Function zlib_decompress

depends/lodepng/lodepng.cpp:2226–2249

expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */

/*expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */
static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size,
                                const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) {
  unsigned error;
  if(settings->custom_zlib) {
    error = settings->custom_zlib(out, outsize, in, insize, settings);
    if(error) {
      /*the custom zlib is allowed to have its own error codes, however, we translate it to code 110*/
      error = 110;
      /*if there's a max output size, and the custom zlib returned error, then indicate that error instead*/
      if(settings->max_output_size && *outsize > settings->max_output_size) error = 109;
    }
  } else {
    ucvector v = ucvector_init(*out, *outsize);
    if(expected_size) {
      /*reserve the memory to avoid intermediate reallocations*/
      ucvector_resize(&v, *outsize + expected_size);
      v.size = *outsize;
    }
    error = lodepng_zlib_decompressv(&v, in, insize, settings);
    *out = v.data;
    *outsize = v.size;
  }
  return error;
}

#endif /*LODEPNG_COMPILE_DECODER*/