CAMP

CAMP is a small binary protocol for sending arbitrary messages, large data and real-time information over WebSocket. It uses fixed frame types for acknowledgements, heartbeats, UTF-8 text, binary payloads and streamed transactions.

This is a client implementation of the CAMP protocol specified at CAMP-Protocol

CAMP-Client-Browser / Overview

The CAMP Browser client takes care of the following:

• Authentication at the server
• Correct framing and structuring of received and sent data

The client provides a public API for creating and destroying an instance. It provides access incoming communication via events

Setup

To set up a CAMP Client, simply import the camp function from the camp-client-browser package.

The camp-function takes two arguments:

• host
  • a required host string
• bearer
  • a required authentication token string
• timeout
  • an optional timeout value, indicating how long the client should wait until a connection request to the server is aborted

CAMPClientWebsocketSession / Overview

Public methods

| Name | Parameter | Description | Returns | |-------|----------------|-------------------------------|---------| | Close | reason: string | Closes the session gracefully | |

CAMP-Functionality is divided among namespaces as defined in CAMP.

Base

Accessible via session.base.<method>(...);

| Name | Parameter | Description | Returns | |------------|-----------------|------------------------------------------|---------| | Ping | | Pings the client | | | SendUTF8 | data: string | Sends the passed utf8 text to the client | | | SendBinary | data: Buffer | Sends the passed buffer to the client | | | SendError | message: string | Send an error to the client | |

Transaction

Accessible via session.transaction.<method>(...);

| Name | Parameter | Description | Returns | |--------------------|-----------------------------------------------------------------------------------|-------------------------------------------------------------|-------------------------| | Stream | source: Readable, options: { streamName: string, behaviour: CAMP_FLOW_BEHAVIOUR } | Streams a readable to the client | | | WaitForStream | name: string, timeout: number | Waits for a named stream from client | Promise<CAMPReadable> | | StreamRequestRange | stream: CAMPReadable, start: bigint, end: bigint | When in TX_PULL-mode, requests a byte range from the client | | | StreamCancel | stream: CAMPReadable | Cancels a Stream | |

Data Events

These events are emitted when the server-side session receives data from a client-side session

| Name | Parameter | Description | |----------------|--------------|----------------------------------------------------------------| | message-utf8 | string | Emitted, when the session receives a utf8 text message | | message-binary | CAMPBuffer | Emitted, when the session receives an arbitrary binary message | | message-error | data: string | Emitted, when the session receives an error message |

Meta events

This category of events is emitted when the session state changes

| Name | Parameter | Description | |--------------|--------------------------------|-------------------------------------------------| | connected | | Emitted, when the session successfully connects | | disconnected | | Emitted, when the session has been disconnected | | reconnected | | Emitted, when the session has reconnected | | closed | [code: number, reason: string] | Emitted, when the session is closed |

CAMP-Client / Example

import {camp} from "camp-client-browser";

const HOST = "localhost:8080";
const TOKEN = "SOME_AUTH_TOKEN";

const client = await camp(HOST, TOKEN, 10000);
client.on("connected", () => {
    console.info(`Successfully connected to ${HOST}`);
});