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improvements to zlib streams (patch 929416):

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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
This commit is contained in:
Václav Slavík
2004-04-11 19:34:56 +00:00
parent 3e0a7f68f9
commit 4c68a10264
4 changed files with 172 additions and 70 deletions
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3
docs/changes.txt
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@@ -42,6 +42,9 @@ INCOMPATIBLE CHANGES SINCE 2.4.x
- wxTaskBarIcon objects must now be destroyed before the application can exit. - wxTaskBarIcon objects must now be destroyed before the application can exit.
Previously, the application terminated if there were no top level windows; 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. 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 wxTaskBarIcon must be explicitly destroyed now, otherwise the application
won't exit even though there are no top level windows won't exit even though there are no top level windows

55
docs/latex/wx/strmzlib.tex
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@@ -4,7 +4,8 @@
\section{\class{wxZlibInputStream}}\label{wxzlibinputstream} \section{\class{wxZlibInputStream}}\label{wxzlibinputstream}
This filter stream decompresses a stream that is in zlib or gzip format. 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 The stream is not seekable, \helpref{SeekI()}{wxinputstreamseeki} returns
{\it wxInvalidOffset}. Also \helpref{GetSize()}{wxstreambasegetsize} is {\it wxInvalidOffset}. Also \helpref{GetSize()}{wxstreambasegetsize} is
@@ -27,25 +28,45 @@ not supported, it always returns $0$.
\membersection{wxZlibInputStream::wxZlibInputStream} \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 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. 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: The following symbols can be use for the flags:
\begin{verbatim} \begin{verbatim}
// Flags // Flags
enum { enum {
wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum #if WXWIN_COMPATIBILITY_2_4
wxZLIB_ZLIB = 1, // zlib header and checksum wxZLIB_24COMPATIBLE = 4, // read v2.4.x data without error
wxZLIB_GZIP = 2 // gzip header and checksum, requires zlib 1.2+ #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} \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 % wxZlibOutputStream
@@ -54,7 +75,8 @@ enum {
This stream compresses all data written to it. The compressed output can be This stream compresses all data written to it. The compressed output can be
in zlib or gzip format. 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 The stream is not seekable, \helpref{SeekO()}{wxoutputstreamseeko} returns
{\it wxInvalidOffset}. {\it wxInvalidOffset}.
@@ -86,8 +108,11 @@ value (currently equivalent to 6).
The {\it flags} wxZLIB\_ZLIB and wxZLIB\_GZIP specify whether the output data 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. 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: The following symbols can be use for the compression level and flags:
@@ -104,7 +129,13 @@ enum {
enum { enum {
wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum
wxZLIB_ZLIB = 1, // zlib header and 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} \end{verbatim}
\membersection{wxZlibOutputStream::CanHandleGZip}\label{wxoutputstreamcanhandlegzip}
\func{static bool}{CanHandleGZip}{\void}
Returns true if zlib library in use can handle gzip compressed data.

23
include/wx/zstream.h
View File

@@ -31,19 +31,25 @@ enum {
// Flags // Flags
enum { enum {
wxZLIB_NO_HEADER = 0, // raw deflate stream, no header or checksum #if WXWIN_COMPATIBILITY_2_4
wxZLIB_ZLIB = 1, // zlib header and checksum wxZLIB_24COMPATIBLE = 4, // read v2.4.x data without error
wxZLIB_GZIP = 2 // gzip header and checksum, requires zlib 1.2+ #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 { class WXDLLIMPEXP_BASE wxZlibInputStream: public wxFilterInputStream {
public: public:
wxZlibInputStream(wxInputStream& stream, int flags = wxZLIB_ZLIB | wxZLIB_GZIP); wxZlibInputStream(wxInputStream& stream, int flags = wxZLIB_AUTO);
virtual ~wxZlibInputStream(); virtual ~wxZlibInputStream();
char Peek() { return wxInputStream::Peek(); } char Peek() { return wxInputStream::Peek(); }
size_t GetSize() const { return wxInputStream::GetSize(); } size_t GetSize() const { return wxInputStream::GetSize(); }
static bool CanHandleGZip();
protected: protected:
size_t OnSysRead(void *buffer, size_t size); size_t OnSysRead(void *buffer, size_t size);
off_t OnSysTell() const { return m_pos; } off_t OnSysTell() const { return m_pos; }
@@ -53,8 +59,11 @@ class WXDLLIMPEXP_BASE wxZlibInputStream: public wxFilterInputStream {
unsigned char *m_z_buffer; unsigned char *m_z_buffer;
struct z_stream_s *m_inflate; struct z_stream_s *m_inflate;
off_t m_pos; 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 { class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream {
@@ -65,6 +74,8 @@ class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream {
void Sync() { DoFlush(false); } void Sync() { DoFlush(false); }
size_t GetSize() const { return (size_t)m_pos; } size_t GetSize() const { return (size_t)m_pos; }
static bool CanHandleGZip();
protected: protected:
size_t OnSysWrite(const void *buffer, size_t size); size_t OnSysWrite(const void *buffer, size_t size);
off_t OnSysTell() const { return m_pos; } off_t OnSysTell() const { return m_pos; }
@@ -77,7 +88,7 @@ class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream {
struct z_stream_s *m_deflate; struct z_stream_s *m_deflate;
off_t m_pos; off_t m_pos;
DECLARE_NO_COPY_CLASS(wxZlibOutputStream) DECLARE_NO_COPY_CLASS(wxZlibOutputStream)
}; };
#endif #endif

161
src/common/zstream.cpp
View File

@@ -38,7 +38,9 @@
#endif #endif
enum { 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_z_size = ZSTREAM_BUFFER_SIZE;
m_pos = 0; 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) { if (m_z_buffer) {
m_inflate = new z_stream_s; m_inflate = new z_stream_s;
if (m_inflate) { if (m_inflate) {
memset(m_inflate, 0, sizeof(z_stream_s)); memset(m_inflate, 0, sizeof(z_stream_s));
wxASSERT((flags & ~(wxZLIB_ZLIB | wxZLIB_GZIP)) == 0); // see zlib.h for documentation on windowBits
int windowBits = MAX_WBITS;
// when autodetecting between gzip & zlib, silently drop gzip flag switch (flags) {
// if the version of zlib doesn't support it case wxZLIB_NO_HEADER: windowBits = -MAX_WBITS; break;
if (flags == (wxZLIB_ZLIB | wxZLIB_GZIP) case wxZLIB_ZLIB: windowBits = MAX_WBITS; break;
&& strcmp(zlib_version, "1.2.") < 0) case wxZLIB_GZIP: windowBits = MAX_WBITS | ZSTREAM_GZIP; break;
flags &= ~wxZLIB_GZIP; case wxZLIB_AUTO: windowBits = MAX_WBITS | ZSTREAM_AUTO; break;
default: wxFAIL_MSG(wxT("Invalid zlib flag"));
}
int bits = flags ? MAX_WBITS : -MAX_WBITS; if (inflateInit2(m_inflate, windowBits) == Z_OK)
if (flags & wxZLIB_GZIP)
bits |= (flags & wxZLIB_ZLIB) ? 0x20 : 0x10;
if (inflateInit2(m_inflate, bits) == Z_OK)
return; return;
} }
} }
@@ -102,36 +122,49 @@ size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
m_inflate->avail_out = size; m_inflate->avail_out = size;
while (err == Z_OK && m_inflate->avail_out > 0) { 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_parent_i_stream->Read(m_z_buffer, m_z_size);
m_inflate->next_in = m_z_buffer; m_inflate->next_in = m_z_buffer;
m_inflate->avail_in = m_parent_i_stream->LastRead(); m_inflate->avail_in = m_parent_i_stream->LastRead();
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;
break;
}
} }
err = inflate(m_inflate, Z_NO_FLUSH); err = inflate(m_inflate, Z_SYNC_FLUSH);
} }
if (err == Z_STREAM_END) { switch (err) {
// Unread any data taken from past the end of the deflate stream, so that case Z_OK:
// any additional data can be read from the underlying stream (the crc break;
// in a gzip for example)
if (m_inflate->avail_in) { case Z_STREAM_END:
m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in); // Unread any data taken from past the end of the deflate stream, so that
m_inflate->avail_in = 0; // any additional data can be read from the underlying stream (the crc
} // in a gzip for example)
m_lasterror = wxSTREAM_EOF; if (m_inflate->avail_in) {
} else if (err != Z_OK) { m_parent_i_stream->Ungetch(m_inflate->next_in, m_inflate->avail_in);
wxString msg(m_inflate->msg, *wxConvCurrent); m_inflate->avail_in = 0;
if (!msg) }
msg.Format(_("zlib error %d"), err); m_lasterror = wxSTREAM_EOF;
wxLogError(_("Can't read from inflate stream: %s\n"), msg.c_str()); break;
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; size -= m_inflate->avail_out;
@@ -139,6 +172,15 @@ size_t wxZlibInputStream::OnSysRead(void *buffer, size_t size)
return 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 // 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!")); wxASSERT_MSG(level >= 0 && level <= 9, wxT("wxZlibOutputStream compression level must be between 0 and 9!"));
} }
// 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_z_buffer) { if (m_z_buffer) {
m_deflate = new z_stream_s; m_deflate = new z_stream_s;
if (m_deflate) { if (m_deflate) {
memset(m_deflate, 0, sizeof(z_stream_s)); memset(m_deflate, 0, sizeof(z_stream_s));
m_deflate->next_out = m_z_buffer; m_deflate->next_out = m_z_buffer;
m_deflate->avail_out = m_z_size; m_deflate->avail_out = m_z_size;
wxASSERT(flags == 0 || flags == wxZLIB_ZLIB || flags == wxZLIB_GZIP);
int bits = flags ? MAX_WBITS : -MAX_WBITS; // see zlib.h for documentation on windowBits
if (flags & wxZLIB_GZIP) int windowBits = MAX_WBITS;
bits |= 0x10; 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, bits, if (deflateInit2(m_deflate, level, Z_DEFLATED, windowBits,
8, Z_DEFAULT_STRATEGY) == Z_OK) 8, Z_DEFAULT_STRATEGY) == Z_OK)
return; return;
} }
} }
wxLogError(_("Can't initialize zlib deflate stream.")); 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); wxString msg(m_deflate->msg, *wxConvCurrent);
if (!msg) if (!msg)
msg.Format(_("zlib error %d"), err); 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; size -= m_deflate->avail_in;
@@ -269,6 +321,11 @@ size_t wxZlibOutputStream::OnSysWrite(const void *buffer, size_t size)
return size; return size;
} }
/* static */ bool wxZlibOutputStream::CanHandleGZip()
{
return wxZlibInputStream::CanHandleGZip();
}
#endif #endif
// wxUSE_ZLIB && wxUSE_STREAMS // wxUSE_ZLIB && wxUSE_STREAMS