vmap/plugins/archivezip/zlibstream.h

71 lines
2 KiB
C++

/*
Copyright (C) 2001-2006, William Joseph.
All Rights Reserved.
This file is part of GtkRadiant.
GtkRadiant is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
GtkRadiant is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GtkRadiant; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#if !defined( INCLUDED_ZLIBSTREAM_H )
#define INCLUDED_ZLIBSTREAM_H
#include "zlib.h"
#include "idatastream.h"
/// \brief A wrapper around an InputStream of data compressed with the zlib deflate algorithm.
///
/// - Uses z_stream to decompress the data stream on the fly.
/// - Uses a buffer to reduce the number of times the wrapped stream must be read.
class DeflatedInputStream : public InputStream {
InputStream &m_istream;
z_stream m_zipstream;
enum unnamed0 { m_bufsize = 1024 };
unsigned char m_buffer[m_bufsize];
public:
DeflatedInputStream(InputStream &istream)
: m_istream(istream)
{
m_zipstream.zalloc = 0;
m_zipstream.zfree = 0;
m_zipstream.opaque = 0;
m_zipstream.avail_in = 0;
inflateInit2(&m_zipstream, -MAX_WBITS);
}
~DeflatedInputStream()
{
inflateEnd(&m_zipstream);
}
size_type read(byte_type *buffer, size_type length)
{
m_zipstream.next_out = buffer;
m_zipstream.avail_out = static_cast<uInt>( length );
while (m_zipstream.avail_out != 0) {
if (m_zipstream.avail_in == 0) {
m_zipstream.next_in = m_buffer;
m_zipstream.avail_in = static_cast<uInt>( m_istream.read(m_buffer, m_bufsize));
}
if (inflate(&m_zipstream, Z_SYNC_FLUSH) != Z_OK) {
break;
}
}
return length - m_zipstream.avail_out;
}
};
#endif