github.com/maypok86/otter@v1.2.1/internal/stats/stats.go (about)

     1  // Copyright (c) 2023 Alexey Mayshev. All rights reserved.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package stats
    16  
    17  import (
    18  	"sync/atomic"
    19  	"unsafe"
    20  
    21  	"github.com/maypok86/otter/internal/xruntime"
    22  )
    23  
    24  // Stats is a thread-safe statistics collector.
    25  type Stats struct {
    26  	hits                   *counter
    27  	misses                 *counter
    28  	rejectedSets           *counter
    29  	evictedCountersPadding [xruntime.CacheLineSize - 2*unsafe.Sizeof(atomic.Int64{})]byte
    30  	evictedCount           atomic.Int64
    31  	evictedCost            atomic.Int64
    32  }
    33  
    34  // New creates a new Stats collector.
    35  func New() *Stats {
    36  	return &Stats{
    37  		hits:         newCounter(),
    38  		misses:       newCounter(),
    39  		rejectedSets: newCounter(),
    40  	}
    41  }
    42  
    43  // IncHits increments the hits counter.
    44  func (s *Stats) IncHits() {
    45  	if s == nil {
    46  		return
    47  	}
    48  
    49  	s.hits.increment()
    50  }
    51  
    52  // Hits returns the number of cache hits.
    53  func (s *Stats) Hits() int64 {
    54  	if s == nil {
    55  		return 0
    56  	}
    57  
    58  	return s.hits.value()
    59  }
    60  
    61  // IncMisses increments the misses counter.
    62  func (s *Stats) IncMisses() {
    63  	if s == nil {
    64  		return
    65  	}
    66  
    67  	s.misses.increment()
    68  }
    69  
    70  // Misses returns the number of cache misses.
    71  func (s *Stats) Misses() int64 {
    72  	if s == nil {
    73  		return 0
    74  	}
    75  
    76  	return s.misses.value()
    77  }
    78  
    79  // IncRejectedSets increments the rejectedSets counter.
    80  func (s *Stats) IncRejectedSets() {
    81  	if s == nil {
    82  		return
    83  	}
    84  
    85  	s.rejectedSets.increment()
    86  }
    87  
    88  // RejectedSets returns the number of rejected sets.
    89  func (s *Stats) RejectedSets() int64 {
    90  	if s == nil {
    91  		return 0
    92  	}
    93  
    94  	return s.rejectedSets.value()
    95  }
    96  
    97  // IncEvictedCount increments the evictedCount counter.
    98  func (s *Stats) IncEvictedCount() {
    99  	if s == nil {
   100  		return
   101  	}
   102  
   103  	s.evictedCount.Add(1)
   104  }
   105  
   106  // EvictedCount returns the number of evicted entries.
   107  func (s *Stats) EvictedCount() int64 {
   108  	if s == nil {
   109  		return 0
   110  	}
   111  
   112  	return s.evictedCount.Load()
   113  }
   114  
   115  // AddEvictedCost adds cost to the evictedCost counter.
   116  func (s *Stats) AddEvictedCost(cost uint32) {
   117  	if s == nil {
   118  		return
   119  	}
   120  
   121  	s.evictedCost.Add(int64(cost))
   122  }
   123  
   124  // EvictedCost returns the sum of costs of evicted entries.
   125  func (s *Stats) EvictedCost() int64 {
   126  	if s == nil {
   127  		return 0
   128  	}
   129  
   130  	return s.evictedCost.Load()
   131  }
   132  
   133  func (s *Stats) Clear() {
   134  	if s == nil {
   135  		return
   136  	}
   137  
   138  	s.hits.reset()
   139  	s.misses.reset()
   140  	s.rejectedSets.reset()
   141  	s.evictedCount.Store(0)
   142  	s.evictedCost.Store(0)
   143  }