[ew] Add basic classes.

chrome/browser/extensions/api/file_system/entry_watcher_service.cc

+// Copyright 2014 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/extensions/api/file_system/entry_watcher_service.h"
+
+#include "base/thread_task_runner_handle.h"
+#include "chrome/browser/extensions/extension_util.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/extensions/api/file_system.h"
+#include "components/keyed_service/content/browser_context_dependency_manager.h"
+#include "content/public/browser/browser_context.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/storage_partition.h"
+#include "extensions/browser/event_router.h"
+#include "webkit/browser/fileapi/file_system_context.h"
+
+namespace extensions {
+namespace {
+
+// Default implementation for dispatching an event. Can be replaced for unit
+// tests by EntryWatcherService::SetDispatchEventImplForTesting().
+void DispatchEventImpl(EventRouter* event_router,
+                       const std::string& extension_id,
+                       scoped_ptr<Event> event) {
+  event_router->DispatchEventToExtension(extension_id, event.Pass());
+}
+
+// Default implementation for acquiring a file system context for a specific
+// |extension_id| and |context|.
+storage::FileSystemContext* GetFileSystemContextImpl(
+    const std::string& extension_id,
+    content::BrowserContext* context) {
+  const GURL site = util::GetSiteForExtensionId(extension_id, context);
+  return content::BrowserContext::GetStoragePartitionForSite(context, site)
+      ->GetFileSystemContext();
+}
+
+}  // namespace
+
+EntryWatcherService::EntryWatcherService(content::BrowserContext* context)
+    : context_(context),
+      dispatch_event_impl_(
+          base::Bind(&DispatchEventImpl, EventRouter::Get(context))),
+      get_file_system_context_impl_(base::Bind(&GetFileSystemContextImpl)),
+      observing_(this),
+      weak_ptr_factory_(this) {
+  // TODO(mtomasz): Restore persistent watchers.
+}
+
+EntryWatcherService::~EntryWatcherService() {
+}
+
+void EntryWatcherService::SetDispatchEventImplForTesting(
+    const DispatchEventImplCallback& callback) {
+  dispatch_event_impl_ = callback;
+}
+
+void EntryWatcherService::SetGetFileSystemContextImplForTesting(
+    const GetFileSystemContextImplCallback& callback) {
+  get_file_system_context_impl_ = callback;
+}
+
+void EntryWatcherService::WatchDirectory(
+    const std::string& extension_id,
+    const storage::FileSystemURL& url,
+    bool recursive,
+    const storage::WatcherManager::StatusCallback& callback) {
+  // TODO(mtomasz): Add support for recursive watchers.
+  if (recursive) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(callback, base::File::FILE_ERROR_INVALID_OPERATION));
+    return;
+  }
+
+  storage::FileSystemContext* const context =
+      get_file_system_context_impl_.Run(extension_id, context_);
+  DCHECK(context);
+
+  storage::WatcherManager* const watcher_manager =
+      context->GetWatcherManager(url.type());
+  if (!watcher_manager) {
+    // Post a task instead of calling the callback directly, since the caller
+    // may expect the callback to be called asynchronously.
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(callback, base::File::FILE_ERROR_INVALID_OPERATION));
+    return;
+  }
+
+  // Passing a pointer to WatcherManager is safe, since the pointer is required
+  // to be valid until shutdown.
+  context->default_file_task_runner()->PostNonNestableTask(
+      FROM_HERE,
+      base::Bind(&storage::WatcherManager::WatchDirectory,
+                 base::Unretained(watcher_manager),  // Outlives the service.
+                 url,
+                 recursive,
+                 base::Bind(&EntryWatcherService::OnWatchDirectoryCompleted,
+                            weak_ptr_factory_.GetWeakPtr(),
+                            watcher_manager,  // Outlives the service.
+                            extension_id,
+                            url,
+                            recursive,
+                            callback)));
+}
+
+void EntryWatcherService::UnwatchEntry(
+    const std::string& extension_id,
+    const storage::FileSystemURL& url,
+    const storage::WatcherManager::StatusCallback& callback) {
+  storage::FileSystemContext* const context =
+      get_file_system_context_impl_.Run(extension_id, context_);
+  DCHECK(context);
+
+  storage::WatcherManager* const watcher_manager =
+      context->GetWatcherManager(url.type());
+  if (!watcher_manager) {
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
+        FROM_HERE,
+        base::Bind(callback, base::File::FILE_ERROR_INVALID_OPERATION));
+    return;
+  }
+
+  // Passing a pointer to WatcherManager is safe, since the pointer is required
+  // to be valid until shutdown.
+  context->default_file_task_runner()->PostNonNestableTask(
+      FROM_HERE,
+      base::Bind(&storage::WatcherManager::UnwatchEntry,
+                 base::Unretained(watcher_manager),  // Outlives the service.
+                 url,
+                 base::Bind(&EntryWatcherService::OnUnwatchEntryCompleted,
+                            weak_ptr_factory_.GetWeakPtr(),
+                            extension_id,
+                            url,
+                            callback)));
+}
+
+std::vector<storage::FileSystemURL> EntryWatcherService::GetWatchedEntries(
+    const std::string& extension_id) {
+  std::vector<storage::FileSystemURL> result;
+  for (WatcherMap::const_iterator it = watchers_.begin(); it != watchers_.end();
+       ++it) {
+    const std::map<std::string, EntryWatcher>::const_iterator watcher_it =
+        it->second.find(extension_id);
+    if (watcher_it != it->second.end())
+      result.push_back(watcher_it->second.url);
+  }
+
+  return result;
+}
+
+void EntryWatcherService::OnEntryChanged(const storage::FileSystemURL& url) {
+  const WatcherMap::const_iterator it = watchers_.find(url);
+  DCHECK(it != watchers_.end());
+  for (std::map<std::string, EntryWatcher>::const_iterator watcher_it =
+           it->second.begin();
+       watcher_it != it->second.end();
+       ++watcher_it) {
+    const std::string& extension_id = watcher_it->first;
+    api::file_system::EntryChangedEvent event;
+    dispatch_event_impl_.Run(
+        extension_id,
+        make_scoped_ptr(
+            new Event(api::file_system::OnEntryChanged::kEventName,
+                      api::file_system::OnEntryChanged::Create(event))));
+  }
+}
+
+void EntryWatcherService::OnEntryRemoved(const storage::FileSystemURL& url) {
+  WatcherMap::const_iterator it = watchers_.find(url);
+  DCHECK(it != watchers_.end());
+  for (std::map<std::string, EntryWatcher>::const_iterator watcher_it =
+           it->second.begin();
+       watcher_it != it->second.end();
+       ++watcher_it) {
+    const std::string& extension_id = watcher_it->first;
+    api::file_system::EntryRemovedEvent event;
+    dispatch_event_impl_.Run(
+        extension_id,
+        make_scoped_ptr(
+            new Event(api::file_system::OnEntryRemoved::kEventName,
+                      api::file_system::OnEntryRemoved::Create(event))));
+  }
+}
+
+void EntryWatcherService::OnWatchDirectoryCompleted(
+    storage::WatcherManager* watcher_manager,
+    const std::string& extension_id,
+    const storage::FileSystemURL& url,
+    bool recursive,
+    const storage::WatcherManager::StatusCallback& callback,
+    base::File::Error result) {
+  if (result != base::File::FILE_OK) {
+    callback.Run(result);
+    return;
+  }
+
+  storage::FileSystemContext* const context =
+      get_file_system_context_impl_.Run(extension_id, context_);
+  DCHECK(context);
+
+  // Observe the manager if not observed yet.
+  if (!observing_.IsObserving(watcher_manager))
+    observing_.Add(watcher_manager);
+
+  watchers_[url][extension_id] =
+      EntryWatcher(url, true /* directory */, recursive);
+
+  // TODO(mtomasz): Save in preferences.
+
+  callback.Run(base::File::FILE_OK);
+}
+
+void EntryWatcherService::OnUnwatchEntryCompleted(
+    const std::string& extension_id,
+    const storage::FileSystemURL& url,
+    const storage::WatcherManager::StatusCallback& callback,
+    base::File::Error result) {
+  if (result != base::File::FILE_OK) {
+    callback.Run(result);
+    return;
+  }
+
+  if (watchers_[url].erase(extension_id) == 0) {
+    callback.Run(base::File::FILE_ERROR_NOT_FOUND);
+    return;
+  }
+
+  if (watchers_[url].empty())
+    watchers_.erase(url);
+
+  // TODO(mtomasz): Save in preferences.
+
+  callback.Run(base::File::FILE_OK);
+}
+
+EntryWatcherService::EntryWatcher::EntryWatcher()
+    : directory(false), recursive(false) {
+}
+
+EntryWatcherService::EntryWatcher::EntryWatcher(
+    const storage::FileSystemURL& url,
+    bool directory,
+    bool recursive)
+    : url(url), directory(directory), recursive(recursive) {
+}
+
+EntryWatcherService::EntryWatcher::~EntryWatcher() {
+}
+
+}  // namespace extensions