tactless/root.js

Parser for Blizzard TACT files.

const { Parser } = require('binary-parser');
const assert = require('node:assert');

const parser = new Parser()
  .uint32le("magic", { assert: 0x4d465354 })
  .uint32le("total_file_count")
  .uint32le("named_file_count")
  .array("blocks", {
    readUntil: "eof",
    type: new Parser()
      .uint32le("num_records")
      .uint32le("flags")
      .uint32le("locale")
      .array("fdid_deltas", {
        length: "num_records",
        type: "int32le",
      })
      .array("content_keys", {
        length: "num_records",
        type: new Parser().string("", { encoding: "hex", length: 16 }),
      })
      .array("name_hashes", {
        length: function() {
          return (this.flags & 0x10000000) ? 0 : this.num_records;
        },
        type: new Parser().string("", { encoding: "hex", length: 8 }),
      }),
  });

function parseRoot(buf) {
  const data = parser.parse(buf);
  const name2fdid = new Map();
  const fdid2ckey = new Map();
  for (const block of data.blocks) {
    let fdid = -1;
    for (let i = 0; i < block.num_records; ++i) {
      fdid = fdid + 1 + block.fdid_deltas[i];
      if (!fdid2ckey.has(fdid)) {
        fdid2ckey.set(fdid, []);
      }
      fdid2ckey.get(fdid).push({
        ckey: block.content_keys[i],
        flags: block.flags,
        locale: block.locale,
      });
      const name = block.name_hashes[i];
      if (name) {
        assert(!name2fdid.has(name) || name2fdid.get(name) == fdid);
        name2fdid.set(name, fdid);
      }
    }
  }
  return {
    fdid2ckey: fdid2ckey,
    name2fdid: name2fdid,
  };
}

module.exports = {
  parse: parseRoot,
};