Bug 938023 - Download API (Asynchronous Responses for API Tests). r=fabrice, gwagner

dom/downloads/tests/serve_file.sjs

@@ -1,5 +1,4 @@
-
-// Serves a file with a given mime type and size.
+// Serves a file with a given mime type and size at an optionally given rate.
 
 function getQuery(request) {
   var query = {};
@@ -10,25 +9,99 @@ function getQuery(request) {
   return query;
 }
 
+// Timer used to handle the request response.
+var timer = null;
+
+function handleResponse() {
+  // Is this a rate limited response?
+  if (this.state.rate > 0) {
+    // Calculate how many bytes we have left to send.
+    var bytesToWrite = this.state.totalBytes - this.state.sentBytes;
+
+    // Do we have any bytes left to send? If not we'll just fall thru and
+    // cancel our repeating timer and finalize the response.
+    if (bytesToWrite > 0) {
+      // Figure out how many bytes to send, based on the rate limit.
+      bytesToWrite =
+        (bytesToWrite > this.state.rate) ? this.state.rate : bytesToWrite;
+
+      for (let i = 0; i < bytesToWrite; i++) {
+        this.response.write("0");
+      }
+
+      // Update the number of bytes we've sent to the client.
+      this.state.sentBytes += bytesToWrite;
+
+      // Wait until the next call to do anything else.
+      return;
+    }
+  }
+  else {
+    // Not rate limited, write it all out.
+    for (let i = 0; i < this.state.totalBytes; i++) {
+      this.response.write("0");
+    }
+  }
+
+  // Finalize the response.
+  this.response.finish();
+
+  // All done sending, go ahead and cancel our repeating timer.
+  timer.cancel();
+}
+
 function handleRequest(request, response) {
   var query = getQuery(request);
 
-  // Default values for content type and size.
+  // Default values for content type, size and rate.
   var contentType = "text/plain";
   var size = 1024;
+  var rate = 0;
 
+  // optional content type to be used by our response.
   if ("contentType" in query) {
     contentType = query["contentType"];
   }
 
+  // optional size (in bytes) for generated file.
   if ("size" in query) {
-    size = query["size"];
+    size = parseInt(query["size"]);
   }
 
-  // Generate the content.
+  // optional rate (in bytes/s) at which to send the file.
+  if ("rate" in query) {
+    rate = parseInt(query["rate"]);
+  }
+
+  // The context for the responseHandler.
+  var context = {
+    response: response,
+    state: {
+      contentType: contentType,
+      totalBytes: size,
+      sentBytes: 0,
+      rate: rate
+    }
+  };
+
+  // The notify implementation for the timer.
+  context.notify = handleResponse.bind(context);
+
+  timer =
+    Components.classes["@mozilla.org/timer;1"]
+              .createInstance(Components.interfaces.nsITimer);
+
+  // sending at a specific rate requires our response to be asynchronous so
+  // we handle all requests asynchronously. See handleResponse().
+  response.processAsync();
+
+  // generate the content.
   response.setHeader("Content-Type", contentType, false);
+  response.setHeader("Content-Length", size.toString(), false);
+
+  // initialize the timer and start writing out the response.
+  timer.initWithCallback(context,
+                         1000,
+                         Components.interfaces.nsITimer.TYPE_REPEATING_SLACK);
 
-  for (let i = 0; i < size; i++) {
-    response.write("0");
-  }
 }

dom/downloads/tests/test_downloads_pause_remove.html

@@ -15,7 +15,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=938023
 <p id="display"></p>
 <div id="content" style="display: none">
 </div>
-<a href="serve_file.sjs?contentType=application/octet-stream&size=102400" download="test.bin" id="download1">Large Download</a>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=102400&rate=1024" download="test.bin" id="download1">Large Download</a>
 <pre id="test">
 <script class="testbody" type="text/javascript;version=1.7">
 

dom/downloads/tests/test_downloads_pause_resume.html

@@ -15,7 +15,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=938023
 <p id="display"></p>
 <div id="content" style="display: none">
 </div>
-<a href="serve_file.sjs?contentType=application/octet-stream&size=102400" download="test.bin" id="download1">Large Download</a>
+<a href="serve_file.sjs?contentType=application/octet-stream&size=102400&rate=1024" download="test.bin" id="download1">Large Download</a>
 <pre id="test">
 <script class="testbody" type="text/javascript;version=1.7">