libp2p-gossipsub
Version:
A typescript implementation of gossipsub
50 lines (49 loc) • 1.63 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.SimpleTimeCache = void 0;
/**
* This is similar to https://github.com/daviddias/time-cache/blob/master/src/index.js
* for our own need, we don't use lodash throttle to improve performance.
* This gives 4x - 5x performance gain compared to npm TimeCache
*/
class SimpleTimeCache {
constructor(options) {
this.lastPruneTime = 0;
this.entries = new Map();
this.validityMs = options.validityMs;
// allow negative validityMs so that this does not cache anything, spec test compliance.spec.js
// sends duplicate messages and expect peer to receive all. Application likely uses positive validityMs
}
put(key, value) {
this.entries.set(key, { value, validUntilMs: Date.now() + this.validityMs });
this.prune();
}
prune() {
const now = Date.now();
if (now - this.lastPruneTime < 200) {
return;
}
this.lastPruneTime = now;
for (const [k, v] of this.entries.entries()) {
if (v.validUntilMs < now) {
this.entries.delete(k);
}
else {
// sort by insertion order
break;
}
}
}
has(key) {
return this.entries.has(key);
}
get(key) {
const value = this.entries.get(key);
return (value && value.validUntilMs >= Date.now()) ? value.value : undefined;
}
clear() {
this.entries = new Map();
this.lastPruneTime = 0;
}
}
exports.SimpleTimeCache = SimpleTimeCache;