Token Bucket

1class TokenBucket {
2  private tokens: number
3  private last = 0
4 
5  constructor(private capacity: number, private ratePerSec: number) {
6    this.tokens = capacity
7  }
8 
9  tryConsume(nowMs: number): boolean {
10    const elapsed = (nowMs - this.last) / 1000
11    this.last = nowMs
12    this.tokens = Math.min(this.capacity, this.tokens + elapsed * this.ratePerSec)
13 
14    if (this.tokens >= 1) {
15      this.tokens -= 1
16      return true
17    }
18    return false
19  }
20}