SingleBackendTransactionManager(RemoteExecutor& executor,

const char* backend_name)

: executor_(executor), backend_(backend_name) {}

bool begin() override {

auto r = executor_.execute_dml(backend_.c_str(),

sql_parser::StringRef{"BEGIN", 5});

if (r.success) in_txn_ = true;

return r.success;

}

bool commit() override {

auto r = executor_.execute_dml(backend_.c_str(),

sql_parser::StringRef{"COMMIT", 6});

if (r.success) in_txn_ = false;

return r.success;

}

bool rollback() override {

auto r = executor_.execute_dml(backend_.c_str(),

sql_parser::StringRef{"ROLLBACK", 8});

if (r.success) in_txn_ = false;

return r.success;

}

bool savepoint(const char* name) override {

if (!in_txn_) return false;

std::string sql = "SAVEPOINT " + std::string(name);

auto r = executor_.execute_dml(backend_.c_str(),

sql_parser::StringRef{sql.c_str(),

static_cast<uint32_t>(sql.size())});

return r.success;

}

bool rollback_to(const char* name) override {

if (!in_txn_) return false;

std::string sql = "ROLLBACK TO SAVEPOINT " + std::string(name);

auto r = executor_.execute_dml(backend_.c_str(),

sql_parser::StringRef{sql.c_str(),

static_cast<uint32_t>(sql.size())});

return r.success;

}

bool release_savepoint(const char* name) override {

if (!in_txn_) return false;

std::string sql = "RELEASE SAVEPOINT " + std::string(name);

auto r = executor_.execute_dml(backend_.c_str(),

sql_parser::StringRef{sql.c_str(),

static_cast<uint32_t>(sql.size())});

return r.success;

}

bool in_transaction() const override { return in_txn_; }

bool is_auto_commit() const override { return auto_commit_; }

void set_auto_commit(bool ac) override { auto_commit_ = ac; }

const std::string& backend_name() const { return backend_; }

RemoteExecutor& executor_;

std::string backend_;

bool in_txn_ = false;

bool auto_commit_ = true;