tencentcloud-edgeone-migration-nodejs-v2
Version:
tencentcloud cdn config copy to edgeone
88 lines • 3.16 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.StickyLoadBalancer = void 0;
const __1 = require("../..");
const plugins_1 = require("../../plugins");
const utils_1 = require("../../utils");
const weak_1 = require("../../weak");
const kDefaultOptions = {
/**
* 过期时间
* * 当值 ≤0 时：则不启用此插件
* * 当值为 `Infinity` 时：不启用过期
*/
expireTime: 10 * utils_1.kMinutes
};
/**
* Sticky Load Balancer
* The returned instance of each call is the same
* until it is not appear in the instance list or exceed expiration time
*/
class StickyLoadBalancer {
constructor(next, options) {
this.next = next;
this.name = "StickyLoadBalancer";
this.type = plugins_1.PluginType.LoadBalancer;
this.disposed = false;
this.sessions = Object.create(null);
this.options = Object.assign(Object.assign({}, kDefaultOptions), options);
this.supportedWeightType = next.supportedWeightType;
}
// #region dispose
dispose() {
if (!this.disposed) {
Object.values(this.sessions).forEach((session) => {
clearTimeout(session.timer);
});
this.disposed = true;
}
}
get isDisposed() {
return this.disposed;
}
// #endregion
choose(namespace, service, instances, args) {
if (this.disposed) {
throw new __1.StateError("Already disposed");
}
if (this.options.expireTime <= 0) {
return this.next.choose(namespace, service, instances, args);
}
const session = this.sessions[`${namespace}.${service}`];
let stickiedInstance;
if (session) {
const { ref, timer } = session;
stickiedInstance = ref.find(instances);
if (stickiedInstance === undefined) {
stickiedInstance = this.next.choose(namespace, service, instances, args);
ref.reset(stickiedInstance);
session.timer = this.buildOrRefreshTimer(namespace, service, timer);
}
}
else {
stickiedInstance = this.next.choose(namespace, service, instances, args);
this.sessions[`${namespace}.${service}`] = {
ref: new weak_1.WeakReference(stickiedInstance),
timer: this.buildOrRefreshTimer(namespace, service)
};
}
return stickiedInstance;
}
buildOrRefreshTimer(namespace, service, timer) {
if (this.options.expireTime === Infinity) {
return;
}
if (typeof (timer === null || timer === void 0 ? void 0 : timer.refresh) === "function") { /** Timeout.refresh() only available for Node.js 10.2.0 and higher */
timer.refresh();
return timer;
}
if (timer) {
clearTimeout(timer);
}
return setTimeout(() => {
delete this.sessions[`${namespace}.${service}`];
}, this.options.expireTime).unref();
}
}
exports.StickyLoadBalancer = StickyLoadBalancer;
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