sapphire/deps/datReader/zlib.cpp

#include "zlib.h"
#include <string>
#include <stdexcept>
#include <zlib/zlib.h>
#include <vector>

namespace xiv::utils::zlib
{

  void compress( const std::vector< char >& in, std::vector< char >& out )
  {
    // Fetching upper bound for out size
    auto out_size = compressBound( static_cast< uLong >( in.size() ) );
    out.resize( out_size );

    auto ret = compress2( reinterpret_cast< uint8_t* >( out.data() ), &out_size,
                          reinterpret_cast< const uint8_t* >( in.data() ), static_cast< uLong >( in.size() ), Z_BEST_COMPRESSION );

    if( ret != Z_OK )
    {
      throw std::runtime_error( "Error at zlib uncompress: " + std::to_string( ret ) );
    }

    out.resize( out_size );
  }

  void no_header_decompress( uint8_t* in, size_t in_size, uint8_t* out, size_t out_size )
  {
    z_stream strm;
    strm.zalloc = Z_NULL;
    strm.zfree = Z_NULL;
    strm.opaque = Z_NULL;
    strm.avail_in = static_cast< uInt >( in_size );
    strm.next_in = Z_NULL;

    // Init with -15 because we do not have header in this compressed data
    auto ret = inflateInit2( &strm, -15 );
    if( ret != Z_OK )
    {
      throw std::runtime_error( "Error at zlib init: " + std::to_string( ret ) );
    }

    // Set pointers to the right addresses
    strm.next_in = in;
    strm.avail_out = static_cast< uInt >( out_size );
    strm.next_out = out;

    // Effectively decompress data
    ret = inflate( &strm, Z_NO_FLUSH );
    if( ret != Z_STREAM_END )
    {
      throw std::runtime_error( "Error at zlib inflate: " + std::to_string( ret ) );
    }

    // Clean up
    inflateEnd( &strm );
  }

}