Sanic框架下的高性能异步Web开发

Sanic是一个类似Flask的Python 3.5&＃43; Web服务器&＃xff0c;它的写入速度非常快。除了Flask之外&＃xff0c;Sanic还支持异步请求处理程序。这意味着你可以使用Python 3.5中新的闪亮的异步/等待语法&＃xff0c;使你的代码非阻塞和快速。

在上一篇博文中已经讲到&＃xff0c;如何在Sanic中使用COOKIE&＃xff0c;接下来将介绍一下Sanic的流的使用&＃xff1a;

请求流式传输

Sanic允许通过流获取请求数据&＃xff0c;如下所示&＃xff0c;当请求结束时&＃xff0c;request.stream.get()返回为None&＃xff0c;只有post、put和patch decorator拥有流参数&＃xff1a;

from sanic.response import stream&＃64;app.post("/post_stream",stream&＃61;True)
async def post_stream(request):async def streaming(response):while True:body &＃61; await request.stream.get()if body is None:breakbody &＃61; body.decode("utf-8")reponse.write(body)return stream(streaming)&＃64;app.put("/put_stream",stream&＃61;True)
async def put_stream(request):async def streaming(response):while True:body &＃61; await request.stream.get()if body is None:breakbody &＃61; body.decode("utf-8")response.write("utf-8")return stream(streaming)

除了上述例子的方法之外&＃xff0c;我们之前还讲过用add_route方法动态添加路由&＃xff1a;

from sanic.response import text
from sanic.views import HTTPMethodView
from sanic.views import stream as stream_decoratorclass StreamView(HTTPMethodView)&＃64;stream_decoratorasync def post(self,request)result &＃61; &＃39;&＃39;while True:body &＃61; await request.stream.get()if body is None:breakbody &＃61; body.decode(&＃39;utf-8&＃39;)result &＃43;&＃61; bodyreturn text(result)app.add_route(StreamView.as_view(),"/method_view")

值得注意的是&＃xff0c;stream_decorator装饰器中处理函数的函数名称&＃xff0c;若为post则为post请求&＃xff0c;若为put则为put请求。在之前讲述路由的博文中讲到一个CompositionView类来自定义一个路由&＃xff0c;CompositionView在流式请求中同样适用:

from sanic.views import CompositionViewasync def post_stream_view(request):result &＃61; &＃39;&＃39;while True:body &＃61; await request.stream.get()if body is None:breakbody &＃61; body.decode(&＃39;utf-8&＃39;)result &＃43;&＃61; bodyreturn text(result)view &＃61; CompositionView()
view.add([&＃39;POST&＃39;],post_stream_view,stream&＃61;True)
app.add_route(view,"/post_stream_view")

响应流式传输

Sanic允许你使用stream方法将内容传输到客户端&＃xff0c;该方法接受一个通过StreamingHTTPResponse传入的对象的协程回调&＃xff0c;举个栗子&＃xff1a;

from sanic.response import stream&＃64;app.route("/post_stream_info",methods&＃61;["POST"])
async def post_stream_info(request):async def streaming(response):response.write("no")response.write("bug")return stream(streaming)