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 x0.9-2.6 hit rate of LRU.

'Cache even 100'
'LRU hit rate', 9.77
'DWC hit rate', 10.04
'DWC ratio', 70, 69
'DWC / LRU hit rate ratio', '102%'

'Cache uneven 100'
'LRU hit rate', 18.48
'DWC hit rate', 35.85
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '193%'

'Cache uneven 100 transitive distribution'
'LRU hit rate', 18.25
'DWC hit rate', 36.41
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '199%'

'Cache uneven 100 transitive bias'
'LRU hit rate', 10.57
'DWC hit rate', 10.55
'DWC ratio', 1, 1
'DWC / LRU hit rate ratio', '99%'

'Cache uneven 100 sequential'
'LRU hit rate', 13.51
'DWC hit rate', 37.15
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '274%'

'Cache uneven 100 adversarial'
'LRU hit rate', 42.25
'DWC hit rate', 49.89
'DWC ratio', 94, 93
'DWC / LRU hit rate ratio', '118%'

https://github.com/falsandtru/spica/runs/4800911644

Benchmark

Slower x0.0-0.1 of lru-cache.

'LRUCache simulation 100 x 4,713,953 ops/sec ±1.06% (65 runs sampled)'

'DW-Cache simulation 100 x 2,966,041 ops/sec ±3.13% (57 runs sampled)'

'LRUCache simulation 1,000 x 2,868,502 ops/sec ±2.80% (46 runs sampled)'

'DW-Cache simulation 1,000 x 2,864,095 ops/sec ±2.99% (59 runs sampled)'

'LRUCache simulation 10,000 x 2,975,807 ops/sec ±3.11% (59 runs sampled)'

'DW-Cache simulation 10,000 x 2,213,014 ops/sec ±3.04% (59 runs sampled)'

'LRUCache simulation 100,000 x 1,747,886 ops/sec ±3.25% (53 runs sampled)'

'DW-Cache simulation 100,000 x 1,538,661 ops/sec ±4.95% (56 runs sampled)'

https://github.com/falsandtru/spica/runs/4800947409

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>;
}