#include "absl/synchronization/mutex.h"
#include "tensorflow/c/env.h"
#include "tensorflow/c/tf_status.h"

namespace tf_gcs_filesystem {

/// \brief An LRU cache of string keys and arbitrary values, with configurable
/// max item age (in seconds) and max entries.
///
/// This class is thread safe.
template <typename T>
class ExpiringLRUCache {
 public:

  /// allocation API.
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` if `options` and `num_options` set.
  ///     If there is no configurable option, `num_options` should be 0.
  ///   * Might use any other error value for `status` to signal other errors.
  ///
  /// DEFAULT IMPLEMENTATION: return 0 options and `TF_OK`.