[fsp] Simplify aborting logic.

chrome/browser/chromeos/file_system_provider/queue.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "base/thread_task_runner_handle.h"
 #include "chrome/browser/chromeos/file_system_provider/queue.h"
@@ skipping 18 matching lines @@
   DCHECK_LT(0u, max_in_parallel);
 }
 
 Queue::~Queue() {
 }
 
 size_t Queue::NewToken() {
   return next_token_++;
 }
 
-AbortCallback Queue::Enqueue(size_t token, const AbortableCallback& callback) {
+void Queue::Enqueue(size_t token, const AbortableCallback& callback) {
 #if !NDEBUG
   const auto it = executed_.find(token);
   DCHECK(it == executed_.end());
   for (auto& task : pending_) {
     DCHECK(token != task.token);
   }
 #endif
   pending_.push_back(Task(token, callback));
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(&Queue::MaybeRun, weak_ptr_factory_.GetWeakPtr()));
-  return base::Bind(&Queue::Abort, weak_ptr_factory_.GetWeakPtr(), token);
 }
 
 void Queue::Complete(size_t token) {
   const auto it = executed_.find(token);
   DCHECK(it != executed_.end() && !it->second.completed);
   it->second.completed = true;
 }
 
 void Queue::Remove(size_t token) {
   const auto it = executed_.find(token);
@@ skipping 10 matching lines @@
   }
 
   DCHECK_GT(max_in_parallel_, executed_.size());
   Task task = pending_.front();
   pending_.pop_front();
 
   executed_[task.token] = task;
   executed_[task.token].abort_callback = task.callback.Run();
 }
 
-void Queue::Abort(size_t token,
-                  const storage::AsyncFileUtil::StatusCallback& callback) {
+void Queue::Abort(size_t token) {
   // Check if it's running.
   const auto it = executed_.find(token);
   if (it != executed_.end()) {
     const Task& task = it->second;
     // If the task is marked as completed, then it's impossible to abort it.
-    if (task.completed) {
-      callback.Run(base::File::FILE_ERROR_INVALID_OPERATION);
-      return;
-    }
+    DCHECK(!task.completed);
     DCHECK(!task.abort_callback.is_null());
-    it->second.abort_callback.Run(callback);
+    it->second.abort_callback.Run();
     executed_.erase(it);

[hirono, 2015/01/14 05:36:06]

Aborted task should not be removed from the queue.

[mtomasz, 2015/01/14 08:55:10]

Good catch. Fixed + upgraded tests. Done.

     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(&Queue::MaybeRun, weak_ptr_factory_.GetWeakPtr()));
     return;
   }
 
   // Aborting not running tasks is linear. TODO(mtomasz): Optimize if feasible.
   for (auto it = pending_.begin(); it != pending_.end(); ++it) {
     if (token == it->token) {
       pending_.erase(it);

[hirono, 2015/01/14 05:36:06]

ditto

[mtomasz, 2015/01/14 08:55:09]

Done.

-      callback.Run(base::File::FILE_OK);
       base::ThreadTaskRunnerHandle::Get()->PostTask(
           FROM_HERE,
           base::Bind(&Queue::MaybeRun, weak_ptr_factory_.GetWeakPtr()));
       return;
     }
   }
 
   // The task is already removed.
-  callback.Run(base::File::FILE_ERROR_INVALID_OPERATION);
+  NOTREACHED();
 }
 
 }  // namespace file_system_provider
 }  // namespace chromeos