Class FixedWindowRateLimiter

java.lang.Object

tech.riemann.nif.web.ratelimit.FixedWindowRateLimiter

All Implemented Interfaces:

RateLimiter

public class FixedWindowRateLimiter
extends Object
implements RateLimiter

固定窗口限流器

核心思想： 1. 在固定时间窗口内计数 2. 超过阈值则拒绝请求 3. 窗口结束后重置计数

适用场景：简单限流，对精度要求不高的场景

缺点： - 窗口边界可能出现2倍流量（前一个窗口最后1秒 + 后一个窗口第1秒）

Author:

Kerbores(kerbores@riemann.tech)

Constructor Summary

Constructors

Constructor	Description
FixedWindowRateLimiter()
FixedWindowRateLimiter(int maxKeys)

Method Summary

Modifier and Type	Method	Description
RateLimitAlgorithm	getAlgorithm()	获取支持的限流算法
boolean	tryAcquire(String key, double permitsPerSecond)	尝试获取许可（默认1秒窗口）
boolean	tryAcquire(String key, int permits, long windowSizeMs)	尝试获取许可（自定义时间窗口）

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

FixedWindowRateLimiter

public FixedWindowRateLimiter()

FixedWindowRateLimiter

public FixedWindowRateLimiter(int maxKeys)

Method Details

tryAcquire

public boolean tryAcquire(String key,
 double permitsPerSecond)

Description copied from interface: RateLimiter

尝试获取许可（默认1秒窗口）

Specified by:

tryAcquire in interface RateLimiter

Parameters:

key - 限流key

permitsPerSecond - 每秒允许的请求数

Returns:

是否获取成功

tryAcquire

public boolean tryAcquire(String key,
 int permits,
 long windowSizeMs)

Description copied from interface: RateLimiter

尝试获取许可（自定义时间窗口）

Specified by:

tryAcquire in interface RateLimiter

Parameters:

key - 限流key

permits - 时间窗口内允许的请求数

windowSizeMs - 时间窗口大小（毫秒）

Returns:

是否获取成功

getAlgorithm

public RateLimitAlgorithm getAlgorithm()

Description copied from interface: RateLimiter

获取支持的限流算法

Specified by:

getAlgorithm in interface RateLimiter

Returns:

限流算法