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#pragma once
#include "clickhouse_config.h"
#if USE_CASSANDRA
#error #include <cassandra.h>
#include <utility>
#include <memory>
namespace DB
{
namespace Cassandra
{
template<typename CassT>
CassT * defaultCtor() { return nullptr; }
/// RAII wrapper for raw pointers to objects from cassandra driver library
template<typename CassT, auto Dtor, auto Ctor = defaultCtor<CassT>>
class ObjectHolder
{
CassT * ptr = nullptr;
public:
template<typename... Args>
ObjectHolder(Args &&... args) : ptr(Ctor(std::forward<Args>(args)...)) {} /// NOLINT
ObjectHolder(CassT * ptr_) : ptr(ptr_) {} /// NOLINT
ObjectHolder(const ObjectHolder &) = delete;
ObjectHolder & operator = (const ObjectHolder &) = delete;
ObjectHolder(ObjectHolder && rhs) noexcept : ptr(rhs.ptr) { rhs.ptr = nullptr; }
ObjectHolder & operator = (ObjectHolder && rhs) noexcept
{
if (ptr)
Dtor(ptr);
ptr = rhs.ptr;
rhs.ptr = nullptr;
return *this;
}
~ObjectHolder()
{
if (ptr)
Dtor(ptr);
}
/// For implicit conversion when passing object to driver library functions
operator CassT * () { return ptr; } /// NOLINT
operator const CassT * () const { return ptr; } /// NOLINT
};
}
/// These object are created on pointer construction
using CassClusterPtr = Cassandra::ObjectHolder<CassCluster, cass_cluster_free, cass_cluster_new>;
using CassStatementPtr = Cassandra::ObjectHolder<CassStatement, cass_statement_free, cass_statement_new>;
using CassSessionPtr = Cassandra::ObjectHolder<CassSession, cass_session_free, cass_session_new>;
/// Share connections between streams. Executing statements in one session object is thread-safe
using CassSessionShared = std::shared_ptr<CassSessionPtr>;
using CassSessionWeak = std::weak_ptr<CassSessionPtr>;
/// The following objects are created inside Cassandra driver library,
/// but must be freed by user code
using CassFuturePtr = Cassandra::ObjectHolder<CassFuture, cass_future_free>;
using CassResultPtr = Cassandra::ObjectHolder<const CassResult, cass_result_free>;
using CassIteratorPtr = Cassandra::ObjectHolder<CassIterator, cass_iterator_free>;
/// Checks return code, throws exception on error
void cassandraCheck(CassError code);
void cassandraWaitAndCheck(CassFuturePtr & future);
/// By default driver library prints logs to stderr.
/// It should be redirected (or, at least, disabled) before calling other functions from the library.
void setupCassandraDriverLibraryLogging(CassLogLevel level);
void cassandraLogCallback(const CassLogMessage * message, void * data);
}
#endif
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