Auto merge of #12448 - jdm:file-reading-task-source-2, r=KiChjang

Implement file reading task source

Implement the task source API for the File Reader task source, enabling using task sources from non-main threads.

---
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix (partially) #7959 (github issue number if applicable).
- [X] These changes do not require tests because they're refactoring existing code

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---
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1 files changed, 18 insertions, 44 deletions

diff --git a/components/script/dom/filereader.rs b/components/script/dom/filereader.rs
index be57d67f7c0..a82e4dc47bc 100644
--- a/components/script/dom/filereader.rs
+++ b/components/script/dom/filereader.rs
@@ -23,12 +23,12 @@ use encoding::label::encoding_from_whatwg_label;
 use encoding::types::{DecoderTrap, EncodingRef};
 use hyper::mime::{Attr, Mime};
 use rustc_serialize::base64::{CharacterSet, Config, Newline, ToBase64};
-use script_runtime::ScriptThreadEventCategory::FileRead;
-use script_runtime::{ScriptChan, CommonScriptMsg};
-use script_thread::Runnable;
+use script_thread::RunnableWrapper;
 use std::cell::Cell;
 use std::sync::Arc;
 use string_cache::Atom;
+use task_source::TaskSource;
+use task_source::file_reading::{FileReadingTaskSource, FileReadingRunnable, FileReadingTask};
 use util::thread::spawn_named;
 
 #[derive(PartialEq, Clone, Copy, JSTraceable, HeapSizeOf)]
@@ -358,10 +358,11 @@ impl FileReader {
         let fr = Trusted::new(self);
         let gen_id = self.generation_id.get();
 
-        let script_chan = self.global().r().file_reading_task_source();
+        let wrapper = self.global().r().get_runnable_wrapper();
+        let task_source = self.global().r().file_reading_task_source();
 
         spawn_named("file reader async operation".to_owned(), move || {
-            perform_annotated_read_operation(gen_id, load_data, blob_contents, fr, script_chan)
+            perform_annotated_read_operation(gen_id, load_data, blob_contents, fr, task_source, wrapper)
         });
         Ok(())
     }
@@ -371,47 +372,20 @@ impl FileReader {
     }
 }
 
-#[derive(Clone)]
-pub enum FileReaderEvent {
-    ProcessRead(TrustedFileReader, GenerationId),
-    ProcessReadData(TrustedFileReader, GenerationId),
-    ProcessReadError(TrustedFileReader, GenerationId, DOMErrorName),
-    ProcessReadEOF(TrustedFileReader, GenerationId, ReadMetaData, Arc<Vec<u8>>)
-}
-
-impl Runnable for FileReaderEvent {
-    fn name(&self) -> &'static str { "FileReaderEvent" }
-
-    fn handler(self: Box<FileReaderEvent>) {
-        let file_reader_event = *self;
-        match file_reader_event {
-            FileReaderEvent::ProcessRead(filereader, gen_id) => {
-                FileReader::process_read(filereader, gen_id);
-            },
-            FileReaderEvent::ProcessReadData(filereader, gen_id) => {
-                FileReader::process_read_data(filereader, gen_id);
-            },
-            FileReaderEvent::ProcessReadError(filereader, gen_id, error) => {
-                FileReader::process_read_error(filereader, gen_id, error);
-            },
-            FileReaderEvent::ProcessReadEOF(filereader, gen_id, data, blob_contents) => {
-                FileReader::process_read_eof(filereader, gen_id, data, blob_contents);
-            }
-        }
-    }
-}
-
 // https://w3c.github.io/FileAPI/#thread-read-operation
-fn perform_annotated_read_operation(gen_id: GenerationId, data: ReadMetaData, blob_contents: Arc<Vec<u8>>,
-    filereader: TrustedFileReader, script_chan: Box<ScriptChan + Send>) {
-    let chan = &script_chan;
+fn perform_annotated_read_operation(gen_id: GenerationId,
+                                    data: ReadMetaData,
+                                    blob_contents: Arc<Vec<u8>>,
+                                    filereader: TrustedFileReader,
+                                    task_source: FileReadingTaskSource,
+                                    wrapper: RunnableWrapper) {
     // Step 4
-    let thread = box FileReaderEvent::ProcessRead(filereader.clone(), gen_id);
-    chan.send(CommonScriptMsg::RunnableMsg(FileRead, thread)).unwrap();
+    let task = FileReadingRunnable::new(FileReadingTask::ProcessRead(filereader.clone(), gen_id));
+    task_source.queue_with_wrapper(task, &wrapper).unwrap();
 
-    let thread = box FileReaderEvent::ProcessReadData(filereader.clone(), gen_id);
-    chan.send(CommonScriptMsg::RunnableMsg(FileRead, thread)).unwrap();
+    let task = FileReadingRunnable::new(FileReadingTask::ProcessReadData(filereader.clone(), gen_id));
+    task_source.queue_with_wrapper(task, &wrapper).unwrap();
 
-    let thread = box FileReaderEvent::ProcessReadEOF(filereader, gen_id, data, blob_contents);
-    chan.send(CommonScriptMsg::RunnableMsg(FileRead, thread)).unwrap();
+    let task = FileReadingRunnable::new(FileReadingTask::ProcessReadEOF(filereader, gen_id, data, blob_contents));
+    task_source.queue_with_wrapper(task, &wrapper).unwrap();
 }