Step11: 加缓存为接口提速

Author: zmrenwu

Pipfile

@@ -18,6 +18,8 @@ django-haystack = "*"
 djangorestframework = "*"
 django-filter = "*"
 drf-haystack = "*"
+drf-extensions = "*"
+django-redis-cache = "*"
 
 [requires]
 python_version = "3"

Pipfile.lock

@@ -199,6 +199,7 @@ $ git clone https://github.com/HelloGitHub-Team/HelloDjango-REST-framework-tutor
 10. [实现分类、标签、归档日期接口](https://www.zmrenwu.com/courses/django-rest-framework-tutorial/materials/99/)
 11. [评论接口](https://www.zmrenwu.com/courses/django-rest-framework-tutorial/materials/100/))
 12. [基于 drf-haystack 实现文章搜索接口](https://www.zmrenwu.com/courses/django-rest-framework-tutorial/materials/101/))
+13. [加缓存为接口提速](https://www.zmrenwu.com/courses/django-rest-framework-tutorial/materials/102/))
 
 ## 公众号
 <p align="center">

README.md

@@ -1,8 +1,11 @@
 import re
+from datetime import datetime
 
 import markdown
 from django.contrib.auth.models import User
+from django.core.cache import cache
 from django.db import models
+from django.db.models.signals import post_delete, post_save
 from django.urls import reverse
 from django.utils import timezone
 from django.utils.functional import cached_property
@@ -148,3 +151,11 @@ def body_html(self):
     @cached_property
     def rich_content(self):
         return generate_rich_content(self.body)
+
+
+def change_post_updated_at(sender=None, instance=None, *args, **kwargs):
+    cache.set("post_updated_at", datetime.utcnow())
+
+
+post_save.connect(receiver=change_post_updated_at, sender=Post)
+post_delete.connect(receiver=change_post_updated_at, sender=Post)

blog/models.py

@@ -1,4 +1,9 @@
+from datetime import datetime
+
+from django.core.cache import cache
 from django.utils.html import strip_tags
+from rest_framework_extensions.key_constructor.bits import KeyBitBase
+
 from haystack.utils import Highlighter as HaystackHighlighter
 
 
@@ -14,3 +19,14 @@ def highlight(self, text_block):
         if len(text_block) < self.max_length:
             start_offset = 0
         return self.render_html(highlight_locations, start_offset, end_offset)
+
+
+class UpdatedAtKeyBit(KeyBitBase):
+    key = "updated_at"
+
+    def get_data(self, **kwargs):
+        value = cache.get(self.key, None)
+        if not value:
+            value = datetime.utcnow()
+            cache.set(self.key, value=value)
+        return str(value)

blog/utils.py

@@ -8,22 +8,28 @@
 from rest_framework.permissions import AllowAny
 from rest_framework.response import Response
 from rest_framework.serializers import DateField
-from rest_framework.views import APIView
+from rest_framework_extensions.cache.decorators import cache_response
+from rest_framework_extensions.key_constructor.bits import (
+    ListSqlQueryKeyBit,
+    PaginationKeyBit,
+    RetrieveSqlQueryKeyBit,
+)
+from rest_framework_extensions.key_constructor.constructors import DefaultKeyConstructor
 
 from comments.serializers import CommentSerializer
 from drf_haystack.viewsets import HaystackViewSet
 from pure_pagination.mixins import PaginationMixin
 
 from .filters import PostFilter
 from .models import Category, Post, Tag
-from .search_indexes import PostIndex
 from .serializers import (
     CategorySerializer,
     PostHaystackSerializer,
     PostListSerializer,
     PostRetrieveSerializer,
     TagSerializer,
 )
+from .utils import UpdatedAtKeyBit
 
 
 class IndexView(PaginationMixin, ListView):
@@ -78,6 +84,36 @@ def get(self, request, *args, **kwargs):
         return response
 
 
+# ---------------------------------------------------------------------------
+#   Django REST framework 接口
+# ---------------------------------------------------------------------------
+
+
+class PostUpdatedAtKeyBit(UpdatedAtKeyBit):
+    key = "post_updated_at"
+
+
+class CommentUpdatedAtKeyBit(UpdatedAtKeyBit):
+    key = "comment_updated_at"
+
+
+class PostListKeyConstructor(DefaultKeyConstructor):
+    list_sql = ListSqlQueryKeyBit()
+    pagination = PaginationKeyBit()
+    updated_at = PostUpdatedAtKeyBit()
+
+
+class PostObjectKeyConstructor(DefaultKeyConstructor):
+    retrieve_sql = RetrieveSqlQueryKeyBit()
+    updated_at = PostUpdatedAtKeyBit()
+
+
+class CommentListKeyConstructor(DefaultKeyConstructor):
+    list_sql = ListSqlQueryKeyBit()
+    pagination = PaginationKeyBit()
+    updated_at = CommentUpdatedAtKeyBit()
+
+
 class IndexPostListAPIView(ListAPIView):
     serializer_class = PostListSerializer
     queryset = Post.objects.all()
@@ -103,6 +139,14 @@ def get_serializer_class(self):
             self.action, super().get_serializer_class()
         )
 
+    @cache_response(timeout=5 * 60, key_func=PostListKeyConstructor())
+    def list(self, request, *args, **kwargs):
+        return super().list(request, *args, **kwargs)
+
+    @cache_response(timeout=5 * 60, key_func=PostObjectKeyConstructor())
+    def retrieve(self, request, *args, **kwargs):
+        return super().retrieve(request, *args, **kwargs)
+
     @action(
         methods=["GET"], detail=False, url_path="archive/dates", url_name="archive-date"
     )
@@ -112,6 +156,7 @@ def list_archive_dates(self, request, *args, **kwargs):
         data = [date_field.to_representation(date) for date in dates]
         return Response(data=data, status=status.HTTP_200_OK)
 
+    @cache_response(timeout=5 * 60, key_func=CommentListKeyConstructor())
     @action(
         methods=["GET"],
         detail=True,

blog/views.py

@@ -1,8 +1,25 @@
 from .common import *
 
-SECRET_KEY = os.environ['DJANGO_SECRET_KEY']
+SECRET_KEY = os.environ["DJANGO_SECRET_KEY"]
 
-DEBUG = False
+DEBUG = True
 
-ALLOWED_HOSTS = ['hellodjango-blog-tutorial-demo.zmrenwu.com']
-HAYSTACK_CONNECTIONS['default']['URL'] = 'http://hellodjango_blog_tutorial_elasticsearch:9200/'
+ALLOWED_HOSTS = [
+    "hellodjango-blog-tutorial-demo.zmrenwu.com",
+    "127.0.0.1",
+    "192.168.10.73",
+]
+HAYSTACK_CONNECTIONS["default"]["URL"] = "http://elasticsearch:9200/"
+
+CACHES = {
+    "default": {
+        "BACKEND": "redis_cache.RedisCache",
+        "LOCATION": "redis://:UJaoRZlNrH40BDaWU6fi@redis:6379/0",
+        "OPTIONS": {
+            "CONNECTION_POOL_CLASS": "redis.BlockingConnectionPool",
+            "CONNECTION_POOL_CLASS_KWARGS": {"max_connections": 50, "timeout": 20},
+            "MAX_CONNECTIONS": 1000,
+            "PICKLE_VERSION": -1,
+        },
+    },
+}

blogproject/settings/production.py

@@ -1,19 +1,31 @@
+from datetime import datetime
+
+from django.core.cache import cache
 from django.db import models
+from django.db.models.signals import post_delete, post_save
 from django.utils import timezone
 
 
 class Comment(models.Model):
-    name = models.CharField('名字', max_length=50)
-    email = models.EmailField('邮箱')
-    url = models.URLField('网址', blank=True)
-    text = models.TextField('内容')
-    created_time = models.DateTimeField('创建时间', default=timezone.now)
-    post = models.ForeignKey('blog.Post', verbose_name='文章', on_delete=models.CASCADE)
+    name = models.CharField("名字", max_length=50)
+    email = models.EmailField("邮箱")
+    url = models.URLField("网址", blank=True)
+    text = models.TextField("内容")
+    created_time = models.DateTimeField("创建时间", default=timezone.now)
+    post = models.ForeignKey("blog.Post", verbose_name="文章", on_delete=models.CASCADE)
 
     class Meta:
-        verbose_name = '评论'
+        verbose_name = "评论"
         verbose_name_plural = verbose_name
-        ordering = ['-created_time']
+        ordering = ["-created_time"]
 
     def __str__(self):
-        return '{}: {}'.format(self.name, self.text[:20])
+        return "{}: {}".format(self.name, self.text[:20])
+
+
+def change_comment_updated_at(sender=None, instance=None, *args, **kwargs):
+    cache.set("comment_updated_at", datetime.utcnow())
+
+
+post_save.connect(receiver=change_comment_updated_at, sender=Comment)
+post_delete.connect(receiver=change_comment_updated_at, sender=Comment)

comments/models.py

@@ -6,7 +6,7 @@ COPY ./compose/production/nginx/sources.list /etc/apt/
 RUN apt-get update && apt-get install -y --allow-unauthenticated certbot python-certbot-nginx
 
 RUN rm /etc/nginx/conf.d/default.conf
-COPY ./compose/production/nginx/hellodjango-blog-tutorial.conf /etc/nginx/conf.d/hellodjango-blog-tutorial.conf
+COPY ./compose/production/nginx/hellodjango-rest-framework-tutorial.conf /etc/nginx/conf.d/hellodjango-rest-framework-tutorial.conf