django-rest-framework(五)(节流)
节流
需求:控制用户的访问的频率(10秒中内访问三次)
思想：设立一个全局变量字典，对于匿名用户，将用户的IP作为字典的键；对于登陆用户，将用户的用户名作为字典的键。设置字典的值为一个列表，列表中存储了用户访问的时间，可以通过对列表中的时间进行操作来控制访问频率
代码实现
from django.http import JsonResponse
import time
from rest_framework.views import APIView
from api.models import UserInfo, UserToken
#可以将字典放在缓存中
VISIT_RECODE = dict()
class MyThrottles(object):
def __init__(self):
self.history = None
def allow_request(self, request, view):
# 获取用户访问的ID
remote_addr = request._request.META.get('REMOTE_ADDR')
ctime = time.time()
# 如果用户是第一次访问，将用户的IP作为字典的键,将用户的第一访问时间作为值放入字典中
if remote_addr not in VISIT_RECODE:
VISIT_RECODE[remote_addr] = [ctime, ]
# 如果用户不是第一次访问，获取列表
histiory = VISIT_RECODE.get(remote_addr)
self.history = histiory
# 筛选出10秒中列表的时间个数
while histiory and histiory[-1] < ctime - 10:
histiory.pop()
# 如果是小于3个，则可以进行访问；否则不能进行访问
if len(histiory) < 3:
histiory.insert(0, ctime)
return True # 返回True则表示可以进行访问
# return False # 返回False则表示不能进行访问
def wait(self):
ctime = time.time()
return 10-(ctime - self.history[-1])
class AuthView(APIView):
'''
用于登录认证,控制用户的访问的频率(10秒中内访问三次)
'''
authentication_classes = []
throttle_classes = [MyThrottles, ]
def post(self, request, *args, **kwargs):
ret = {'code': 1000, 'msg': None}
try:
user = request._request.POST.get('username')
password = request._request.POST.get('password')
obj = UserInfo.objects.filter(username=user, password=password).first()
# print(obj)
if not obj:
ret['code'] = 1001
ret['msg'] = '用户名或者密码错误'
# 创建token
token = md5(user)
# logging.info(token)
print(token)
UserToken.objects.update_or_create(user=obj, defaults={'token': token})
except Exception as e:
print(e)
return JsonResponse(ret)
节流的全局使用
- 在setting中配置
REST_FRAMEWORK = {
#认证配置
'DEFAULT_AUTHENTICATION_CLASSES': ['api.utils.auth.MyAuthtication'],
# 当认证为匿名用户时，request.user = '匿名用户'/None
'UNAUTHENTICATED_USER': lambda: '匿名用户', # None
# 当认证为匿名用户时，request.auth = None
'UNAUTHENTICATED_TOKEN': None,
# 权限配置
'DEFAULT_PERMISSION_CLASSES': ['api.utils.permission.MyPermission'],
# 节流配置
'DEFAULT_THROTTLE_CLASSES': ['api.utils.throttles.MyThrottles']
}
- 将节流类写在新的地方
django-rest-framework中内置的节流
from __future__ import unicode_literals
import time
from django.core.cache import cache as default_cache
from django.core.exceptions import ImproperlyConfigured
from rest_framework.settings import api_settings
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
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
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:
,
"""
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)
class AnonRateThrottle(SimpleRateThrottle):
"""
Limits the rate of API calls that may be made by a anonymous users.
The IP address of the request will be used as the unique cache key.
"""
scope = 'anon'
def get_cache_key(self, request, view):
if request.user.is_authenticated:
return None # Only throttle unauthenticated requests.
return self.cache_format % {
'scope': self.scope,
'ident': self.get_ident(request)
}
class UserRateThrottle(SimpleRateThrottle):
"""
Limits the rate of API calls that may be made by a given user.
The user id will be used as a unique cache key if the user is
authenticated. For anonymous requests, the IP address of the request will
be used.
"""
scope = 'user'
def get_cache_key(self, request, view):
if request.user.is_authenticated:
ident = request.user.pk
else:
ident = self.get_ident(request)
return self.cache_format % {
'scope': self.scope,
'ident': ident
}
class ScopedRateThrottle(SimpleRateThrottle):
"""
Limits the rate of API calls by different amounts for various parts of
the API. Any view that has the `throttle_scope` property set will be
throttled. The unique cache key will be generated by concatenating the
user id of the request, and the scope of the view being accessed.
"""
scope_attr = 'throttle_scope'
def __init__(self):
# Override the usual SimpleRateThrottle, because we can't determine
# the rate until called by the view.
pass
def allow_request(self, request, view):
# We can only determine the scope once we're called by the view.
self.scope = getattr(view, self.scope_attr, None)
# If a view does not have a `throttle_scope` always allow the request
if not self.scope:
return True
# Determine the allowed request rate as we normally would during
# the `__init__` call.
self.rate = self.get_rate()
self.num_requests, self.duration = self.parse_rate(self.rate)
# We can now proceed as normal.
return super(ScopedRateThrottle, self).allow_request(request, view)
def get_cache_key(self, request, view):
"""
If `view.throttle_scope` is not set, don't apply this throttle.
Otherwise generate the unique cache key by concatenating the user id
with the '.throttle_scope` property of the view.
"""
if request.user.is_authenticated:
ident = request.user.pk
else:
ident = self.get_ident(request)
return self.cache_format % {
'scope': self.scope,
'ident': ident
}
- 继承BaseThrottle类
要实现两个方法allow_request、wait - 继承SimpleRateThrottle类
重写get_cache_key方法，并设置参数scope和setting中的配置
节流类的书写
from rest_framework.throttling import BaseThrottle, SimpleRateThrottle
class MyThrottles(SimpleRateThrottle):
'''匿名用户的节流限制'''
scope = 'wang'
def get_cache_key(self, request, view):
return self.get_ident(request)
class MyThrottles1(SimpleRateThrottle):
'''登陆用户的节流限制'''
scope = 'wang1'
def get_cache_key(self, request, view):
return request.user.username
setting中的配置
REST_FRAMEWORK = {
#认证配置
'DEFAULT_AUTHENTICATION_CLASSES': ['api.utils.auth.MyAuthtication'],
# 当认证为匿名用户时，request.user = '匿名用户'/None
'UNAUTHENTICATED_USER': lambda: '匿名用户', # None
# 当认证为匿名用户时，request.auth = None
'UNAUTHENTICATED_TOKEN': None,
# 权限配置
'DEFAULT_PERMISSION_CLASSES': ['api.utils.permission.MyPermission'],
# 节流配置
'DEFAULT_THROTTLE_CLASSES': ['api.utils.throttles.MyThrottles'],
'DEFAULT_THROTTLE_RATES': {
'wang': '3/m', # 1分钟内访问3次
'wang1': '10/m' # 1分钟内访问10次
},
}
view的书写
class AuthView(APIView):
'''
用于登录认证,控制用户的访问的频率(1分钟中内访问三次)
'''
authentication_classes = []
permission_classes = []
throttle_classes = [MyThrottles, ]
def post(self, request, *args, **kwargs):
ret = {'code': 1000, 'msg': None}
try:
user = request._request.POST.get('username')
password = request._request.POST.get('password')
obj = UserInfo.objects.filter(username=user, password=password).first()
# print(obj)
if not obj:
ret['code'] = 1001
ret['msg'] = '用户名或者密码错误'
# 创建token
token = md5(user)
# logging.info(token)
print(token)
UserToken.objects.update_or_create(user=obj, defaults={'token': token})
except Exception as e:
print(e)
return JsonResponse(ret)
class OrderView(APIView):
'''
订单相关业务,只有SVIP能够访问,控制用户的访问的频率(1分钟中内访问十次)
'''
def get(self, request, *args, **kwargs):
# self.dispatch
print(request.user, request.auth)
ret = {'code': 1000, 'msg': None, 'data': None}
ret['data'] = ORDER_DICT
return JsonResponse(ret)