kaspa_txscript/
caches.rs

1use indexmap::IndexMap;
2use parking_lot::RwLock;
3use rand::Rng;
4use std::{
5    collections::hash_map::RandomState,
6    hash::BuildHasher,
7    sync::{
8        atomic::{AtomicU64, Ordering},
9        Arc,
10    },
11};
12
13#[derive(Clone)]
14pub struct Cache<TKey: Clone + std::hash::Hash + Eq + Send + Sync, TData: Clone + Send + Sync, S = RandomState> {
15    // We use IndexMap and not HashMap, because it makes it cheaper to remove a random element when the cache is full.
16    map: Arc<RwLock<IndexMap<TKey, TData, S>>>,
17    size: usize,
18    counters: Arc<TxScriptCacheCounters>,
19}
20
21impl<TKey: Clone + std::hash::Hash + Eq + Send + Sync, TData: Clone + Send + Sync, S: BuildHasher + Default> Cache<TKey, TData, S> {
22    pub fn new(size: u64) -> Self {
23        Self::with_counters(size, Default::default())
24    }
25
26    pub fn with_counters(size: u64, counters: Arc<TxScriptCacheCounters>) -> Self {
27        Self {
28            map: Arc::new(RwLock::new(IndexMap::with_capacity_and_hasher(size as usize, S::default()))),
29            size: size as usize,
30            counters,
31        }
32    }
33
34    pub(crate) fn get(&self, key: &TKey) -> Option<TData> {
35        self.map.read().get(key).cloned().inspect(|_data| {
36            self.counters.get_counts.fetch_add(1, Ordering::Relaxed);
37        })
38    }
39
40    pub(crate) fn insert(&self, key: TKey, data: TData) {
41        if self.size == 0 {
42            return;
43        }
44        let mut write_guard = self.map.write();
45        if write_guard.len() == self.size {
46            write_guard.swap_remove_index(rand::thread_rng().gen_range(0..self.size));
47        }
48        write_guard.insert(key, data);
49        self.counters.insert_counts.fetch_add(1, Ordering::Relaxed);
50    }
51}
52
53#[derive(Default)]
54pub struct TxScriptCacheCounters {
55    pub insert_counts: AtomicU64,
56    pub get_counts: AtomicU64,
57}
58
59impl TxScriptCacheCounters {
60    pub fn snapshot(&self) -> TxScriptCacheCountersSnapshot {
61        TxScriptCacheCountersSnapshot {
62            insert_counts: self.insert_counts.load(Ordering::Relaxed),
63            get_counts: self.get_counts.load(Ordering::Relaxed),
64        }
65    }
66}
67
68#[derive(Debug, PartialEq, Eq)]
69pub struct TxScriptCacheCountersSnapshot {
70    pub insert_counts: u64,
71    pub get_counts: u64,
72}
73
74impl TxScriptCacheCountersSnapshot {
75    pub fn hit_ratio(&self) -> f64 {
76        if self.insert_counts > 0 {
77            self.get_counts as f64 / self.insert_counts as f64
78        } else {
79            0f64
80        }
81    }
82}
83
84impl core::ops::Sub for &TxScriptCacheCountersSnapshot {
85    type Output = TxScriptCacheCountersSnapshot;
86
87    fn sub(self, rhs: Self) -> Self::Output {
88        Self::Output {
89            insert_counts: self.insert_counts.saturating_sub(rhs.insert_counts),
90            get_counts: self.get_counts.saturating_sub(rhs.get_counts),
91        }
92    }
93}
kaspa_txscript/caches.rs

kaspa_txscript/
caches.rs
