SyncFS: Introduce SyncFileSystemBackend

webkit/browser/fileapi/syncable/sync_file_system_backend.cc

+// Copyright 2013 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 "webkit/browser/fileapi/syncable/sync_file_system_backend.h"
+
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+#include "webkit/browser/fileapi/async_file_util_adapter.h"
+#include "webkit/browser/fileapi/file_system_context.h"
+#include "webkit/browser/fileapi/obfuscated_file_util.h"
+#include "webkit/browser/fileapi/sandbox_quota_observer.h"
+#include "webkit/browser/fileapi/syncable/syncable_file_system_operation.h"
+#include "webkit/browser/fileapi/syncable/syncable_file_system_util.h"
+#include "webkit/common/fileapi/file_system_util.h"
+
+namespace sync_file_system {
+
+namespace {
+const char kSyncableOriginsCountLabel[] = "FileSystem.SyncableOriginsCount";
+}  // namespace
+
+SyncFileSystemBackend::SyncFileSystemBackend(
+    base::SequencedTaskRunner* file_task_runner,
+    const fileapi::FileSystemOptions& file_system_options)
+    : SandboxFileSystemBackend(NULL, file_task_runner, file_system_options) {
+}
+
+SyncFileSystemBackend::~SyncFileSystemBackend() {
+  file_task_runner_->DeleteSoon(FROM_HERE, change_tracker_.release());
+}
+
+bool SyncFileSystemBackend::CanHandleType(
+    fileapi::FileSystemType type) const {
+  return type == fileapi::kFileSystemTypeSyncable ||
+         type == fileapi::kFileSystemTypeSyncableForInternalSync;
+}
+
+void SyncFileSystemBackend::InitializeFileSystem(
+    const GURL& origin_url,
+    fileapi::FileSystemType type,
+    fileapi::OpenFileSystemMode mode,
+    fileapi::FileSystemContext* context,
+    const InitializeFileSystemCallback& callback) {
+  if (!sandbox_context_)
+    LazyInitialize(context->sandbox_context());
+  SandboxFileSystemBackend::InitializeFileSystem(
+      origin_url, type, mode, context, callback);
+}
+
+fileapi::FileSystemFileUtil* SyncFileSystemBackend::GetFileUtil(
+    fileapi::FileSystemType type,
+    const fileapi::FileSystemContext* context) {
+  if (!sandbox_context_)
+    LazyInitialize(context->sandbox_context());
+  return sandbox_context_->sync_file_util();
+}
+
+fileapi::AsyncFileUtil* SyncFileSystemBackend::GetAsyncFileUtil(
+    fileapi::FileSystemType type,
+    const fileapi::FileSystemContext* context) {
+  if (!sandbox_context_)
+    LazyInitialize(context->sandbox_context());
+  return sandbox_context_->file_util();
+}
+
+fileapi::FileSystemOperation*
+SyncFileSystemBackend::CreateFileSystemOperation(
+    const fileapi::FileSystemURL& url,
+    fileapi::FileSystemContext* context,
+    base::PlatformFileError* error_code) const {
+  if (!IsAccessValid(url)) {
+    *error_code = base::PLATFORM_FILE_ERROR_SECURITY;
+    return NULL;
+  }
+
+  if (url.type() == fileapi::kFileSystemTypeSyncableForInternalSync) {
+    return SandboxFileSystemBackend::CreateFileSystemOperation(
+        url, context, error_code);
+  }
+
+  scoped_ptr<fileapi::FileSystemOperationContext> operation_context(
+      new fileapi::FileSystemOperationContext(context));
+  operation_context->set_update_observers(syncable_update_observers_);
+  operation_context->set_change_observers(syncable_change_observers_);
+
+  return new SyncableFileSystemOperation(
+      url, context, operation_context.Pass());
+}
+
+void SyncFileSystemBackend::GetOriginsForTypeOnFileThread(
+    fileapi::FileSystemType type,
+    std::set<GURL>* origins) {
+  DCHECK(CanHandleType(type));
+  DCHECK(origins);
+  scoped_ptr<OriginEnumerator> enumerator(CreateOriginEnumerator());
+  GURL origin;
+  while (!(origin = enumerator->Next()).is_empty()) {
+    if (enumerator->HasFileSystemType(type))
+      origins->insert(origin);
+  }
+  switch (type) {
+    case fileapi::kFileSystemTypeSyncable:
+      UMA_HISTOGRAM_COUNTS(kSyncableOriginsCountLabel, origins->size());
+      break;
+    default:
+      break;
+  }
+}
+
+void SyncFileSystemBackend::AddFileUpdateObserver(
+    fileapi::FileSystemType type,
+    fileapi::FileUpdateObserver* observer,
+    base::SequencedTaskRunner* task_runner) {
+  DCHECK(CanHandleType(type));
+  if (type == fileapi::kFileSystemTypeSyncableForInternalSync) {
+    SandboxFileSystemBackend::AddFileUpdateObserver(
+        type, observer, task_runner);
+    return;
+  }
+  fileapi::UpdateObserverList* list = &syncable_update_observers_;
+  *list = list->AddObserver(observer, task_runner);
+}
+
+void SyncFileSystemBackend::AddFileChangeObserver(
+    fileapi::FileSystemType type,
+    fileapi::FileChangeObserver* observer,
+    base::SequencedTaskRunner* task_runner) {
+  DCHECK(CanHandleType(type));
+  if (type == fileapi::kFileSystemTypeSyncableForInternalSync) {
+    SandboxFileSystemBackend::AddFileChangeObserver(
+        type, observer, task_runner);
+    return;
+  }
+  fileapi::ChangeObserverList* list = &syncable_change_observers_;
+  *list = list->AddObserver(observer, task_runner);
+}
+
+const fileapi::UpdateObserverList* SyncFileSystemBackend::GetUpdateObservers(
+    fileapi::FileSystemType type) const {
+  DCHECK(CanHandleType(type));
+  if (type == fileapi::kFileSystemTypeSyncableForInternalSync)
+    return &update_observers_;
+  return &syncable_update_observers_;
+}
+
+const fileapi::ChangeObserverList* SyncFileSystemBackend::GetChangeObservers(
+    fileapi::FileSystemType type) const {
+  DCHECK(CanHandleType(type));
+  if (type == fileapi::kFileSystemTypeSyncableForInternalSync)
+    return &change_observers_;
+  return &syncable_change_observers_;
+}
+
+// static
+SyncFileSystemBackend* SyncFileSystemBackend::GetBackend(
+    const fileapi::FileSystemContext* file_system_context) {
+  return static_cast<SyncFileSystemBackend*>(
+      file_system_context->GetFileSystemBackend(
+          fileapi::kFileSystemTypeSyncable));
+}
+
+void SyncFileSystemBackend::set_change_tracker(

[kinuko, 2013/07/22 05:51:19]

When a setter is not inline and do more than just assigning a value, I think we
usually use regular method naming style (i.e. SetChangeTracker).

[nhiroki, 2013/07/22 06:33:38]

Removed this setter for now.

+    scoped_ptr<LocalFileChangeTracker> tracker) {
+  DCHECK(!change_tracker_.get());
+  DCHECK(tracker.get());
+  change_tracker_ = tracker.Pass();
+  AddFileUpdateObserver(fileapi::kFileSystemTypeSyncable,
+                        change_tracker_.get(),
+                        file_task_runner_);
+  AddFileChangeObserver(fileapi::kFileSystemTypeSyncable,
+                        change_tracker_.get(),
+                        file_task_runner_);
+}
+
+void SyncFileSystemBackend::set_sync_context(
+    sync_file_system::LocalFileSyncContext* sync_context) {
+  sync_context_ = sync_context;
+}
+
+void SyncFileSystemBackend::LazyInitialize(
+    fileapi::SandboxContext* sandbox_context) {
+  DCHECK(!sandbox_context_);
+  sandbox_context_ = sandbox_context;
+  // Set quota observers.
+  if (enable_usage_tracking_) {
+    update_observers_ = update_observers_.AddObserver(
+        sandbox_context_->quota_observer(), file_task_runner_);
+    access_observers_ = access_observers_.AddObserver(
+        sandbox_context_->quota_observer(), NULL);
+    syncable_update_observers_ = syncable_update_observers_.AddObserver(
+        sandbox_context_->quota_observer(), file_task_runner_);
+  }
+}
+
+}  // namespace sync_file_system