src/helper/ReservationId.h

   1 /*
   2  * Copyright (C) 1996-2020 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 #ifndef _SQUID_SRC_HELPER_RESERVATIONID_H
  10 #define _SQUID_SRC_HELPER_RESERVATIONID_H
  11
  12 #include <ostream>
  13
  14 namespace Helper
  15 {
  16 /// a (temporary) lock on a (stateful) helper channel
  17 class ReservationId
  18 {
  19 public:
  20     static ReservationId Next();
  21
  22     bool reserved() const { return id > 0; }
  23
  24     explicit operator bool() const { return reserved(); }
  25     bool operator !() const { return !reserved(); }
  26     bool operator ==(const Helper::ReservationId &other) const { return id == other.id; }
  27     bool operator !=(const Helper::ReservationId &other) const { return !(*this == other); }
  28
  29     void clear() { id = 0; }
  30     uint64_t value() const {return id;}
  31
  32     /// dumps the reservation info for debugging
  33     std::ostream &print(std::ostream &os) const;
  34
  35 private:
  36     uint64_t id = 0; ///< uniquely identifies this reservation
  37 };
  38
  39 }; // namespace Helper
  40
  41 inline std::ostream &
  42 operator <<(std::ostream &os, const Helper::ReservationId &id)
  43 {
  44     return id.print(os);
  45 }
  46
  47 namespace std {
  48 /// default hash functor to support std::unordered_map<HelperReservationId, *>
  49 template <>
  50 struct hash<Helper::ReservationId>
  51 {
  52     typedef Helper::ReservationId argument_type;
  53     typedef std::size_t result_type;
  54     result_type operator()(const argument_type &reservation) const noexcept
  55     {
  56         std::hash<uint64_t> aHash;
  57         return aHash(reservation.value());
  58     }
  59 };
  60 }
  61
  62 #endif
  63