Module: Sabrina::Bytestream::ByteOutput

Included in:
Sabrina::Bytestream
Defined in:
lib/sabrina/bytestream/byte_output.rb

Overview

Methods that allow Sabrina::Bytestream to output the raw byte data or export it to various formats. Subclasses should override #to_bytes to allow generation from an internal representation if present, and add to the list of output formats if necessary.

Instance Method Summary collapse

Instance Method Details

#generate_bytes ⇒ Object

Subclasses should override this to return a string of bytes generated from the representation.



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# File 'lib/sabrina/bytestream/byte_output.rb', line 42

def generate_bytes
  @bytes_cache = present
end

#present ⇒ Object

Subclasses should override this to update the representation from byte data.



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# File 'lib/sabrina/bytestream/byte_output.rb', line 48

def present
  @representation ||= to_bytes
end

#to_b ⇒ Object

Same as #to_bytes.



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# File 'lib/sabrina/bytestream/byte_output.rb', line 53

def to_b
  to_bytes
end

#to_bytes ⇒ String

Outputs a raw byte string. ROM and either table and index (recommended) or offset should have been specified, otherwise the return string will be empty. This method is relied on for write and save operations.

This method uses an internal cache. The cache should be wiped automatically on changes to ROM or internal data, otherwise it can be wiped manually with RomOperations#clear_cache.

Subclasses should define #generate_bytes to create the bytestream from the internal representation instead and only read from the ROM if the internal representation is absent.

Returns:

  • (String) 


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# File 'lib/sabrina/bytestream/byte_output.rb', line 21

def to_bytes
  return @bytes_cache if @bytes_cache
  return @bytes_cache = generate_bytes if @representation

  l_offset = offset
  if @rom && offset
    if @lz77
      data = @rom.read_lz77(l_offset)
      @length_cache = data[:original_length]
      @lz77_cache = data[:original_stream]
      return @bytes_cache = data[:stream]
    end
    return @bytes_cache = @rom.read_string(l_offset) if @is_gba_string
    return @bytes_cache = @rom.read(l_offset, @length) if @length
  end

  return ''
end

#to_hex(pretty = false) ⇒ String

Returns a hexadecimal representation of the byte data, optionally grouping it into quartets if passed true as a parameter.

Returns:

  • (String) 


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# File 'lib/sabrina/bytestream/byte_output.rb', line 61

def to_hex(pretty = false)
  h = to_bytes.each_byte.to_a.map { |x| format('%02x', x) }.join('')
  return h unless pretty

  h.scan(/......../).map { |x| x.scan(/../).join(':') }.join(' ')
end

#to_hex_reverse ⇒ String

Same as #to_hex, but reverses the bytes before conversion.

Returns:

  • (String) 


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# File 'lib/sabrina/bytestream/byte_output.rb', line 71

def to_hex_reverse
  to_bytes.each_byte.to_a.map { |x| format('%02x', x) }.reverse.join('')
end

#to_i ⇒ Integer

Returns the byte data converted to a base-16 integer.

Returns:

  • (Integer) 


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# File 'lib/sabrina/bytestream/byte_output.rb', line 77

def to_i
  to_hex.hex
end

#to_lz77 ⇒ String

Outputs the byte data as a GBA-compatible Lz77-compressed stream, raising an error when the data is empty. RomOperations#write_to_rom relies on this method when :lz77 is set to true.

This method uses an internal cache. The cache should be wiped automatically on changes to ROM or internal data, otherwise it can be wiped manually with RomOperations#clear_cache.

Subclasses should clear the internal cache by calling RomOperations#clear_cache whenever the internal representation has changed.

Returns:

  • (String) 


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# File 'lib/sabrina/bytestream/byte_output.rb', line 94

def to_lz77
  return @lz77_cache if @lz77_cache
  b = to_bytes
  fail 'Cannot compress empty data.' if b.empty?
  @lz77_cache = Lz77.compress(b)
end

#to_s ⇒ String

Returns the output of #to_hex.

Subclasses should override this to provide a concise textual representation of the internal data.

Returns:

  • (String) 


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# File 'lib/sabrina/bytestream/byte_output.rb', line 107

def to_s
  "#{to_hex(true)}"
end