dist_lock_strategy.hpp

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#pragma once
 
/// @file userver/dist_lock/dist_lock_strategy.hpp
/// @brief @copybrief dist_lock::DistLockStrategyBase
 
#include <chrono>
#include <exception>
#include <string>
 
USERVER_NAMESPACE_BEGIN
 
namespace dist_lock {
 
/// Indicates that lock cannot be acquired because it's busy.
class LockIsAcquiredByAnotherHostException : public std::exception {};
 
/// @ingroup userver_base_classes userver_concurrency
///
/// @brief Interface for distributed lock strategies
///
/// ## Example
///
/// @snippet core/src/dist_lock/dist_lock_test.cpp Sample distlock strategy
class DistLockStrategyBase {
 public:
  virtual ~DistLockStrategyBase() = default;
 
  /// Acquires the distributed lock.
  ///
  /// @param lock_ttl The duration for which the lock must be held.
  /// @param locker_id Globally unique ID of the locking entity.
  /// @throws LockIsAcquiredByAnotherHostError when the lock is busy
  /// @throws anything else when the locking fails, strategy is responsible for
  /// cleanup, Release won't be invoked.
  virtual void Acquire(std::chrono::milliseconds lock_ttl,
                       const std::string& locker_id) = 0;
 
  /// Releases the lock.
  ///
  /// @param locker_id Globally unique ID of the locking entity, must be the
  /// same as in Acquire().
  /// @note Exceptions are ignored.
  virtual void Release(const std::string& locker_id) = 0;
};
 
}  // namespace dist_lock
 
USERVER_NAMESPACE_END