Add project files

src/worker.mts

@@ -0,0 +1,133 @@
+import type { MessagePort as NodeMessagePort } from "worker_threads";
+import type { Chapter, ChapterTag, FFprobe, FileInfo, FramesInfo, FSFilesystems, FSMountOptions, Stream } from "./ffprobe-wasm-shared";
+
+export type IncomingMessage = { port: MessagePort | NodeMessagePort } & IncomingData;
+
+export type IncomingData =
+  | {
+      type: "getFileInfo";
+      payload: [fileName: string, mountOptions: FSMountOptions];
+    }
+  | {
+      type: "getFrames";
+      payload: [fileName: string, mountOptions: FSMountOptions, offset: number];
+    };
+
+export type OutgoingMessage =
+  | ({ status: "success" } & OutgoingData)
+  | { status: "error"; message: string };
+
+export type OutgoingData =
+  | {
+      type: "getFileInfo";
+      payload: FileInfo;
+    }
+  | {
+      type: "getFrames";
+      payload: FramesInfo;
+    };
+
+export function createListener(
+  ffprobePromise: Promise<FFprobe>,
+  fsType: keyof FSFilesystems,
+) {
+  return onmessage;
+
+  async function onmessage(data: IncomingMessage) {
+    try {
+      switch (data.type) {
+        case "getFileInfo":
+          data.port.postMessage({
+            status: "success",
+            payload: await getFileInfo(...data.payload),
+            type: data.type,
+          });
+          break;
+        case "getFrames":
+          data.port.postMessage({
+            status: "success",
+            payload: await getFrames(...data.payload),
+            type: data.type,
+          });
+          break;
+        default:
+          const _: never = data;
+          throw new Error(`Unknown event: ${JSON.stringify(_)}`);
+      }
+    } catch (error) {
+      console.error(error);
+      data.port.postMessage({
+        status: "error",
+        message: error instanceof Error ? error.message : "Unknown error",
+      });
+    }
+  }
+
+  async function getFileInfo(fileName: string, mountOptions: FSMountOptions): Promise<FileInfo> {
+    const { FS, get_file_info } = await ffprobePromise;
+    try {
+      if (!FS.analyzePath("/work").exists) {
+        FS.mkdir("/work");
+      }
+      FS.mount(FS.filesystems[fsType], mountOptions, "/work");
+
+      // Call the wasm module.
+      const rawInfo = get_file_info(`/work/${fileName}`);
+
+      // Remap streams into collection.
+      const streams: Stream[] = [];
+      for (let i = 0; i < rawInfo.streams.size(); i++) {
+        streams.push(rawInfo.streams.get(i));
+      }
+
+      // Remap chapters into collection.
+      const chapters: Chapter[] = [];
+      for (let i = 0; i < rawInfo.chapters.size(); i++) {
+        const rawChapter = rawInfo.chapters.get(i);
+
+        const tags: ChapterTag[] = [];
+        for (let j = 0; j < rawChapter.tags.size(); j++) {
+          tags.push(rawChapter.tags.get(j));
+        }
+
+        chapters.push({ ...rawChapter, tags });
+      }
+
+      return {
+        ...rawInfo,
+        streams,
+        chapters,
+      };
+    } finally {
+      // Cleanup mount.
+      FS.unmount("/work");
+    }
+  }
+
+  async function getFrames(fileName: string, mountOptions: FSMountOptions, offset: number): Promise<FramesInfo> {
+    const { FS, get_frames } = await ffprobePromise;
+    try {
+      if (!FS.analyzePath("/work").exists) {
+        FS.mkdir("/work");
+      }
+      FS.mount(FS.filesystems.WORKERFS, mountOptions, "/work");
+
+      // Call the wasm module.
+      const framesInfo = get_frames(`/work/${fileName}`, offset);
+
+      // Remap frames into collection.
+      const frames = [];
+      for (let i = 0; i < framesInfo.frames.size(); i++) {
+        frames.push(framesInfo.frames.get(i));
+      }
+
+      return {
+        ...framesInfo,
+        frames,
+      };
+    } finally {
+      // Cleanup mount.
+      FS.unmount("/work");
+    }
+  }
+}