频率认证
源码分析部分
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)
自定义频率类
# 1) 自定义一个继承 SimpleRateThrottle 类 的频率类 # 2) 设置一个 scope 类属性,属性值为任意见名知意的字符串 # 3) 在settings配置文件中,配置drf的DEFAULT_THROTTLE_RATES,格式为 {scope字符串: ‘次数/时间‘} # 4) 在自定义频率类中重写 get_cache_key 方法 # 限制的对象返回 与限制信息有关的字符串 # 不限制的对象返回 None (只能放回None,不能是False或是‘‘等)
例子:短信接口 1/min 频率限制
频率:api/throttles.py
from rest_framework.throttling import SimpleRateThrottle class SMSRateThrottle(SimpleRateThrottle): scope = ‘sms‘ # 只对提交手机号的get方法进行限制 def get_cache_key(self, request, view): mobile = request.query_params.get(‘mobile‘) # 没有手机号,就不做频率限制 if not mobile: return None # 返回可以根据手机号动态变化,且不易重复的字符串,作为操作缓存的key return ‘throttle_%(scope)s_%(ident)s‘ % {‘scope‘: self.scope, ‘ident‘: mobile}
配置:settings.py
# drf配置 REST_FRAMEWORK = { # 频率限制条件配置 ‘DEFAULT_THROTTLE_RATES‘: { ‘sms‘: ‘1/min‘ }, }
视图:views.py
from .throttles import SMSRateThrottle class TestSMSAPIView(APIView): # 局部配置频率认证 throttle_classes = [SMSRateThrottle] def get(self, request, *args, **kwargs): return APIResponse(0, ‘get 获取验证码 OK‘) def post(self, request, *args, **kwargs): return APIResponse(0, ‘post 获取验证码 OK‘)
路由:api/url.py
url(r‘^sms/$‘, views.TestSMSAPIView.as_view()),
限制的接口
# 只会对 /api/sms/?mobile=具体手机号 接口才会有频率限制 # 1)对 /api/sms/ 或其他接口发送无限制 # 2)对数据包提交mobile的/api/sms/接口无限制 # 3)对不是mobile(如phone)字段提交的电话接口无限制
总结:
DRF中频率认证源码部分执行流程简述
‘‘‘ 先写一个频率校验的类(继承SimpleRateThrottle) ---> 在该类中 配置 scope参数---> 重写 get_cache_key 方法 并返回self.get_ident(request)---->在需要校验的类中配置 该校验类 执行步骤: 1.APIView 2.---->dispatch 3.---->self.initial(request, *args, **kwargs) 4.---->self.check_throttles(request) 5.---->throttle.allow_request(request, self) 6.---->self.get_cache_key(request, view)(自己重写的)(返回的是ip) 7.---->self.cache.get(self.key, []) 根据ip获取当前ip的 时间列表 8.---->需要用到参数(self.rate,self.num_requests,self.duration)在类实例化的时已经执行了如下代码(__init__): 8.1--> self.rate = self.get_rate()-->self.THROTTLE_RATES[self.scope] -->api_settings.DEFAULT_THROTTLE_RATES(配置文件中找) 这里 self.rate ---> 是前面配置的 ‘qzk‘:‘3/m‘ 8.2-->self.num_requests, self.duration = self.parse_rate(self.rate) 这里 self.num_requests 是设定的访问限制次数(3) self.duration 是访问的时间限制(60) 9.----> 通过如上数据,并进行一通逻辑判断, 返回 True:——> 执行throttle_success: self.history.insert(0, self.now) # 把当前访问时间添加到时间列表 # 再将 key,history,duration 在 {} 中更新 self.cache.set(self.key, self.history, self.duration) False :---> 执行throttle_failure ,返回 Ture ‘‘‘
原文地址:https://www.cnblogs.com/AbrahamChen/p/11729595.html
时间: 2024-10-04 03:45:33