protons

protons

Protocol Buffers for Node.js and the browser without compilation.

Forked from protocol-buffers.

Lead Maintainer

Alex Potsides

Table of Contents

• Install
• Usage
• Properties
• Performance
• Leveldb encoding compatibility
• License

Install

> npm install protons

Usage

Assuming the following test.proto file exists

enum FOO {
  BAR = 1;
}

message Test {
  required float num  = 1;
  required string payload = 2;
}

message AnotherOne {
  repeated FOO list = 1;
}

message WithOptional {
  optional string payload = 1;
}

Use the above proto file to encode/decode messages by doing

const protons = require('protons')

// pass a proto file as a buffer/string or pass a parsed protobuf-schema object
const messages = protons(fs.readFileSync('test.proto'))

const buf = messages.Test.encode({
  num: 42,
  payload: 'hello world'
})

console.log(buf) // should print a buffer

To decode a message use Test.decode

const obj = messages.Test.decode(buf)
console.log(obj) // should print an object similar to above

Enums are accessed in the same way as messages

const buf = messages.AnotherOne.encode({
  list: [
    messages.FOO.BAR
  ]
})

Nested emums are accessed as properties on the corresponding message

const buf = message.SomeMessage.encode({
  list: [
    messages.SomeMessage.NESTED_ENUM.VALUE
  ]
})

See the Google Protocol Buffers docs for more information about the available types etc.

Properties

Decoded object properties can be interacted with using accessor methods:

 const obj = messages.WithOptional.decode(messages.WithOptional.encode({}))

obj.hasPayload() // false
obj.getPayload() // ''
obj.setPayload('hello world')
obj.getPayload() // 'hello world'
obj.clearPayload()
obj.getPayload() // undefined

Performance

This module is pretty fast.

You can run the benchmarks yourself by doing npm run bench.

On my Macbook Pro it gives the following results

JSON (encode) x 703,160 ops/sec ±2.06% (91 runs sampled)
JSON (decode) x 619,564 ops/sec ±1.60% (94 runs sampled)
JSON (encode + decode) x 308,635 ops/sec ±1.74% (92 runs sampled)
protocol-buffers@4.1.0 (encode) x 693,570 ops/sec ±1.55% (92 runs sampled)
protocol-buffers@4.1.0 (decode) x 1,894,031 ops/sec ±1.61% (93 runs sampled)
protocol-buffers@4.1.0 (encode + decode) x 444,229 ops/sec ±1.50% (93 runs sampled)
protons@1.0.1 (encode) x 435,058 ops/sec ±1.46% (91 runs sampled)
protons@1.0.1 (decode) x 29,548 ops/sec ±3.29% (78 runs sampled)
protons@1.0.1 (encode + decode) x 27,042 ops/sec ±4.41% (80 runs sampled)

Note that JSON parsing/serialization in node is a native function that is really fast.

Leveldb encoding compatibility

Compiled protocol buffers messages are valid levelup encodings. This means you can pass them as valueEncoding and keyEncoding.

const level = require('level')
const db = level('db')

db.put('hello', {payload:'world'}, {valueEncoding:messages.Test}, (err) => {
  db.get('hello', {valueEncoding:messages.Test}, (err, message) => {
    console.log(message)
  })
})

License

MIT