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', 10.28
'DWC hit rate', 10.49
'DWC ratio', 74, 73
'DWC / LRU hit rate ratio', '102%'

'Cache uneven 100'
'LRU hit rate', 19.3
'DWC hit rate', 36.91
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '191%'

'Cache uneven 100 transitive distribution'
'LRU hit rate', 18.84
'DWC hit rate', 37.07
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '196%'

'Cache uneven 100 transitive bias'
'LRU hit rate', 11.67
'DWC hit rate', 11.63
'DWC ratio', 5, 5
'DWC / LRU hit rate ratio', '99%'

'Cache uneven 100 sequential'
'LRU hit rate', 13.62
'DWC hit rate', 37.15
'DWC ratio', 95, 95
'DWC / LRU hit rate ratio', '272%'

'Cache uneven 100 adversarial'
'LRU hit rate', 42.22
'DWC hit rate', 49.81
'DWC ratio', 94, 93
'DWC / LRU hit rate ratio', '117%'

https://github.com/falsandtru/spica/runs/4958547921

Benchmark

Slower x0.0-0.1 of lru-cache.

'LRUCache simulation 100 x 3,409,743 ops/sec ±0.88% (61 runs sampled)'

'DW-Cache simulation 100 x 3,383,173 ops/sec ±1.00% (61 runs sampled)'

'LRUCache simulation 1,000 x 3,318,113 ops/sec ±1.37% (59 runs sampled)'

'DW-Cache simulation 1,000 x 3,075,874 ops/sec ±1.11% (60 runs sampled)'

'LRUCache simulation 10,000 x 2,018,025 ops/sec ±3.01% (54 runs sampled)'

'DW-Cache simulation 10,000 x 1,975,316 ops/sec ±3.24% (60 runs sampled)'

'LRUCache simulation 100,000 x 1,263,983 ops/sec ±2.99% (59 runs sampled)'

'DW-Cache simulation 100,000 x 1,147,544 ops/sec ±5.18% (53 runs sampled)'

https://github.com/falsandtru/spica/runs/4958568364

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>;
}