mediaview: Support watchers in ArcFileSystemOperationRunner.

chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.cc

 // Copyright 2016 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 "chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner_util.h"
 
 #include <utility>
 #include <vector>
 
-#include "chrome/browser/chromeos/arc/fileapi/arc_file_system_operation_runner.h"
 #include "components/arc/arc_service_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "url/gurl.h"
 
 using content::BrowserThread;
 
 namespace arc {
 
 namespace file_system_operation_runner_util {
 
@@ skipping 58 matching lines @@
       ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
   if (!runner) {
     LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
                << "File system operations are dropped.";
     callback.Run(base::nullopt);
     return;
   }
   runner->GetChildDocuments(authority, parent_document_id, callback);
 }
 
+void AddWatcherOnUIThread(const std::string& authority,
+                          const std::string& document_id,
+                          const WatcherCallback& watcher_callback,
+                          const AddWatcherCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  auto* runner =
+      ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
+  if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "

[dcheng, 2017/03/03 09:31:14]

DLOG(ERROR) for all the other LOG(ERROR) introduced by this CL too.

[Shuhei Takahashi, 2017/03/03 10:11:58]

Sure, done.

+               << "File system operations are dropped.";
+    callback.Run(-1);
+    return;
+  }
+  runner->AddWatcher(authority, document_id, watcher_callback, callback);
+}
+
+void RemoveWatcherOnUIThread(int64_t watcher_id,
+                             const RemoveWatcherCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  auto* runner =
+      ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
+  if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
+    callback.Run(false);
+    return;
+  }
+  runner->RemoveWatcher(watcher_id, callback);
+}
+
+void AddObserverOnUIThread(scoped_refptr<ObserverIOThreadWrapper> observer) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  auto* runner =
+      ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
+  if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
+    return;
+  }
+  runner->AddObserver(observer.get());
+}
+
+void RemoveObserverOnUIThread(scoped_refptr<ObserverIOThreadWrapper> observer) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  auto* runner =
+      ArcServiceManager::GetGlobalService<ArcFileSystemOperationRunner>();
+  if (!runner) {
+    LOG(ERROR) << "ArcFileSystemOperationRunner unavailable. "
+               << "File system operations are dropped.";
+    return;
+  }
+  runner->RemoveObserver(observer.get());
+}
+
 }  // namespace
 
+ObserverIOThreadWrapper::ObserverIOThreadWrapper(
+    ArcFileSystemOperationRunner::Observer* underlying_observer)
+    : underlying_observer_(underlying_observer) {}
+
+ObserverIOThreadWrapper::~ObserverIOThreadWrapper() = default;
+
+void ObserverIOThreadWrapper::Disable() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  disabled_ = true;
+}
+
+void ObserverIOThreadWrapper::OnWatchersCleared() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE,
+      base::Bind(&ObserverIOThreadWrapper::OnWatchersClearedOnIOThread, this));
+}
+
+void ObserverIOThreadWrapper::OnWatchersClearedOnIOThread() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  if (disabled_)
+    return;
+  underlying_observer_->OnWatchersCleared();
+}
+
 void GetFileSizeOnIOThread(const GURL& url,
                            const GetFileSizeCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&GetFileSizeOnUIThread, url,
                  base::Bind(&PostToIOThread<int64_t>, callback)));
 }
 
 void OpenFileToReadOnIOThread(const GURL& url,
@@ skipping 21 matching lines @@
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(
           &GetChildDocumentsOnUIThread, authority, parent_document_id,
           base::Bind(
               &PostToIOThread<base::Optional<std::vector<mojom::DocumentPtr>>>,
               callback)));
 }
 
+void AddWatcherOnIOThread(const std::string& authority,
+                          const std::string& document_id,
+                          const WatcherCallback& watcher_callback,
+                          const AddWatcherCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(
+          &AddWatcherOnUIThread, authority, document_id,
+          base::Bind(&PostToIOThread<ArcFileSystemOperationRunner::ChangeType>,
+                     watcher_callback),
+          base::Bind(&PostToIOThread<int64_t>, callback)));
+}
+
+void RemoveWatcherOnIOThread(int64_t watcher_id,
+                             const RemoveWatcherCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(
+      BrowserThread::UI, FROM_HERE,
+      base::Bind(&RemoveWatcherOnUIThread, watcher_id,
+                 base::Bind(&PostToIOThread<bool>, callback)));
+}
+
+void AddObserverOnIOThread(scoped_refptr<ObserverIOThreadWrapper> observer) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,

[dcheng, 2017/03/03 09:31:14]

Btw... does ObserverListThreadSafe help with this at all? This seems pretty
complicated =)

[Shuhei Takahashi, 2017/03/03 10:11:58]

I tried ObserverListThreadSafe actually, but I still needed
RefCountedThreadSafe. I agree this is complicated. I welcome if you have any
idea to make this simpler.

+                          base::Bind(&AddObserverOnUIThread, observer));
+}
+
+void RemoveObserverOnIOThread(scoped_refptr<ObserverIOThreadWrapper> observer) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  // Disable the observer now to guarantee the underlying observer is never
+  // called after this function returns.
+  observer->Disable();
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          base::Bind(&RemoveObserverOnUIThread, observer));
+}
+
 }  // namespace file_system_operation_runner_util
 
 }  // namespace arc