Capnp-split NPM

capnp-split

Split up a capnp stream into its individual messages.

Installation

npm i --save capnp-split
or
yarn add capnp-split

Usage

const CapnpStream = require('capnp-split');

var msgStream = new CapnpStream();
msgStream.on('message', function (data) {
  // data is a buffer containing exactly 1 capnp message
  // this message can still contain any number of segments
});

fs.createReadStream('/path/to/capnp/log').pipe(msgStream);

API

`new CapnpStream()` => `WritableStream`

Creates a new writable stream that takes in buffers and emits a message event whenever a whole capnp message is readable. Buffers the rest for the next chunk of data.

`CapnpStream.readSize(buff, offset)` => `int`

Read the total size of the message starting at offset. This method does not esure that the buffer is long enough to contain the message.

buff: (Buffer) The buffer to look at for the size information
offset: (optional Number) Defaults to 0. An offset position in bytes to read the size data from.

`CapnpStream.readMessage(buff, offset)` => `Buffer`

Read the actual message starting at offset. The result buffer will be a .slice of the original, meaning the data will not be copied and modifications made to the result will affect the original buffer.

buff: (Buffer) The buffer containing the message data
offset: (optional Number) Defaults to 0. An offset position in bytes to read the data from.