refactored stream transforms

app/ece.js

@@ -1,15 +1,12 @@
 import 'buffer';
-import {
+import { transform } from './streams';
-  TStream as TransformStream,
-  RStream as ReadableStream
-} from './streams';
 
 const NONCE_LENGTH = 12;
 const TAG_LENGTH = 16;
 const KEY_LENGTH = 16;
 const MODE_ENCRYPT = 'encrypt';
 const MODE_DECRYPT = 'decrypt';
-const RS = 1024 * 1024;
+const RS = 1024 * 64;
 
 const encoder = new TextEncoder();
 
@@ -277,6 +274,7 @@ class StreamSlicer {
       this.chunkSize = this.rs;
     }
     this.partialChunk = new Uint8Array(this.chunkSize);
+    this.offset = 0;
   }
 
   //reslice input into record sized chunks
@@ -292,26 +290,25 @@ class StreamSlicer {
 
       if (this.offset === this.chunkSize) {
         this.send(this.partialChunk, controller);
-        this.offset = 0;
       }
     }
 
     while (i < chunk.byteLength) {
-      if (chunk.byteLength - i >= this.chunkSize) {
+      const remainingBytes = chunk.byteLength - i;
+      if (remainingBytes >= this.chunkSize) {
         const record = chunk.slice(i, i + this.chunkSize);
         i += this.chunkSize;
         this.send(record, controller);
       } else {
-        const end = chunk.slice(i, this.chunkSize);
+        const end = chunk.slice(i, i + remainingBytes);
-        i += end.length;
+        i += end.byteLength;
         this.partialChunk.set(end);
-        this.offset = end.length;
+        this.offset = end.byteLength;
       }
     }
   }
 
   flush(controller) {
-    //console.log('slice stream ends')
     if (this.offset > 0) {
       controller.enqueue(this.partialChunk.slice(0, this.offset));
     }
@@ -356,15 +353,11 @@ export default class ECE {
         new BlobSlicer(this.input, this.rs, this.mode)
       );
     } else {
-      const sliceStream = new TransformStream(
+      inputStream = transform(this.input, new StreamSlicer(this.rs, this.mode));
-        new StreamSlicer(this.rs, this.mode)
-      );
-      inputStream = this.input.pipeThrough(sliceStream);
     }
-
+    return transform(
-    const cryptoStream = new TransformStream(
+      inputStream,
       new ECETransformer(this.mode, this.key, this.rs, this.salt)
     );
-    return inputStream.pipeThrough(cryptoStream);
   }
 }

app/serviceWorker.js

@@ -1,6 +1,6 @@
 import Keychain from './keychain';
 import { downloadStream } from './api';
-import { TStream as TransformStream, wrapReadable } from './streams';
+import { transform } from './streams';
 
 let noSave = false;
 const map = new Map();
@@ -17,29 +17,26 @@ async function decryptStream(request) {
   const id = request.url.split('/')[5];
   try {
     const file = map.get(id);
+    const keychain = new Keychain(file.key);
 
-    file.download = downloadStream(id, file.keychain);
+    file.download = downloadStream(id, keychain);
 
-    const stream = await file.download.result;
+    const body = await file.download.result;
 
-    // eslint-disable-next-line no-undef
+    const readStream = transform(body, {
-    const progStream = new TransformStream({
       transform: (chunk, controller) => {
         file.progress += chunk.length;
         controller.enqueue(chunk);
       }
     });
-
+    const decrypted = keychain.decryptStream(readStream);
-    const readStream = wrapReadable(stream).pipeThrough(progStream);
-    const decrypted = file.keychain.decryptStream(readStream);
 
     const headers = {
       'Content-Disposition': 'attachment; filename=' + file.filename,
       'Content-Type': file.type,
       'Content-Length': file.size
     };
-    const body = decrypted.isPony ? decrypted.toNative() : decrypted;
+    return new Response(decrypted, { headers });
-    return new Response(body, { headers });
   } catch (e) {
     if (noSave) {
       return new Response(null, { status: e.message });
@@ -47,6 +44,9 @@ async function decryptStream(request) {
 
     const redirectRes = await fetch(`/download/${id}`);
     return new Response(redirectRes.body, { status: 302 });
+  } finally {
+    // TODO: need to clean up, but not break progress
+    // map.delete(id)
   }
 }
 
@@ -61,7 +61,7 @@ self.onmessage = event => {
   if (event.data.request === 'init') {
     noSave = event.data.noSave;
     const info = {
-      keychain: new Keychain(event.data.key),
+      key: event.data.key,
       filename: event.data.filename,
       type: event.data.type,
       size: event.data.size,
@@ -69,23 +69,28 @@ self.onmessage = event => {
       cancelled: false
     };
     if (event.data.requiresPassword) {
-      info.keychain.setPassword(event.data.password, event.data.url);
+      info.password = event.data.password;
+      info.url = event.data.url;
     }
     map.set(event.data.id, info);
 
     event.ports[0].postMessage('file info received');
   } else if (event.data.request === 'progress') {
     const file = map.get(event.data.id);
-    if (file.cancelled) {
+    if (!file) {
+      event.ports[0].postMessage({ progress: 0 });
+    } else if (file.cancelled) {
       event.ports[0].postMessage({ error: 'cancelled' });
     } else {
       event.ports[0].postMessage({ progress: file.progress });
     }
   } else if (event.data.request === 'cancel') {
     const file = map.get(event.data.id);
-    file.cancelled = true;
+    if (file) {
-    if (file.download) {
+      file.cancelled = true;
-      file.download.cancel();
+      if (file.download) {
+        file.download.cancel();
+      }
     }
     event.ports[0].postMessage('download cancelled');
   }

app/streams.js

@@ -1,35 +1,36 @@
-/* global TransformStream ReadableStream */
+/* global ReadableStream */
-import { createReadableStreamWrapper } from '@mattiasbuelens/web-streams-adapter';
-import {
-  TransformStream as TransformStreamPony,
-  ReadableStream as ReadableStreamPony
-} from 'web-streams-ponyfill';
 
-const toNativeReadable = createReadableStreamWrapper(ReadableStream);
+export function transform(readable, transformer) {
-const toPonyReadable = createReadableStreamWrapper(ReadableStreamPony);
+  const reader = readable.getReader();
+  const tstream = new ReadableStream({
+    start(controller) {
+      if (transformer.start) {
+        return transformer.start(controller);
+      }
+    },
+    async pull(controller) {
+      let enqueued = false;
+      const c = {
+        enqueue(d) {
+          enqueued = true;
+          controller.enqueue(d);
+        }
+      };
+      while (!enqueued) {
+        const x = await reader.read();
+        if (x.done) {
+          if (transformer.flush) {
+            await transformer.flush(controller);
+          }
+          return controller.close();
+        }
+        await transformer.transform(x.value, c);
+      }
+    },
+    cancel() {
+      readable.cancel();
+    }
+  });
 
-export let TStream;
+  return tstream;
-if (typeof TransformStream === 'function') {
-  TStream = TransformStream;
-} else {
-  TStream = TransformStreamPony;
-  TStream.prototype.isPony = true;
-}
-
-export let RStream = ReadableStream;
-try {
-  new ReadableStream().pipeThrough(new TransformStream());
-} catch (e) {
-  RStream = ReadableStreamPony;
-  RStream.prototype.isPony = true;
-  RStream.prototype.toNative = function() {
-    return toNativeReadable(this);
-  };
-}
-
-export function wrapReadable(stream) {
-  if (RStream === ReadableStream) {
-    return stream;
-  }
-  return toPonyReadable(stream);
 }

package-lock.json

@@ -88,12 +88,6 @@
       "integrity": "sha1-9vGlzl05caSt6RoR0i1MRZrNN18=",
       "dev": true
     },
-    "@mattiasbuelens/web-streams-adapter": {
-      "version": "0.1.0-alpha.1",
-      "resolved": "https://registry.npmjs.org/@mattiasbuelens/web-streams-adapter/-/web-streams-adapter-0.1.0-alpha.1.tgz",
-      "integrity": "sha512-8YK2ZY6CAgrzFGfW2uPyNDMYvh7OmWjrlbdP+GeHiMJhzPF3XwrQaHyLQ4IZqGTj8NW879ttfbcqbLqQxWvtsw==",
-      "dev": true
-    },
     "@mrmlnc/readdir-enhanced": {
       "version": "2.2.1",
       "resolved": "https://registry.npmjs.org/@mrmlnc/readdir-enhanced/-/readdir-enhanced-2.2.1.tgz",
@@ -16277,12 +16271,6 @@
         "minimalistic-assert": "1.0.1"
       }
     },
-    "web-streams-ponyfill": {
-      "version": "1.4.2",
-      "resolved": "https://registry.npmjs.org/web-streams-ponyfill/-/web-streams-ponyfill-1.4.2.tgz",
-      "integrity": "sha512-LCHW+fE2UBJ2vjhqJujqmoxh1ytEDEr0dPO3CabMdMDJPKmsaxzS90V1Ar6LtNE5VHLqxR4YMEj1i4lzMAccIA==",
-      "dev": true
-    },
     "webpack": {
       "version": "4.16.0",
       "resolved": "https://registry.npmjs.org/webpack/-/webpack-4.16.0.tgz",

package.json

@@ -57,7 +57,6 @@
   },
   "devDependencies": {
     "@dannycoates/webpack-dev-server": "^3.1.4",
-    "@mattiasbuelens/web-streams-adapter": "0.1.0-alpha.1",
     "asmcrypto.js": "^0.22.0",
     "babel-core": "^6.26.3",
     "babel-loader": "^7.1.4",
@@ -113,7 +112,6 @@
     "svgo-loader": "^2.1.0",
     "testpilot-ga": "^0.3.0",
     "val-loader": "^1.1.1",
-    "web-streams-ponyfill": "^1.4.2",
     "webpack": "^4.15.1",
     "webpack-cli": "^3.0.8",
     "webpack-dev-middleware": "^3.1.3",