Initial release

src/index.js

@@ -0,0 +1,146 @@
+import { createReadStream, statSync } from "node:fs";
+import { fileURLToPath } from "node:url";
+import { parseSingleRange } from "./range.js";
+
+export { parseSingleRange } from "./range.js";
+
+export const PACKAGE_ID = "dsh-client-liang-intensity-skin";
+export const SETTINGS_NAMESPACE = "liang-intensity-skin";
+export const ASSET_PREFIX = `/plugins/${PACKAGE_ID}/assets/`;
+
+const ASSET_SPECS = [
+  ["liang-evolution.webm", "video/webm"],
+  ["liang-evolution.mp4", "video/mp4"],
+  ["liang-poster.png", "image/png"],
+  ["portrait-source-v2/stage-00.png", "image/png"],
+  ["portrait-source-v2/stage-06.png", "image/png"],
+  ["portrait-source-v2/stage-12.png", "image/png"],
+  ["portrait-source-v2/bridge-15.png", "image/png"],
+  ["portrait-source-v2/stage-18.png", "image/png"],
+  ["portrait-source-v2/stage-24.png", "image/png"],
+  ["portrait-source-v2/bridge-27.png", "image/png"],
+  ["portrait-source-v2/stage-30.png", "image/png"],
+];
+
+function send(res, status, headers = {}) {
+  res.writeHead(status, {
+    "X-Content-Type-Options": "nosniff",
+    ...headers,
+  });
+  res.end();
+}
+
+function buildAssets() {
+  const assetDirectory = fileURLToPath(new URL("../assets/", import.meta.url));
+  const assets = new Map();
+  for (const [name, type] of ASSET_SPECS) {
+    const path = fileURLToPath(new URL(`../assets/${name}`, import.meta.url));
+    try {
+      const info = statSync(path);
+      if (!info.isFile()) continue;
+      assets.set(`${ASSET_PREFIX}${name}`, {
+        path,
+        type,
+        size: info.size,
+        etag: `W/\"${info.size.toString(16)}-${Math.trunc(info.mtimeMs).toString(16)}\"`,
+      });
+    } catch {
+      // A missing optional medium is handled by the browser fallback chain.
+    }
+  }
+  return { assetDirectory, assets };
+}
+
+function createAssetHandler(assets, activeStreams) {
+  return (req, res) => {
+    const method = req.method ?? "GET";
+    if (method !== "GET" && method !== "HEAD") {
+      send(res, 405, { Allow: "GET, HEAD" });
+      return;
+    }
+
+    let pathname;
+    try {
+      pathname = new URL(req.url ?? "/", "http://dsh.local").pathname;
+    } catch {
+      send(res, 404);
+      return;
+    }
+    const asset = assets.get(pathname);
+    if (asset === undefined) {
+      send(res, 404);
+      return;
+    }
+
+    if (req.headers["if-none-match"] === asset.etag) {
+      send(res, 304, { ETag: asset.etag });
+      return;
+    }
+
+    const ifRange = req.headers["if-range"];
+    const rangeHeader = ifRange !== undefined && ifRange !== asset.etag
+      ? undefined
+      : req.headers.range;
+    const range = parseSingleRange(rangeHeader, asset.size);
+    if (range === false) {
+      send(res, 416, { "Content-Range": `bytes */${asset.size}` });
+      return;
+    }
+
+    const start = range?.start ?? 0;
+    const end = range?.end ?? asset.size - 1;
+    const status = range === null ? 200 : 206;
+    const headers = {
+      "Accept-Ranges": "bytes",
+      "Cache-Control": "private, max-age=3600, must-revalidate",
+      "Content-Length": String(end - start + 1),
+      "Content-Type": asset.type,
+      ETag: asset.etag,
+      ...(range === null ? {} : { "Content-Range": `bytes ${start}-${end}/${asset.size}` }),
+    };
+
+    if (method === "HEAD") {
+      send(res, status, headers);
+      return;
+    }
+
+    res.writeHead(status, {
+      "X-Content-Type-Options": "nosniff",
+      ...headers,
+    });
+    const stream = createReadStream(asset.path, { start, end });
+    activeStreams.add(stream);
+    const release = () => activeStreams.delete(stream);
+    stream.once("close", release);
+    stream.once("end", release);
+    stream.once("error", () => {
+      release();
+      if (!res.headersSent) send(res, 500);
+      else res.destroy();
+    });
+    res.once("close", () => {
+      if (!stream.destroyed) stream.destroy();
+    });
+    stream.pipe(res);
+  };
+}
+
+export const inject = ["webServer"];
+
+export function apply(ctx) {
+  const { assets } = buildAssets();
+  const activeStreams = new Set();
+  ctx.effect(() => {
+    const handler = createAssetHandler(assets, activeStreams);
+    const unregister = [...assets.keys()].map((path) => ctx.webServer.register({
+      kind: "exact",
+      path,
+      handler,
+    }));
+    return () => {
+      for (const dispose of unregister) dispose();
+      for (const stream of activeStreams) stream.destroy();
+      activeStreams.clear();
+    };
+  }, "liang-intensity-skin: static media route");
+}