Auto merge of #11716 - izgzhen:impl-blob-url-dom, r=Manishearth

Implement Blob URL's DOM interfaces

r? @Manishearth

Implement the two functions in `URL` to create/revoke Blob URLs, and related code to approximate our proposed design to make things work together.

<!-- Please describe your changes on the following line: -->

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix part of #10539, related to #11131

<!-- Either: -->
- [x] There are tests for these changes OR

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11716)
<!-- Reviewable:end -->

components/script/dom/url.rs

@@ -3,18 +3,25 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use dom::bindings::cell::DOMRefCell;
+use dom::bindings::codegen::Bindings::BlobBinding::BlobMethods;
 use dom::bindings::codegen::Bindings::URLBinding::{self, URLMethods};
 use dom::bindings::error::{Error, ErrorResult, Fallible};
 use dom::bindings::global::GlobalRef;
 use dom::bindings::js::{JS, MutNullableHeap, Root};
 use dom::bindings::reflector::{Reflectable, Reflector, reflect_dom_object};
 use dom::bindings::str::{DOMString, USVString};
+use dom::blob::Blob;
 use dom::urlhelper::UrlHelper;
 use dom::urlsearchparams::URLSearchParams;
+use ipc_channel::ipc;
+use net_traits::IpcSend;
+use net_traits::blob_url_store::{BlobURLStoreEntry, BlobURLStoreMsg, parse_blob_url};
+use net_traits::filemanager_thread::FileManagerThreadMsg;
 use std::borrow::ToOwned;
 use std::default::Default;
 use url::quirks::domain_to_unicode;
 use url::{Host, Url};
+use uuid::Uuid;
 
 // https://url.spec.whatwg.org/#url
 #[dom_struct]
@@ -105,6 +112,90 @@ impl URL {
     pub fn DomainToUnicode(_: GlobalRef, origin: USVString) -> USVString {
         USVString(domain_to_unicode(&origin.0))
     }
+
+    // https://w3c.github.io/FileAPI/#dfn-createObjectURL
+    pub fn CreateObjectURL(global: GlobalRef, blob: &Blob) -> DOMString {
+        /// XXX: Second field is an unicode-serialized Origin, it is a temporary workaround
+        ///      and should not be trusted. See issue https://github.com/servo/servo/issues/11722
+        let origin = global.get_url().origin().unicode_serialization();
+
+        if blob.IsClosed() {
+            // Generate a dummy id
+            let id = Uuid::new_v4().simple().to_string();
+            return DOMString::from(URL::unicode_serialization_blob_url(&origin, &id));
+        }
+
+        let filemanager = global.resource_threads().sender();
+
+        let slice = blob.get_slice_or_empty();
+        let bytes = slice.get_bytes();
+
+        let entry = BlobURLStoreEntry {
+            type_string: blob.Type().to_string(),
+            filename: None, // XXX: the filename is currently only in File object now
+            size: blob.Size(),
+            bytes: bytes.to_vec(),
+        };
+
+        let (tx, rx) = ipc::channel().unwrap();
+
+        let msg = BlobURLStoreMsg::AddEntry(entry, origin.clone(), tx);
+
+        let _ = filemanager.send(FileManagerThreadMsg::BlobURLStoreMsg(msg));
+
+        match rx.recv().unwrap() {
+            Ok(id) => {
+                DOMString::from(URL::unicode_serialization_blob_url(&origin, &id))
+            }
+            Err(_) => {
+                // Generate a dummy id
+                let id = Uuid::new_v4().simple().to_string();
+                DOMString::from(URL::unicode_serialization_blob_url(&origin, &id))
+            }
+        }
+    }
+
+    // https://w3c.github.io/FileAPI/#dfn-revokeObjectURL
+    pub fn RevokeObjectURL(global: GlobalRef, url: DOMString) {
+        /*
+            If the url refers to a Blob that has a readability state of CLOSED OR
+            if the value provided for the url argument is not a Blob URL, OR
+            if the value provided for the url argument does not have an entry in the Blob URL Store,
+
+            this method call does nothing. User agents may display a message on the error console.
+
+            NOTE: The first step is unnecessary, since closed blobs do not exist in the store
+        */
+
+        match Url::parse(&url) {
+            Ok(url) => match parse_blob_url(&url) {
+                Some((id, _)) => {
+                    let filemanager = global.resource_threads().sender();
+                    let msg = BlobURLStoreMsg::DeleteEntry(id.simple().to_string());
+                    let _ = filemanager.send(FileManagerThreadMsg::BlobURLStoreMsg(msg));
+                }
+                None => {}
+            },
+            Err(_) => {}
+        }
+    }
+
+    // https://w3c.github.io/FileAPI/#unicodeSerializationOfBlobURL
+    fn unicode_serialization_blob_url(origin: &str, id: &str) -> String {
+        // Step 1, 2
+        let mut result = "blob:".to_string();
+
+        // Step 3
+        result.push_str(origin);
+
+        // Step 4
+        result.push('/');
+
+        // Step 5
+        result.push_str(id);
+
+        result
+    }
 }
 
 impl URLMethods for URL {

components/script/dom/webidls/URL.webidl

@@ -23,6 +23,11 @@ interface URL {
   readonly attribute URLSearchParams searchParams;
            attribute USVString hash;
 
+  // https://w3c.github.io/FileAPI/#creating-revoking
+  static DOMString createObjectURL(Blob blob);
+  // static DOMString createFor(Blob blob);
+  static void revokeObjectURL(DOMString url);
+
   // This is only doing as well as gecko right now.
   // https://github.com/servo/servo/issues/7590 is on file for
   // adding attribute stringifier support.

components/script/dom/window.rs

@@ -3,7 +3,6 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 use app_units::Au;
-use blob_url_store::BlobURLStore;
 use devtools_traits::{ScriptToDevtoolsControlMsg, TimelineMarker, TimelineMarkerType, WorkerId};
 use dom::bindings::callback::ExceptionHandling;
 use dom::bindings::cell::DOMRefCell;
@@ -167,9 +166,6 @@ pub struct Window {
     scheduler_chan: IpcSender<TimerEventRequest>,
     timers: OneshotTimers,
 
-    /// Blob URL store
-    blob_url_store: DOMRefCell<BlobURLStore>,
-
     next_worker_id: Cell<WorkerId>,
 
     /// For sending messages to the memory profiler.
@@ -1641,7 +1637,6 @@ impl Window {
             console: Default::default(),
             crypto: Default::default(),
             navigator: Default::default(),
-            blob_url_store: DOMRefCell::new(BlobURLStore::new()),
             image_cache_thread: image_cache_thread,
             mem_profiler_chan: mem_profiler_chan,
             time_profiler_chan: time_profiler_chan,

components/script/dom/worker.rs

@@ -147,7 +147,10 @@ impl WorkerMethods for Worker {
     fn PostMessage(&self, cx: *mut JSContext, message: HandleValue) -> ErrorResult {
         let data = try!(StructuredCloneData::write(cx, message));
         let address = Trusted::new(self);
-        self.sender.send((address, WorkerScriptMsg::DOMMessage(data))).unwrap();
+
+        // NOTE: step 9 of https://html.spec.whatwg.org/multipage/#dom-messageport-postmessage
+        // indicates that a nonexistent communication channel should result in a silent error.
+        let _ = self.sender.send((address, WorkerScriptMsg::DOMMessage(data)));
         Ok(())
     }
 

components/script/dom/workerglobalscope.rs

@@ -2,9 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-use blob_url_store::BlobURLStore;
 use devtools_traits::{DevtoolScriptControlMsg, ScriptToDevtoolsControlMsg, WorkerId, DevtoolsPageInfo};
-use dom::bindings::cell::DOMRefCell;
 use dom::bindings::codegen::Bindings::FunctionBinding::Function;
 use dom::bindings::codegen::Bindings::WorkerGlobalScopeBinding::WorkerGlobalScopeMethods;
 use dom::bindings::error::{Error, ErrorResult, Fallible, report_pending_exception};
@@ -115,8 +113,6 @@ pub struct WorkerGlobalScope {
     console: MutNullableHeap<JS<Console>>,
     crypto: MutNullableHeap<JS<Crypto>>,
     timers: OneshotTimers,
-    /// Blob URL store
-    blob_url_store: DOMRefCell<BlobURLStore>,
 
     #[ignore_heap_size_of = "Defined in std"]
     mem_profiler_chan: mem::ProfilerChan,
@@ -177,7 +173,6 @@ impl WorkerGlobalScope {
             console: Default::default(),
             crypto: Default::default(),
             timers: OneshotTimers::new(timer_event_chan, init.scheduler_chan.clone()),
-            blob_url_store: DOMRefCell::new(BlobURLStore::new()),
             mem_profiler_chan: init.mem_profiler_chan,
             time_profiler_chan: init.time_profiler_chan,
             to_devtools_sender: init.to_devtools_sender,