlib + flags = wxZLIB_ZLIB; + } + else { + wxLogError(_("Gzip not supported by this version of zlib")); + m_lasterror = wxSTREAM_READ_ERROR; + return; + } + } + if (m_z_buffer) { m_inflate = new z_stream_s; if (m_inflate) { memset(m_inflate, 0, sizeof(z_stream_s)); - wxASSERT((flags & ~(wxZLIB_ZLIB | wxZLIB_GZIP)) == 0); - - // when autodetecting between gzip & zlib, silently drop gzip flag - // if the version of zlib doesn't support it - if (flags == (wxZLIB_ZLIB | wxZLIB_GZIP) - && strcmp(zlib_version, "1.2.") < 0) - flags &= ~wxZLIB_GZIP; - - int bits = flags ? MAX_WBITS : -MAX_WBITS; - if (flags & wxZLIB_GZIP) - bits |= (flags & wxZLIB_ZLIB) ? 0x20 : 0x10; + // see zlib.h for documentation on windowBits + int windowBits = MAX_WBITS; + switch (flags) { + case wxZLIB_NO_HEADER: windowBits = -MAX_WBITS; break; + case wxZLIB_ZLIB: windowBits = MAX_WBITS; break; + case wxZLIB_GZIP: windowBits = MAX_WBITS | ZSTREAM_GZIP; break; + case wxZLIB_AUTO: windowBits = MAX_WBITS | ZSTREAM_AUTO; break; + default: wxFAIL_MSG(wxT("Invalid zlib flag")); + } - if (inflateInit2(m_inflate, bits) == Z_OK) + if (inflateInit2(m_inflate, windowBits) == Z_OK) return; } } @@ -102,36 +122,49 @@ size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size) m_inflate->avail_out = size; while (err == Z_OK && m_inflate->avail_out > 0) { - if (m_inflate->avail_in == 0) { + if (m_inflate->avail_in == 0 && m_parent_i_stream->IsOk()) { m_parent_i_stream->Read(m_z_buffer, m_z_size); m_inflate->next_in = m_z_buffer; m_inflate->avail_in = m_parent_i_stream->LastRead(); + } + err = inflate(m_inflate, Z_SYNC_FLUSH); + } - if (m_inflate->avail_in == 0) { - if (m_parent_i_stream->Eof()) - wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream.")); - m_lasterror = wxSTREAM_READ_ERROR; + switch (err) { + case Z_OK: break; + + case Z_STREAM_END: + // Unread any data taken from past the end of the deflate stream, so that + // any additional data can be read from the underlying stream (the crc + // in a gzip for example) + if (m_inflate->avail_in) { + m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in); + m_inflate->avail_in = 0; } - } - err = inflate(m_inflate, Z_NO_FLUSH); - } + m_lasterror = wxSTREAM_EOF; + break; - if (err == Z_STREAM_END) { - // Unread any data taken from past the end of the deflate stream, so that - // any additional data can be read from the underlying stream (the crc - // in a gzip for example) - if (m_inflate->avail_in) { - m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in); - m_inflate->avail_in = 0; - } - m_lasterror = wxSTREAM_EOF; - } else if (err != Z_OK) { - wxString msg(m_inflate->msg, *wxConvCurrent); - if (!msg) - msg.Format(_("zlib error %d"), err); - wxLogError(_("Can't read from inflate stream: %s\n"), msg.c_str()); - m_lasterror = wxSTREAM_READ_ERROR; + case Z_BUF_ERROR: + // Indicates that zlib was expecting more data, but the parent stream + // has none. Other than Eof the error will have been already reported + // by the parent strean, + m_lasterror = wxSTREAM_READ_ERROR; + if (m_parent_i_stream->Eof()) +#if WXWIN_COMPATIBILITY_2_4 + if (m_24compatibilty) + m_lasterror = wxSTREAM_EOF; + else +#endif + wxLogError(_("Can't read inflate stream: unexpected EOF in underlying stream.")); + break; + + default: + wxString msg(m_inflate->msg, *wxConvCurrent); + if (!msg) + msg.Format(_("zlib error %d"), err); + wxLogError(_("Can't read from inflate stream: %s"), msg.c_str()); + m_lasterror = wxSTREAM_READ_ERROR; } size -= m_inflate->avail_out; @@ -139,6 +172,15 @@ size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size) return size; } +/* static */ bool wxZlibInputStream::CanHandleGZip() +{ + const char *dot = strchr(zlibVersion(), '.'); + int major = atoi(zlibVersion()); + int minor = dot ? atoi(dot + 1) : 0; + return major > 1 || (major == 1 && minor >= 2); +} + + ////////////////////// // wxZlibOutputStream ////////////////////// @@ -162,24 +204,34 @@ wxZlibOutputStream::wxZlibOutputStream(wxOutputStream& stream, wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!")); } - if (m_z_buffer) { - m_deflate = new z_stream_s; + // if gzip is asked for but not supported... + if (flags == wxZLIB_GZIP && !CanHandleGZip()) { + wxLogError(_("Gzip not supported by this version of zlib")); + m_lasterror = wxSTREAM_WRITE_ERROR; + return; + } - if (m_deflate) { - memset(m_deflate, 0, sizeof(z_stream_s)); - m_deflate->next_out = m_z_buffer; - m_deflate->avail_out = m_z_size; + if (m_z_buffer) { + m_deflate = new z_stream_s; - wxASSERT(flags == 0 || flags == wxZLIB_ZLIB || flags == wxZLIB_GZIP); + if (m_deflate) { + memset(m_deflate, 0, sizeof(z_stream_s)); + m_deflate->next_out = m_z_buffer; + m_deflate->avail_out = m_z_size; - int bits = flags ? MAX_WBITS : -MAX_WBITS; - if (flags & wxZLIB_GZIP) - bits |= 0x10; - - if (deflateInit2(m_deflate, level, Z_DEFLATED, bits, - 8, Z_DEFAULT_STRATEGY) == Z_OK) - return; - } + // see zlib.h for documentation on windowBits + int windowBits = MAX_WBITS; + switch (flags) { + case wxZLIB_NO_HEADER: windowBits = -MAX_WBITS; break; + case wxZLIB_ZLIB: windowBits = MAX_WBITS; break; + case wxZLIB_GZIP: windowBits = MAX_WBITS | ZSTREAM_GZIP; break; + default: wxFAIL_MSG(wxT("Invalid zlib flag")); + } + + if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits, + 8, Z_DEFAULT_STRATEGY) == Z_OK) + return; + } } wxLogError(_("Can't initialize zlib deflate stream.")); @@ -261,7 +313,7 @@ size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size) wxString msg(m_deflate->msg, *wxConvCurrent); if (!msg) msg.Format(_("zlib error %d"), err); - wxLogError(_("Can't write to deflate stream: %s\n"), msg.c_str()); + wxLogError(_("Can't write to deflate stream: %s"), msg.c_str()); } size -= m_deflate->avail_in; @@ -269,6 +321,11 @@ size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size) return size; } +/* static */ bool wxZlibOutputStream::CanHandleGZip() +{ + return wxZlibInputStream::CanHandleGZip(); +} + #endif // wxUSE_ZLIB && wxUSE_STREAMS -- 2.45.2