django_profiler.py

# Copyright (C) 2011 by Blade Polska s.c.
# Full rights belong to Tomek Kopczuk (@tkopczuk).
# www.askthepony.com
# 
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

from datetime import datetime
import cProfile
import os
import StringIO

class InstrumentMiddleware(object):
    def process_request(self, request):
        if 'profile' in request.GET:
            request.profiler = cProfile.Profile()
            request.profiler.enable()
            print 'profiler enabled'

    def process_response(self, request, response):
        if hasattr(request, 'profiler'):
            request.profiler.disable()
            print 'profiler disabled'
            stamp = (request.META['REMOTE_ADDR'], datetime.now())
            request.profiler.dump_stats('/tmp/%s-%s.pro' % stamp)
            import pstats
            stream = StringIO.StringIO()
            stats = pstats.Stats('/tmp/%s-%s.pro' % stamp, stream=stream)
            stats.strip_dirs()
            stats.sort_stats('time')
            stats.print_stats(12)
            stats.print_callers(12)
            stats.print_callees(12)
            os.remove('/tmp/%s-%s.pro' % stamp)
            response._container[0] += "<pre>"+stream.getvalue()+"</pre>"
            stream.close()
        return response