aws-crt
Version:
NodeJS/browser bindings to the aws-c-* libraries
203 lines • 7.48 kB
JavaScript
;
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
* SPDX-License-Identifier: Apache-2.0.
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.PublishAcknowledgementHandle = exports.queueAcknowledgeableEvent = exports.emitAcknowledgeableEvent = exports.PublishAcknowledgementHandleWrapper = exports.isValidTopic = exports.isValidTopicFilter = exports.DEFAULT_KEEP_ALIVE = exports.normalize_payload_to_buffer = exports.normalize_payload = void 0;
/**
* Converts payload to Buffer or string regardless of the supplied type
* @param payload The payload to convert
* @internal
*/
function normalize_payload(payload) {
if (payload instanceof Buffer) {
// pass Buffer through
return payload;
}
if (typeof payload === 'string') {
// pass string through
return payload;
}
if (ArrayBuffer.isView(payload)) {
// return Buffer with view upon the same bytes (no copy)
const view = payload;
return Buffer.from(view.buffer, view.byteOffset, view.byteLength);
}
if (payload instanceof ArrayBuffer) {
// return Buffer with view upon the same bytes (no copy)
return Buffer.from(payload);
}
if (typeof payload === 'object') {
// Convert Object to JSON string
return JSON.stringify(payload);
}
if (!payload) {
return "";
}
throw new TypeError("payload parameter must be a string, object, or DataView.");
}
exports.normalize_payload = normalize_payload;
/**
* Converts payload to Buffer only, regardless of the supplied type
* @param payload The payload to convert
* @internal
*/
function normalize_payload_to_buffer(payload) {
let normalized = normalize_payload(payload);
if (typeof normalized === 'string') {
// pass string through
return Buffer.from(normalized);
}
return normalized;
}
exports.normalize_payload_to_buffer = normalize_payload_to_buffer;
/** @internal */
exports.DEFAULT_KEEP_ALIVE = 1200;
function isValidTopicInternal(topic, isFilter) {
if (topic.length === 0 || topic.length > 65535) {
return false;
}
let sawHash = false;
for (let segment of topic.split('/')) {
if (sawHash) {
return false;
}
if (segment.length === 0) {
continue;
}
if (segment.includes("+")) {
if (!isFilter) {
return false;
}
if (segment.length > 1) {
return false;
}
}
if (segment.includes("#")) {
if (!isFilter) {
return false;
}
if (segment.length > 1) {
return false;
}
sawHash = true;
}
}
return true;
}
function isValidTopicFilter(topicFilter) {
if (typeof (topicFilter) !== 'string') {
return false;
}
let topicFilterAsString = topicFilter;
return isValidTopicInternal(topicFilterAsString, true);
}
exports.isValidTopicFilter = isValidTopicFilter;
function isValidTopic(topic) {
if (typeof (topic) !== 'string') {
return false;
}
let topicAsString = topic;
return isValidTopicInternal(topicAsString, false);
}
exports.isValidTopic = isValidTopic;
/**
* Wrapper class containing a one-use singleton handle that can be used to trigger sending the acknowledgement (Puback in
* QoS 1, Pubrec in QoS 2) packet for an incoming publish.
*/
class PublishAcknowledgementHandleWrapper {
constructor(handle) {
this.ackHandle = handle;
}
/**
* Attempt to take the acknowledgement handle held by the wrapper. This will only succeed for the first caller;
* after the initial call, null will be returned. By taking the handle, the caller assumes responsibility
* for sending the acknowledgement packet associated with the incoming publish packet. Failing to trigger the
* acknowledgement will cause the broker to potentially re-send the publish.
*/
acquireHandle() {
let handle = this.ackHandle;
this.ackHandle = null;
return handle;
}
}
exports.PublishAcknowledgementHandleWrapper = PublishAcknowledgementHandleWrapper;
function movePublishAcknowledgementHandleWrapper(wrapper, compositionFunctor) {
if (wrapper) {
let handle = wrapper.acquireHandle();
if (compositionFunctor && handle) {
let interiorHandle = handle;
handle = new PublishAcknowledgementHandle(() => {
interiorHandle.invokeAcknowledgement();
compositionFunctor();
});
}
return new PublishAcknowledgementHandleWrapper(handle);
}
return undefined;
}
/** @internal */
function emitAcknowledgeableEvent(emitter, ackEvent, ackEventPayload, wrapperFieldName, ackHandleWrapper, compositionFunctor) {
ackHandleWrapper = movePublishAcknowledgementHandleWrapper(ackHandleWrapper, compositionFunctor);
if (ackHandleWrapper) {
ackEventPayload[wrapperFieldName] = ackHandleWrapper;
emitter.emitWithCallback(ackEvent, () => {
if (ackHandleWrapper) {
let handle = ackHandleWrapper.acquireHandle();
if (handle) {
// Even if corked, all listeners have had a chance to react to the event
// and acquire the acknowledgement handle if they wanted to. If no one did so, then we do it ourselves.
handle.invokeAcknowledgement();
}
}
}, ackEventPayload);
}
else {
emitter.emit(ackEvent, ackEventPayload);
}
}
exports.emitAcknowledgeableEvent = emitAcknowledgeableEvent;
/** @internal */
function queueAcknowledgeableEvent(emitter, ackEvent, ackEventPayload, wrapperFieldName, ackHandleWrapper, compositionFunctor) {
let wrapper = movePublishAcknowledgementHandleWrapper(ackHandleWrapper, compositionFunctor);
queueMicrotask(() => {
if (wrapper) {
ackEventPayload[wrapperFieldName] = wrapper;
emitter.emitWithCallback(ackEvent, () => {
if (wrapper) {
let handle = wrapper.acquireHandle();
if (handle) {
// Even if corked, all listeners have had a chance to react to the event
// and acquire the acknowledgement handle if they wanted to. If no one did so, then we do it ourselves.
handle.invokeAcknowledgement();
}
}
}, ackEventPayload);
}
else {
emitter.emit(ackEvent, ackEventPayload);
}
});
}
exports.queueAcknowledgeableEvent = queueAcknowledgeableEvent;
/**
* Object that allows the holder to trigger the acknowledgement for an associated publish packet.
*/
class PublishAcknowledgementHandle {
constructor(acknowledgementFunction) {
this.acknowledgementFunction = acknowledgementFunction;
}
/**
* trigger the acknowledgement for an associated Publish packet
*/
invokeAcknowledgement() {
let acknowledgementFunction = this.acknowledgementFunction;
this.acknowledgementFunction = undefined;
if (acknowledgementFunction) {
acknowledgementFunction();
}
}
}
exports.PublishAcknowledgementHandle = PublishAcknowledgementHandle;
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