src/mem/Meter.h

   1 /*
   2  * Copyright (C) 1996-2023 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 "time/gadgets.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     /// flush the meter level back to 0, but leave peak records
  24     void flush() {level=0;}
  25
  26     ssize_t currentLevel() const {return level;}
  27     ssize_t peak() const {return hwater_level;}
  28     time_t peakTime() const {return hwater_stamp;}
  29
  30     Meter &operator ++() {++level; checkHighWater(); return *this;}
  31     Meter &operator --() {--level; return *this;}
  32
  33     Meter &operator +=(ssize_t n) { level += n; checkHighWater(); return *this;}
  34     Meter &operator -=(ssize_t n) { level -= n; return *this;}
  35
  36 private:
  37     /// check the high-water level of this meter and raise if necessary
  38     /// recording the timestamp of last high-water peak change
  39     void checkHighWater() {
  40         if (hwater_level < level) {
  41             hwater_level = level;
  42             hwater_stamp = squid_curtime ? squid_curtime : time(nullptr);
  43         }
  44     }
  45
  46     ssize_t level = 0; ///< current level (count or volume)
  47     ssize_t hwater_level = 0; ///< high water mark
  48     time_t hwater_stamp = 0; ///< timestamp of last high water mark change
  49 };
  50
  51 /**
  52  * Object to track per-pool memory usage (alloc = inuse+idle)
  53  */
  54 class PoolMeter
  55 {
  56 public:
  57     /// Object to track per-pool cumulative counters
  58     struct mgb_t {
  59         double count = 0.0;
  60         double bytes = 0.0;
  61     };
  62
  63     /// flush counters back to 0, but leave historic peak records
  64     void flush() {
  65         alloc.flush();
  66         inuse.flush();
  67         idle.flush();
  68         gb_allocated = mgb_t();
  69         gb_oallocated = mgb_t();
  70         gb_saved = mgb_t();
  71         gb_freed = mgb_t();
  72     }
  73
  74     Meter alloc;
  75     Meter inuse;
  76     Meter idle;
  77
  78     /** history Allocations */
  79     mgb_t gb_allocated;
  80     mgb_t gb_oallocated;
  81
  82     /** account Saved Allocations */
  83     mgb_t gb_saved;
  84
  85     /** account Free calls */
  86     mgb_t gb_freed;
  87 };
  88
  89 } // namespace Mem
  90
  91 #endif /* SQUID_SRC_MEM_METER_H */
  92