+/////////////////////////////////////////////////////////////////////////////
+// Name: gzstream.cpp
+// Purpose: Streams for Gzip files
+// Author: Mike Wetherell
+// RCS-ID: $Id$
+// Copyright: (c) 2003 Mike Wetherell
+// Licence: wxWindows licence
+/////////////////////////////////////////////////////////////////////////////
+
+#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
+#pragma implementation "gzstream.h"
+#endif
+
+// For compilers that support precompilation, includes "wx.h".
+#include "wx/wxprec.h"
+
+#ifdef __BORLANDC__
+ #pragma hdrstop
+#endif
+
+#if wxUSE_STREAMS && wxUSE_GZSTREAM && wxUSE_ZLIB
+
+#include "wx/log.h"
+#include "wx/intl.h"
+#include "wx/datstrm.h"
+#include "wx/txtstrm.h"
+#include "wx/filename.h"
+#include "wx/zstream.h"
+#include "wx/gzstream.h"
+
+#if defined(__WXMSW__) && !defined(__WX_SETUP_H__) && !defined(wxUSE_ZLIB_H_IN_PATH)
+ #include "../zlib/zlib.h"
+#else
+ #include "zlib.h"
+#endif
+
+
+/////////////////////////////////////////////////////////////////////////////
+// Notes:
+//
+// See RFC-1952 and the Gzip/Zlib sources for the details of the Gzip format
+//
+// Errors are displayed with wxLogError, but not errors from the compressor
+// or underlying stream, since they will display their own errors.
+//
+// Gzip doesn't use flag 2 to indicate a header crc, so I think it's
+// probably better not to use it for the moment.
+//
+
+// Flags
+enum {
+ GZ_ASCII_FLAG = 0x01,
+ GZ_HEAD_CRC = 0x02,
+ GZ_EXTRA_FIELD = 0x04,
+ GZ_ORIG_NAME = 0x08,
+ GZ_COMMENT = 0x10,
+ GZ_RESERVED = 0xE0
+};
+
+// Extra flags
+enum {
+ GZ_SLOWEST = 2,
+ GZ_FASTEST = 4
+};
+
+const wxUint16 GZ_MAGIC = 0x8b1f;
+
+
+/////////////////////////////////////////////////////////////////////////////
+// Input stream
+
+wxGzipInputStream::wxGzipInputStream(wxInputStream& stream,
+ wxMBConv& conv /*=wxConvFile*/)
+ : wxFilterInputStream(stream)
+{
+ m_decomp = NULL;
+ m_crc = crc32(0, Z_NULL, 0);
+
+ // Try to read the Gzip magic numbers 0x1f, 0x8b. If not found then the
+ // underlying stream isn't gzipped after all, so unread the bytes taken
+ // so that the underlying stream can be read directly instead.
+ wxUint8 magic[2];
+ size_t n = m_parent_i_stream->Read(magic, sizeof(magic)).LastRead();
+
+ if (n < sizeof(magic) || ((magic[1] << 8) | magic[0]) != GZ_MAGIC) {
+ if (n)
+ m_parent_i_stream->Ungetch(magic, n);
+ // Set EOF rather than error to indicate no gzip data
+ m_lasterror = wxSTREAM_EOF;
+ return;
+ }
+
+ wxDataInputStream ds(*m_parent_i_stream);
+
+ // read method, flags, timestamp, extra flags and OS-code
+ int method = ds.Read8();
+ int flags = ds.Read8();
+#if wxUSE_DATETIME
+ wxUint32 datetime = ds.Read32();
+ if (datetime) // zero means not set (not -1 as usual for time_t)
+ m_datetime = wxLongLong(0, datetime) * 1000L;
+#else
+ ds.Read32();
+#endif
+ ds.Read8();
+ ds.Read8();
+
+ if (flags & GZ_HEAD_CRC)
+ ds.Read16();
+
+ if (flags & GZ_EXTRA_FIELD)
+ for (int i = ds.Read16(); i > 0 && m_parent_i_stream->IsOk(); i--)
+ m_parent_i_stream->GetC();
+
+ // RFC-1952 specifies ISO-8859-1 for these fields
+ if (flags & GZ_ORIG_NAME) {
+#if wxUSE_UNICODE
+ wxTextInputStream tis(*m_parent_i_stream, wxT(" \t"), conv);
+#else
+ wxTextInputStream tis(*m_parent_i_stream);
+ (void)conv;
+#endif
+ wxChar c;
+ while ((c = tis.GetChar()) != 0 && m_parent_i_stream->IsOk())
+ m_name += c;
+ }
+
+ if (flags & GZ_COMMENT)
+ while (m_parent_i_stream->GetC() != 0 && m_parent_i_stream->IsOk())
+ ; // empty loop
+
+ m_lasterror = wxSTREAM_READ_ERROR;
+ if (!*m_parent_i_stream) {
+ wxLogDebug(wxT("Error reading Gzip header"));
+ return;
+ }
+
+ if (flags & GZ_RESERVED)
+ wxLogWarning(_("Unsupported flag in Gzip header"));
+
+ switch (method) {
+ case Z_DEFLATED:
+ m_decomp = new wxZlibInputStream(*m_parent_i_stream, wxZLIB_NO_HEADER);
+ break;
+
+ default:
+ wxLogError(_("unsupported compression method in Gzip stream"));
+ return;
+ }
+
+ if (m_decomp)
+ m_lasterror = m_decomp->GetLastError();
+}
+
+
+wxGzipInputStream::~wxGzipInputStream()
+{
+ delete m_decomp;
+}
+
+
+size_t wxGzipInputStream::OnSysRead(void *buffer, size_t size)
+{
+ wxASSERT_MSG(m_decomp, wxT("Gzip not open"));
+
+ if (!m_decomp)
+ m_lasterror = wxSTREAM_READ_ERROR;
+ if (!IsOk() || !size)
+ return 0;
+
+ m_decomp->Read(buffer, size);
+ m_crc = crc32(m_crc, (Byte*)buffer, m_decomp->LastRead());
+
+ if (m_decomp->Eof()) {
+ wxDataInputStream ds(*m_parent_i_stream);
+ m_lasterror = wxSTREAM_READ_ERROR;
+
+ if (m_parent_i_stream->IsOk() && ds.Read32() != m_crc)
+ wxLogError(_("reading Gzip stream: bad crc"));
+ else if (m_parent_i_stream->IsOk() && ds.Read32() != (wxUint32)TellI())
+ wxLogError(_("reading Gzip stream: incorrect length"));
+ else if (m_parent_i_stream->IsOk())
+ m_lasterror = wxSTREAM_EOF;
+ }
+ else if (!*m_decomp) {
+ m_lasterror = wxSTREAM_READ_ERROR;
+ }
+
+ return m_decomp->LastRead();
+}
+
+
+/////////////////////////////////////////////////////////////////////////////
+// Output stream
+
+wxGzipOutputStream::wxGzipOutputStream(
+ wxOutputStream& stream,
+ const wxString& originalName /*=wxEmptyString*/,
+ int level /*=-1*/,
+ wxMBConv& conv /*=wxConvFile*/)
+ : wxFilterOutputStream(stream)
+{
+ m_comp = NULL;
+ m_crc = crc32(0, Z_NULL, 0);
+
+ wxFileName filename(originalName);
+
+#if wxUSE_DATETIME
+ wxDateTime datetime;
+
+ if (filename.FileExists())
+ datetime = filename.GetModificationTime();
+ else
+ datetime = wxDateTime::Now();
+
+ wxUint32 timestamp = (datetime.GetValue() / 1000L).GetLo();
+#else
+ wxUint32 timestamp = 0;
+#endif
+
+ // RFC-1952 specifies ISO-8859-1 for the name. Also it should be just the
+ // name part, no directory, folded to lowercase if case insensitive
+ wxString name = filename.GetFullName();
+ const wxWX2MBbuf mbName = conv.cWX2MB(name);
+
+ wxDataOutputStream ds(*m_parent_o_stream);
+
+ // write signature, method, flags, timestamp, extra flags and OS-code
+ ds.Write16(GZ_MAGIC);
+ ds.Write8(Z_DEFLATED);
+ ds.Write8(mbName && *mbName ? GZ_ORIG_NAME : 0);
+ ds.Write32(timestamp);
+ ds.Write8(level == 1 ? GZ_FASTEST : level == 9 ? GZ_SLOWEST : 0);
+ ds.Write8(255);
+
+ if (mbName && *mbName)
+ m_parent_o_stream->Write(mbName, strlen(mbName) + 1);
+
+ m_lasterror = wxSTREAM_WRITE_ERROR;
+ if (!*m_parent_o_stream) {
+ wxLogDebug(wxT("Error writing Gzip header"));
+ return;
+ }
+
+ m_comp = new wxZlibOutputStream(*m_parent_o_stream, level, wxZLIB_NO_HEADER);
+
+ if (m_comp)
+ m_lasterror = m_comp->GetLastError();
+}
+
+
+wxGzipOutputStream::~wxGzipOutputStream()
+{
+ if (m_comp && m_comp->IsOk()) {
+ wxUint32 len = (wxUint32)m_comp->TellO();
+ delete m_comp;
+ if (m_parent_o_stream->IsOk()) {
+ wxDataOutputStream ds(*m_parent_o_stream);
+ ds.Write32(m_crc);
+ ds.Write32(len); // underlying stream will report errors
+ }
+ } else {
+ delete m_comp;
+ }
+}
+
+
+void wxGzipOutputStream::Sync()
+{
+ wxASSERT_MSG(m_comp, wxT("Gzip not open"));
+
+ if (!m_comp)
+ m_lasterror = wxSTREAM_WRITE_ERROR;
+ if (IsOk())
+ m_comp->Sync();
+}
+
+
+size_t wxGzipOutputStream::OnSysWrite(const void *buffer, size_t size)
+{
+ wxASSERT_MSG(m_comp, wxT("Gzip not open"));
+
+ if (!m_comp)
+ m_lasterror = wxSTREAM_WRITE_ERROR;
+ if (!IsOk() || !size)
+ return 0;
+
+ if (m_comp->Write(buffer, size).LastWrite() != size)
+ m_lasterror = wxSTREAM_WRITE_ERROR;
+ m_crc = crc32(m_crc, (Byte*)buffer, size);
+
+ return m_comp->LastWrite();
+}
+
+
+#endif // wxUSE_STREAMS && wxUSE_GZSTREAM && wxUSE_ZLIB
projects / wxWidgets.git / commitdiff
