src/mem/Meter.h

   1 /*
   2  * Copyright (C) 1996-2017 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_MEM_METER_H
  10 #define SQUID_SRC_MEM_METER_H
  11
  12 #include "SquidTime.h"
  13
  14 namespace Mem
  15 {
  16
  17 /**
  18  * object to track per-action memory usage (e.g. #idle objects)
  19  */
  20 class Meter
  21 {
  22 public:
  23     Meter() : level(0), hwater_level(0), hwater_stamp(0) {}
  24
  25     /// flush the meter level back to 0, but leave peak records
  26     void flush() {level=0;}
  27
  28     ssize_t currentLevel() const {return level;}
  29     ssize_t peak() const {return hwater_level;}
  30     time_t peakTime() const {return hwater_stamp;}
  31
  32     Meter &operator ++() {++level; checkHighWater(); return *this;}
  33     Meter &operator --() {--level; return *this;}
  34
  35     Meter &operator +=(ssize_t n) { level += n; checkHighWater(); return *this;}
  36     Meter &operator -=(ssize_t n) { level -= n; return *this;}
  37
  38 private:
  39     /// check the high-water level of this meter and raise if necessary
  40     /// recording the timestamp of last high-water peak change
  41     void checkHighWater() {
  42         if (hwater_level < level) {
  43             hwater_level = level;
  44             hwater_stamp = squid_curtime ? squid_curtime : time(NULL);
  45         }
  46     }
  47
  48     ssize_t level;          ///< current level (count or volume)
  49     ssize_t hwater_level;   ///< high water mark
  50     time_t hwater_stamp;    ///< timestamp of last high water mark change
  51 };
  52
  53 } // namespace Mem
  54
  55 #endif /* SQUID_SRC_MEM_METER_H */
  56