dw-cache

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.

https://github.com/falsandtru/spica

Performance comparison

Hit rate

Higher x1.0-2.7 hit rate of LRU.

'Cache even 100'
'LRU hit rate', 9.79
'DWC hit rate', 10.28
'DWC ratio', 51, 50
'DWC / LRU hit rate ratio', '105%'

'Cache uneven 100'
'LRU hit rate', 17.59
'DWC hit rate', 34.36
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '195%'

'Cache uneven 100 transitive distribution'
'LRU hit rate', 17.8
'DWC hit rate', 36.11
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '202%'

'Cache uneven 100 transitive bias'
'LRU hit rate', 11.44
'DWC hit rate', 11.34
'DWC ratio', 4, 4
'DWC / LRU hit rate ratio', '99%'

'Cache uneven 100 sequential'
'LRU hit rate', 14.53
'DWC hit rate', 38.56
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '265%'

'Cache uneven 100 adversarial'
'LRU hit rate', 41.85
'DWC hit rate', 50.2
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '119%'

https://github.com/falsandtru/spica/runs/4964436570

Benchmark

Faster 0-5% of lru-cache.

'LRUCache simulation 100 x 3,783,174 ops/sec ±1.21% (61 runs sampled)'

'DW-Cache simulation 100 x 3,884,868 ops/sec ±0.92% (63 runs sampled)'

'LRUCache simulation 1,000 x 3,686,511 ops/sec ±1.07% (64 runs sampled)'

'DW-Cache simulation 1,000 x 3,851,667 ops/sec ±0.87% (63 runs sampled)'

'LRUCache simulation 10,000 x 2,443,805 ops/sec ±3.62% (53 runs sampled)'

'DW-Cache simulation 10,000 x 2,637,761 ops/sec ±3.11% (61 runs sampled)'

'LRUCache simulation 100,000 x 1,420,836 ops/sec ±2.85% (56 runs sampled)'

'DW-Cache simulation 100,000 x 1,424,037 ops/sec ±6.24% (55 runs sampled)'

https://github.com/falsandtru/spica/runs/4964461101

API

export interface CacheOptions<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;
  };
}

export class Cache<K, V = undefined> {
  constructor(
    capacity: number,
    opts: CacheOptions<K, V> = {},
  );
  put(key: K, value: V, size?: number, age?: number): boolean;
  set(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>;
}