auto merge of #1313 : pcwalton/servo/parallel-layout, r=larsbergstrom

This is one small step toward parallel layout.

r? @larsbergstrom

src/components/main/layout/layout_task.rs

@@ -675,15 +675,15 @@ impl LayoutTask {
     // to the script task, and ultimately cause the image to be
     // re-requested. We probably don't need to go all the way back to
     // the script task for this.
-    fn make_on_image_available_cb(&self) -> @ImageResponder {
+    fn make_on_image_available_cb(&self) -> ~ImageResponder:Send {
         // This has a crazy signature because the image cache needs to
         // make multiple copies of the callback, and the dom event
         // channel is not a copyable type, so this is actually a
         // little factory to produce callbacks
-        @LayoutImageResponder {
+        ~LayoutImageResponder {
             id: self.id.clone(),
             script_chan: self.script_chan.clone(),
-        } as @ImageResponder
+        } as ~ImageResponder:Send
     }
 
     /// Handles a message to destroy layout data. Layout data must be destroyed on *this* task

src/components/net/image_cache_task.rs

@@ -48,22 +48,13 @@ pub enum Msg {
     Exit(Chan<()>),
 }
 
+#[deriving(Clone)]
 pub enum ImageResponseMsg {
     ImageReady(Arc<~Image>),
     ImageNotReady,
     ImageFailed
 }
 
-impl ImageResponseMsg {
-    fn clone(&self) -> ImageResponseMsg {
-        match *self {
-            ImageReady(ref img) => ImageReady(img.clone()),
-            ImageNotReady => ImageNotReady,
-            ImageFailed => ImageFailed,
-        }
-    }
-}
-
 impl Eq for ImageResponseMsg {
     fn eq(&self, other: &ImageResponseMsg) -> bool {
         // FIXME: Bad copies
@@ -243,11 +234,11 @@ impl ImageCache {
         }
     }
 
-    fn set_state(&self, url: Url, state: ImageState) {
+    fn set_state(&mut self, url: Url, state: ImageState) {
         self.state_map.insert(url, state);
     }
 
-    fn prefetch(&self, url: Url) {
+    fn prefetch(&mut self, url: Url) {
         match self.get_state(url.clone()) {
             Init => {
                 let to_cache = self.chan.clone();
@@ -278,7 +269,7 @@ impl ImageCache {
         }
     }
 
-    fn store_prefetched_image_data(&self, url: Url, data: Result<Cell<~[u8]>, ()>) {
+    fn store_prefetched_image_data(&mut self, url: Url, data: Result<Cell<~[u8]>, ()>) {
         match self.get_state(url.clone()) {
           Prefetching(next_step) => {
             match data {
@@ -307,7 +298,7 @@ impl ImageCache {
         }
     }
 
-    fn decode(&self, url: Url) {
+    fn decode(&mut self, url: Url) {
         match self.get_state(url.clone()) {
             Init => fail!(~"decoding image before prefetch"),
 
@@ -350,7 +341,7 @@ impl ImageCache {
         }
     }
 
-    fn store_image(&self, url: Url, image: Option<Arc<~Image>>) {
+    fn store_image(&mut self, url: Url, image: Option<Arc<~Image>>) {
 
         match self.get_state(url.clone()) {
           Decoding => {
@@ -377,7 +368,7 @@ impl ImageCache {
 
     }
 
-    fn purge_waiters(&self, url: Url, f: &fn() -> ImageResponseMsg) {
+    fn purge_waiters(&mut self, url: Url, f: &fn() -> ImageResponseMsg) {
         match self.wait_map.pop(&url) {
             Some(waiters) => {
                 for response in waiters.iter() {
@@ -399,7 +390,7 @@ impl ImageCache {
         }
     }
 
-    fn wait_for_image(&self, url: Url, response: Chan<ImageResponseMsg>) {
+    fn wait_for_image(&mut self, url: Url, response: Chan<ImageResponseMsg>) {
         match self.get_state(url.clone()) {
             Init => fail!(~"request for image before prefetch"),
 

src/components/net/local_image_cache.rs

@@ -33,10 +33,11 @@ pub fn LocalImageCache(image_cache_task: ImageCacheTask) -> LocalImageCache {
 pub struct LocalImageCache {
     priv image_cache_task: ImageCacheTask,
     priv round_number: uint,
-    priv on_image_available: Option<@ImageResponder>,
-    priv state_map: UrlMap<@mut ImageState>
+    priv on_image_available: Option<~ImageResponder:Send>,
+    priv state_map: UrlMap<ImageState>
 }
 
+#[deriving(Clone)]
 struct ImageState {
     prefetched: bool,
     decoded: bool,
@@ -47,29 +48,39 @@ struct ImageState {
 impl LocalImageCache {
     /// The local cache will only do a single remote request for a given
     /// URL in each 'round'. Layout should call this each time it begins
-    pub fn next_round(&mut self, on_image_available: @ImageResponder) {
+    pub fn next_round(&mut self, on_image_available: ~ImageResponder:Send) {
         self.round_number += 1;
         self.on_image_available = Some(on_image_available);
     }
 
-    pub fn prefetch(&self, url: &Url) {
+    pub fn prefetch(&mut self, url: &Url) {
+        {
             let state = self.get_state(url);
-        if !state.prefetched {
-            self.image_cache_task.send(Prefetch((*url).clone()));
-            state.prefetched = true;
-        }
+            if state.prefetched {
+                return
             }
 
-    pub fn decode(&self, url: &Url) {
+            state.prefetched = true;
+        }
+
+        self.image_cache_task.send(Prefetch((*url).clone()));
+    }
+
+    pub fn decode(&mut self, url: &Url) {
+        {
             let state = self.get_state(url);
-        if !state.decoded {
-            self.image_cache_task.send(Decode((*url).clone()));
+            if state.decoded {
+                return
+            }
             state.decoded = true;
         }
+
+        self.image_cache_task.send(Decode((*url).clone()));
     }
 
     // FIXME: Should return a Future
-    pub fn get_image(&self, url: &Url) -> Port<ImageResponseMsg> {
+    pub fn get_image(&mut self, url: &Url) -> Port<ImageResponseMsg> {
+        {
             let state = self.get_state(url);
 
             // Save the previous round number for comparison
@@ -99,6 +110,7 @@ impl LocalImageCache {
                     return port;
                 }
             }
+        }
 
         let (response_port, response_chan) = comm::stream();
         self.image_cache_task.send(GetImage((*url).clone(), response_chan));
@@ -113,7 +125,7 @@ impl LocalImageCache {
                 // on the image to load and triggering layout
                 let image_cache_task = self.image_cache_task.clone();
                 assert!(self.on_image_available.is_some());
-                let on_image_available = self.on_image_available.unwrap().respond();
+                let on_image_available = self.on_image_available.as_ref().unwrap().respond();
                 let url = (*url).clone();
                 do task::spawn {
                     let (response_port, response_chan) = comm::stream();
@@ -130,24 +142,24 @@ impl LocalImageCache {
             ImageNotReady => ImageNotReady,
             ImageFailed => ImageFailed
         };
-        state.last_response = response_copy;
+        self.get_state(url).last_response = response_copy;
 
         let (port, chan) = comm::stream();
         chan.send(response);
         return port;
     }
 
-    fn get_state(&self, url: &Url) -> @mut ImageState {
-        let state = do self.state_map.find_or_insert_with(url.clone()) |_| {
-            let new_state = @mut ImageState {
+    fn get_state<'a>(&'a mut self, url: &Url) -> &'a mut ImageState {
+        let state = self.state_map.find_or_insert_with(url.clone(), |_| {
+            let new_state = ImageState {
                 prefetched: false,
                 decoded: false,
                 last_request_round: 0,
                 last_response: ImageNotReady
             };
             new_state
-        };
-        *state  // Unborrowing the state
+        });
+        state
     }
 }
 

src/components/util/url.rs

@@ -147,8 +147,9 @@ mod make_url_tests {
 
 }
 
-pub type UrlMap<T> = @mut HashMap<Url, T>;
+pub type UrlMap<T> = HashMap<Url, T>;
 
 pub fn url_map<T: Clone + 'static>() -> UrlMap<T> {
-    @mut HashMap::new()
+    HashMap::new()
 }
+