botframework-streaming
Version:
Streaming library for the Microsoft Bot Framework
110 lines • 5.17 kB
JavaScript
"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.PayloadReceiver = void 0;
const payloadTypes_1 = require("../payloads/payloadTypes");
const headerSerializer_1 = require("../payloads/headerSerializer");
const payloadConstants_1 = require("../payloads/payloadConstants");
const transportDisconnectedEvent_1 = require("./transportDisconnectedEvent");
/**
* Payload receiver for streaming.
*/
class PayloadReceiver {
/**
* Get current connected state
*
* @returns true if connected to a transport sender.
*/
get isConnected() {
return this._receiver != null;
}
/**
* Connects to a transport receiver
*
* @param receiver The [ITransportReceiver](xref:botframework-streaming.ITransportReceiver) object to pull incoming data from.
* @returns a promise that resolves when the receiver is complete
*/
connect(receiver) {
this._receiver = receiver;
return this.receivePackets();
}
/**
* Allows subscribing to this receiver in order to be notified when new data comes in.
*
* @param getStream Callback when a new stream has been received.
* @param receiveAction Callback when a new message has been received.
*/
subscribe(getStream, receiveAction) {
this._getStream = getStream;
this._receiveAction = receiveAction;
}
/**
* Force this receiver to disconnect.
*
* @param event Event arguments to include when broadcasting disconnection event.
*/
disconnect(event = transportDisconnectedEvent_1.TransportDisconnectedEvent.Empty) {
var _a, _b;
if (!this.isConnected) {
return;
}
try {
this._receiver.close();
(_a = this.disconnected) === null || _a === void 0 ? void 0 : _a.call(this, this, event);
}
catch (err) {
(_b = this.disconnected) === null || _b === void 0 ? void 0 : _b.call(this, this, new transportDisconnectedEvent_1.TransportDisconnectedEvent(err.message));
}
finally {
this._receiver = null;
}
}
receivePackets() {
return __awaiter(this, void 0, void 0, function* () {
while (this.isConnected) {
try {
let readSoFar = 0;
while (readSoFar < payloadConstants_1.PayloadConstants.MaxHeaderLength) {
this._receiveHeaderBuffer = yield this._receiver.receive(payloadConstants_1.PayloadConstants.MaxHeaderLength - readSoFar);
if (this._receiveHeaderBuffer) {
readSoFar += this._receiveHeaderBuffer.length;
}
}
const header = headerSerializer_1.HeaderSerializer.deserialize(this._receiveHeaderBuffer);
const isStream = header.payloadType === payloadTypes_1.PayloadTypes.stream;
if (header.payloadLength > 0) {
let bytesActuallyRead = 0;
const contentStream = this._getStream(header);
while (bytesActuallyRead < header.payloadLength &&
bytesActuallyRead < payloadConstants_1.PayloadConstants.MaxPayloadLength) {
const count = Math.min(header.payloadLength - bytesActuallyRead, payloadConstants_1.PayloadConstants.MaxPayloadLength);
this._receivePayloadBuffer = yield this._receiver.receive(count);
bytesActuallyRead += this._receivePayloadBuffer.byteLength;
contentStream.write(this._receivePayloadBuffer);
// If this is a stream we want to keep handing it up as it comes in
if (isStream) {
this._receiveAction(header, contentStream, bytesActuallyRead);
}
}
if (!isStream) {
this._receiveAction(header, contentStream, bytesActuallyRead);
}
}
}
catch (err) {
this.disconnect(new transportDisconnectedEvent_1.TransportDisconnectedEvent(err.message));
}
}
});
}
}
exports.PayloadReceiver = PayloadReceiver;
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