This page hosts a formal specification of .pak file format of Games based on Haxe Game Framework "Heaps" (e.g. Dead Cells) using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Ruby generated by Kaitai Struct depends on the Ruby runtime library. You have to install it before you can parse data.
The Ruby runtime library can be installed from RubyGems:
gem install kaitai-struct
Parse a local file and get structure in memory:
data = HeapsPak.from_file("path/to/local/file.pak")
Or parse structure from a string of bytes:
bytes = "\x00\x01\x02..."
data = HeapsPak.new(Kaitai::Struct::Stream.new(bytes))
After that, one can get various attributes from the structure by invoking getter methods like:
data.header # => get header
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
require 'kaitai/struct/struct'
unless Gem::Version.new(Kaitai::Struct::VERSION) >= Gem::Version.new('0.9')
raise "Incompatible Kaitai Struct Ruby API: 0.9 or later is required, but you have #{Kaitai::Struct::VERSION}"
end
##
# @see https://github.com/HeapsIO/heaps/blob/2bbc2b386952dfd8856c04a854bb706a52cb4b58/hxd/fmt/pak/Reader.hx Source
class HeapsPak < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@header = Header.new(@_io, self, @_root)
self
end
class Header < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@magic1 = @_io.read_bytes(3)
raise Kaitai::Struct::ValidationNotEqualError.new([80, 65, 75].pack('C*'), magic1, _io, "/types/header/seq/0") if not magic1 == [80, 65, 75].pack('C*')
@version = @_io.read_u1
@len_header = @_io.read_u4le
@len_data = @_io.read_u4le
@_raw_root_entry = @_io.read_bytes((len_header - 16))
_io__raw_root_entry = Kaitai::Struct::Stream.new(@_raw_root_entry)
@root_entry = Entry.new(_io__raw_root_entry, self, @_root)
@magic2 = @_io.read_bytes(4)
raise Kaitai::Struct::ValidationNotEqualError.new([68, 65, 84, 65].pack('C*'), magic2, _io, "/types/header/seq/5") if not magic2 == [68, 65, 84, 65].pack('C*')
self
end
##
# @see https://github.com/HeapsIO/heaps/blob/2bbc2b386952dfd8856c04a854bb706a52cb4b58/hxd/fmt/pak/Data.hx Source
class Entry < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@len_name = @_io.read_u1
@name = (@_io.read_bytes(len_name)).force_encoding("UTF-8")
@flags = Flags.new(@_io, self, @_root)
case flags.is_dir
when true
@body = Dir.new(@_io, self, @_root)
when false
@body = File.new(@_io, self, @_root)
end
self
end
class Flags < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@unused = @_io.read_bits_int_be(7)
@is_dir = @_io.read_bits_int_be(1) != 0
self
end
attr_reader :unused
attr_reader :is_dir
end
attr_reader :len_name
attr_reader :name
attr_reader :flags
attr_reader :body
end
class File < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@ofs_data = @_io.read_u4le
@len_data = @_io.read_u4le
@checksum = @_io.read_bytes(4)
self
end
def data
return @data unless @data.nil?
io = _root._io
_pos = io.pos
io.seek((_root.header.len_header + ofs_data))
@data = io.read_bytes(len_data)
io.seek(_pos)
@data
end
attr_reader :ofs_data
attr_reader :len_data
attr_reader :checksum
end
class Dir < Kaitai::Struct::Struct
def initialize(_io, _parent = nil, _root = self)
super(_io, _parent, _root)
_read
end
def _read
@num_entries = @_io.read_u4le
@entries = []
(num_entries).times { |i|
@entries << Entry.new(@_io, self, @_root)
}
self
end
attr_reader :num_entries
attr_reader :entries
end
attr_reader :magic1
attr_reader :version
attr_reader :len_header
attr_reader :len_data
attr_reader :root_entry
attr_reader :magic2
attr_reader :_raw_root_entry
end
attr_reader :header
end