From 8e0860edcf85f631cd7a7021ebeebb638b945568 Mon Sep 17 00:00:00 2001
From: Alex Hultman <alexhultman@gmail.com>
Date: Thu, 17 Jan 2019 06:31:55 +0100
Subject: [PATCH] Wrap onAborted, hook up VideoStreamer

---
 examples/VideoStreamer.js | 76 +++++++++++++++++++--------------------
 src/HttpResponseWrapper.h | 16 +++++++++
 uWebSockets               |  2 +-
 3 files changed, 54 insertions(+), 40 deletions(-)

diff --git a/examples/VideoStreamer.js b/examples/VideoStreamer.js
index e249609..6f8a00f 100644
--- a/examples/VideoStreamer.js
+++ b/examples/VideoStreamer.js
@@ -4,7 +4,6 @@
 
 const uWS = require('../dist/uws.js');
 const fs = require('fs');
-const crypto = require('crypto');
 
 const port = 9001;
 const fileName = '/home/alexhultman/Downloads/Sintel.2010.720p.mkv';
@@ -17,56 +16,55 @@ function toArrayBuffer(buffer) {
   return buffer.buffer.slice(buffer.byteOffset, buffer.byteOffset + buffer.byteLength);
 }
 
-/* Returns true on success, false if it's having backpressure */
-function tryStream(res, chunk, requestDataCb) {
-  /* Stream as far as we can */
-  let lastOffset = res.getWriteOffset();
-  if (!res.tryEnd(chunk, totalSize)) {
-    /* Save unsent chunk for when we can send it */
-    res.chunk = chunk;
-    res.chunkOffset = lastOffset;
+/* Helper function to pipe the ReadaleStream over an Http responses */
+function pipeStreamOverResponse(res, readStream, totalSize) {
+  /* Careful! If Node.js would emit error before the first res.tryEnd, res will hang and never time out */
+  /* For this demo, I skipped checking for Node.js errors, you are free to PR fixes to this example */
+  readStream.on('data', (chunk) => {
+    /* We only take standard V8 units of data */
+    const ab = toArrayBuffer(chunk);
 
-    res.onWritable((offset) => {
-      if (res.tryEnd(res.chunk.slice(offset - res.chunkOffset), totalSize)) {
-        requestDataCb();
-        return true;
-      }
-      return false;
-    });
-    /* Return failure */
-    return false;
-  }
-  /* Return success */
-  return true;
+    /* Stream as far as we can */
+    let lastOffset = res.getWriteOffset();
+    if (!res.tryEnd(ab, totalSize)) {
+      /* If we could not send this chunk, pause */
+      readStream.pause();
+
+      /* Save unsent chunk for when we can send it */
+      res.ab = ab;
+      res.abOffset = lastOffset;
+
+      /* Register async handlers for drainage */
+      res.onWritable((offset) => {
+        if (res.tryEnd(res.ab.slice(offset - res.abOffset), totalSize)) {
+          readStream.resume();
+          return true;
+        }
+        return false;
+      });
+
+      /* Register async abortion handlers */
+      res.onAborted(() => {
+        console.log('Res is no longer valid!');
+        readStream.destroy();
+      });
+    }
+  }).on('end', () => {
+    /* Todo: handle errors of the stream, probably good to simply close the response */
+  });
 }
 
 /* Yes, you can easily swap to SSL streaming by uncommenting here */
-const app = uWS./*SSL*/App({
+const app = uWS.SSLApp({
   key_file_name: '/home/alexhultman/key.pem',
   cert_file_name: '/home/alexhultman/cert.pem',
   passphrase: '1234'
 }).get('/sintel.mkv', (res, req) => {
   /* Log */
   console.log("Streaming Sintel video...");
-
   /* Create read stream with Node.js and start streaming over Http */
   const readStream = fs.createReadStream(fileName);
-  const hash = crypto.createHash('md5');
-  readStream.on('data', (chunk) => {
-
-    const ab = toArrayBuffer(chunk);
-    hash.update(chunk);
-
-    if (!tryStream(res, ab, () => {
-      /* Called once we want more data */
-      readStream.resume();
-    })) {
-      /* If we could not send this chunk, pause */
-      readStream.pause();
-    }
-  }).on('end', () => {
-    console.log("md5: " + hash.digest('hex'));
-  });
+  pipeStreamOverResponse(res, readStream, totalSize);
 }).get('/*', (res, req) => {
   /* Make sure to always handle every route */
   res.end('Nothing to see here!');
diff --git a/src/HttpResponseWrapper.h b/src/HttpResponseWrapper.h
index 8ddcc2d..ecd51c8 100644
--- a/src/HttpResponseWrapper.h
+++ b/src/HttpResponseWrapper.h
@@ -14,6 +14,21 @@ struct HttpResponseWrapper {
     // res.onData(JS function)
     // res.onAborted
 
+    template <bool SSL>
+    static void res_onAborted(const FunctionCallbackInfo<Value> &args) {
+        /* This thing perfectly fits in with unique_function, and will Reset on destructor */
+        UniquePersistent<Function> p(isolate, Local<Function>::Cast(args[0]));
+
+        getHttpResponse<SSL>(args)->onAborted([p = std::move(p)]() {
+            HandleScope hs(isolate);
+
+            Local<Value> argv[] = {};
+            Local<Function>::New(isolate, p)->Call(isolate->GetCurrentContext()->Global(), 0, argv);
+        });
+
+        args.GetReturnValue().Set(args.Holder());
+    }
+
     /* Returns the current write offset */
     template <bool SSL>
     static void res_getWriteOffset(const FunctionCallbackInfo<Value> &args) {
@@ -108,6 +123,7 @@ struct HttpResponseWrapper {
 
         resTemplateLocal->PrototypeTemplate()->Set(String::NewFromUtf8(isolate, "getWriteOffset"), FunctionTemplate::New(isolate, res_getWriteOffset<SSL>));
         resTemplateLocal->PrototypeTemplate()->Set(String::NewFromUtf8(isolate, "onWritable"), FunctionTemplate::New(isolate, res_onWritable<SSL>));
+        resTemplateLocal->PrototypeTemplate()->Set(String::NewFromUtf8(isolate, "onAborted"), FunctionTemplate::New(isolate, res_onAborted<SSL>));
 
         /* Create our template */
         Local<Object> resObjectLocal = resTemplateLocal->GetFunction()->NewInstance(isolate->GetCurrentContext()).ToLocalChecked();
diff --git a/uWebSockets b/uWebSockets
index 0ca061e..6718301 160000
--- a/uWebSockets
+++ b/uWebSockets
@@ -1 +1 @@
-Subproject commit 0ca061e7727df4fcc0c840e67188e093f966e7d3
+Subproject commit 6718301ac9f0385f3146bab70c9fd7d8fa305562