Avsc

Pure JavaScript implementation of the Avro specification.

Features

• Blazingly fast and compact serialization! Typically faster than JSON with much smaller encodings.
• All the Avro goodness and more: type inference, schema evolution, and remote procedure calls.
• Support for serializing arbitrary JavaScript objects.
• Unopinionated 64-bit integer compatibility.

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

• Home
• API
• Quickstart
• Advanced usage
• Benchmarks

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);
  });