Class: PNG::Decoder

Inherits:

Object

• Object
• PNG::Decoder

Defined in:

ext/png/png.c

Instance Method Summary

• #decode(data) ⇒ Object (also: #decompress, #<<)
• #initialize(*args) ⇒ Object constructor
• #read_header(data) ⇒ Object

Constructor Details

#initialize(*args) ⇒ Object

# File 'ext/png/png.c', line 752

static VALUE
rb_decoder_initialize(int argc, VALUE* argv, VALUE self)
{
  png_decoder_t* ptr;
  VALUE opt;

  /*
   * strip object
   */
  Data_Get_Struct(self, png_decoder_t, ptr);

  /*
   * parse argument
   */
  rb_scan_args(argc, argv, "01", &opt);
  if (opt != Qnil) Check_Type(opt, T_HASH);

  /*
   * set context
   */
  set_decoder_context(ptr, opt);

  return Qtrue;
}

Instance Method Details

#decode(data) ⇒ Object Also known as: decompress, <<

# File 'ext/png/png.c', line 1410

static VALUE
rb_decoder_decode(VALUE self, VALUE data)
{
  VALUE ret;
  png_decoder_t* ptr;
  decode_arg_t arg;

  /*
   * argument check
   */
  Check_Type(data, T_STRING);

  /*
   * strip object
   */
  Data_Get_Struct(self, png_decoder_t, ptr);

  /*
   * call decode funcs
   */
  arg.ptr  = ptr;
  arg.data = data;

  if (ptr->common.api_type == API_SIMPLIFIED) {
    ret = rb_ensure(decode_simplified_api_body, (VALUE)&arg,
                    decode_simplified_api_ensure, (VALUE)ptr);

  } else {
    ret = rb_ensure(decode_classic_api_body, (VALUE)&arg,
                    decode_classic_api_ensure, (VALUE)ptr);
  }

  return ret;
}

#read_header(data) ⇒ Object

# File 'ext/png/png.c', line 1181

static VALUE
rb_decoder_read_header(VALUE self, VALUE data)
{
  VALUE ret;
  png_decoder_t* ptr;
  read_header_arg_t arg;

  /*
   * argument check
   */
  Check_Type(data, T_STRING);

  if (RSTRING_LEN(data) < 8) {
    RUNTIME_ERROR("data too short.");
  }

  if (png_sig_cmp((png_const_bytep)RSTRING_PTR(data), 0, 8)) {
    RUNTIME_ERROR("Invalid PNG signature.");
  }

  /*
   * strip object
   */
  Data_Get_Struct(self, png_decoder_t, ptr);

  /*
   * call read header funciton
   */
  arg.ptr  = ptr;
  arg.data = data;

  ret = rb_ensure(read_header_body, (VALUE)&arg,
                  read_header_ensure, (VALUE)ptr);

  return ret;
}