.pak file format of Games based on Haxe Game Framework "Heaps" (e.g. Dead Cells): Python parsing library

Application

Games based on Haxe Game Framework "Heaps" (e.g. Dead Cells)

File extension

pak

KS implementation details

License: MIT

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.

Usage

Runtime library

All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.

The Python runtime library can be installed from PyPI:

python3 -m pip install kaitaistruct

Code

Parse a local file and get structure in memory:

data = HeapsPak.from_file("path/to/local/file.pak")

Or parse structure from a bytes:

from kaitaistruct import KaitaiStream, BytesIO

raw = b"\x00\x01\x02..."
data = HeapsPak(KaitaiStream(BytesIO(raw)))

After that, one can get various attributes from the structure by invoking getter methods like:

data.header # => get header

Python source code to parse .pak file format of Games based on Haxe Game Framework "Heaps" (e.g. Dead Cells)

heaps_pak.py

# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

from pkg_resources import parse_version
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO


if parse_version(kaitaistruct.__version__) < parse_version('0.9'):
    raise Exception("Incompatible Kaitai Struct Python API: 0.9 or later is required, but you have %s" % (kaitaistruct.__version__))

class HeapsPak(KaitaiStruct):
    """
    .. seealso::
       Source - https://github.com/HeapsIO/heaps/blob/2bbc2b386952dfd8856c04a854bb706a52cb4b58/hxd/fmt/pak/Reader.hx
    """
    def __init__(self, _io, _parent=None, _root=None):
        self._io = _io
        self._parent = _parent
        self._root = _root if _root else self
        self._read()

    def _read(self):
        self.header = HeapsPak.Header(self._io, self, self._root)

    class Header(KaitaiStruct):
        def __init__(self, _io, _parent=None, _root=None):
            self._io = _io
            self._parent = _parent
            self._root = _root if _root else self
            self._read()

        def _read(self):
            self.magic1 = self._io.read_bytes(3)
            if not self.magic1 == b"\x50\x41\x4B":
                raise kaitaistruct.ValidationNotEqualError(b"\x50\x41\x4B", self.magic1, self._io, u"/types/header/seq/0")
            self.version = self._io.read_u1()
            self.len_header = self._io.read_u4le()
            self.len_data = self._io.read_u4le()
            self._raw_root_entry = self._io.read_bytes((self.len_header - 16))
            _io__raw_root_entry = KaitaiStream(BytesIO(self._raw_root_entry))
            self.root_entry = HeapsPak.Header.Entry(_io__raw_root_entry, self, self._root)
            self.magic2 = self._io.read_bytes(4)
            if not self.magic2 == b"\x44\x41\x54\x41":
                raise kaitaistruct.ValidationNotEqualError(b"\x44\x41\x54\x41", self.magic2, self._io, u"/types/header/seq/5")

        class Entry(KaitaiStruct):
            """
            .. seealso::
               Source - https://github.com/HeapsIO/heaps/blob/2bbc2b386952dfd8856c04a854bb706a52cb4b58/hxd/fmt/pak/Data.hx
            """
            def __init__(self, _io, _parent=None, _root=None):
                self._io = _io
                self._parent = _parent
                self._root = _root if _root else self
                self._read()

            def _read(self):
                self.len_name = self._io.read_u1()
                self.name = (self._io.read_bytes(self.len_name)).decode(u"UTF-8")
                self.flags = HeapsPak.Header.Entry.Flags(self._io, self, self._root)
                _on = self.flags.is_dir
                if _on == True:
                    self.body = HeapsPak.Header.Dir(self._io, self, self._root)
                elif _on == False:
                    self.body = HeapsPak.Header.File(self._io, self, self._root)

            class Flags(KaitaiStruct):
                def __init__(self, _io, _parent=None, _root=None):
                    self._io = _io
                    self._parent = _parent
                    self._root = _root if _root else self
                    self._read()

                def _read(self):
                    self.unused = self._io.read_bits_int_be(7)
                    self.is_dir = self._io.read_bits_int_be(1) != 0



        class File(KaitaiStruct):
            def __init__(self, _io, _parent=None, _root=None):
                self._io = _io
                self._parent = _parent
                self._root = _root if _root else self
                self._read()

            def _read(self):
                self.ofs_data = self._io.read_u4le()
                self.len_data = self._io.read_u4le()
                self.checksum = self._io.read_bytes(4)

            @property
            def data(self):
                if hasattr(self, '_m_data'):
                    return self._m_data if hasattr(self, '_m_data') else None

                io = self._root._io
                _pos = io.pos()
                io.seek((self._root.header.len_header + self.ofs_data))
                self._m_data = io.read_bytes(self.len_data)
                io.seek(_pos)
                return self._m_data if hasattr(self, '_m_data') else None


        class Dir(KaitaiStruct):
            def __init__(self, _io, _parent=None, _root=None):
                self._io = _io
                self._parent = _parent
                self._root = _root if _root else self
                self._read()

            def _read(self):
                self.num_entries = self._io.read_u4le()
                self.entries = [None] * (self.num_entries)
                for i in range(self.num_entries):
                    self.entries[i] = HeapsPak.Header.Entry(self._io, self, self._root)