Statistics for cache performance monitoring. More...

#include <simple_lru_cache.h>

Collaboration diagram for kcenon::pacs::services::cache::cache_stats:

Public Member Functions
double	hit_rate () const noexcept
	Calculate the cache hit rate.

std::uint64_t	total_accesses () const noexcept
	Get total number of cache accesses (hits + misses)

void	reset () noexcept
	Reset all statistics to zero.

Public Attributes
std::atomic< std::uint64_t >	hits {0}
	Number of cache hits.

std::atomic< std::uint64_t >	misses {0}
	Number of cache misses.

std::atomic< std::uint64_t >	insertions {0}
	Number of insertions.

std::atomic< std::uint64_t >	evictions {0}
	Number of LRU evictions.

std::atomic< std::uint64_t >	expirations {0}
	Number of TTL expirations.

std::atomic< std::size_t >	current_size {0}
	Current number of entries.

Detailed Description

Statistics for cache performance monitoring.

All counters are atomic to allow lock-free reading of statistics while the cache is being modified.

Definition at line 78 of file simple_lru_cache.h.

Member Function Documentation

◆ hit_rate()

double kcenon::pacs::services::cache::cache_stats::hit_rate ( ) const

inlinenodiscardnoexcept

Calculate the cache hit rate.

Returns: Hit rate as a percentage (0.0 to 100.0), or 0.0 if no accesses

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/simple_lru_cache.h.

Definition at line 90 of file simple_lru_cache.h.

                                                   {
        const auto total_hits = hits.load(std::memory_order_relaxed);
        const auto total_misses = misses.load(std::memory_order_relaxed);
        const auto total = total_hits + total_misses;
        if (total == 0) {
            return 0.0;
        }
        return (static_cast<double>(total_hits) / static_cast<double>(total)) * 100.0;
    }

References hits, and misses.

Referenced by kcenon::pacs::services::cache::query_cache::hit_rate(), and kcenon::pacs::services::cache::simple_lru_cache< Key, Value, Hash, KeyEqual >::hit_rate().

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◆ reset()

void kcenon::pacs::services::cache::cache_stats::reset ( )

inlinenoexcept

Reset all statistics to zero.

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/simple_lru_cache.h.

Definition at line 112 of file simple_lru_cache.h.

                          {
        hits.store(0, std::memory_order_relaxed);
        misses.store(0, std::memory_order_relaxed);
        insertions.store(0, std::memory_order_relaxed);
        evictions.store(0, std::memory_order_relaxed);
        expirations.store(0, std::memory_order_relaxed);
        // Note: current_size is not reset as it reflects actual cache state
    }

References evictions, expirations, hits, insertions, and misses.

Referenced by kcenon::pacs::services::cache::simple_lru_cache< Key, Value, Hash, KeyEqual >::reset_stats().

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◆ total_accesses()

std::uint64_t kcenon::pacs::services::cache::cache_stats::total_accesses ( ) const

inlinenodiscardnoexcept

Get total number of cache accesses (hits + misses)

Returns: Total access count

Examples: /home/runner/work/pacs_system/pacs_system/include/kcenon/pacs/services/cache/simple_lru_cache.h.

Definition at line 104 of file simple_lru_cache.h.

                                                              {
        return hits.load(std::memory_order_relaxed) +
               misses.load(std::memory_order_relaxed);
    }

References hits, and misses.