momoko tornado 连接池 异步

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import tornado.ioloop

import tornado.web

import momoko

from tornado import gen


class BaseHandler(tornado.web.RequestHandler):

    @property

    def db(self):

        # Create a database connection when a request handler is called

        # and store the connection in the application object.

        if not hasattr(self.application,'db'):

            self.application.db = momoko.AsyncClient({

                'host':'',

                'database': '',

                'user': '',

                'password': '',

                'min_conn': 1,

                'max_conn': 20,

                'cleanup_timeout': 10

            })

        return self.application.db



class SingleQueryHandler(BaseHandler):

    @tornado.web.asynchronous

    @gen.engine

    def get(self):

        # One simple query

        cursor = yield gen.Task(self.db.execute,'SELECT 42, 12, %s, 11;', (25,))

        self.write('Query results: %s' % cursor.fetchall())

        self.finish()

        

class LSingleQueryHandler(BaseHandler):

    @tornado.web.asynchronous

    @gen.engine

    def get(self):

        # One simple query

        cursor = yield gen.Task(self.db.execute,'select count(*) from asd a,asd b,asd c')

        self.write('Query results: %s' % cursor.fetchall())

        self.finish()



class BatchQueryHandler(BaseHandler):

    @tornado.web.asynchronous

    @gen.engine

    def get(self):

        # These queries are executed all at once and therefore they need to be

        # stored in an dictionary so you know where the resulting cursors

        # come from, because they won't arrive in the same order.

        cursors = yield gen.Task(self.db.batch, {

            'query1': ['SELECT 42, 12, %s, %s;', (23,56)],

            'query2':'SELECT 1, 2, 3, 4, 5;',

            'query3':'SELECT 465767, 4567, 3454;'

        })


        for key, cursor in cursors.items():

            self.write('Query results: %s = %s<br>' % (key, cursor.fetchall()))

        self.finish()



class QueryChainHandler(BaseHandler):

    @tornado.web.asynchronous

    @gen.engine

    def get(self):

        # Execute a list of queries in the order you specified

        cursors = yield gen.Task(self.db.chain, (

            ['SELECT 42, 12, %s, 11;', (23,)],

            'SELECT 1, 2, 3, 4, 5;'

        ))


        for cursor in cursors:

            self.write('Query results: %s<br>' % cursor.fetchall())

        self.finish()



class MultiQueryHandler(BaseHandler):

    @tornado.web.asynchronous

    @gen.engine

    def get(self):

        cursor1, cursor2, cursor3 = yield [

            gen.Task(self.db.execute, 'SELECT 42, 12, %s, 11;', (25,)),

            gen.Task(self.db.execute, 'SELECT 42, 12, %s, %s;', (23,56)),

            gen.Task(self.db.execute, 'SELECT 465767, 4567, 3454;')

        ]


        self.write('Query 1 results: %s<br>' % cursor1.fetchall())

        self.write('Query 2 results: %s<br>' % cursor2.fetchall())

        self.write('Query 3 results: %s' % cursor3.fetchall())


        self.finish()



class CallbackWaitHandler(BaseHandler):

    @tornado.web.asynchronous

    @gen.engine

    def get(self):


        self.db.execute('SELECT 42, 12, %s, 11;', (25,),

            callback=(yield gen.Callback('q1')))

        self.db.execute('SELECT 42, 12, %s, %s;', (23,56),

            callback=(yield gen.Callback('q2')))

        self.db.execute('SELECT 465767, 4567, 3454;',

            callback=(yield gen.Callback('q3')))


        cursor1 = yield gen.Wait('q1')

        cursor2 = yield gen.Wait('q2')

        cursor3 = yield gen.Wait('q3')


        self.write('Query 1 results: %s<br>' % cursor1.fetchall())

        self.write('Query 2 results: %s<br>' % cursor2.fetchall())

        self.write('Query 3 results: %s' % cursor3.fetchall())


        self.finish()


class MainHandler(tornado.web.RequestHandler):

    def get(self):

        self.write("You requested the main page")


class StoryHandler(tornado.web.RequestHandler):

    def get(self, story_id):

        self.write(str(story_id))

        


application = tornado.web.Application([

    (r"/", MainHandler),

    (r"/story/([0-9]+)", StoryHandler),

    (r"/test", SingleQueryHandler),

    (r"/ltest", LSingleQueryHandler),

    

])


if __name__ == "__main__":

    application.listen(8888)

    tornado.ioloop.IOLoop.instance().start()

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