avro-js
v1.12.0
Published
JavaScript Avro implementation
Downloads
113,229
Readme
Avro-js
Pure JavaScript implementation of the Avro specification.
Features
- Fast! Typically twice as fast as JSON with much smaller encodings.
- Full Avro support, including recursive schemas, sort order, and evolution.
- Serialization of arbitrary JavaScript objects via logical types.
- Unopinionated 64-bit integer compatibility.
- No dependencies,
avro-js
even runs in the browser.
Installation
$ npm install avro-js
avro-js
is compatible with all versions of node.js since 0.11
and major
browsers via browserify.
Documentation
See doc/
folder.
Examples
Inside a node.js module, or using browserify:
var avro = require('avro-js');
Encode and decode objects:
// We can declare a schema inline: var type = avro.parse({ name: 'Pet', type: 'record', fields: [ {name: 'kind', type: {name: 'Kind', type: 'enum', symbols: ['CAT', 'DOG']}}, {name: 'name', type: 'string'} ] }); var pet = {kind: 'CAT', name: 'Albert'}; var buf = type.toBuffer(pet); // Serialized object. var obj = type.fromBuffer(buf); // {kind: 'CAT', name: 'Albert'}
Generate random instances of a schema:
// We can also parse a JSON-stringified schema: var type = avro.parse('{"type": "fixed", "name": "Id", "size": 4}'); var id = type.random(); // E.g. Buffer([48, 152, 2, 123])
Check whether an object fits a given schema:
// Or we can specify a path to a schema file (not in the browser): var type = avro.parse('./Person.avsc'); var person = {name: 'Bob', address: {city: 'Cambridge', zip: '02139'}}; var status = type.isValid(person); // Boolean status.
Get a readable stream of decoded records from an Avro container file (not in the browser):
avro.createFileDecoder('./records.avro') .on('metadata', function (type) { /* `type` is the writer's type. */ }) .on('data', function (record) { /* Do something with the record. */ });
Implement recursive schemata (due to lack of duck-typing):
// example type: linked list with one long-int as element value const recursiveRecordType = avro.parse({ "type": "record", "name": "LongList", "fields" : [ {"name": "value", "type": "long"}, {"name": "next", "type": ["null", "LongList"]} // optional next element via recursion ] }); // will work const validRecursiveRecordDTO = { value: 1, next: { // no duck-typing support: from first nested level on the // recursive type has to be explicitly specified. LongList: { value: 2, next: null } } }; const serializedValid = recursiveRecordType.parse(validRecursiveRecordDTO); // will throw error const invalidRecursiveRecordDTO = { value: 1, next: { value: 2, next: null } }; const serializedInvalid = recursiveRecordType.parse(invalidRecursiveRecordDTO);