实现 WakeUpPing

src/app/service/service_worker/gm_api/gm_api.ts

@@ -54,6 +54,7 @@ import { headerModifierMap, headersReceivedMap } from "./gm_xhr";
 import { BgGMXhr } from "@App/pkg/utils/xhr/bg_gm_xhr";
 import { mightPrepareSetClipboard, setClipboard } from "../clipboard";
 import { nativePageWindowOpen } from "../../offscreen/gm_api";
+import { WakeUpCommand, wakeupPingCommand } from "@App/pkg/utils/wakeup-ping";
 
 let generatedUniqueMarkerIDs = "";
 let generatedUniqueMarkerIDWhen = "";
@@ -799,11 +800,27 @@ export default class GMApi {
     if (!sender.isType(GetSenderType.CONNECT)) {
       throw new Error("GM_xmlhttpRequest ERROR: sender is not MessageConnect");
     }
+
+    // https://github.com/scriptscat/scriptcat/issues/1343
+    let wakeupTrigger = true;
+    wakeupPingCommand(WakeUpCommand.START);
+    const wakeupStop = () => {
+      try {
+        if (wakeupTrigger) {
+          wakeupTrigger = false;
+          wakeupPingCommand(WakeUpCommand.STOP);
+        }
+      } catch {
+        // ignored
+      }
+    };
+
     const msgConn = sender.getConnect()!;
 
     let isConnDisconnected = false;
     msgConn.onDisconnect(() => {
       isConnDisconnected = true;
+      wakeupStop();
     });
 
     // 关联自己生成的请求id与chrome.webRequest的请求id
@@ -854,6 +871,7 @@ export default class GMApi {
         useFetch = isFetch || !!redirect || anonymous || isBufferStream;
       }
       const loadendCleanUp = () => {
+        wakeupStop();
         redirectedUrls.delete(markerID);
         nwErrorResults.delete(markerID);
         const reqId = scXhrRequests.get(markerID);
@@ -905,6 +923,7 @@ export default class GMApi {
         msgConn.onDisconnect(offscreenCon.disconnect.bind(offscreenCon));
       }
     } catch (e: any) {
+      wakeupStop();
       const errorMsg = `GM_xmlhttpRequest ERROR: ${e?.message || e || "Unknown Error"}`;
       if (!isConnDisconnected) {
         msgConn.sendMessage({

src/offscreen.ts

@@ -2,6 +2,7 @@ import LoggerCore from "./app/logger/core";
 import MessageWriter from "./app/logger/message_writer";
 import { OffscreenManager } from "./app/service/offscreen";
 import { ServiceWorkerClientMessage } from "@Packages/message/window_message";
+import { initializeWakeupPing } from "./pkg/utils/wakeup-ping";
 
 function main() {
   // 通过postMessage与SW通信,支持结构化克隆(Blob等)
@@ -15,6 +16,7 @@ function main() {
   // 初始化管理器
   const manager = new OffscreenManager(swPostMessage);
   manager.initManager();
+  initializeWakeupPing();
 }
 
 main();

src/pkg/utils/wakeup-ping.ts

@@ -0,0 +1,90 @@
+const PING_INTERVAL_MS_1 = 13_225;
+const PING_INTERVAL_MS_2 = 17_765;
+
+export const WakeUpCommand = {
+  START: 0x100,
+  STOP: 0x200,
+} as const;
+
+export type WakeUpCommand = ValueOf<typeof WakeUpCommand>;
+
+/**
+ * scheduler 用于后台排程：Chrome 94+, Firefox 142+
+ * @link https://developer.mozilla.org/en-US/docs/Web/API/Scheduler/postTask
+ */
+const nativeScheduler =
+  //@ts-ignore
+  typeof scheduler !== "undefined" && typeof scheduler?.postTask === "function" && scheduler;
+
+// 高效的 BroadcastChannel 通讯：service worker 和 offscreen 共用同一通道
+const channel = new BroadcastChannel("custom-ping"); // offscreen -> sw
+const channelCommand = new BroadcastChannel("custom-ping-command"); // sw -> offscreen
+let startCounter = 0;
+
+// initializeWakeupPing only execute once in offscreen
+export const initializeWakeupPing = () => {
+  if (typeof frameElement === "object" && typeof document === "object" && document) {
+    let counter = 0;
+    let isMutationPending = false;
+
+    const pingNode = document.createComment("0");
+
+    const incrementCounter = () => {
+      if (startCounter >= 1 && !isMutationPending) {
+        isMutationPending = true;
+        counter = counter & 8 ? 1 : counter + 1;
+        pingNode.data = `${counter}`;
+      }
+    };
+
+    const pingTask = async () => {
+      channel.postMessage(true);
+      incrementCounter();
+    };
+
+    const mutationObserver = new MutationObserver(() => {
+      if (isMutationPending) {
+        isMutationPending = false;
+        const pingIntervalMs = Math.random() * (PING_INTERVAL_MS_2 - PING_INTERVAL_MS_1) + PING_INTERVAL_MS_1;
+        if (nativeScheduler) {
+          nativeScheduler.postTask(pingTask, { priority: "background", delay: pingIntervalMs });
+        } else {
+          setTimeout(pingTask, pingIntervalMs);
+        }
+      }
+    });
+    mutationObserver.observe(pingNode, { characterData: true });
+    // incrementCounter();
+
+    channelCommand.onmessage = (e) => {
+      if (e.data === WakeUpCommand.START) {
+        startCounter++;
+        if (startCounter === 1) {
+          incrementCounter();
+        }
+      } else if (e.data === WakeUpCommand.STOP) {
+        if (startCounter > 0) startCounter--;
+      }
+    };
+  }
+};
+
+// initializeWakeupPing only execute once in service worker
+export const listenWakeupPing = (onWakeupPing: (...args: any) => any) => {
+  chrome.storage.session.onChanged.addListener((obj) => {
+    // 消耗 persistentWakeup
+    if (typeof obj.persistentWakeup !== "undefined") {
+      // 执行任意 callback
+      onWakeupPing();
+    }
+  });
+  channel.onmessage = (e) => {
+    // 触发 chrome storage onChanged 使 service worker 保持活跃
+    chrome.storage.session.set({ persistentWakeup: `${e.timeStamp}` });
+  };
+};
+
+// wakeupPingCommand only execute in service worker
+export const wakeupPingCommand = (command: WakeUpCommand) => {
+  channelCommand.postMessage(command);
+};

src/service_worker.ts

@@ -8,6 +8,7 @@ import { MessageQueue } from "@Packages/message/message_queue";
 import { ServiceWorkerMessageSend } from "@Packages/message/window_message";
 import migrate, { migrateChromeStorage } from "./app/migrate";
 import { cleanInvalidKeys } from "./app/repo/resource";
+import { listenWakeupPing } from "./pkg/utils/wakeup-ping";
 
 migrate();
 migrateChromeStorage();
@@ -59,6 +60,11 @@ async function setupOffscreenDocument() {
   }
 }
 
+export const onWakeupPing = () => {
+  //@ts-ignore
+  self.lastWakeupPing = new Date().toLocaleString("zh"); // 僅在後台DevTools debug用
+};
+
 function main() {
   cleanInvalidKeys();
   // 初始化管理器
@@ -77,6 +83,7 @@ function main() {
   manager.initManager();
   // 初始化沙盒环境
   setupOffscreenDocument();
+  listenWakeupPing(onWakeupPing);
 }
 
 main();