Don't cache HTTP.

michaelfig · Dec 10, 2018 · 676ba6a · 676ba6a
1 parent 240bc0c
commit 676ba6a
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Showing 5 changed files with 47 additions and 24 deletions.
diff --git a/.vscode/launch.json b/.vscode/launch.json
@@ -8,10 +8,11 @@
             "name": "Cacao Server",
             "program": "bin/cacao.dart",
             "args": ["-p", "9000",
+                "-h", "0.0.0.0",
                 "http://www.google.ca",
                 "/stewart=file:///Users/stewart/cacao/static",
                 "/michael=file:///Users/michael/src/cacao/static",
-                "/mjpeg=http://oviso.axiscam.net/axis-cgi/mjpg/video.cgi"],
+                "/mjpeg=http://216.8.159.21/mjpg/video.mjpg"],
             "request": "launch",
             "type": "dart"
         }

diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.3.2
+
+- Prevent caching of HTTP requests.
+
 ## 0.3.1
 
 - Fix HTTP proxy connection leak.

diff --git a/lib/src/io/serveHttp.dart b/lib/src/io/serveHttp.dart
@@ -6,21 +6,32 @@ Future<void> serveHttp(HttpRequest request, Uri uri) async {
   final targetRequest = await client.openUrl(request.method, uri);
   bool clientClosed = false;
   request.response.done
-    .then((_) => clientClosed = true);
+    .then((_) => clientClosed = true)
+    .catchError((_) => clientClosed = true);
 
   // Add the required headers to the request.
-  request.headers.forEach((hdr, val) =>
-    targetRequest.headers.set(hdr, val));
+  request.headers.forEach((hdr, val) {
+    // print('$hdr: $val');
+    if (hdr.toLowerCase() == 'connection') {
+      val = val.first.toLowerCase() == 'upgrade' ? val : ['close'];
+    }
+    targetRequest.headers.set(hdr, val);
+  });
 
   // Make sure we request the right host.
   targetRequest.headers.set('Host', uri.host);
   await targetRequest.flush();
 
-  // Stream the request.
-  targetRequest
-    ..bufferOutput = false
-    ..addStream(request)
-    .then((_) => targetRequest.close());
+  if (true) {
+    // Stream the request.
+    targetRequest
+      ..bufferOutput = false
+      ..addStream(request)
+      .then((_) => targetRequest.close());
+  }
+  else {
+    targetRequest.close();
+  }
 
   final targetResponse = await targetRequest.done;
 
@@ -39,9 +50,9 @@ Future<void> serveHttp(HttpRequest request, Uri uri) async {
       request.response.headers.contentType = targetResponse.headers.contentType;
 
       // Do the magic: add the allow origin.
-      request.response.headers.remove('X-Content-Type-Options', 'nosniff');
-      request.response.headers.remove('X-Frame-Options', 'SAMEORIGIN');
       request.response.headers.set('Access-Control-Allow-Origin', '*');
+      request.response.headers.set('Cache-Control', 'no-cache');
+      await request.response.flush();
     }
     request.response.add(event);
   }

diff --git a/pubspec.yaml b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: cacao
 description: Cacao (CORS Access-Control-Allow-Origin) Proxy
-version: 0.3.1
+version: 0.3.2-a1
 homepage: https://github.com/michaelfig/cacao
 author: Michael FIG <[email protected]>
 

diff --git a/static/mjpeg.html b/static/mjpeg.html
@@ -3,11 +3,11 @@
     <head><title>Cacao - MJPEG to MediaStream</title></head>
     <body>
         <h1>Cacao - MJPEG to MediaStream</h1>
-        <p>First, run "cacao -p9000 /mjpeg=SOME-MJPEG-URL".  Then click
-            <button onclick="go('http://localhost:9000/mjpeg')">Go</button>.  After a few seconds, you should see the image, canvas, and video all populate and synchronize.
+        <p>First, run "cacao -p9000 /mjpeg=SOME-MJPEG-URL".  Then:
+            <input type="text" id="url" value="/mjpeg" /><button onclick="go(url.value)">Go</button>.  After a few seconds, you should see the image, canvas, and video all populate and synchronize.
         </p>
         <table>
-            <tr><th>Video</th> <td><video id="video" autoplay playsinline /></td></tr>
+            <tr><th>Video</th> <td><video style="background: black" id="video" autoplay playsinline /></td></tr>
             <tr><th>Image</th> <td><img id="image"/></td></tr>
             <tr><th>Canvas</th> <td><canvas id="canvas"></canvas></td></tr>
         </table>
@@ -16,26 +16,33 @@ <h1>Cacao - MJPEG to MediaStream</h1>
     var ctx = canvas.getContext('2d');
 
     var TYPE_JPEG = 'image/jpeg';
-    function go(url) {
+    function go(src) {
         // This function adapted from: https://github.com/aruntj/mjpeg-readable-stream/blob/master/index.html
         // MIT License.
-        fetch(url, {mode: 'cors'})
+        fetch(src, {mode: 'cors'})
         .then(function fetchComplete(response) {
             if (!response.ok) {
-                throw Error(response.status+' '+response.statusText)
+                var reason = response.status+' '+response.statusText;
+                alert('Cannot fetch ' + src + ': ' + reason);
+                throw Error(reason);
             }
             if (!response.body) {
                 alert('ReadableStream not supported.\n' +
                   'If you are using Firefox, go to about:config and set:\n' +
                   'dom.streams.enabled and javascript.options.streams');
-                throw Error('ReadableStream not yet supported in this browser.')
+                throw Error('ReadableStream not yet supported in this browser.');
             }
 
-            var stream = canvas.captureStream();
-            whenStreamIsActive(stream, setSrc);
-            function setSrc() {
-                console.log('setting active video stream');
-                video.srcObject = stream;
+            try {
+                var stream = canvas.captureStream();
+                whenStreamIsActive(stream, setSrc);
+                function setSrc() {
+                    console.log('setting active video stream');
+                    video.srcObject = stream;
+                }
+            }
+            catch (e) {
+                console.error('Cannot captureStream', e);
             }
 
             var reader = response.body.getReader();