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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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161
src/common/zstream.cpp
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@@ -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;
// 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"));
}
int bits = flags ? MAX_WBITS : -MAX_WBITS;
if (flags & wxZLIB_GZIP)
bits |= (flags & wxZLIB_ZLIB) ? 0x20 : 0x10;
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();
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) {
// 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;
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;
}
m_lasterror = wxSTREAM_EOF;
break;
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 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) {
m_deflate = new z_stream_s;
m_deflate = new z_stream_s;
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;
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;
// 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, bits,
8, Z_DEFAULT_STRATEGY) == Z_OK)
return;
}
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