rsc-archiver

compress and decompress runescape classic .jag/.mem cache files. these files contain a proprietary header describing the size of the archive, and of each individual entry (file). filenames are stored with a hash so it's impossible to recover the originals without bruteforcing (unless they're under ~5 characters).

this module works in the browser and node.

install

$ npm install @2003scape/rsc-archiver # -g for CLI program

cli usage

rsc-archiver <command>

Commands:
  rsc-archiver x <archive> <files..>  extract a file from an archive
                                                              [aliases: extract]
  rsc-archiver a <archive> <files..>  add files to an archive     [aliases: add]
  rsc-archiver d <archive> <files..>  remove files from an archive
                                                               [aliases: delete]
  rsc-archiver l <archive>            list hashes and file sizes in an archive
                                                                 [aliases: list]
  rsc-archiver h <name>               return the integer hash of a filename stri
                                      ng                         [aliases: hash]

Options:
  --help     Show help                                                 [boolean]
  --version  Show version number                                       [boolean]

Examples:
  rsc-archiver l ./cache/config85.jag       list the hashes in config85.jag
  rsc-archiver a ./cache/jagex.jag logo.tg  add logo.tga to jagex.jag
  a

example

import fs from 'fs/promises';
import { JagArchive } from './src/index.js';

const archive = new JagArchive();
await archive.init();
archive.readArchive(await fs.readFile('./cache/sounds1.mem'));

console.log(`cache has ${archive.entries.size} files`);

// get death.pcm from the archive and write it to disk
await fs.writeFile('death.pcm', archive.getEntry('death.pcm'));

// create a new archive and add a text file to it
archive.entries.clear();
archive.putEntry('test.txt', Buffer.from('test string'));
await fs.writeFile('./cache/test.jag', archive.toArchive(true));

// read the new archive and retrive the file from it
archive.readArchive(await fs.readFile('./cache/test.jag'))

console.log(`cache has ${archive.entries.size} files`);
console.log(Buffer.from(archive.getEntry('test.txt')).toString());

api

hashFilename(filename)

convert filename to integer hash used in archives.

archive = new JagArchive()

create a new jag (de)compressor instance.

archive.entries

Map of hashes -> decompressed file buffers.

async archive.init()

initialize the bzip wasm.

archive.readArchive(buffer)

decompress buffer and populate entries with each file within.

archive.hasEntry(name)

check if archive contains entry based on hash or filename.

archive.getEntry(name)

return entry based on name or hash.

archive.putEntry(name, buffer)

add a file to the archive buffer.

archive.removeEntry(name)

remove entry based on name or hash.

archive.toArchive(individualCompress=true)

compress entries to a jagex archive. if individualCompress is true, bzip each file separately. otherwise, concatinate all of the files and then bzip that result instead.

license

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License along with this program. If not, see http://www.gnu.org/licenses/.