gzstream.cpp

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// ============================================================================
// gzstream, C++ iostream classes wrapping the zlib compression library.
// Copyright (C) 2001  Deepak Bandyopadhyay, Lutz Kettner
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
// ============================================================================
//
// File          : gzstream.C
// Revision      : Revision: 1.7
// Revision_date : Date: 2003/01/08 14:41:27
// Author(s)     : Deepak Bandyopadhyay, Lutz Kettner
//
// Standard streambuf implementation following Nicolai Josuttis, "The
// Standard C++ Library".
// ============================================================================
//
// DD: 05/03/2012 - changes to improve portability; ios:out append enabled;
//

#include "precomp.hpp"
#include <fix8/f8config.h>
#ifdef FIX8_HAVE_ZLIB_H

#include <fix8/gzstream.hpp>

#ifdef GZSTREAM_NAMESPACE
namespace GZSTREAM_NAMESPACE {
#endif

// ----------------------------------------------------------------------------
// Internal classes to implement gzstream. See header file for user classes.
// ----------------------------------------------------------------------------

// --------------------------------------
// class gzstreambuf:
// --------------------------------------

gzstreambuf* gzstreambuf::open(const char* name, int open_mode)
{
    if (is_open())
        return nullptr;
    mode = open_mode;
    // no input append nor read/write mode
    if ((mode & std::ios::ate) || ((mode & std::ios::in) && (mode & std::ios::out)))
        return nullptr;
    char fmode[10], *fmodeptr = fmode;
    if (mode & std::ios::in)
        *fmodeptr++ = 'r';
    else if (mode & std::ios::app)
        *fmodeptr++ = 'a';
    else if (mode & std::ios::out)
        *fmodeptr++ = 'w';
    *fmodeptr++ = 'b';
    *fmodeptr = 0;
    if ((file = gzopen( name, fmode)) == 0)
        return nullptr;
    opened = 1;
    return this;
}

gzstreambuf *gzstreambuf::close()
{
    if (is_open())
    {
        sync();
        opened = 0;
        if (gzclose( file) == Z_OK)
            return this;
    }
    return nullptr;
}

int gzstreambuf::underflow()
{ // used for input buffer only
    if (gptr() && (gptr() < egptr()))
        return * reinterpret_cast<unsigned char *>(gptr());

    if (! (mode & std::ios::in) || !opened)
        return EOF;
    // Josuttis' implementation of inbuf
    int n_putback = gptr() - eback();
    if (n_putback > 4)
        n_putback = 4;
    memcpy(buffer + (4 - n_putback), gptr() - n_putback, n_putback);

    int num = gzread( file, buffer+4, bufferSize-4);
    if (num <= 0) // ERROR or EOF
        return EOF;

    // reset buffer pointers
    setg( buffer + (4 - n_putback),   // beginning of putback area
          buffer + 4,                 // read position
          buffer + 4 + num);          // end of buffer

    // return next character
    return * reinterpret_cast<unsigned char *>( gptr());
}

int gzstreambuf::flush_buffer()
{
    // Separate the writing of the buffer from overflow() and
    // sync() operation.
    int w = pptr() - pbase();
    if (gzwrite( file, pbase(), w) != w)
        return EOF;
    pbump( -w);
    return w;
}

int gzstreambuf::overflow(int c)
{ // used for output buffer only
    if ( !(mode & std::ios::out) || !opened)
        return EOF;
    if (c != EOF)
    {
        *pptr() = c;
        pbump(1);
    }
    if (flush_buffer() == EOF)
        return EOF;
    return c;
}

int gzstreambuf::sync()
{
    // Changed to use flush_buffer() instead of overflow( EOF)
    // which caused improper behavior with std::endl and flush(),
    // bug reported by Vincent Ricard.
    if (pptr() && pptr() > pbase())
    {
        if (flush_buffer() == EOF)
            return -1;
    }
    return 0;
}

// --------------------------------------
// class gzstreambase:
// --------------------------------------

gzstreambase::gzstreambase(const char* name, int mode)
{
    init( &buf);
    open( name, mode);
}

gzstreambase::~gzstreambase()
{
    buf.close();
}

void gzstreambase::open(const char* name, int open_mode)
{
    if (!buf.open( name, open_mode))
        clear(rdstate() | std::ios::badbit);
//  else
//     setstate(rdstate() | std::ios::badbit);
}

void gzstreambase::close()
{
    if (buf.is_open())
        if (! buf.close())
            clear( rdstate() | std::ios::badbit);
}

#ifdef GZSTREAM_NAMESPACE
} // namespace GZSTREAM_NAMESPACE
#endif
#endif // FIX8_HAVE_ZLIB_H

// ============================================================================
// EOF //