pandora-metrics
Version:
## Overview
73 lines • 2.14 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const events_1 = require("events");
const defaultCapacity = 100;
class CommonCache extends events_1.EventEmitter {
constructor(capacity) {
super();
this.innerCache = [];
this.capacity = capacity || defaultCapacity;
this.on('add', () => {
if (this.innerCache.length > this.capacity) {
this.innerCache.shift();
}
});
}
push(item) {
this.innerCache.push(item);
this.emit('add');
}
/**
* 支持两种行为，取最后几条数据以及取特定时间之后的数据
* @param options
* @returns {any}
*/
query(options = {
by: 'size',
value: 0,
}) {
let results;
if (options.by && options.value && options.value > 0) {
if (options.by === 'size') {
if (options.value < this.capacity) {
results = this.innerCache.slice(-1 * options.value);
}
}
else {
results = this.innerCache.filter((data) => {
let value = data[options.by];
if (value) {
return value >= options.value;
}
return true;
});
}
}
if (!results) {
results = this.innerCache.slice();
}
if (options.offset != null && options.limit != null) {
const offset = options.offset;
const limit = options.limit;
results = this.innerCache.slice(offset, offset + limit);
}
if (options.order === 'DESC') {
results.reverse();
}
return results;
}
clear() {
this.innerCache.length = 0;
}
updateCapacity(newCapacity) {
this.capacity = newCapacity;
}
getCapacity() {
return this.capacity;
}
getSize() {
return this.innerCache.length;
}
}
exports.CommonCache = CommonCache;
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