@fanoutio/grip/build/utilities/ws-over-http.js

GRIP Interface Library

import debug from './debug.js';
import { ConnectionIdMissingException, WebSocketContext, WebSocketDecodeEventException } from '../data/index.js';
import { decodeWebSocketEvents } from './webSocketEvents.js';
export const CONTENT_TYPE_APPLICATION = 'application';
export const CONTENT_SUBTYPE_WEBSOCKET_EVENTS = 'websocket-events';
export const CONTENT_TYPE_WEBSOCKET_EVENTS = `${CONTENT_TYPE_APPLICATION}/${CONTENT_SUBTYPE_WEBSOCKET_EVENTS}`;
export function isWsOverHttpImpl(method, headers) {
    if (method !== 'POST') {
        return false;
    }
    let contentTypeHeader = headers.get('content-type');
    if (contentTypeHeader != null) {
        const at = contentTypeHeader.indexOf(';');
        if (at >= 0) {
            contentTypeHeader = contentTypeHeader.slice(0, at);
        }
        contentTypeHeader = contentTypeHeader.trim();
        debug('content-type header', contentTypeHeader);
    }
    else {
        debug('content-type header not present');
    }
    if (contentTypeHeader !== CONTENT_TYPE_WEBSOCKET_EVENTS) {
        return false;
    }
    const acceptTypesHeader = headers.get('accept');
    if (acceptTypesHeader == null) {
        debug('accept header not present');
        return false;
    }
    debug('accept header', acceptTypesHeader);
    for (let acceptType of acceptTypesHeader.split(',')) {
        const at = acceptType.indexOf(';');
        if (at >= 0) {
            acceptType = acceptType.slice(0, at);
        }
        acceptType = acceptType.trim();
        if (acceptType === '*/*' ||
            acceptType === `${CONTENT_TYPE_APPLICATION}/*` ||
            acceptType === CONTENT_TYPE_WEBSOCKET_EVENTS) {
            return true;
        }
    }
    return false;
}
export async function getWebSocketContextImpl(headers, getBody, prefix) {
    const cid = headers.get('connection-id');
    if (cid == null) {
        throw new ConnectionIdMissingException();
    }
    debug('Connection ID', cid);
    // Handle meta keys
    debug('Handling Meta - start');
    const meta = {};
    for (const [key, value] of headers.entries()) {
        const lKey = key.toLowerCase();
        if (lKey.startsWith('meta-')) {
            const k = lKey.slice(5);
            meta[k] = value;
            debug(k, '=', value);
        }
    }
    debug('Handling Meta - end');
    const body = await getBody();
    debug('Decode body - start');
    let events = null;
    try {
        events = decodeWebSocketEvents(body);
    }
    catch (err) {
        throw new WebSocketDecodeEventException();
    }
    debug('Decode body - end');
    debug('Websocket Events', events);
    debug('Creating Websocket Context - start');
    const wsContext = new WebSocketContext(cid, meta, events, prefix);
    debug('Creating Websocket Context - end');
    return wsContext;
}
export function isWsOverHttp(req) {
    return isWsOverHttpImpl(req.method, req.headers);
}
export async function getWebSocketContextFromReq(req, prefix = '') {
    const getBody = async () => {
        const arrayBuffer = await req.arrayBuffer();
        return new Uint8Array(arrayBuffer);
    };
    return getWebSocketContextImpl(req.headers, getBody, prefix);
}