\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
\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
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}.
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:
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.
+
// 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; }
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 {
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; }
struct z_stream_s *m_deflate;
off_t m_pos;
- DECLARE_NO_COPY_CLASS(wxZlibOutputStream)
+ DECLARE_NO_COPY_CLASS(wxZlibOutputStream)
};
#endif
#endif
enum {
- ZSTREAM_BUFFER_SIZE = 16384
+ ZSTREAM_BUFFER_SIZE = 16384,
+ ZSTREAM_GZIP = 0x10, // gzip header
+ ZSTREAM_AUTO = 0x20 // auto detect between gzip and zlib
};
//////////////////////
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;
}
}
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;
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
//////////////////////
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."));
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;
return size;
}
+/* static */ bool wxZlibOutputStream::CanHandleGZip()
+{
+ return wxZlibInputStream::CanHandleGZip();
+}
+
#endif
// wxUSE_ZLIB && wxUSE_STREAMS
projects / wxWidgets.git / commitdiff
