knifer / mdict-js

A pure Javascript implementation for parsing MDict file (mdx/mdd) in local.

mdict-js

A pure Javascript implementation of MDict Parser (mdx/mdd).

-- NOW UNDER DEVELOPMENT --

View online demo at http://fengdh.github.io/mdict-js/

Features

• Pure JavaScript implementation, no dependence on native module.
• Parse both mdx/mdd file in local, no data being passed to server, no need for server processing.
• Limited support for data compression & encryption:
  • Data block compressed in GZip/LZO format.
  • Keyword index block encrypted with RIPEMD128.
• Look up single word or search candidate word list with wild card (*?, i.e. *a**ly).
• Fast and very fast for human ineraction:
  • Parsing mdx/mdd header only, e.g. <200ms in total for a pair of mdx(80M, >180k entries) and mdd(1Gb, >150k entries) file.
  • Each querying completed in no more than serveral 10ms.
• Low memory usage:
  • Parsing mdx/mdd header ahead, although loading only block index into memory that demanding for <2M in most case besides full keyword list.
  • Loading Word definition or resource on demand by slicing part of mdx/mdd file instead of whole one.
• Providing asynchornous API powered by bluebird (support for Promises A+, https://github.com/petkaantonov/bluebird).
• Sample renderer with support for embeded resource (image/audio/css/javascript etc.), currently working on Chrome(pc & mobile)/FireFox.

Issues & TODOs:

• Not support 64-bit number (>4G) used for data offset or length due to number format in ECMAScript 5 standard.
• Not support encrypted keyword header that requires external or embedded regkey.
• Audio support for plain wave (.wav) and speex (.spx) format. Currently *.mp3 or WavMP3 processed *.wav file is not supported by FireFox, though Chrome is OK.
• TODO: convert to node.js module.
• TODO: stylesheet (text pattern) substitution.
• TODO: load and relase emebeded resource with LRU based cache.
• TODO: scoped CSS stylesheet for FireFox, or shadow DOM to confine css rules for Chrome.
• TODO: support look-up word variation using Porter 2 stemmar.
• TODO: support old IE (>9.0) without TextDecoder.
• TODO: CSS stylesheet overriden and plugin to combine multiple dictionaries.
• TODO: Chrome extension or app aimed for vocabulary building or read-assit with local dictionaries.
• TODO: WordNet visiualization.