[WIP] Provided file system from NACL.

chrome/browser/chromeos/file_system_provider/file_system_plugin/plugin_service.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 "chrome/browser/chromeos/file_system_provider/file_system_plugin/plugin_service.h"
+
+#include "chrome/browser/chromeos/file_system_provider/file_system_plugin/plugin_service_factory.h"
+#include "chrome/browser/chromeos/file_system_provider/mount_path_util.h"
+#include "chrome/browser/chromeos/file_system_provider/throttled_file_system.h"
+#include "storage/browser/fileapi/external_mount_points.h"
+#include "storage/common/fileapi/file_system_mount_option.h"
+
+namespace chromeos {
+namespace file_system_provider {
+namespace {
+
+// Maximum number of plugin filesystems
+const size_t kMaxFileSystems = 16;
+
+ProvidedFileSystemAdapter* CreateProvidedFileSystem(
+    Profile* profile,
+    const ProvidedFileSystemInfo& file_system_info) {
+  DCHECK(profile);
+  return new ProvidedFileSystemAdapter(
+             make_scoped_ptr(
+                new ThrottledFileSystem(make_scoped_ptr(
+                    new ProvidedFileSystem<PluginDestination>(
+                        profile, file_system_info)))));
+}
+
+} // namespace
+
+PluginService::PluginService(Profile *profile)
+    : profile_(profile),
+      weak_ptr_factory_(this) {
+}
+
+PluginService::~PluginService() {
+  // Remove any remaining plugin backend
+  ProvidedFileSystemMap::iterator it = file_system_map_.begin();
+  while (it != file_system_map_.end()) {
+    const std::string file_system_id =
+        it->second->GetProvidedFileSystem()->
+            GetFileSystemInfo().file_system_id();
+    const std::string source_id =
+        it->second->GetProvidedFileSystem()->GetFileSystemInfo().source_id();
+    ++it;
+    const base::File::Error unmount_result = UnmountFileSystem(
+        source_id, file_system_id, UNMOUNT_REASON_SHUTDOWN);
+    DCHECK_EQ(base::File::FILE_OK, unmount_result);
+  }
+
+  DCHECK_EQ(0u, file_system_map_.size());
+  STLDeleteValues(&file_system_map_);
+}
+
+
+// static
+PluginService* PluginService::Get(content::BrowserContext *context) {
+  return PluginServiceFactory::Get(context);
+}
+
+void PluginService::AddObserver(Observer *observer) {
+  DCHECK(observer);
+  observers_.AddObserver(observer);
+}
+
+void PluginService::RemoveObserver(Observer *observer) {
+  DCHECK(observer);
+  observers_.RemoveObserver(observer);
+}
+
+ProvidedFileSystemAdapter*PluginService::GetProvidedFileSystemAdapter(
+    const std::string& plugin_id, const std::string& file_system_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  const ProvidedFileSystemMap::const_iterator file_system_it =
+      file_system_map_.find(FileSystemKey(plugin_id, file_system_id));
+  if (file_system_it == file_system_map_.end())
+    return NULL;
+
+  return file_system_it->second;
+}
+
+ProvidedFileSystemInterface* PluginService::GetProvidedFileSystem(
+    const std::string& source_id,
+    const std::string& file_system_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const ProvidedFileSystemMap::const_iterator file_system_it =
+      file_system_map_.find(FileSystemKey(source_id, file_system_id));
+  if (file_system_it == file_system_map_.end())
+    return NULL;
+
+  return file_system_it->second->GetProvidedFileSystem();
+}
+
+ProvidedFileSystemInterface* PluginService::GetProvidedFileSystem(
+    const std::string& mount_point_name) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const MountPointNameToKeyMap::const_iterator mapping_it =
+      mount_point_name_to_key_map_.find(mount_point_name);
+  if (mapping_it == mount_point_name_to_key_map_.end())
+    return NULL;
+
+  const ProvidedFileSystemMap::const_iterator file_system_it =
+      file_system_map_.find(mapping_it->second);
+  if (file_system_it == file_system_map_.end())
+    return NULL;
+
+  return file_system_it->second->GetProvidedFileSystem();
+}
+
+std::vector<ProvidedFileSystemInfo>
+PluginService::GetProvidedFileSystemInfoList() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  std::vector<ProvidedFileSystemInfo> result;
+  for (ProvidedFileSystemMap::const_iterator it = file_system_map_.begin();
+       it != file_system_map_.end();
+       ++it) {
+    result.push_back(it->second->GetProvidedFileSystem()->GetFileSystemInfo());
+  }
+  return result;
+}
+
+base::File::Error PluginService::MountFileSystem(
+    const std::string &source_id, const MountOptions &options) {
+  return MountFileSystemInternal( source_id, options, MOUNT_CONTEXT_USER );
+}
+
+base::File::Error PluginService::MountFileSystemInternal(
+    const std::string& source_id,
+    const MountOptions& options, MountContext context) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // If already exists a file system provided by the same source with this
+  // id, then abort.
+  if (GetProvidedFileSystem(source_id, options.file_system_id)) {
+    FOR_EACH_OBSERVER(
+        Observer, observers_,
+        OnProvidedFileSystemMount(ProvidedFileSystemInfo(), context,
+                                  base::File::FILE_ERROR_EXISTS));
+    return base::File::FILE_ERROR_EXISTS;
+  }
+
+  // Restrict number of file systems to prevent system abusing.
+  if (file_system_map_.size() + 1 > kMaxFileSystems) {
+    FOR_EACH_OBSERVER(
+        Observer, observers_,
+        OnProvidedFileSystemMount(ProvidedFileSystemInfo(), context,
+                                  base::File::FILE_ERROR_TOO_MANY_OPENED));
+    return base::File::FILE_ERROR_TOO_MANY_OPENED;
+  }
+  storage::ExternalMountPoints* const mount_points =
+      storage::ExternalMountPoints::GetSystemInstance();
+  DCHECK(mount_points);
+
+  const base::FilePath& mount_path = util::GetPluginMountPath(
+        profile_, source_id, options.file_system_id);
+  const std::string mount_point_name = mount_path.BaseName().AsUTF8Unsafe();
+
+  if (!mount_points->RegisterFileSystem(
+          mount_point_name, storage::kFileSystemTypePluginProvided,
+          storage::FileSystemMountOption(
+              storage::FlushPolicy::FLUSH_ON_COMPLETION),
+          mount_path)) {
+    FOR_EACH_OBSERVER(
+        Observer, observers_,
+        OnProvidedFileSystemMount(ProvidedFileSystemInfo(), context,
+                                  base::File::FILE_ERROR_INVALID_OPERATION));
+    return base::File::FILE_ERROR_INVALID_OPERATION;
+  }
+
+  ProvidedFileSystemAdapter* file_system = NULL;
+  ProvidedFileSystemInfo file_system_info = ProvidedFileSystemInfo(
+        source_id,
+        options,
+        mount_path,
+        false,
+        extensions::SOURCE_NETWORK,
+        Source_Type::plugin);
+    file_system = CreateProvidedFileSystem(profile_, file_system_info);
+
+  DCHECK(file_system);
+  file_system_map_[FileSystemKey(source_id, options.file_system_id)] =
+      file_system;
+  mount_point_name_to_key_map_[mount_point_name] =
+      FileSystemKey(source_id, options.file_system_id);
+
+
+  FOR_EACH_OBSERVER(Observer, observers_,
+                    OnProvidedFileSystemMount(file_system_info, context,
+                                              base::File::FILE_OK));
+
+  return base::File::FILE_OK;
+}
+
+base::File::Error PluginService::UnmountFileSystem(
+    const std::string &source_id,
+    const std::string &file_system_id,
+    UnmountReason /*reason*/) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  const ProvidedFileSystemMap::iterator file_system_it =
+      file_system_map_.find(FileSystemKey(source_id, file_system_id));
+  if (file_system_it == file_system_map_.end()) {
+    const ProvidedFileSystemInfo empty_file_system_info;
+    FOR_EACH_OBSERVER(
+        Observer,
+        observers_,
+        OnProvidedFileSystemUnmount(empty_file_system_info,
+                                    base::File::FILE_ERROR_NOT_FOUND));
+    return base::File::FILE_ERROR_NOT_FOUND;
+  }
+
+  storage::ExternalMountPoints* const mount_points =
+      storage::ExternalMountPoints::GetSystemInstance();
+  DCHECK(mount_points);
+
+  const ProvidedFileSystemInfo& file_system_info =
+      file_system_it->second->GetProvidedFileSystem()->GetFileSystemInfo();
+
+  const std::string mount_point_name =
+      file_system_info.mount_path().BaseName().value();
+  if (!mount_points->RevokeFileSystem(mount_point_name)) {
+    FOR_EACH_OBSERVER(
+        Observer,
+        observers_,
+        OnProvidedFileSystemUnmount(file_system_info,
+                                    base::File::FILE_ERROR_INVALID_OPERATION));
+    return base::File::FILE_ERROR_INVALID_OPERATION;
+  }
+
+  FOR_EACH_OBSERVER(
+      Observer,
+      observers_,
+      OnProvidedFileSystemUnmount(file_system_info, base::File::FILE_OK));
+
+  mount_point_name_to_key_map_.erase(mount_point_name);
+
+  delete file_system_it->second;
+  file_system_map_.erase(file_system_it);
+
+  return base::File::FILE_OK;
+}
+
+} // namespace file_system_provider
+} // namespace chromeos
+