Press n or j to go to the next uncovered block, b, p or k for the previous block.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 | 1x 1x 1x 6x 6x 6x 6x 6x 6x 6x 6x 6x 8x 8x 1x 7x 7x 8x 8x 8x 8x 15x 15x 9x 9x 7x 2x 1x 1x 1x 1x 1x 6x 1x 1x 1x 1x 1x | export interface CacheEntry<T> {
t: number; // Time created.
value: T;
}
const noop = () => {};
export class Cache<T> {
ttl = 10000; // Time how long item is kept in cache without refreshing.
evictionTime = 20000; // After this time item is evicted from cache.
gcPeriod = 30000; // How often to run GC.
maxEntries = 100000;
private entries = 0; // Number of values in cache.
public map = new Map<string, CacheEntry<T>>();
private timer: any; // GC setTimeout Timer.
constructor(public method: (key: string) => Promise<T> = noop as any) {}
put(key: string, value: T) {
const entry = {
t: Date.now(),
value,
};
if (this.map.get(key)) {
this.map.set(key, entry);
} else {
this.map.set(key, entry);
this.entries++;
}
if (this.entries > this.maxEntries) {
for (const iterationKey of this.map.keys()) {
if (key !== iterationKey) {
this.map.delete(iterationKey);
this.entries--;
break;
}
}
}
}
I
async getFromSource(key: string): Promise<T> {
const value = await this.method(key);
this.put(key, value);
return value;
}
async get(key: string): Promise<T> {
const entry = this.map.get(key);
if (entry) {
const now = Date.now();
if (now - entry.t <= this.ttl) {
return entry.value;
} else if (now - entry.t <= this.evictionTime) {
this.getFromSource(key).catch(noop);
return entry.value;
} else {
this.map.delete(key);
this.entries--;
return await this.getFromSource(key);
}
} else {
return await this.getFromSource(key);
}
}
getSync(key: string): T | null {
const entry = this.map.get(key);
if (!entry) return null;
const now = Date.now();
if (now - entry.t <= this.ttl) {
return entry.value;
} else if (now - entry.t <= this.evictionTime) {
this.getFromSource(key).catch(noop);
return entry.value;
}
return null;
}
exists(key: string): boolean {
const entry = this.map.get(key);
if (!entry) return false;
const now = Date.now();
return now - entry.t <= this.evictionTime;
}
scheduleGC() {
this.timer = setTimeout(this.runGC, this.gcPeriod);
this.timer.unref();
}
startGC() {
this.scheduleGC();
}
runGC = () => {
const now = Date.now();
for (const key of this.map.keys()) {
const entry = this.map.get(key);
if (entry && now - entry.t >= this.evictionTime) {
this.map.delete(key);
this.entries--;
}
}
this.scheduleGC();
};
I
stopGC = () => {
clearTimeout(this.timer);
};
retire(key: string, newTime: number = 0): boolean {
const entry = this.map.get(key);
if (!entry) return false;
entry.t = newTime;
return true;
}
remove(key: string): boolean {
const success = this.map.delete(key);
if (success) this.entries--;
return success;
}
}
|