content/browser/indexed_db/indexed_db_leveldb_operations.h

// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_LEVELDB_OPERATIONS_H_
#define CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_LEVELDB_OPERATIONS_H_

#include <memory>
#include <string>
#include <string_view>

#include "base/files/file_path.h"
#include "base/time/time.h"
#include "components/services/storage/indexed_db/transactional_leveldb/leveldb_write_batch.h"
#include "content/browser/indexed_db/indexed_db_data_loss_info.h"
#include "content/browser/indexed_db/indexed_db_leveldb_coding.h"
#include "content/browser/indexed_db/status.h"
#include "content/common/content_export.h"
#include "third_party/blink/public/common/indexeddb/indexeddb_key_path.h"
#include "third_party/leveldatabase/src/include/leveldb/comparator.h"

// Contains common operations for LevelDBTransactions and/or LevelDBDatabases.

namespace storage {
struct BucketLocator;
}  // namespace storage

namespace content::indexed_db {

class TransactionalLevelDBDatabase;
class TransactionalLevelDBIterator;
class TransactionalLevelDBTransaction;
class LevelDBDirectTransaction;

base::FilePath ComputeCorruptionFileName(
    const storage::BucketLocator& bucket_locator);

// If a corruption file for the given `storage_key` at the given |path_base|
// exists it is deleted, and the message is returned. If the file does not
// exist, or if there is an error parsing the message, then this method returns
// an empty string (and deletes the file).
std::string CONTENT_EXPORT
ReadCorruptionInfo(const base::FilePath& path_base,
                   const storage::BucketLocator& bucket_locator);

// Was able to use LevelDB to read the data w/o error, but the data read was not
// in the expected format.
Status CONTENT_EXPORT InternalInconsistencyStatus();

Status InvalidDBKeyStatus();

Status IOErrorStatus();

template <typename Transaction>
Status PutValue(Transaction* transaction,
                std::string_view key,
                std::string* value) {
  return Status(transaction->Put(key, value));
}

// This function must be declared as 'inline' to avoid duplicate symbols.
template <>
inline Status PutValue(LevelDBWriteBatch* write_batch,
                       std::string_view key,
                       std::string* value) {
  write_batch->Put(key, std::string_view(*value));
  return Status::OK();
}

// Note - this uses DecodeInt, which is a 'dumb' varint decoder. See DecodeInt.
template <typename DBOrTransaction>
Status GetInt(DBOrTransaction* db,
              std::string_view key,
              int64_t* found_int,
              bool* found) {
  std::string result;
  Status s(db->Get(key, &result, found));
  if (!s.ok())
    return s;
  if (!*found)
    return Status::OK();
  std::string_view slice(result);
  if (DecodeInt(&slice, found_int) && slice.empty())
    return s;
  return InternalInconsistencyStatus();
}

[[nodiscard]] Status PutBool(TransactionalLevelDBTransaction* transaction,
                             std::string_view key,
                             bool value);

// Note - this uses EncodeInt, which is a 'dumb' varint encoder. See EncodeInt.
template <typename TransactionOrWriteBatch>
[[nodiscard]] Status PutInt(TransactionOrWriteBatch* transaction_or_write_batch,
                            std::string_view key,
                            int64_t value) {
  DCHECK_GE(value, 0);
  std::string buffer;
  EncodeInt(value, &buffer);
  return PutValue(transaction_or_write_batch, key, &buffer);
}

template <typename DBOrTransaction>
[[nodiscard]] Status GetVarInt(DBOrTransaction* db,
                               std::string_view key,
                               int64_t* found_int,
                               bool* found);

template <typename TransactionOrWriteBatch>
[[nodiscard]] Status PutVarInt(TransactionOrWriteBatch* transaction,
                               std::string_view key,
                               int64_t value);

template <typename DBOrTransaction>
[[nodiscard]] Status GetString(DBOrTransaction* db,
                               std::string_view key,
                               std::u16string* found_string,
                               bool* found);

[[nodiscard]] Status PutString(TransactionalLevelDBTransaction* transaction,
                               std::string_view key,
                               const std::u16string& value);

[[nodiscard]] Status PutIDBKeyPath(TransactionalLevelDBTransaction* transaction,
                                   std::string_view key,
                                   const blink::IndexedDBKeyPath& value);

template <typename DBOrTransaction>
[[nodiscard]] Status GetMaxObjectStoreId(DBOrTransaction* db,
                                         int64_t database_id,
                                         int64_t* max_object_store_id);

[[nodiscard]] Status SetMaxObjectStoreId(
    TransactionalLevelDBTransaction* transaction,
    int64_t database_id,
    int64_t object_store_id);

[[nodiscard]] Status GetNewVersionNumber(
    TransactionalLevelDBTransaction* transaction,
    int64_t database_id,
    int64_t object_store_id,
    int64_t* new_version_number);

[[nodiscard]] Status SetMaxIndexId(TransactionalLevelDBTransaction* transaction,
                                   int64_t database_id,
                                   int64_t object_store_id,
                                   int64_t index_id);

[[nodiscard]] Status VersionExists(TransactionalLevelDBTransaction* transaction,
                                   int64_t database_id,
                                   int64_t object_store_id,
                                   int64_t version,
                                   const std::string& encoded_primary_key,
                                   bool* exists);

template <typename Transaction>
[[nodiscard]] Status GetNewDatabaseId(Transaction* transaction,
                                      int64_t* new_id);

[[nodiscard]] bool CheckObjectStoreAndMetaDataType(
    const TransactionalLevelDBIterator* it,
    const std::string& stop_key,
    int64_t object_store_id,
    int64_t meta_data_type);

[[nodiscard]] bool CheckIndexAndMetaDataKey(
    const TransactionalLevelDBIterator* it,
    const std::string& stop_key,
    int64_t index_id,
    unsigned char meta_data_type);

[[nodiscard]] bool FindGreatestKeyLessThanOrEqual(
    TransactionalLevelDBTransaction* transaction,
    const std::string& target,
    std::string* found_key,
    Status* s);

[[nodiscard]] bool GetBlobNumberGeneratorCurrentNumber(
    LevelDBDirectTransaction* leveldb_transaction,
    int64_t database_id,
    int64_t* blob_number_generator_current_number);

[[nodiscard]] bool UpdateBlobNumberGeneratorCurrentNumber(
    LevelDBDirectTransaction* leveldb_transaction,
    int64_t database_id,
    int64_t blob_number_generator_current_number);

// Maximum time delays for tombstone sweeping and compaction tasks, throttled on
// global and per-bucket frequencies, triggered by backing store close.
static constexpr base::TimeDelta kMaxGlobalSweepDelay = base::Hours(1);
static constexpr base::TimeDelta kMaxBucketSweepDelay = base::Days(3);
static constexpr base::TimeDelta kMaxGlobalCompactionDelay = base::Hours(1);
static constexpr base::TimeDelta kMaxBucketCompactionDelay = base::Days(3);

// Get or update the earliest tombstone sweeping and compaction times, using
// global and per-bucket delays.
base::Time GetEarliestSweepTime(TransactionalLevelDBDatabase* db);
Status UpdateEarliestSweepTime(LevelDBDirectTransaction* txn);
base::Time GetEarliestCompactionTime(TransactionalLevelDBDatabase* db);
Status UpdateEarliestCompactionTime(LevelDBDirectTransaction* txn);

// Initialize global times for compaction and tombstone sweeping.
void InitializeGlobalSweepAndCompactionTimes();

// Forcibly reset global times for compaction and tombstone sweeping for tests.
CONTENT_EXPORT void ResetGlobalSweepAndCompactionTimesForTest();

CONTENT_EXPORT const leveldb::Comparator* GetDefaultLevelDBComparator();

}  // namespace content::indexed_db

#endif  // CONTENT_BROWSER_INDEXED_DB_INDEXED_DB_LEVELDB_OPERATIONS_H_