/avsc

Avro for JavaScript :zap:

Primary LanguageJavaScriptMIT LicenseMIT

Avsc NPM version Build status Coverage status

Pure JavaScript implementation of the Avro specification.

Features

Installation

$ npm install avsc

avsc is compatible with all versions of node.js since 0.11 and major browsers via browserify (see the full compatibility table here). For convenience, you can also find compiled distributions with the releases (but please host your own copy).

Documentation

Examples

Inside a node.js module, or using browserify:

var avro = require('avsc');
  • Encode and decode values from a known schema:

    var type = avro.parse({
      name: 'Pet',
      type: 'record',
      fields: [
        {name: 'kind', type: {name: 'Kind', type: 'enum', symbols: ['CAT', 'DOG']}},
        {name: 'name', type: 'string'}
      ]
    });
    var buf = type.toBuffer({kind: 'CAT', name: 'Albert'}); // Encoded buffer.
    var val = type.fromBuffer(buf); // {kind: 'CAT', name: 'Albert'}
  • Infer a value's type and encode similar values:

    var val = {city: 'Cambridge', zipCodes: ['02138', '02139'], visits: 2};
    var type = avro.infer(val);
    // We can now encode the value:
    var buf = type.toBuffer(val);
    // And also any values with a matching structure:
    var bufs = [
      type.toBuffer({city: 'Seattle', zipCodes: ['98101'], visits: 3}),
      type.toBuffer({city: 'NYC', zipCodes: [], visits: 0})
    ];
  • Get a readable stream of decoded values from an Avro container file:

    avro.createFileDecoder('./values.avro')
      .on('metadata', function (type) { /* `type` is the writer's type. */ })
      .on('data', function (val) { /* Do something with the decoded value. */ });
  • Implement a TCP server for an IDL-defined protocol:

    avro.assemble('./Ping.avdl', function (err, attrs) {
      // Generate the protocol and attach a handler for `ping` messages:
      var protocol = avro.parse(attrs)
        .on('ping', function (req, ee, cb) { cb(null, 'pong'); });
      // Respond on any incoming connection:
      require('net').createServer()
        .on('connection', function (con) { protocol.createListener(con); })
        .listen(8000);
    });