Files
openchamber/packages/web/server/lib/event-stream/protocol.js
T

101 lines
2.8 KiB
JavaScript

export const MESSAGE_STREAM_GLOBAL_WS_PATH = '/api/global/event/ws';
export const MESSAGE_STREAM_DIRECTORY_WS_PATH = '/api/event/ws';
export const MESSAGE_STREAM_WS_HEARTBEAT_INTERVAL_MS = 15 * 1000;
// Per-client pending outbound WS buffer, not a payload or stream-size limit.
// Healthy clients stay near 0; this only trips when a client is far behind.
export const MESSAGE_STREAM_WS_MAX_BUFFERED_BYTES = 4 * 1024 * 1024;
export function parseSseEventEnvelope(block) {
if (!block || typeof block !== 'string') {
return null;
}
const eventId = block
.split('\n')
.find((line) => line.startsWith('id:'))
?.slice(3)
.trim() || null;
const dataLines = block
.split('\n')
.filter((line) => line.startsWith('data:'))
.map((line) => line.slice(5).replace(/^\s/, ''));
if (dataLines.length === 0) {
return null;
}
const payloadText = dataLines.join('\n').trim();
if (!payloadText) {
return null;
}
try {
const parsed = JSON.parse(payloadText);
if (
parsed &&
typeof parsed === 'object' &&
typeof parsed.payload === 'object' &&
parsed.payload !== null
) {
return {
eventId,
directory: typeof parsed.directory === 'string' && parsed.directory.length > 0 ? parsed.directory : null,
payload: parsed.payload,
};
}
const directory =
typeof parsed?.directory === 'string' && parsed.directory.length > 0
? parsed.directory
: typeof parsed?.properties?.directory === 'string' && parsed.properties.directory.length > 0
? parsed.properties.directory
: null;
return {
eventId,
directory,
payload: parsed,
};
} catch {
return null;
}
}
export function sendMessageStreamWsFrame(socket, payload) {
if (!socket || socket.readyState !== 1) {
return false;
}
if (typeof socket.bufferedAmount === 'number' && socket.bufferedAmount > MESSAGE_STREAM_WS_MAX_BUFFERED_BYTES) {
try {
socket.close(1013, 'Message stream client is too slow');
} catch {
}
return false;
}
try {
socket.send(JSON.stringify(payload));
if (typeof socket.bufferedAmount === 'number' && socket.bufferedAmount > MESSAGE_STREAM_WS_MAX_BUFFERED_BYTES) {
try {
socket.close(1013, 'Message stream client is too slow');
} catch {
}
return false;
}
return true;
} catch {
return false;
}
}
export function sendMessageStreamWsEvent(socket, payload, options = {}) {
return sendMessageStreamWsFrame(socket, {
type: 'event',
payload,
...(typeof options.eventId === 'string' && options.eventId.length > 0 ? { eventId: options.eventId } : {}),
...(typeof options.directory === 'string' && options.directory.length > 0 ? { directory: options.directory } : {}),
});
}