up

electron/package-media.ts

@@ -0,0 +1,44 @@
+import { createReadStream } from 'node:fs'
+import { Readable } from 'node:stream'
+import type { PackageStore } from './package-store.js'
+import { parseRange } from './range.js'
+
+export async function packageMediaResponse(
+  store: PackageStore,
+  request: Request,
+): Promise<Response> {
+  const url = new URL(request.url)
+  const match = /^\/packages\/([a-f0-9]{64})\/([a-f0-9]{64})$/.exec(url.pathname)
+  if (url.host !== 'app' || request.method !== 'GET' || !match)
+    return new Response(null, { status: 404 })
+  try {
+    const file = await store.localFile(match[1]!, match[2]!)
+    const rangeHeader = request.headers.get('range')
+    const range = parseRange(rangeHeader, file.size)
+    const headers: Record<string, string> = {
+      'Content-Type': file.mime,
+      'Accept-Ranges': 'bytes',
+      'Cache-Control': 'no-store',
+      'X-Content-Type-Options': 'nosniff',
+      'Content-Security-Policy': "default-src 'none'; frame-ancestors 'none'; sandbox",
+    }
+    if (!range)
+      return new Response(null, {
+        status: 416,
+        headers: { ...headers, 'Content-Range': `bytes */${file.size}` },
+      })
+    headers['Content-Length'] = String(range.end - range.start + 1)
+    if (rangeHeader) headers['Content-Range'] = `bytes ${range.start}-${range.end}/${file.size}`
+    const stream = createReadStream(file.path, range)
+    const abort = () => stream.destroy()
+    request.signal.addEventListener('abort', abort, { once: true })
+    stream.on('close', () => request.signal.removeEventListener('abort', abort))
+    if (request.signal.aborted) stream.destroy()
+    return new Response(Readable.toWeb(stream) as ReadableStream<Uint8Array>, {
+      status: rangeHeader ? 206 : 200,
+      headers,
+    })
+  } catch {
+    return new Response(null, { status: 404 })
+  }
+}