cache_rs/metrics/
lru.rs

1//! LRU Cache Metrics
2//!
3//! Metrics specific to the LRU (Least Recently Used) cache algorithm.
4
5extern crate alloc;
6
7use super::{CacheMetrics, CoreCacheMetrics};
8use alloc::collections::BTreeMap;
9use alloc::string::String;
10
11/// LRU-specific metrics (extends CoreCacheMetrics)
12///
13/// This struct contains metrics specific to the LRU (Least Recently Used) cache algorithm.
14/// Currently, LRU uses only the core metrics, but this structure allows for future
15/// LRU-specific metrics to be added.
16#[derive(Debug, Clone)]
17pub struct LruCacheMetrics {
18    /// Core metrics common to all cache algorithms
19    pub core: CoreCacheMetrics,
20    // LRU doesn't have algorithm-specific metrics beyond core metrics
21    // But we keep this structure for consistency with other cache algorithms
22    //
23    // Future LRU-specific metrics could include:
24    // - pub recency_distribution: BTreeMap<String, u64>,  // Age distribution of cached items
25    // - pub access_pattern_stats: AccessPatternStats,     // Sequential vs random access patterns
26}
27
28impl LruCacheMetrics {
29    /// Creates a new LruCacheMetrics instance with the specified maximum cache size
30    ///
31    /// # Arguments
32    /// * `max_cache_size_bytes` - The maximum allowed cache size in bytes
33    pub fn new(max_cache_size_bytes: u64) -> Self {
34        Self {
35            core: CoreCacheMetrics::new(max_cache_size_bytes),
36        }
37    }
38
39    /// Converts LRU metrics to a BTreeMap for reporting
40    ///
41    /// This method returns all metrics relevant to the LRU cache algorithm.
42    /// Currently, this includes only core metrics, but LRU-specific metrics
43    /// could be added here in the future.
44    ///
45    /// Uses BTreeMap to ensure consistent, deterministic ordering of metrics.
46    ///
47    /// # Returns
48    /// A BTreeMap containing all LRU cache metrics as key-value pairs
49    pub fn to_btreemap(&self) -> BTreeMap<String, f64> {
50        // LRU-specific metrics would go here
51        // For now, LRU only uses core metrics
52        //
53        // Example future additions:
54        // metrics.insert("avg_item_age".to_string(), self.calculate_avg_age());
55        // metrics.insert("recency_variance".to_string(), self.calculate_recency_variance());
56
57        self.core.to_btreemap()
58    }
59}
60
61impl CacheMetrics for LruCacheMetrics {
62    /// Returns all LRU cache metrics as key-value pairs in deterministic order
63    ///
64    /// # Returns
65    /// A BTreeMap containing all metrics tracked by this LRU cache instance
66    fn metrics(&self) -> BTreeMap<String, f64> {
67        self.to_btreemap()
68    }
69
70    /// Returns the algorithm name for this cache implementation
71    ///
72    /// # Returns
73    /// "LRU" - identifying this as a Least Recently Used cache
74    fn algorithm_name(&self) -> &'static str {
75        "LRU"
76    }
77}
cache_rs/metrics/lru.rs

cache_rs/metrics/
lru.rs
