// Copyright (C) 2010, Guy Barrand. All rights reserved.
// See the file tools.license for terms.

#ifndef tools_gzip_buffer
#define tools_gzip_buffer

// what is needed for root file compression with zlib.

// The gzip library is libz.
// Someone must not confuse zlib with zip.
// In particular to use zip someone has to
// link to -lz that contains inflate, deflate.

#include <zlib.h>

#include <ostream>

namespace tools {

inline bool gzip_buffer(std::ostream& a_out,
                        unsigned int a_level,
                        unsigned int a_srcsize,const char* a_src,
                        unsigned int a_tgtsize,char* a_tgt,
                        unsigned int& a_irep) {

  z_stream stream; // decompression stream

  stream.next_in   = (Bytef*)(a_src);
  stream.avail_in  = (uInt)(a_srcsize);
  stream.next_out  = (Bytef*)a_tgt;
  stream.avail_out = (uInt)(a_tgtsize);
  stream.zalloc    = (alloc_func)0;
  stream.zfree     = (free_func)0;
  stream.opaque    = (voidpf)0;
  
  int err = deflateInit(&stream,a_level);
  if(err!=Z_OK) {
    a_out << "tools::wroot::zip :"
          << " error in zlib/deflateInit." << std::endl;
    a_irep = 0;
    return false;
  }
  
  err = deflate(&stream, Z_FINISH);
  if(err!=Z_STREAM_END) {
    deflateEnd(&stream);
    a_out << "tools::wroot::zip :"
          << " error in zlib/deflate." << std::endl;
    a_irep = 0;
    return false;
  }
  
  deflateEnd(&stream);
   
  //a_out << "tools::gzip_buffer : ok "
  //      << stream.total_out << std::endl;

  a_irep = stream.total_out;

  return true;
}

inline bool gunzip_buffer(std::ostream& a_out,
                          unsigned int a_srcsize,const char* a_src,
                          unsigned int a_tgtsize,char* a_tgt,
                          unsigned int& a_irep) {

  z_stream stream; // decompression stream

  stream.next_in   = (Bytef*)(a_src);
  stream.avail_in  = (uInt)(a_srcsize);
  stream.next_out  = (Bytef*)a_tgt;
  stream.avail_out = (uInt)(a_tgtsize);
  stream.zalloc    = (alloc_func)0;
  stream.zfree     = (free_func)0;
  stream.opaque    = (voidpf)0;
  
  int err = inflateInit(&stream);
  if (err != Z_OK) {
    a_out << "tools::gunzip_buffer :"
          << " error " << err << " in zlib/inflateInit." << std::endl;
    return false;
  }
  
  err = inflate(&stream, Z_FINISH);
  if (err != Z_STREAM_END) {
    inflateEnd(&stream);
    a_out << "tools::gunzip_buffer :"
          << " error " << err << " in zlib/inflate." << std::endl;
    return false;
  }
  
  inflateEnd(&stream);
   
  //a_out << "tools::gunzip_buffer : zlib : ok "
  //      << stream.total_out << std::endl;

  a_irep = stream.total_out;

  return true;
}

}

#endif

//exlib_build_use inlib zlib