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Django rest framework(3) ---节流

时间:2019-10-07 11:38:44      阅读:76      评论:0      收藏:0      [点我收藏+]

标签:字符   classes   *args   错误   sel   views   exception   配置方法   imp   

添加节流

自定义节流的方法 

  • 限制60s内只能访问3次

(1)API文件夹下面新建throttle.py,代码如下:

技术图片
# utils/throttle.py

from rest_framework.throttling import BaseThrottle
import time
VISIT_RECORD = {}   #保存访问记录

class VisitThrottle(BaseThrottle):
    ‘‘‘60s内只能访问3次‘‘‘
    def __init__(self):
        self.history = None   #初始化访问记录

    def allow_request(self,request,view):
        #获取用户ip (get_ident)
        remote_addr = self.get_ident(request)
        ctime = time.time()
        #如果当前IP不在访问记录里面,就添加到记录
        if remote_addr not in VISIT_RECORD:
            VISIT_RECORD[remote_addr] = [ctime,]     #键值对的形式保存
            return True    #True表示可以访问
        #获取当前ip的历史访问记录
        history = VISIT_RECORD.get(remote_addr)
        #初始化访问记录
        self.history = history

        #如果有历史访问记录,并且最早一次的访问记录离当前时间超过60s,就删除最早的那个访问记录,
        #只要为True,就一直循环删除最早的一次访问记录
        while history and history[-1] < ctime - 60:
            history.pop()
        #如果访问记录不超过三次,就把当前的访问记录插到第一个位置(pop删除最后一个)
        if len(history) < 3:
            history.insert(0,ctime)
            return True

    def wait(self):
        ‘‘‘还需要等多久才能访问‘‘‘
        ctime = time.time()
        return 60 - (ctime - self.history[-1])
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(2)settings中全局配置节流

#全局
REST_FRAMEWORK = {
    #节流
    "DEFAULT_THROTTLE_CLASSES":[‘API.utils.throttle.VisitThrottle‘],
}

(3)现在访问auth看看结果:

  • 60s内访问次数超过三次,会限制访问
  • 提示剩余多少时间可以访问

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 技术图片

 

 

节流源码分析

 (1)dispatch

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 def dispatch(self, request, *args, **kwargs):
        """
        `.dispatch()` is pretty much the same as Django‘s regular dispatch,
        but with extra hooks for startup, finalize, and exception handling.
        """
        self.args = args
        self.kwargs = kwargs
        #对原始request进行加工,丰富了一些功能
        #Request(
        #     request,
        #     parsers=self.get_parsers(),
        #     authenticators=self.get_authenticators(),
        #     negotiator=self.get_content_negotiator(),
        #     parser_context=parser_context
        # )
        #request(原始request,[BasicAuthentications对象,])
        #获取原生request,request._request
        #获取认证类的对象,request.authticators
        #1.封装request
        request = self.initialize_request(request, *args, **kwargs)
        self.request = request
        self.headers = self.default_response_headers  # deprecate?

        try:
            #2.认证
            self.initial(request, *args, **kwargs)

            # Get the appropriate handler method
            if request.method.lower() in self.http_method_names:
                handler = getattr(self, request.method.lower(),
                                  self.http_method_not_allowed)
            else:
                handler = self.http_method_not_allowed

            response = handler(request, *args, **kwargs)

        except Exception as exc:
            response = self.handle_exception(exc)

        self.response = self.finalize_response(request, response, *args, **kwargs)
        return self.response
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(2)initial

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 def initial(self, request, *args, **kwargs):
        """
        Runs anything that needs to occur prior to calling the method handler.
        """
        self.format_kwarg = self.get_format_suffix(**kwargs)

        # Perform content negotiation and store the accepted info on the request
        neg = self.perform_content_negotiation(request)
        request.accepted_renderer, request.accepted_media_type = neg

        # Determine the API version, if versioning is in use.
        version, scheme = self.determine_version(request, *args, **kwargs)
        request.version, request.versioning_scheme = version, scheme

        # Ensure that the incoming request is permitted
        #4.实现认证
        self.perform_authentication(request)
        #5.权限判断
        self.check_permissions(request)
        #6.控制访问频率
        self.check_throttles(request)
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(3)check_throttles

里面有个allow_request

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    def check_throttles(self, request):
        """
        Check if request should be throttled.
        Raises an appropriate exception if the request is throttled.
        """
        for throttle in self.get_throttles():
            if not throttle.allow_request(request, self):
                self.throttled(request, throttle.wait())
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(4)get_throttles

    def get_throttles(self):
        """
        Instantiates and returns the list of throttles that this view uses.
        """
        return [throttle() for throttle in self.throttle_classes]

(5)thtottle_classes

 

内置节流类

 上面是写的自定义节流,drf内置了很多节流的类,用起来比较方便。

(1)BaseThrottle

  • 自己要写allow_request和wait方法
  • get_ident就是获取ip
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class BaseThrottle(object):
    """
    Rate throttling of requests.
    """

    def allow_request(self, request, view):
        """
        Return `True` if the request should be allowed, `False` otherwise.
        """
        raise NotImplementedError(‘.allow_request() must be overridden‘)

    def get_ident(self, request):
        """
        Identify the machine making the request by parsing HTTP_X_FORWARDED_FOR
        if present and number of proxies is > 0. If not use all of
        HTTP_X_FORWARDED_FOR if it is available, if not use REMOTE_ADDR.
        """
        xff = request.META.get(‘HTTP_X_FORWARDED_FOR‘)
        remote_addr = request.META.get(‘REMOTE_ADDR‘)
        num_proxies = api_settings.NUM_PROXIES

        if num_proxies is not None:
            if num_proxies == 0 or xff is None:
                return remote_addr
            addrs = xff.split(‘,‘)
            client_addr = addrs[-min(num_proxies, len(addrs))]
            return client_addr.strip()

        return ‘‘.join(xff.split()) if xff else remote_addr

    def wait(self):
        """
        Optionally, return a recommended number of seconds to wait before
        the next request.
        """
        return None
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(2)SimpleRateThrottle

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class SimpleRateThrottle(BaseThrottle):
    """
    A simple cache implementation, that only requires `.get_cache_key()`
    to be overridden.

    The rate (requests / seconds) is set by a `rate` attribute on the View
    class.  The attribute is a string of the form ‘number_of_requests/period‘.

    Period should be one of: (‘s‘, ‘sec‘, ‘m‘, ‘min‘, ‘h‘, ‘hour‘, ‘d‘, ‘day‘)

    Previous request information used for throttling is stored in the cache.
    """
    cache = default_cache
    timer = time.time
    cache_format = ‘throttle_%(scope)s_%(ident)s‘
    scope = None   #这个值自定义,写什么都可以
    THROTTLE_RATES = api_settings.DEFAULT_THROTTLE_RATES

    def __init__(self):
        if not getattr(self, ‘rate‘, None):
            self.rate = self.get_rate()
        self.num_requests, self.duration = self.parse_rate(self.rate)

    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):
        """
        Determine the string representation of the allowed request rate.
        """
        if not getattr(self, ‘scope‘, None):
            msg = ("You must set either `.scope` or `.rate` for ‘%s‘ throttle" %
                   self.__class__.__name__)
            raise ImproperlyConfigured(msg)

        try:
            return self.THROTTLE_RATES[self.scope]
        except KeyError:
            msg = "No default throttle rate set for ‘%s‘ scope" % self.scope
            raise ImproperlyConfigured(msg)

    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)
        duration = {‘s‘: 1, ‘m‘: 60, ‘h‘: 3600, ‘d‘: 86400}[period[0]]
        return (num_requests, duration)

    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()

    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

    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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我们可以通过继承SimpleRateThrottle类,来实现节流,会更加的简单,因为SimpleRateThrottle里面都帮我们写好了

(1)throttle.py

技术图片
from rest_framework.throttling import SimpleRateThrottle

class VisitThrottle(SimpleRateThrottle):
    ‘‘‘匿名用户60s只能访问三次(根据ip)‘‘‘
    scope = ‘NBA‘   #这里面的值,自己随便定义,settings里面根据这个值配置Rate

    def get_cache_key(self, request, view):
        #通过ip限制节流
        return self.get_ident(request)

class UserThrottle(SimpleRateThrottle):
    ‘‘‘登录用户60s可以访问10次‘‘‘
    scope = ‘NBAUser‘    #这里面的值,自己随便定义,settings里面根据这个值配置Rate

    def get_cache_key(self, request, view):
        return request.user.username
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(2)settings.py

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#全局
REST_FRAMEWORK = {
    #节流
    "DEFAULT_THROTTLE_CLASSES":[‘API.utils.throttle.UserThrottle‘],   #全局配置,登录用户节流限制(10/m)
    "DEFAULT_THROTTLE_RATES":{
        ‘NBA‘:‘3/m‘,         #没登录用户3/m,NBA就是scope定义的值
        ‘NBAUser‘:‘10/m‘,    #登录用户10/m,NBAUser就是scope定义的值
    }
}
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(3)views.py

局部配置方法

from API.utils.throttle import VisitThrottle
class AuthView(APIView):
    ‘‘‘用于用户登录验证‘‘‘

    authentication_classes = []  # 里面为空,代表不需要认证
    permission_classes = []  # 不里面为空,代表不需要权限


    # 默认的节流是登录用户(10/m),AuthView不需要登录,这里用匿名用户的节流(3/m)
    throttle_classes = [VisitThrottle]
    def post(self, request, *args, **kwargs):
        self.dispatch
        ret = {code: 1000, msg: None}
        try:
            user = request._request.POST.get(username)
            pwd = request._request.POST.get(password)
            obj = models.UserInfo.objects.filter(username=user, password=pwd).first()

            if not obj:
                ret[code] = 1001
                ret[msg] = 用户名或密码错误
            else:
                # 为用户创建token
                token = md5(user)
                # 存在就更新,不存在就创建
                models.UserToken.objects.update_or_create(user=obj, defaults={token: token})
                ret[code] = 2000
                ret[msg] = "成功"
                ret[token] = token
        except Exception as e:
            ret[code] = 1002
            ret[msg] = 请求异常
        return JsonResponse(ret)

说明:

  • API.utils.throttle.UserThrottle   这个是全局配置(根据ip限制,10/m)
  • DEFAULT_THROTTLE_RATES      --->>>设置访问频率的
  • throttle_classes = [VisitThrottle,]     --->>>局部配置(不适用settings里面默认的全局配置)
from django.shortcuts import render
from django.http import JsonResponse, HttpResponse
from rest_framework.views import APIView
from rest_framework import exceptions

from API import models
from API.utils.permission import SVIPPremission, MyPremission

ORDER_DICT = {
    1: {
        shop: "apple",
        "price": 12,
    },
    2: {
        shop: "pear",
        "price": 15,
    }
}


def md5(user):
    import hashlib
    import time
    # 当前时间,相当于生成一个随机字符串
    ctime = str(time.time())
    m = hashlib.md5(user.encode(utf-8))
    m.update(ctime.encode(utf-8))
    return m.hexdigest()

from API.utils.throttle import VisitThrottle
class AuthView(APIView):
    ‘‘‘用于用户登录验证‘‘‘

    authentication_classes = []  # 里面为空,代表不需要认证
    permission_classes = []  # 不里面为空,代表不需要权限
    throttle_classes = [VisitThrottle]
    def post(self, request, *args, **kwargs):
        self.dispatch
        ret = {code: 1000, msg: None}
        try:
            user = request._request.POST.get(username)
            pwd = request._request.POST.get(password)
            obj = models.UserInfo.objects.filter(username=user, password=pwd).first()

            if not obj:
                ret[code] = 1001
                ret[msg] = 用户名或密码错误
            else:
                # 为用户创建token
                token = md5(user)
                # 存在就更新,不存在就创建
                models.UserToken.objects.update_or_create(user=obj, defaults={token: token})
                ret[code] = 2000
                ret[msg] = "成功"
                ret[token] = token
        except Exception as e:
            ret[code] = 1002
            ret[msg] = 请求异常
        return JsonResponse(ret)


class OrderView(APIView):
    ‘‘‘
        订单相关业务(只有SVIP用户才能看)
        ‘‘‘

    def get(self, request, *args, **kwargs):
        # request.user
        # request.auth

        ret = {code: 1000, msg: None, data: None}
        try:
            ret[data] = ORDER_DICT
        except Exception as e:
            pass
        return JsonResponse(ret)


class UserInfoView(APIView):
    ‘‘‘
           订单相关业务(普通用户和VIP用户可以看)
           ‘‘‘
    permission_classes = [MyPremission, ]  # 不用全局的权限配置的话,这里就要写自己的局部权限

    def get(self, request, *args, **kwargs):

        print(request.user,request.user.username)
        return HttpResponse(用户信息)

总结

基本使用

  • 创建类,继承BaseThrottle, 实现:allow_request ,wait  
  • 创建类,继承SimpleRateThrottle,   实现:  get_cache_key, scope=‘NBA‘      (配置文件中的key)    

全局

技术图片
   #节流
    "DEFAULT_THROTTLE_CLASSES":[‘API.utils.throttle.UserThrottle‘],   #全局配置,登录用户节流限制(10/m)
    "DEFAULT_THROTTLE_RATES":{
        ‘NBA‘:‘3/m‘,         #没登录用户3/m,NBA就是scope定义的值
        ‘NBAUser‘:‘10/m‘,    #登录用户10/m,NBAUser就是scope定义的值
    }
}
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局部

throttle_classes = [VisitThrottle,]

 

认证/权限/节流

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from django.conf.urls import url
from django.contrib import admin
from API import views

urlpatterns = [
    url(r^admin/, admin.site.urls),
    url(r^api/v1/auth/, views.AuthView.as_view()),

    url(r^api/v1/order/, views.OrderView.as_view()),
    url(r^api/v1/info/, views.UserInfoView.as_view()),
]
url.py

 

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#设置全局认证
REST_FRAMEWORK = {
    "DEFAULT_AUTHENTICATION_CLASSES":[API.utils.auth.Authentication,],  #里面写你的认证的类的路径
    "DEFAULT_PERMISSION_CLASSES": [API.utils.permission.SVIPPremission],

    # 节流
    "DEFAULT_THROTTLE_CLASSES": [API.utils.throttle.UserThrottle],  # 全局配置,登录用户节流限制(10/m)
    "DEFAULT_THROTTLE_RATES": {
        NBA: 3/m,  # 没登录用户3/m,NBA就是scope定义的值
        NBAUser: 10/m,  # 登录用户10/m,NBAUser就是scope定义的值
    }
}
setting.py

 

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from django.db import models


class UserInfo(models.Model):
    USER_TYPE = (
        (1, 普通用户),
        (2, VIP),
        (3, SVIP),
    )
    user_type = models.IntegerField(choices=USER_TYPE)
    username = models.CharField(max_length=32)
    password = models.CharField(max_length=64)


class UserToken(models.Model):
    user = models.OneToOneField(UserInfo)
    token = models.CharField(max_length=64)
models.py

 

技术图片
from django.shortcuts import render
from django.http import JsonResponse, HttpResponse
from rest_framework.views import APIView
from rest_framework import exceptions

from API import models
from API.utils.permission import SVIPPremission, MyPremission

ORDER_DICT = {
    1: {
        shop: "apple",
        "price": 12,
    },
    2: {
        shop: "pear",
        "price": 15,
    }
}


def md5(user):
    import hashlib
    import time
    # 当前时间,相当于生成一个随机字符串
    ctime = str(time.time())
    m = hashlib.md5(user.encode(utf-8))
    m.update(ctime.encode(utf-8))
    return m.hexdigest()

from API.utils.throttle import VisitThrottle
class AuthView(APIView):
    ‘‘‘用于用户登录验证‘‘‘

    authentication_classes = []  # 里面为空,代表不需要认证
    permission_classes = []  # 不里面为空,代表不需要权限
    throttle_classes = [VisitThrottle]
    def post(self, request, *args, **kwargs):
        self.dispatch
        ret = {code: 1000, msg: None}
        try:
            user = request._request.POST.get(username)
            pwd = request._request.POST.get(password)
            obj = models.UserInfo.objects.filter(username=user, password=pwd).first()

            if not obj:
                ret[code] = 1001
                ret[msg] = 用户名或密码错误
            else:
                # 为用户创建token
                token = md5(user)
                # 存在就更新,不存在就创建
                models.UserToken.objects.update_or_create(user=obj, defaults={token: token})
                ret[code] = 2000
                ret[msg] = "成功"
                ret[token] = token
        except Exception as e:
            ret[code] = 1002
            ret[msg] = 请求异常
        return JsonResponse(ret)


class OrderView(APIView):
    ‘‘‘
        订单相关业务(只有SVIP用户才能看)
        ‘‘‘

    def get(self, request, *args, **kwargs):
        # request.user
        # request.auth

        ret = {code: 1000, msg: None, data: None}
        try:
            ret[data] = ORDER_DICT
        except Exception as e:
            pass
        return JsonResponse(ret)


class UserInfoView(APIView):
    ‘‘‘
           订单相关业务(普通用户和VIP用户可以看)
           ‘‘‘
    permission_classes = [MyPremission, ]  # 不用全局的权限配置的话,这里就要写自己的局部权限

    def get(self, request, *args, **kwargs):

        print(request.user,request.user.username)
        return HttpResponse(用户信息)
view.py

 

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from rest_framework import exceptions

from API import models
from rest_framework.authentication import BasicAuthentication

class Authentication(BasicAuthentication):
    def authenticate(self, request):

        token = request._request.GET.get("token")
        print(token)
        token_obj = models.UserToken.objects.filter(token=token).first()
        print(token_obj)
        if not token_obj:
            raise exceptions.AuthenticationFailed("认证失败")
        # 在rest framework内部会将这两个字段赋值给request,以供后续操作使用
        return (token_obj.user, token_obj)

    def authenticate_header(self, request):
        pass
auth.py

 

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from rest_framework.permissions import BasePermission

class SVIPPremission(BasePermission):
    message = "必须是SVIP才能访问"
    def has_permission(self,request,view):
        if request.user.user_type != 3:
            return False
        return True


class MyPremission(BasePermission):
    def has_permission(self,request,view):
        if request.user.user_type == 3:
            return False
        return True
permission.py

 

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# from rest_framework.throttling import BaseThrottle
# import time
# VISIT_RECORD = {}   #保存访问记录
#
# class VisitThrottle(BaseThrottle):
#     ‘‘‘60s内只能访问3次‘‘‘
#     def __init__(self):
#         self.history = None   #初始化访问记录
#
#     def allow_request(self,request,view):
#         #获取用户ip (get_ident)
#         remote_addr = self.get_ident(request)
#         ctime = time.time()
#         #如果当前IP不在访问记录里面,就添加到记录
#         if remote_addr not in VISIT_RECORD:
#             VISIT_RECORD[remote_addr] = [ctime,]     #键值对的形式保存
#             return True    #True表示可以访问
#         #获取当前ip的历史访问记录
#         history = VISIT_RECORD.get(remote_addr)
#         #初始化访问记录
#         self.history = history
#
#         #如果有历史访问记录,并且最早一次的访问记录离当前时间超过60s,就删除最早的那个访问记录,
#         #只要为True,就一直循环删除最早的一次访问记录
#         while history and history[-1] < ctime - 60:
#             history.pop()
#         #如果访问记录不超过三次,就把当前的访问记录插到第一个位置(pop删除最后一个)
#         if len(history) < 3:
#             history.insert(0,ctime)
#             return True
#
#     def wait(self):
#         ‘‘‘还需要等多久才能访问‘‘‘
#         ctime = time.time()
#         return 60 - (ctime - self.history[-1])



from rest_framework.throttling import SimpleRateThrottle

class VisitThrottle(SimpleRateThrottle):
    ‘‘‘匿名用户60s只能访问三次(根据ip)‘‘‘
    scope = NBA   #这里面的值,自己随便定义,settings里面根据这个值配置Rate

    def get_cache_key(self, request, view):
        #通过ip限制节流
        return self.get_ident(request)

class UserThrottle(SimpleRateThrottle):
    ‘‘‘登录用户60s可以访问10次‘‘‘
    scope = NBAUser    #这里面的值,自己随便定义,settings里面根据这个值配置Rate

    def get_cache_key(self, request, view):
        return request.user.username
throttle.py

技术图片

 

Django rest framework(3) ---节流

标签:字符   classes   *args   错误   sel   views   exception   配置方法   imp   

原文地址:https://www.cnblogs.com/XLHIT/p/11629640.html

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