Implement snapshotting for non-Drive non-local file systems.

This is for supporting uploading files from those file systems
(MTP, providedFS) to web pages, by a workaround before the
long term solution resolving the issue crbug/126902 comes.

BUG=383207
R=hashimoto@chromium.org

Review URL: https://codereview.chromium.org/339323002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278637 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/chromeos/extensions/file_manager/private_api_util.cc

@@ -17,6 +17,7 @@
 #include "chrome/browser/chromeos/file_manager/fileapi_util.h"
 #include "chrome/browser/chromeos/file_manager/filesystem_api_util.h"
 #include "chrome/browser/chromeos/file_manager/path_util.h"
+#include "chrome/browser/chromeos/file_manager/snapshot_manager.h"
 #include "chrome/browser/chromeos/file_manager/volume_manager.h"
 #include "chrome/browser/chromeos/fileapi/file_system_backend.h"
 #include "chrome/browser/profiles/profile.h"
@@ -72,9 +73,8 @@ void GetFileNativeLocalPathForOpening(Profile* profile,
     return;
   }
 
-  // TODO(kinaba) crbug.com/383207 implement this.
-  NOTREACHED();
-  callback.Run(base::FilePath());
+  VolumeManager::Get(profile)->snapshot_manager()->CreateManagedSnapshot(
+      path, callback);
 }
 
 // Gets a resolved local file path of a non native |path| for file saving.

chrome/browser/chromeos/file_manager/snapshot_manager.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/chromeos/file_manager/snapshot_manager.h"
+
+#include "base/bind.h"
+#include "chrome/browser/chromeos/file_manager/app_id.h"
+#include "chrome/browser/chromeos/file_manager/fileapi_util.h"
+#include "content/public/browser/browser_thread.h"
+#include "google_apis/drive/task_util.h"
+#include "webkit/browser/fileapi/file_system_context.h"
+#include "webkit/common/blob/shareable_file_reference.h"
+
+namespace file_manager {
+namespace {
+
+// Part of CreateManagedSnapshot. Runs CreateSnapshotFile method of fileapi.
+void CreateSnapshotFileOnIOThread(
+    scoped_refptr<fileapi::FileSystemContext> context,
+    const fileapi::FileSystemURL& url,
+    const fileapi::FileSystemOperation::SnapshotFileCallback& callback) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+  context->operation_runner()->CreateSnapshotFile(url, callback);
+}
+
+// Utility for destructing the bound |file_refs| on IO thread. This is meant
+// to be used together with base::Bind. After this function finishes, the
+// Bind callback should destruct the bound argument.
+void FreeReferenceOnIOThread(const std::vector<
+    scoped_refptr<webkit_blob::ShareableFileReference> >& file_refs) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
+}
+
+}  // namespace
+
+SnapshotManager::SnapshotManager(Profile* profile)
+    : profile_(profile), weak_ptr_factory_(this) {
+}
+
+SnapshotManager::~SnapshotManager() {
+  if (!file_refs_.empty()) {
+    bool posted = content::BrowserThread::PostTask(
+        content::BrowserThread::IO,
+        FROM_HERE,
+        base::Bind(&FreeReferenceOnIOThread, file_refs_));
+    DCHECK(posted);
+  }
+}
+
+void SnapshotManager::CreateManagedSnapshot(
+    const base::FilePath& absolute_file_path,
+    const LocalPathCallback& callback) {
+  fileapi::FileSystemContext* context =
+      util::GetFileSystemContextForExtensionId(profile_, kFileManagerAppId);
+  DCHECK(context);
+
+  GURL url;
+  if (!util::ConvertAbsoluteFilePathToFileSystemUrl(
+          profile_, absolute_file_path, kFileManagerAppId, &url)) {
+    callback.Run(base::FilePath());
+    return;
+  }
+
+  // TODO(kinaba): crbug.com/386519 evict old |file_refs_| before creating a new
+  // one if necessary.
+  content::BrowserThread::PostTask(
+      content::BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&CreateSnapshotFileOnIOThread,
+                 make_scoped_refptr(context),
+                 context->CrackURL(url),
+                 google_apis::CreateRelayCallback(
+                     base::Bind(&SnapshotManager::OnCreateSnapshotFile,
+                                weak_ptr_factory_.GetWeakPtr(),
+                                callback))));
+}
+
+void SnapshotManager::OnCreateSnapshotFile(
+    const LocalPathCallback& callback,
+    base::File::Error result,
+    const base::File::Info& file_info,
+    const base::FilePath& platform_path,
+    const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref) {
+  DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+
+  if (result != base::File::FILE_OK) {
+    callback.Run(base::FilePath());
+    return;
+  }
+
+  file_refs_.push_back(file_ref);
+  callback.Run(platform_path);
+}
+
+}  // namespace file_manager

chrome/browser/chromeos/file_manager/snapshot_manager.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_FILE_MANAGER_SNAPSHOT_MANAGER_H_
+#define CHROME_BROWSER_CHROMEOS_FILE_MANAGER_SNAPSHOT_MANAGER_H_
+
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "base/files/file.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+
+class Profile;
+
+namespace base {
+class FilePath;
+}  // namespace base
+
+namespace webkit_blob {
+class ShareableFileReference;
+}  // namespace webkit_blob
+
+namespace file_manager {
+
+// Utility class for creating a snapshot of a file system file on local disk.
+// The class wraps the underlying implementation of fileapi's CreateSnapshotFile
+// and prolongs the lifetime of snapshot files so that the client code that just
+// accepts file paths works without problems.
+class SnapshotManager {
+ public:
+  // The callback type for CreateManagedSnapshot.
+  typedef base::Callback<void(const base::FilePath&)> LocalPathCallback;
+
+  explicit SnapshotManager(Profile* profile);
+  ~SnapshotManager();
+
+  // Creates a snapshot file copy of a file system file |absolute_file_path| and
+  // returns back to |callback|. Returns empty path for failure.
+  void CreateManagedSnapshot(const base::FilePath& absolute_file_path,
+                             const LocalPathCallback& callback);
+
+ private:
+  // Part of CreateManagedSnapshot.
+  void OnCreateSnapshotFile(
+      const LocalPathCallback& callback,
+      base::File::Error result,
+      const base::File::Info& file_info,
+      const base::FilePath& platform_path,
+      const scoped_refptr<webkit_blob::ShareableFileReference>& file_ref);
+
+  Profile* profile_;
+  std::vector<scoped_refptr<webkit_blob::ShareableFileReference> > file_refs_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate the weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<SnapshotManager> weak_ptr_factory_;
+  DISALLOW_COPY_AND_ASSIGN(SnapshotManager);
+};
+
+}  // namespace file_manager
+
+#endif  // CHROME_BROWSER_CHROMEOS_FILE_MANAGER_SNAPSHOT_MANAGER_H_

chrome/browser/chromeos/file_manager/volume_manager.cc

@@ -18,6 +18,7 @@
 #include "chrome/browser/chromeos/drive/file_system_util.h"
 #include "chrome/browser/chromeos/file_manager/mounted_disk_monitor.h"
 #include "chrome/browser/chromeos/file_manager/path_util.h"
+#include "chrome/browser/chromeos/file_manager/snapshot_manager.h"
 #include "chrome/browser/chromeos/file_manager/volume_manager_factory.h"
 #include "chrome/browser/chromeos/file_manager/volume_manager_observer.h"
 #include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
@@ -256,6 +257,7 @@ VolumeManager::VolumeManager(
       mounted_disk_monitor_(
           new MountedDiskMonitor(power_manager_client, disk_mount_manager)),
       file_system_provider_service_(file_system_provider_service),
+      snapshot_manager_(new SnapshotManager(profile_)),
       weak_ptr_factory_(this) {
   DCHECK(disk_mount_manager);
 }
@@ -403,6 +405,7 @@ void VolumeManager::Initialize() {
 void VolumeManager::Shutdown() {
   weak_ptr_factory_.InvalidateWeakPtrs();
 
+  snapshot_manager_.reset();
   pref_change_registrar_.RemoveAll();
   disk_mount_manager_->RemoveObserver(this);
   if (storage_monitor::StorageMonitor::GetInstance())

chrome/browser/chromeos/file_manager/volume_manager.h

@@ -38,6 +38,7 @@ class BrowserContext;
 namespace file_manager {
 
 class MountedDiskMonitor;
+class SnapshotManager;
 class VolumeManagerObserver;
 
 // Identifiers for volume types managed by Chrome OS file manager.
@@ -202,6 +203,8 @@ class VolumeManager : public KeyedService,
   virtual void OnRemovableStorageDetached(
       const storage_monitor::StorageInfo& info) OVERRIDE;
 
+  SnapshotManager* snapshot_manager() { return snapshot_manager_.get(); }
+
  private:
   void OnStorageMonitorInitialized();
   void OnPrivetVolumesAvailable(
@@ -222,6 +225,7 @@ class VolumeManager : public KeyedService,
   chromeos::file_system_provider::Service*
       file_system_provider_service_;  // Not owned by this class.
   std::map<std::string, VolumeInfo> mounted_volumes_;
+  scoped_ptr<SnapshotManager> snapshot_manager_;
 
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.

chrome/chrome_browser_chromeos.gypi

@@ -368,6 +368,8 @@
         'browser/chromeos/file_manager/path_util.h',
         'browser/chromeos/file_manager/select_file_dialog_util.cc',
         'browser/chromeos/file_manager/select_file_dialog_util.h',
+        'browser/chromeos/file_manager/snapshot_manager.cc',
+        'browser/chromeos/file_manager/snapshot_manager.h',
         'browser/chromeos/file_manager/url_util.cc',
         'browser/chromeos/file_manager/url_util.h',
         'browser/chromeos/file_manager/volume_manager.cc',