README

Dual Window Cache

Dual window cache adaptively coordinates the ratio of LRU to LFU using the two sliding windows.

Maintenance

This repository is maintained on the following source repository.

Performance comparison

Hit rate

Higher x1.0-2.7 hit rate of LRU.

'Cache even 100'
'LRU hit rate', 10.19
'DWC hit rate', 10.18
'DWC ratio', 16, 16
'DWC / LRU hit rate ratio', '99%'

'Cache uneven 100'
'LRU hit rate', 19.13
'DWC hit rate', 37.85
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '197%'

'Cache uneven 100 transitive distribution'
'LRU hit rate', 18.5
'DWC hit rate', 37.4
'DWC ratio', 95, 94
'DWC / LRU hit rate ratio', '202%'

'Cache uneven 100 transitive bias'
'LRU hit rate', 11.12
'DWC hit rate', 11.12
'DWC ratio', 0, 0
'DWC / LRU hit rate ratio', '100%'

'Cache uneven 100 sequential'
'LRU hit rate', 14.26
'DWC hit rate', 38.19
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '267%'

'Cache uneven 100 adversarial'
'LRU hit rate', 41.96
'DWC hit rate', 49.54
'DWC ratio', 91, 90
'DWC / LRU hit rate ratio', '118%'

https://github.com/falsandtru/spica/runs/5132749713

Benchmark

±10% speed of lru-cache.

'LRUCache simulation 100 x 4,408,911 ops/sec ±0.50% (67 runs sampled)'

'DW-Cache simulation 100 x 4,068,709 ops/sec ±0.35% (65 runs sampled)'

'LRUCache simulation 1,000 x 4,011,794 ops/sec ±0.35% (66 runs sampled)'

'DW-Cache simulation 1,000 x 4,099,809 ops/sec ±0.35% (68 runs sampled)'

'LRUCache simulation 10,000 x 2,619,249 ops/sec ±2.96% (62 runs sampled)'

'DW-Cache simulation 10,000 x 2,834,672 ops/sec ±3.40% (61 runs sampled)'

'LRUCache simulation 100,000 x 1,392,207 ops/sec ±3.19% (58 runs sampled)'

'DW-Cache simulation 100,000 x 1,366,786 ops/sec ±6.48% (54 runs sampled)'

'LRUCache simulation 1,000,000 x 830,577 ops/sec ±7.29% (55 runs sampled)'

'DW-Cache simulation 1,000,000 x 788,118 ops/sec ±6.14% (58 runs sampled)'

https://github.com/falsandtru/spica/runs/5132776032

API

export class Cache<K, V = undefined> {
  constructor(capacity: number, opts?: Cache.Options<K, V>);
  constructor(opts: Cache.Options<K, V>);
  put(key: K, value: V, size?: number, age?: number): boolean;
  put(this: Cache<K, undefined>, key: K, value?: V, size?: number, age?: number): boolean;
  set(key: K, value: V, size?: number, age?: number): this;
  set(this: Cache<K, undefined>, key: K, value?: V, size?: number, age?: number): this;
  get(key: K): V | undefined;
  has(key: K): boolean;
  delete(key: K): boolean;
  clear(): void;
  readonly length: number;
  readonly size: number;
  [Symbol.iterator](): Iterator<[K, V], undefined, undefined>;
}
namespace Cache {
  export interface Options<K, V = undefined> {
    readonly space?: number;
    readonly age?: number;
    readonly life?: number;
    readonly limit?: number;
    readonly disposer?: (value: V, key: K) => void;
    readonly capture?: {
      readonly delete?: boolean;
      readonly clear?: boolean;
    };
  }
}

dw-cache

Usage no npm install needed!