capnp-ts

What is capnp-ts?

The capnp-ts package is a TypeScript implementation of the Cap'n Proto serialization protocol. It allows for efficient serialization and deserialization of data, making it useful for applications that require high-performance data interchange.

What are capnp-ts's main functionalities?

Serialization

This feature allows you to serialize data into a Cap'n Proto message. The code sample demonstrates how to create a new message, initialize a structure, set a field, and serialize the message into an ArrayBuffer.

const capnp = require('capnp-ts');
const MyStruct = capnp.import('path/to/my-struct.capnp');

const message = new capnp.Message();
const myStruct = message.initRoot(MyStruct);
myStruct.setField('value');

const serializedData = message.toArrayBuffer();

Deserialization

This feature allows you to deserialize data from a Cap'n Proto message. The code sample demonstrates how to create a message from an ArrayBuffer, get the root structure, and retrieve a field value.

const capnp = require('capnp-ts');
const MyStruct = capnp.import('path/to/my-struct.capnp');

const serializedData = /* some ArrayBuffer */;
const message = new capnp.Message(serializedData);
const myStruct = message.getRoot(MyStruct);

const value = myStruct.getField();

Schema Definition

This feature allows you to define schemas using Cap'n Proto's schema language. The code sample shows how to import a schema defined in a .capnp file.

const capnp = require('capnp-ts');
const MyStruct = capnp.import('path/to/my-struct.capnp');

// Define a schema in a .capnp file
// struct MyStruct {
//   field @0 :Text;
// }

Other packages similar to capnp-ts

protobufjs

protobufjs is a JavaScript implementation of Protocol Buffers, another efficient serialization protocol. It offers similar functionality to capnp-ts but uses Protocol Buffers' schema language and wire format.

flatbuffers

flatbuffers is a serialization library that allows for efficient reading and writing of data without parsing/unpacking. It is similar to capnp-ts in terms of performance and use cases but uses a different schema language and format.

avsc

avsc is a JavaScript library for working with Avro data serialization. It provides similar functionality to capnp-ts but uses Avro's schema language and binary format.

README

capnp-ts

A strongly typed Cap'n Proto implementation for the browser and Node.js using TypeScript.

Here's a quick usage example:

import * as capnp from 'capnp-ts';

import {MyStruct} from './myschema.capnp';

export function loadMessage(buffer: ArrayBuffer): MyStruct {

  const message = capnp.Message.fromArrayBuffer(buffer);

  return message.getRoot(MyStruct);

}

An extended readme is available on the project site: https://github.com/jdiaz5513/capnp-ts.

Changelog

0.7.0 (2021-08-19)

⚠ BREAKING CHANGES

• capnpc-js is being retired in favor of compiling directly to js from capnpc-ts instead. This makes the one compiler serve both purposes; js-only users who are annoyed by the extra d.ts files may simply delete them. This was done to work around bugs in source-map-support that prevent importing capnp.js files when a capnp.ts file is also present.

Bug Fixes

• support imports with nested enums (64778e0)