Media Galleries API Picasa: Make PicasaDataProvider handle async PMP and INI parsing robustly.

chrome/browser/media_galleries/fileapi/safe_picasa_album_table_reader.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_album_table_reader.h"
 
+#include "base/logging.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"
 
 using chrome::MediaFileSystemBackend;
 using content::BrowserThread;
 
 namespace picasa {
 
 SafePicasaAlbumTableReader::SafePicasaAlbumTableReader(
     const AlbumTableFiles& album_table_files,
     const ParserCallback& callback)
     : album_table_files_(album_table_files),
       callback_(callback),
       parser_state_(INITIAL_STATE) {
   // TODO(tommycli): Add DCHECK to make sure |album_table_files| are all
   // opened read-only once security adds ability to check PlatformFiles.
   DCHECK(MediaFileSystemBackend::CurrentlyOnMediaTaskRunnerThread());
   DCHECK(!callback_.is_null());
 }
 
 void SafePicasaAlbumTableReader::Start() {
   DCHECK(MediaFileSystemBackend::CurrentlyOnMediaTaskRunnerThread());
+
+  // Don't bother spawning process if any of the files are invalid.
+  if (album_table_files_.indicator_file == base::kInvalidPlatformFileValue ||
+      album_table_files_.category_file == base::kInvalidPlatformFileValue ||
+      album_table_files_.date_file == base::kInvalidPlatformFileValue ||
+      album_table_files_.filename_file == base::kInvalidPlatformFileValue ||
+      album_table_files_.name_file == base::kInvalidPlatformFileValue ||
+      album_table_files_.token_file == base::kInvalidPlatformFileValue ||
+      album_table_files_.uid_file == base::kInvalidPlatformFileValue) {
+    MediaFileSystemBackend::MediaTaskRunner()->PostTask(
+        FROM_HERE,
+        base::Bind(callback_,
+                   make_scoped_refptr(this),
+                   false /* parse_success */,
+                   std::vector<AlbumInfo>(),
+                   std::vector<AlbumInfo>()));
+    return;
+  }
+
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&SafePicasaAlbumTableReader::StartWorkOnIOThread, this));
 }
 
 SafePicasaAlbumTableReader::~SafePicasaAlbumTableReader() {
 }
 
 void SafePicasaAlbumTableReader::StartWorkOnIOThread() {
@@ skipping 55 matching lines @@
 void SafePicasaAlbumTableReader::OnParsePicasaPMPDatabaseFinished(
     bool parse_success,
     const std::vector<AlbumInfo>& albums,
     const std::vector<AlbumInfo>& folders) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (parser_state_ != STARTED_PARSING_STATE)
     return;
 
   MediaFileSystemBackend::MediaTaskRunner()->PostTask(
       FROM_HERE,
-      base::Bind(callback_, parse_success, albums, folders));
+      base::Bind(
+          callback_, make_scoped_refptr(this), parse_success, albums, folders));
   parser_state_ = FINISHED_PARSING_STATE;
 }
 
 void SafePicasaAlbumTableReader::OnProcessCrashed(int exit_code) {
-  OnParsePicasaPMPDatabaseFinished(false, std::vector<AlbumInfo>(),
-                                   std::vector<AlbumInfo>());
+  DLOG(INFO) << "SafePicasaAlbumTableReader::OnProcessCrashed()";
+  OnParsePicasaPMPDatabaseFinished(
+      false, std::vector<AlbumInfo>(), std::vector<AlbumInfo>());
 }
 
 bool SafePicasaAlbumTableReader::OnMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(SafePicasaAlbumTableReader, message)
     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ProcessStarted,
                         OnProcessStarted)
     IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParsePicasaPMPDatabase_Finished,
                         OnParsePicasaPMPDatabaseFinished)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 }  // namespace picasa