瓶服务器：删除路线

Question

我想在我的 bottle 服务器运行时添加和删除路由。

我的一般问题：是否有适当的方法来删除路线？

换句话说：如何撤消我对app.route 所做的操作？

下面我将更详细地描述我的问题。如果您知道我的一般问题的答案，请不要浪费时间阅读它。

这是一个小演示脚本，描述了我如何解决我的问题：

如果调用GET /add：添加一个'Hello World'路由

如果调用 GET /remove：所有具有相同前缀的路由，如 'Hello World' 路由都会被更改以触发 404 错误

import bottle
from bottle import redirect, abort

def addRoute():
    app.route('/route/hello')(lambda :'Hello World')
    print('Routes after calling /add:\n' + '\n'.join([str(route) for route in app.routes]))
    redirect('route/hello')

def removeRoute():
    prefix = '/route/hello'

    #making a list of all routes having the prefix
    #because this is a testfile there is only one rule that startswith prefix
    routes = [route for route in app.routes if route.rule.startswith(prefix)]

    #because there could be multiple routes with the same rule and method,
    #making a list without duplicates
    ruleMethodTuples = list(dict.fromkeys([(route.rule, route.method) for route in routes]))

    for ruleMethod in ruleMethodTuples :

        #Workaround: Overwriting the existing route with a 404
        #Here I'd prefer to make a statement that removes the existing route instead,
        #so the default 404 would be called
        app.route(ruleMethod[0], method = ruleMethod[1])(lambda **kwords: abort(404, 'Route deleted'))

    print('Routes after calling /remove:\n' + '\n'.join([str(route) for route in app.routes]))
    redirect('/route/hello')

if __name__ == '__main__':
    app = bottle.app()
    app.route('/add')(addRoute)
    app.route('/remove')(removeRoute)
    print('Initial routes:\n' + '\n'.join([str(route) for route in app.routes]))
    bottle.run(app, host = 'localhost', port = 8080)

所以这里是启动和调用后的输出：

/添加

/删除

/添加

在每次通话后显示 app.routes 中有哪些路由。

Initial routes:
<GET '/add' <function addRoute at 0x02A876A8>>
<GET '/remove' <function removeRoute at 0x00F5F420>>
Bottle v0.12.17 server starting up (using WSGIRefServer())...
Listening on http://localhost:8080/
Hit Ctrl-C to quit.

Routes after calling /add:
<GET '/add' <function addRoute at 0x02A876A8>>
<GET '/remove' <function removeRoute at 0x00F5F420>>
<GET '/route/hello' <function addRoute.<locals>.<lambda> at 0x030C3E88>>
127.0.0.1 - - [25/Aug/2020 23:19:09] "GET /add HTTP/1.1" 303 0
127.0.0.1 - - [25/Aug/2020 23:19:09] "GET /route/hello HTTP/1.1" 200 11
Routes after calling /remove:
<GET '/add' <function addRoute at 0x02A876A8>>
<GET '/remove' <function removeRoute at 0x00F5F420>>
<GET '/route/hello' <function addRoute.<locals>.<lambda> at 0x030C3E88>>
<GET '/route/hello' <function removeRoute.<locals>.<lambda> at 0x030C3FA8>>
127.0.0.1 - - [25/Aug/2020 23:19:14] "GET /remove HTTP/1.1" 303 0
127.0.0.1 - - [25/Aug/2020 23:19:14] "GET /route/hello HTTP/1.1" 404 720
Routes after calling /add:
<GET '/add' <function addRoute at 0x02A876A8>>
<GET '/remove' <function removeRoute at 0x00F5F420>>
<GET '/route/hello' <function addRoute.<locals>.<lambda> at 0x030C3E88>>
<GET '/route/hello' <function removeRoute.<locals>.<lambda> at 0x030C3FA8>>
<GET '/route/hello' <function addRoute.<locals>.<lambda> at 0x030E0270>>
127.0.0.1 - - [25/Aug/2020 23:19:17] "GET /add HTTP/1.1" 303 0
127.0.0.1 - - [25/Aug/2020 23:19:18] "GET /route/hello HTTP/1.1" 200 11

所以不是替换 GET '/route/hello'，而是调用：app.route 使用相同的方法添加更多路由，并且规则在列表的末尾。

但是到目前为止这很有效，因为首先选择了最新的匹配路由，但我很确定这会导致（或早或晚）性能问题或在调用某些 /add 后导致服务器崩溃s 和 /removes。

此外，我注意到，我可以在不更改实际路由的情况下更改 app.routes，所以 次要问题：

我可以从 app.routes 中删除“已弃用”的路由以防止堆栈溢出吗？

还有第三个问题：

是不是我做错了什么？

Answer 1

我检查了add_route的源代码

它将route 添加到两个对象：self.routes 和 self.router（app.routes 和 app.router），这会产生问题。

def add_route(self, route):
    """ Add a route object, but do not change the :data:`Route.app`
        attribute."""
    self.routes.append(route)
    self.router.add(route.rule, route.method, route, name=route.name)
    if DEBUG: route.prepare()

self.router 是对象Router，具有rules、builder、static dyna_routes，dyna_regexes

如果您在添加新路线之前和之后检查它们，那么您会看到 builder 和 static 的变化。

def addRoute():
    print('--- before ---')
    print(app.router.rules)
    print(app.router.builder)
    print(app.router.static)
    print(app.router.dyna_routes)
    
    app.route('/route/hello')(lambda :'Hello World')

    print('--- after ---')
    print(app.router.rules)
    print(app.router.builder)
    print(app.router.static)
    print(app.router.dyna_routes)

    print('Routes after calling /add:\n' + '\n'.join([str(route) for route in app.routes]))
    redirect('route/hello')

如果我从builder 和static 中删除'/route/hello'，则'/route/hello' 停止工作，但app.routes 仍然显示它们，因此您必须从app.routes 和app.router 中删除'/route/hello' - 但是他们对此没有特殊功能:)

def removeRoute():
    prefix = '/route/hello'

    del app.router.builder[prefix]
    del app.router.static['GET'][prefix]
    
    print('Routes after calling /remove:\n' + '\n'.join([str(route) for route in app.routes]))
    redirect('/route/hello')

---

我的完整代码：

import bottle
from bottle import redirect, abort

def addRoute():
    print('--- before /add ---')
    print(app.router.rules)
    print(app.router.builder)
    print(app.router.static)
    print(app.router.dyna_routes)
    print(app.router.dyna_regexes)
    print('Routes before calling /add:\n' + '\n'.join([str(route) for route in app.routes]))
    
    app.route('/route/hello')(lambda :'Hello World')
    
    print('--- after /add ---')
    print(app.router.rules)
    print(app.router.builder)
    print(app.router.static)
    print(app.router.dyna_routes)
    print(app.router.dyna_regexes)
    print('Routes after calling /add:\n' + '\n'.join([str(route) for route in app.routes]))
    
    redirect('route/hello')

def removeRoute():
    prefix = '/route/hello'

    print('--- before /remove ---')
    print(app.router.rules)
    print(app.router.builder)
    print(app.router.static)
    print(app.router.dyna_routes)
    print(app.router.dyna_regexes)
    print('Routes before calling /remove:\n' + '\n'.join([str(route) for route in app.routes]))

    del app.router.builder[prefix]
    del app.router.static['GET'][prefix]
    
    print('--- after /remove ---')
    print(app.router.rules)
    print(app.router.builder)
    print(app.router.static)
    print(app.router.dyna_routes)
    print(app.router.dyna_regexes)
    print('Routes before calling /remove:\n' + '\n'.join([str(route) for route in app.routes]))

    redirect('/route/hello')

if __name__ == '__main__':
    app = bottle.app()
    app.route('/add')(addRoute)
    app.route('/remove')(removeRoute)
    print('Initial routes:\n' + '\n'.join([str(route) for route in app.routes]))
    bottle.run(app, host = 'localhost', port = 8080)