wxZlibStreams fixes; allow them to be used as deflate [de]compressor in gz/zip files (patch 792562)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@23945 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/zstream.h

@@ -2,7 +2,7 @@
 // Name:        zstream.h
 // Purpose:     Memory stream classes
 // Author:      Guilhem Lavaux
-// Modified by:
+// Modified by: Mike Wetherell
 // Created:     11/07/98
 // RCS-ID:      $Id$
 // Copyright:   (c) Guilhem Lavaux
@@ -21,36 +21,59 @@
 
 #include "wx/stream.h"
 
+// Compression level
+enum {
+    wxZ_DEFAULT_COMPRESSION = -1,
+    wxZ_NO_COMPRESSION = 0,
+    wxZ_BEST_SPEED = 1,
+    wxZ_BEST_COMPRESSION = 9
+};
+
+// Flags
+enum {
+    wxZLIB_NO_HEADER = 1   // required for use in Gzip and Zip files
+};
+
 class WXDLLIMPEXP_BASE wxZlibInputStream: public wxFilterInputStream {
  public:
-  wxZlibInputStream(wxInputStream& stream);
+  wxZlibInputStream(wxInputStream& stream, int flags = 0);
   virtual ~wxZlibInputStream();
 
+  char Peek() { return wxInputStream::Peek(); }
+  size_t GetSize() const { return wxInputStream::GetSize(); }
+
  protected:
   size_t OnSysRead(void *buffer, size_t size);
+  off_t OnSysTell() const { return m_pos; }
 
  protected:
   size_t m_z_size;
   unsigned char *m_z_buffer;
   struct z_stream_s *m_inflate;
+  off_t m_pos;
 
     DECLARE_NO_COPY_CLASS(wxZlibInputStream)
 };
 
 class WXDLLIMPEXP_BASE wxZlibOutputStream: public wxFilterOutputStream {
  public:
-  wxZlibOutputStream(wxOutputStream& stream, int level = -1);
+  wxZlibOutputStream(wxOutputStream& stream, int level = -1, int flags = 0);
   virtual ~wxZlibOutputStream();
 
-  void Sync();
+  void Sync() { DoFlush(false); }
+  size_t GetSize() const { return (size_t)m_pos; }
 
  protected:
   size_t OnSysWrite(const void *buffer, size_t size);
+  off_t OnSysTell() const { return m_pos; }
+
+  virtual void DoFlush(bool final);
 
  protected:
   size_t m_z_size;
   unsigned char *m_z_buffer;
   struct z_stream_s *m_deflate;
+  off_t m_pos;
 
     DECLARE_NO_COPY_CLASS(wxZlibOutputStream)
 };