Django之频率组件

（1）取出访问者的ip

（2）判断当前ip不在访问字典里，添加进去，并且直接返回True，表示第一次访问，在字典里，继续往下走

（3）循坏判断当前ip的列表，有值，并且当前时间减去列表的最后一时间大于60秒，把这种数据pop掉 ，这样列表中只有 60s以内的访问时间；

（4）判断，当列表小于3，说明一分钟 以内访问次数不足3次，把当前时间插入到列表第一个位置，返回True，顺利通过；

（5）当大于等于3，说明一分钟内访问超过3次，返回 False验证失败

import time
自定义频率控制
class MyThrottle():
    visitor_dic = {}

    def __init__(self):
        self.history = None

    def allow_request(self, request, view):
        '''

        #（1）取出访问者ip
        # （2）判断当前ip不在访问字典里，添加进去，并且直接返回True,表示第一次访问，在字典里，继续往下走
        # （3）循环判断当前ip的列表，有值，并且当前时间减去列表的最后一个时间大于60s，把这种数据pop掉，这样列表中只有60s以内的访问时间，
        # （4）判断，当列表小于3，说明一分钟以内访问不足三次，把当前时间插入到列表第一个位置，返回True，顺利通过
        # （5）当大于等于3，说明一分钟内访问超过三次，返回False验证失败
}        '''

        # META:请求所有的东西的字典
        # 拿出ip地址
        ip = request.META.get('REMOTE_ADDR')
        # 当前时间
        ctime = time.time()
        # self先从自身找，再到类中找
        if ip not in self.visitor_dic:
            self.visitor_dic[ip] = [ctime, ]
            return True
        # 根据当前时间者ip，取出访问的时间列表
        history = self.visitor_dic[ip]
        # 记录一下当前访问的人
        self.history = history
        while history and ctime - history[-1] > 60:
            history.pop()
        if len(history) < 3:
            # 将当前时间放到第0个位置上
            history.insert(0, ctime)
            return True
        else:
            return False

    def wait(self):
        # 剩余时间
        ctime = time.time()
        return 60 - (ctime - self.history[-1])

from django.shortcuts import render, HttpResponse


from rest_framework import exceptions
from rest_framework.views import APIView
from app01.myauth import MyThrottle

class Test(APIView):
    throttle_classes = [MyThrottle, ]

    def get(self, request):
        return HttpResponse('ok')
    
    # 将前端提示信息转化成 中文
    def throttled(self, request, wait):
        class MyThottled(exceptions.Throttled):
            default_detail = '傻逼'
            extra_detail_singular = '还剩{wait}秒'
            extra_detail_plural = '还剩{wait}秒'

        raise MyThottled(wait)

from rest_framework.throttling import SimpleRateThrottle
class MyThrottle(SimpleRateThrottle):
    scope = 'luffy'
    def get_cache_key(self, request, view):
        return self.get_ident(request)

REST_FRAMEWORK = {
    'DEFAULT_THROTTLE_RATES':{
        'luffy':'3/m'
    }
}

def check_throttles(self, request):
        for throttle in self.get_throttles():
            if not throttle.allow_request(request, self):
                self.throttled(request, throttle.wait())
    def throttled(self, request, wait):
        #抛异常，可以自定义异常，实现错误信息的中文显示
        raise exceptions.Throttled(wait)

class SimpleRateThrottle(BaseThrottle):
    # 咱自己写的放在了全局变量，他的在django的缓存中
    cache = default_cache
    # 获取当前时间，跟咱写的一样
    timer = time.time
    # 做了一个字符串格式化，
    cache_format = 'throttle_%(scope)s_%(ident)s'
    scope = None
    # 从配置文件中取DEFAULT_THROTTLE_RATES，所以咱配置文件中应该配置，否则报错
    THROTTLE_RATES = api_settings.DEFAULT_THROTTLE_RATES

    def __init__(self):
        if not getattr(self, 'rate', None):
            # 从配置文件中找出scope配置的名字对应的值，比如咱写的‘3/m’,他取出来
            self.rate = self.get_rate()
        #     解析'3/m',解析成 3      m
        self.num_requests, self.duration = self.parse_rate(self.rate)
    # 这个方法需要重写
    def get_cache_key(self, request, view):
        """
        Should return a unique cache-key which can be used for throttling.
        Must be overridden.

        May return `None` if the request should not be throttled.
        """
        raise NotImplementedError('.get_cache_key() must be overridden')
    
    def get_rate(self):
        if not getattr(self, 'scope', None):
            msg = ("You must set either `.scope` or `.rate` for '%s' throttle" %
                   self.__class__.__name__)
            raise ImproperlyConfigured(msg)

        try:
            # 获取在setting里配置的字典中的之，self.scope是 咱写的luffy
            return self.THROTTLE_RATES[self.scope]
        except KeyError:
            msg = "No default throttle rate set for '%s' scope" % self.scope
            raise ImproperlyConfigured(msg)
    # 解析 3/m这种传参
    def parse_rate(self, rate):
        """
        Given the request rate string, return a two tuple of:
        <allowed number of requests>, <period of time in seconds>
        """
        if rate is None:
            return (None, None)
        num, period = rate.split('/')
        num_requests = int(num)
        # 只取了第一位，也就是 3/mimmmmmmm也是代表一分钟
        duration = {'s': 1, 'm': 60, 'h': 3600, 'd': 86400}[period[0]]
        return (num_requests, duration)
    # 逻辑跟咱自定义的相同
    def allow_request(self, request, view):
        """
        Implement the check to see if the request should be throttled.

        On success calls `throttle_success`.
        On failure calls `throttle_failure`.
        """
        if self.rate is None:
            return True

        self.key = self.get_cache_key(request, view)
        if self.key is None:
            return True

        self.history = self.cache.get(self.key, [])
        self.now = self.timer()

        # Drop any requests from the history which have now passed the
        # throttle duration
        while self.history and self.history[-1] <= self.now - self.duration:
            self.history.pop()
        if len(self.history) >= self.num_requests:
            return self.throttle_failure()
        return self.throttle_success()
    # 成功返回true，并且插入到缓存中
    def throttle_success(self):
        """
        Inserts the current request's timestamp along with the key
        into the cache.
        """
        self.history.insert(0, self.now)
        self.cache.set(self.key, self.history, self.duration)
        return True
    # 失败返回false
    def throttle_failure(self):
        """
        Called when a request to the API has failed due to throttling.
        """
        return False

    def wait(self):
        """
        Returns the recommended next request time in seconds.
        """
        if self.history:
            remaining_duration = self.duration - (self.now - self.history[-1])
        else:
            remaining_duration = self.duration

        available_requests = self.num_requests - len(self.history) + 1
        if available_requests <= 0:
            return None

        return remaining_duration / float(available_requests)