Restful framework【第八篇】频率组件

基本使用

频率:
-限制每个ip地址一分钟访问10次
-写一个类
from rest_framework.throttling import SimpleRateThrottle
class VisitThrottle(SimpleRateThrottle):
scope = 'xx' #一定要写它
# 必须重写这个方法,返回什么,就以什么作为访问频率限制的东西,
def get_cache_key(self, request, view):
# return self.get_ident(request)
return request.META.get('REMOTE_ADDR')
-在setting中配置:
'DEFAULT_THROTTLE_RATES': {
#这个key跟scope对应,value值3/m 3/h 4/d
'xx': '3/m'
}
-使用:
-局部使用:
throttle_classes = [VisitThrottle]
-全局使用:
"DEFAULT_THROTTLE_CLASSES":["app01.auth.VisitThrottle"],
-问题?如果网站所有的接口都是一分钟访问10次,但是单独有一个接口要一分钟访问2次,如何做?

自定义频率类,自定义频率规则

自定义的逻辑

(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

代码实现

class MyThrottles():
VISIT_RECORD = {}
def __init__(self):
self.history=None
def allow_request(self,request, view):
#(1)取出访问者ip
# print(request.META)
ip=request.META.get('REMOTE_ADDR')
import time
ctime=time.time()
# (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
if ip not in self.VISIT_RECORD:
self.VISIT_RECORD[ip]=[ctime,]
return True
self.history=self.VISIT_RECORD.get(ip)
# (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,
while self.history and ctime-self.history[-1]>60:
self.history.pop()
# (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
if len(self.history)<3:
self.history.insert(0,ctime)
return True
else:
return False
def wait(self):
import time
ctime=time.time()
return 60-(ctime-self.history[-1])

内置频率类及局部使用

写一个类,继承自SimpleRateThrottle,(根据ip限制)问:要根据用户现在怎么写

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

在setting里配置:(一分钟访问三次)

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

在视图类里使用

throttle_classes = [MyThrottles,]

错误信息的中文提示

class Course(APIView):
authentication_classes = [TokenAuth, ]
permission_classes = [UserPermission, ]
throttle_classes = [MyThrottles,] def get(self, request):
return HttpResponse('get') def post(self, request):
return HttpResponse('post')
def throttled(self, request, wait):
from rest_framework.exceptions import Throttled
class MyThrottled(Throttled):
default_detail = '傻逼啊'
extra_detail_singular = '还有 {wait} second.'
extra_detail_plural = '出了 {wait} seconds.'
raise MyThrottled(wait)

内置频率限制类:

Restful framework【第八篇】频率组件

BaseThrottle是所有类的基类:方法:def get_ident(self, request)获取标识,其实就是获取ip,自定义的需要继承它

AnonRateThrottle:未登录用户ip限制,需要配合auth模块用

SimpleRateThrottle:重写此方法,可以实现频率现在,不需要咱们手写上面自定义的逻辑

UserRateThrottle:登录用户频率限制,这个得配合auth模块来用

ScopedRateThrottle:应用在局部视图上的(忽略)

内置频率类及全局使用

REST_FRAMEWORK = {
'DEFAULT_THROTTLE_CLASSES':['app01.utils.VisitThrottle',],
'DEFAULT_THROTTLE_RATES':{
'luffy':'3/m'
}
}

源码分析

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)

SimpleRateThrottle源码分析

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)

  

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