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', 9.85
'DWC hit rate', 9.85
'DWC ratio', 0, 0
'DWC / LRU hit rate ratio', '100%'

'Cache uneven 100'
'LRU hit rate', 18.53
'DWC hit rate', 36.07
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '194%'

'Cache uneven 100 transitive distribution'
'LRU hit rate', 18.57
'DWC hit rate', 36.48
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '196%'

'Cache uneven 100 transitive bias'
'LRU hit rate', 11.33
'DWC hit rate', 11.34
'DWC ratio', 0, 0
'DWC / LRU hit rate ratio', '100%'

'Cache uneven 100 sequential'
'LRU hit rate', 14.05
'DWC hit rate', 38.31
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '272%'

'Cache uneven 100 adversarial'
'LRU hit rate', 42.35
'DWC hit rate', 49.94
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '117%'

https://github.com/falsandtru/spica/runs/4797806800

Benchmark

Slower x0.0-0.1 of lru-cache.

'LRUCache simulation 100 x 4,955,203 ops/sec ±1.26% (31 runs sampled)'

'DW-Cache simulation 100 x 4,096,862 ops/sec ±0.84% (33 runs sampled)'

'LRUCache simulation 1,000 x 4,623,945 ops/sec ±0.83% (30 runs sampled)'

'DW-Cache simulation 1,000 x 3,000,306 ops/sec ±2.75% (31 runs sampled)'

'LRUCache simulation 10,000 x 2,529,548 ops/sec ±2.67% (31 runs sampled)'

'DW-Cache simulation 10,000 x 2,408,576 ops/sec ±2.64% (29 runs sampled)'

'LRUCache simulation 100,000 x 1,501,336 ops/sec ±3.31% (28 runs sampled)'

'DW-Cache simulation 100,000 x 1,556,012 ops/sec ±5.51% (30 runs sampled)'

https://github.com/falsandtru/spica/runs/4797822151

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>;
}