.dat file format of Fallout 2: JavaScript parsing library

Application

Fallout 2

File extension

dat

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of .dat file format of Fallout 2 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 JavaScript generated by Kaitai Struct depends on the JavaScript runtime library. You have to install it before you can parse data.

The JavaScript runtime library is available at npm:

npm install kaitai-struct

Code

See the usage examples in the JavaScript notes.

Parse structure from an ArrayBuffer:

var arrayBuffer = ...;
var data = new Fallout2Dat(new KaitaiStream(arrayBuffer));

After that, one can get various attributes from the structure by accessing fields or properties like:

data.footer // => get footer

JavaScript source code to parse .dat file format of Fallout 2

Fallout2Dat.js

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

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define(['kaitai-struct/KaitaiStream'], factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(require('kaitai-struct/KaitaiStream'));
  } else {
    root.Fallout2Dat = factory(root.KaitaiStream);
  }
}(typeof self !== 'undefined' ? self : this, function (KaitaiStream) {
var Fallout2Dat = (function() {
  Fallout2Dat.Compression = Object.freeze({
    NONE: 0,
    ZLIB: 1,

    0: "NONE",
    1: "ZLIB",
  });

  function Fallout2Dat(_io, _parent, _root) {
    this._io = _io;
    this._parent = _parent;
    this._root = _root || this;

    this._read();
  }
  Fallout2Dat.prototype._read = function() {
  }

  var Pstr = Fallout2Dat.Pstr = (function() {
    function Pstr(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    Pstr.prototype._read = function() {
      this.size = this._io.readU4le();
      this.str = KaitaiStream.bytesToStr(this._io.readBytes(this.size), "ASCII");
    }

    return Pstr;
  })();

  var Footer = Fallout2Dat.Footer = (function() {
    function Footer(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    Footer.prototype._read = function() {
      this.indexSize = this._io.readU4le();
      this.fileSize = this._io.readU4le();
    }

    return Footer;
  })();

  var Index = Fallout2Dat.Index = (function() {
    function Index(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    Index.prototype._read = function() {
      this.fileCount = this._io.readU4le();
      this.files = [];
      for (var i = 0; i < this.fileCount; i++) {
        this.files.push(new File(this._io, this, this._root));
      }
    }

    return Index;
  })();

  var File = Fallout2Dat.File = (function() {
    function File(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    File.prototype._read = function() {
      this.name = new Pstr(this._io, this, this._root);
      this.flags = this._io.readU1();
      this.sizeUnpacked = this._io.readU4le();
      this.sizePacked = this._io.readU4le();
      this.offset = this._io.readU4le();
    }
    Object.defineProperty(File.prototype, 'contentsRaw', {
      get: function() {
        if (this._m_contentsRaw !== undefined)
          return this._m_contentsRaw;
        if (this.flags == Fallout2Dat.Compression.NONE) {
          var io = this._root._io;
          var _pos = io.pos;
          io.seek(this.offset);
          this._m_contentsRaw = io.readBytes(this.sizeUnpacked);
          io.seek(_pos);
        }
        return this._m_contentsRaw;
      }
    });
    Object.defineProperty(File.prototype, 'contentsZlib', {
      get: function() {
        if (this._m_contentsZlib !== undefined)
          return this._m_contentsZlib;
        if (this.flags == Fallout2Dat.Compression.ZLIB) {
          var io = this._root._io;
          var _pos = io.pos;
          io.seek(this.offset);
          this._raw__m_contentsZlib = io.readBytes(this.sizePacked);
          this._m_contentsZlib = KaitaiStream.processZlib(this._raw__m_contentsZlib);
          io.seek(_pos);
        }
        return this._m_contentsZlib;
      }
    });
    Object.defineProperty(File.prototype, 'contents', {
      get: function() {
        if (this._m_contents !== undefined)
          return this._m_contents;
        if ( ((this.flags == Fallout2Dat.Compression.ZLIB) || (this.flags == Fallout2Dat.Compression.NONE)) ) {
          this._m_contents = (this.flags == Fallout2Dat.Compression.ZLIB ? this.contentsZlib : this.contentsRaw);
        }
        return this._m_contents;
      }
    });

    return File;
  })();
  Object.defineProperty(Fallout2Dat.prototype, 'footer', {
    get: function() {
      if (this._m_footer !== undefined)
        return this._m_footer;
      var _pos = this._io.pos;
      this._io.seek((this._io.size - 8));
      this._m_footer = new Footer(this._io, this, this._root);
      this._io.seek(_pos);
      return this._m_footer;
    }
  });
  Object.defineProperty(Fallout2Dat.prototype, 'index', {
    get: function() {
      if (this._m_index !== undefined)
        return this._m_index;
      var _pos = this._io.pos;
      this._io.seek(((this._io.size - 8) - this.footer.indexSize));
      this._m_index = new Index(this._io, this, this._root);
      this._io.seek(_pos);
      return this._m_index;
    }
  });

  return Fallout2Dat;
})();
return Fallout2Dat;
}));