Add LocalFileChangeTracker database to record non-synced dirty files

webkit/fileapi/syncable/local_file_change_tracker.cc

 // Copyright (c) 2012 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 "webkit/fileapi/syncable/local_file_change_tracker.h"
 
+#include "base/location.h"
+#include "base/logging.h"
 #include "base/sequenced_task_runner.h"
+#include "third_party/leveldatabase/src/include/leveldb/db.h"
+#include "webkit/fileapi/file_system_util.h"
 #include "webkit/fileapi/syncable/local_file_sync_status.h"
 
+namespace {
+const FilePath::CharType kDatabaseName[] =
+    FILE_PATH_LITERAL("LocalFileChangeTracker");
+const char kMark[] = "d";
+}  // namespace
+
 namespace fileapi {
 
+// A database class that stores local file changes in a local database. This
+// object must be destructed on file_task_runner.
+class LocalFileChangeTracker::TrackerDB {
+ public:
+  explicit TrackerDB(const FilePath& profile_path);
+
+  bool MarkDirty(const std::string& url);
+  bool ClearDirty(const std::string& url);
+
+ private:
+  enum InitStatus {
+    INIT_STATUS_OK = 0,
+    INIT_STATUS_CORRUPTION,
+    INIT_STATUS_IO_ERROR,
+    INIT_STATUS_UNKNOWN_ERROR,
+    INIT_STATUS_MAX,
+  };
+
+  enum RecoveryOption {
+    REPAIR_ON_CORRUPTION,
+    FAIL_ON_CORRUPTION,
+  };
+
+  bool Init(RecoveryOption recovery_option);
+  bool Repair(const std::string& db_path);
+  void HandleError(const tracked_objects::Location& from_here,
+                   const leveldb::Status& status);
+
+  const FilePath profile_path_;
+  scoped_ptr<leveldb::DB> db_;
+  bool db_disabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(TrackerDB);
+};
+
+// LocalFileChangeTracker ------------------------------------------------------
+
 LocalFileChangeTracker::LocalFileChangeTracker(
     LocalFileSyncStatus* sync_status,
+    const FilePath& profile_path,
     base::SequencedTaskRunner* file_task_runner)
     : sync_status_(sync_status),
-      file_task_runner_(file_task_runner) {}
+      file_task_runner_(file_task_runner),
+      tracker_db_(new TrackerDB(profile_path)) {}
 
 LocalFileChangeTracker::~LocalFileChangeTracker() {
-  // file_task_runner_->PostTask(FROM_HERE, base::Bind(&DropDatabase));
-  // TODO(kinuko): implement.
+  if (tracker_db_.get())
+    file_task_runner_->DeleteSoon(FROM_HERE, tracker_db_.release());
 }
 
 void LocalFileChangeTracker::OnStartUpdate(const FileSystemURL& url) {
   DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
   // TODO(kinuko): we may want to reduce the number of this call if
   // the URL is already marked dirty.
   MarkDirtyOnDatabase(url);
 }
 
 void LocalFileChangeTracker::OnEndUpdate(const FileSystemURL& url) {
@@ skipping 65 matching lines @@
 }
 
 void LocalFileChangeTracker::CollectLastDirtyChanges(FileChangeMap* changes) {
   // TODO(kinuko): implement.
   NOTREACHED();
 }
 
 void LocalFileChangeTracker::RecordChange(
     const FileSystemURL& url, const FileChange& change) {
   DCHECK(file_task_runner_->RunsTasksOnCurrentThread());
+  // TODO(nhiroki): propagate the error code (see http://crbug.com/152127).
+  MarkDirtyOnDatabase(url);
   changes_[url].Update(change);
 }
 
 void LocalFileChangeTracker::MarkDirtyOnDatabase(const FileSystemURL& url) {
-  // TODO(kinuko): implement.
+  tracker_db_->MarkDirty(SerializeExternalFileSystemURL(url));
 }
 
 void LocalFileChangeTracker::ClearDirtyOnDatabase(const FileSystemURL& url) {
-  // TODO(kinuko): implement.
+  tracker_db_->ClearDirty(SerializeExternalFileSystemURL(url));
+}
+
+std::string LocalFileChangeTracker::SerializeExternalFileSystemURL(
+    const FileSystemURL& url) {
+  return GetFileSystemRootURI(url.origin(), kFileSystemTypeExternal).spec() +
+      url.filesystem_id() + "/" + url.path().AsUTF8Unsafe();
+}
+
+bool LocalFileChangeTracker::DeserializeExternalFileSystemURL(
+    const std::string& serialized_url, FileSystemURL* url) {
+  *url = FileSystemURL(GURL(serialized_url));
+  return url->is_valid();
+}
+
+// TrackerDB -------------------------------------------------------------------
+
+LocalFileChangeTracker::TrackerDB::TrackerDB(const FilePath& profile_path)
+  : profile_path_(profile_path),
+    db_disabled_(false) {}
+
+bool LocalFileChangeTracker::TrackerDB::Init(RecoveryOption recovery_option) {
+  if (db_.get())
+    return true;
+
+  std::string path = FilePathToString(profile_path_.Append(kDatabaseName));
+  leveldb::Options options;
+  options.create_if_missing = true;
+  leveldb::DB* db;
+  leveldb::Status status = leveldb::DB::Open(options, path, &db);
+  if (status.ok()) {
+    db_.reset(db);
+    return true;
+  }
+
+  HandleError(FROM_HERE, status);
+  if (!status.IsCorruption())
+    return false;
+
+  switch (recovery_option) {
+    case FAIL_ON_CORRUPTION:
+      return false;
+    case REPAIR_ON_CORRUPTION:
+      return Repair(path);
+  }
+  NOTREACHED();
+  return false;
+}
+
+bool LocalFileChangeTracker::TrackerDB::Repair(const std::string& db_path) {
+  DCHECK(!db_.get());
+  LOG(WARNING) << "Attempting to repair TrackerDB.";
+
+  if (leveldb::RepairDB(db_path, leveldb::Options()).ok() &&
+      Init(FAIL_ON_CORRUPTION)) {
+    // TODO(nhiroki): perform some consistency checks between TrackerDB and
+    // syncable file system.
+    LOG(WARNING) << "Repairing TrackerDB completed.";
+    return true;
+  }
+
+  LOG(WARNING) << "Failed to repair TrackerDB.";
+  return false;
+}
+
+// TODO(nhiroki): factor out the common methods into somewhere else.
+void LocalFileChangeTracker::TrackerDB::HandleError(
+    const tracked_objects::Location& from_here,
+    const leveldb::Status& status) {
+  LOG(ERROR) << "LocalFileChangeTracker::TrackerDB failed at: "
+             << from_here.ToString() << " with error: " << status.ToString();
+}
+
+bool LocalFileChangeTracker::TrackerDB::MarkDirty(const std::string& url) {
+  if (db_disabled_)
+    return false;
+
+  if (!Init(REPAIR_ON_CORRUPTION)) {
+    db_disabled_ = true;
+    db_.reset();
+    return false;
+  }
+
+  leveldb::Status status = db_->Put(leveldb::WriteOptions(), url, kMark);
+  if (!status.ok()) {
+    HandleError(FROM_HERE, status);
+    db_disabled_ = true;
+    db_.reset();
+    return false;
+  }
+  return true;
+}
+
+bool LocalFileChangeTracker::TrackerDB::ClearDirty(const std::string& url) {
+  if (db_disabled_)
+    return false;
+
+  // Should not reach here before initializing the database. The database should
+  // be cleared after read, and should be initialized during read if
+  // uninitialized.
+  DCHECK(db_.get());
+
+  leveldb::Status status = db_->Delete(leveldb::WriteOptions(), url);
+  if (!status.ok() && !status.IsNotFound()) {
+    HandleError(FROM_HERE, status);
+    db_disabled_ = true;
+    db_.reset();
+    return false;
+  }
+  return true;
 }
 
 }  // namespace fileapi