Extract protobuf database into a new 'leveldb_proto' component

components/leveldb_proto/leveldb_database.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 "components/leveldb_proto/leveldb_database.h"
+
+#include <string>
+#include <vector>
+
+#include "base/file_util.h"
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "third_party/leveldatabase/src/include/leveldb/db.h"
+#include "third_party/leveldatabase/src/include/leveldb/iterator.h"
+#include "third_party/leveldatabase/src/include/leveldb/options.h"
+#include "third_party/leveldatabase/src/include/leveldb/slice.h"
+#include "third_party/leveldatabase/src/include/leveldb/status.h"
+#include "third_party/leveldatabase/src/include/leveldb/write_batch.h"
+
+namespace leveldb_proto {
+
+LevelDB::LevelDB() {}
+
+LevelDB::~LevelDB() { DFAKE_SCOPED_LOCK(thread_checker_); }
+
+bool LevelDB::Init(const base::FilePath& database_dir) {
+  DFAKE_SCOPED_LOCK(thread_checker_);
+
+  leveldb::Options options;
+  options.create_if_missing = true;
+  options.max_open_files = 0;  // Use minimum.
+
+  std::string path = database_dir.AsUTF8Unsafe();
+
+  leveldb::DB* db = NULL;
+  leveldb::Status status = leveldb::DB::Open(options, path, &db);
+  if (status.IsCorruption()) {
+    base::DeleteFile(database_dir, true);
+    status = leveldb::DB::Open(options, path, &db);
+  }
+
+  if (status.ok()) {
+    CHECK(db);
+    db_.reset(db);
+    return true;
+  }
+
+  LOG(WARNING) << "Unable to open " << database_dir.value() << ": "
+               << status.ToString();
+  return false;
+}
+
+bool LevelDB::Save(
+    const std::vector<std::pair<std::string, std::string> >& entries_to_save,
+    const std::vector<std::string>& keys_to_remove) {
+  DFAKE_SCOPED_LOCK(thread_checker_);
+
+  leveldb::WriteBatch updates;
+  for (std::vector<std::pair<std::string, std::string> >::const_iterator it =
+           entries_to_save.begin();
+       it != entries_to_save.end(); ++it) {
+    updates.Put(leveldb::Slice(it->first), leveldb::Slice(it->second));
+  }
+  for (std::vector<std::string>::const_iterator it = keys_to_remove.begin();
+       it != keys_to_remove.end(); ++it) {
+    updates.Delete(leveldb::Slice(*it));
+  }
+
+  leveldb::WriteOptions options;
+  options.sync = true;
+  leveldb::Status status = db_->Write(options, &updates);
+  if (status.ok()) return true;
+
+  DLOG(WARNING) << "Failed writing leveldb_proto entries: "
+                << status.ToString();
+  return false;
+}
+
+bool LevelDB::Load(std::vector<std::string>* entries) {
+  DFAKE_SCOPED_LOCK(thread_checker_);
+
+  leveldb::ReadOptions options;
+  scoped_ptr<leveldb::Iterator> db_iterator(db_->NewIterator(options));
+  for (db_iterator->SeekToFirst(); db_iterator->Valid(); db_iterator->Next()) {
+    leveldb::Slice value_slice = db_iterator->value();
+    std::string entry(value_slice.data(), value_slice.size());
+    entries->push_back(entry);
+  }
+  return true;
+}
+
+}  // namespace leveldb_proto