servo: Decode images in the ImageCache

Source-Repo: https://github.com/servo/servo
Source-Revision: 872a82b9f0cf628676960cd87a3b9e72f688b4f2

--HG--
rename : servo/src/test/test.jpeg => servo/src/servo/image/test.jpeg

servo/src/servo/image/base.rs

@@ -2,6 +2,7 @@ export Image;
 
 export load;
 export load_from_memory;
+export test_image_bin;
 
 import stb_image::image::{image, load, load_from_memory};
 
@@ -9,3 +10,7 @@ import stb_image::image::{image, load, load_from_memory};
 // reference count them.
 
 type Image = image;
+
+fn test_image_bin() -> ~[u8] {
+    #include_bin("test.jpeg")
+}

servo/src/servo/resource/image_cache_task.rs

@@ -3,13 +3,15 @@ export ImageResponseMsg, ImageReady, ImageNotReady;
 export ImageCacheTask;
 export image_cache_task;
 
-import image::base::{Image, load_from_memory};
+import image::base::{Image, load_from_memory, test_image_bin};
 import std::net::url::url;
 import util::url::{make_url, UrlMap, url_map};
 import comm::{chan, port};
 import task::spawn_listener;
 import resource::resource_task;
 import resource_task::ResourceTask;
+import core::arc::arc;
+import clone_arc = core::arc::clone;
 
 enum Msg {
     Prefetch(url),
@@ -18,7 +20,7 @@ enum Msg {
 }
 
 enum ImageResponseMsg {
-    ImageReady(Image),
+    ImageReady(arc<~Image>),
     ImageNotReady
 }
 
@@ -29,7 +31,8 @@ fn image_cache_task(resource_task: ResourceTask) -> ImageCacheTask {
         ImageCache {
             resource_task: resource_task,
             from_client: from_client,
-            prefetch_map: url_map()
+            prefetch_map: url_map(),
+            image_map: url_map()
         }.run();
     }
 }
@@ -37,12 +40,13 @@ fn image_cache_task(resource_task: ResourceTask) -> ImageCacheTask {
 struct ImageCache {
     resource_task: ResourceTask;
     from_client: port<Msg>;
-    prefetch_map: UrlMap<PrefetchData>;
+    prefetch_map: UrlMap<@PrefetchData>;
+    image_map: UrlMap<@arc<~Image>>;
 }
 
 struct PrefetchData {
-    response_port: @port<resource_task::ProgressMsg>;
-    data: @mut ~[u8];
+    response_port: port<resource_task::ProgressMsg>;
+    mut data: ~[u8];
 }
 
 impl ImageCache {
@@ -59,18 +63,53 @@ impl ImageCache {
                 let response_port = port();
                 self.resource_task.send(resource_task::Load(url, response_port.chan()));
 
-                let prefetch_data = PrefetchData {
-                    response_port: @response_port,
-                    data: @mut ~[]
+                let prefetch_data = @PrefetchData {
+                    response_port: response_port,
+                    data: ~[]
                 };
 
                 self.prefetch_map.insert(url, prefetch_data);
               }
               GetImage(url, response) => {
-                if self.prefetch_map.contains_key(url) {
-                    response.send(ImageNotReady);
-                } else {
-                    fail ~"got a request for image data without prefetch";
+                match self.prefetch_map.find(url) {
+                  some(prefetch_data) => {
+
+                    let mut image_sent = false;
+
+                    while prefetch_data.response_port.peek() {
+                        match prefetch_data.response_port.recv() {
+                          resource_task::Payload(data) => {
+                            prefetch_data.data += data;
+                          }
+                          resource_task::Done(result::ok(*)) => {
+                            // We've got the entire image binary
+                            let mut data = ~[];
+                            data <-> prefetch_data.data;
+                            // FIXME: Need to do this in parallel
+                            let image = @arc(~load_from_memory(data));
+                            response.send(ImageReady(clone_arc(image)));
+                            self.prefetch_map.remove(url);
+                            self.image_map.insert(url, image);
+                            image_sent = true;
+                            break;
+                          }
+                          resource_task::Done(result::err(*)) => {
+                            fail ~"FIXME: what happens now?"
+                          }
+                        }
+                    }
+
+                    if !image_sent {
+                        response.send(ImageNotReady);
+                    }
+                  }
+                  none => {
+                    // FIXME: Probably faster to hit this map before the prefetch map
+                    match self.image_map.find(url) {
+                      some(image) => response.send(ImageReady(clone_arc(image))),
+                      none => fail ~"got a request for image data without prefetch"
+                    }
+                  }
                 }
               }
               Exit => break
@@ -198,4 +237,90 @@ fn should_return_image_not_ready_if_data_has_not_arrived() {
     assert response_port.recv() == ImageNotReady;
     image_cache_task.send(Exit);
     mock_resource_task.send(resource_task::Exit);
-}
+}
+
+#[test]
+fn should_return_decoded_image_data_if_data_has_arrived() {
+
+    let image_bin_sent = port();
+    let image_bin_sent_chan = image_bin_sent.chan();
+
+    let mock_resource_task = do spawn_listener |from_client| {
+
+        // infer me
+        let from_client: port<resource_task::ControlMsg> = from_client;
+
+        loop {
+            match from_client.recv() {
+              resource_task::Load(_, response) => {
+                response.send(resource_task::Payload(test_image_bin()));
+                response.send(resource_task::Done(result::ok(())));
+                image_bin_sent_chan.send(());
+              }
+              resource_task::Exit => break
+            }
+        }
+    };
+
+    let image_cache_task = image_cache_task(mock_resource_task);
+    let url = make_url(~"file", none);
+
+    image_cache_task.send(Prefetch(url));
+
+    // Wait until our mock resource task has sent the image to the image cache
+    image_bin_sent.recv();
+
+    let response_port = port();
+    image_cache_task.send(GetImage(url, response_port.chan()));
+    match response_port.recv() {
+      ImageReady(_) => (),
+      _ => fail
+    }
+
+    image_cache_task.send(Exit);
+    mock_resource_task.send(resource_task::Exit);
+}
+
+#[test]
+fn should_return_decoded_image_data_for_multiple_requests() {
+
+    let image_bin_sent = port();
+    let image_bin_sent_chan = image_bin_sent.chan();
+
+    let mock_resource_task = do spawn_listener |from_client| {
+
+        // infer me
+        let from_client: port<resource_task::ControlMsg> = from_client;
+
+        loop {
+            match from_client.recv() {
+              resource_task::Load(_, response) => {
+                response.send(resource_task::Payload(test_image_bin()));
+                response.send(resource_task::Done(result::ok(())));
+                image_bin_sent_chan.send(());
+              }
+              resource_task::Exit => break
+            }
+        }
+    };
+
+    let image_cache_task = image_cache_task(mock_resource_task);
+    let url = make_url(~"file", none);
+
+    image_cache_task.send(Prefetch(url));
+
+    // Wait until our mock resource task has sent the image to the image cache
+    image_bin_sent.recv();
+
+    for iter::repeat(2) {
+        let response_port = port();
+        image_cache_task.send(GetImage(url, response_port.chan()));
+        match response_port.recv() {
+          ImageReady(_) => (),
+          _ => fail
+        }
+    }
+
+    image_cache_task.send(Exit);
+    mock_resource_task.send(resource_task::Exit);
+}