Media Galleries API Picasa: Put INI indexing step into sandboxed utility process.

chrome/browser/media_galleries/fileapi/safe_picasa_albums_indexer.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 "chrome/browser/media_galleries/fileapi/safe_picasa_albums_indexer.h"
+
+#include "base/file_util.h"
+#include "chrome/browser/media_galleries/fileapi/media_file_system_backend.h"
+#include "chrome/common/chrome_utility_messages.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/child_process_data.h"
+#include "content/public/browser/utility_process_host.h"
+
+using chrome::MediaFileSystemBackend;
+using content::BrowserThread;
+using content::UtilityProcessHost;
+
+namespace picasa {
+
+namespace {
+
+// Picasa INI files are named "picasa.ini" on Picasa for Windows before version
+// 71.18. Later versions and Picasa for Mac uses ".picasa.ini".
+// See: https://support.google.com/picasa/answer/11257?hl=en
+const char kPicasaINIFilename[]       = ".picasa.ini";
+const char kPicasaINIFilenameLegacy[] = "picasa.ini";
+
+// Arbitrarily chosen to be a decent size but not block thread too much.
+const int kPicasaINIReadBatchSize = 10;
+
+}  // namespace
+
+SafePicasaAlbumsIndexer::SafePicasaAlbumsIndexer(
+    const AlbumMap& albums,
+    const AlbumMap& folders,
+    const DoneCallback& callback)
+    : callback_(callback),
+      parser_state_(INITIAL_STATE),
+      weak_factory_(this) {
+  DCHECK(MediaFileSystemBackend::CurrentlyOnMediaTaskRunnerThread());
+  DCHECK(!callback_.is_null());
+
+  folders_inis_.reserve(folders.size());
+
+  for (AlbumMap::const_iterator it = albums.begin(); it != albums.end(); ++it)
+    album_uids_.insert(it->second.uid);
+
+  for (AlbumMap::const_iterator it = folders.begin(); it != folders.end(); ++it)
+    folders_queue_.push(it->second.path);
+}
+
+void SafePicasaAlbumsIndexer::Start() {
+  DCHECK(MediaFileSystemBackend::CurrentlyOnMediaTaskRunnerThread());
+  DCHECK_EQ(INITIAL_STATE, parser_state_);
+
+  parser_state_ = STARTED_READING_INI_FILES_STATE;
+
+  ProcessFoldersBatch();
+}
+
+SafePicasaAlbumsIndexer::~SafePicasaAlbumsIndexer() {
+}
+
+void SafePicasaAlbumsIndexer::ProcessFoldersBatch() {
+  DCHECK(MediaFileSystemBackend::CurrentlyOnMediaTaskRunnerThread());
+  DCHECK_EQ(STARTED_READING_INI_FILES_STATE, parser_state_);
+
+  for (int i = 0; i < kPicasaINIReadBatchSize && !folders_queue_.empty(); ++i) {
+    base::FilePath folder_path = folders_queue_.front();
+    folders_queue_.pop();
+
+    folders_inis_.push_back(FolderINIContents());
+
+    bool ini_read =
+        file_util::ReadFileToString(
+            folder_path.AppendASCII(kPicasaINIFilename),
+            &folders_inis_.back().ini_contents) ||
+        file_util::ReadFileToString(
+            folder_path.AppendASCII(kPicasaINIFilenameLegacy),
+            &folders_inis_.back().ini_contents);
+
+    // See kPicasaINIFilename declaration for details.
+    if (ini_read)
+      folders_inis_.back().folder_path = folder_path;
+    else
+      folders_inis_.pop_back();
+  }
+
+  // If queue of folders to process not empty, post self onto task runner again.
+  if (!folders_queue_.empty()) {
+    MediaFileSystemBackend::MediaTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(&SafePicasaAlbumsIndexer::ProcessFoldersBatch,
+                   weak_factory_.GetWeakPtr()));
+  } else {
+    parser_state_ = FINISHED_READING_INI_FILES_STATE;
+    BrowserThread::PostTask(
+        BrowserThread::IO,
+        FROM_HERE,
+        base::Bind(&SafePicasaAlbumsIndexer::StartWorkOnIOThread, this));
+  }
+}
+
+void SafePicasaAlbumsIndexer::StartWorkOnIOThread() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  DCHECK_EQ(FINISHED_READING_INI_FILES_STATE, parser_state_);

[vandebo (ex-Chrome), 2013/07/24 18:15:54]

nit: shouldn't access parser_state_ from multiple threads.

[tommycli, 2013/07/25 17:02:51]

Done. Removed parser_state_ access on MediaTaskRunner. Probably not worth using
a lock.

[Lei Zhang, 2013/07/25 23:14:58]

Sounds good. The communication with the utility process is the only bit that's
out of our control. So the state check is more important there.

+
+  UtilityProcessHost* host =
+      UtilityProcessHost::Create(this, base::MessageLoopProxy::current());
+  host->EnableZygote();
+  host->Send(new ChromeUtilityMsg_IndexPicasaAlbumsContents(album_uids_,
+                                                            folders_inis_));
+  parser_state_ = STARTED_PARSING_STATE;
+}
+
+void SafePicasaAlbumsIndexer::OnIndexPicasaAlbumsContentsFinished(
+    const AlbumImagesMap& albums_images) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (parser_state_ != STARTED_PARSING_STATE)
+    return;
+
+  MediaFileSystemBackend::MediaTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(callback_, true, albums_images));
+  parser_state_ = FINISHED_PARSING_STATE;
+}
+
+void SafePicasaAlbumsIndexer::OnProcessCrashed(int exit_code) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  MediaFileSystemBackend::MediaTaskRunner()->PostTask(
+      FROM_HERE,
+      base::Bind(callback_, false, AlbumImagesMap()));
+}
+
+bool SafePicasaAlbumsIndexer::OnMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(SafePicasaAlbumsIndexer, message)
+    IPC_MESSAGE_HANDLER(
+        ChromeUtilityHostMsg_IndexPicasaAlbumsContents_Finished,
+        OnIndexPicasaAlbumsContentsFinished)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+}  // namespace picasa