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# -*- coding: utf-8 -*-
"""
werkzeug.contrib.profiler
~~~~~~~~~~~~~~~~~~~~~~~~~
This module provides a simple WSGI profiler middleware for finding
bottlenecks in web application. It uses the :mod:`profile` or
:mod:`cProfile` module to do the profiling and writes the stats to the
stream provided (defaults to stderr).
Example usage::
from werkzeug.contrib.profiler import ProfilerMiddleware
app = ProfilerMiddleware(app)
:copyright: (c) 2014 by the Werkzeug Team, see AUTHORS for more details.
:license: BSD, see LICENSE for more details.
"""
import sys
import time
import os.path
try:
try:
from cProfile import Profile
except ImportError:
from profile import Profile
from pstats import Stats
available = True
except ImportError:
available = False
class MergeStream(object):
"""An object that redirects `write` calls to multiple streams.
Use this to log to both `sys.stdout` and a file::
f = open('profiler.log', 'w')
stream = MergeStream(sys.stdout, f)
profiler = ProfilerMiddleware(app, stream)
"""
def __init__(self, *streams):
if not streams:
raise TypeError('at least one stream must be given')
self.streams = streams
def write(self, data):
for stream in self.streams:
stream.write(data)
class ProfilerMiddleware(object):
"""Simple profiler middleware. Wraps a WSGI application and profiles
a request. This intentionally buffers the response so that timings are
more exact.
By giving the `profile_dir` argument, pstat.Stats files are saved to that
directory, one file per request. Without it, a summary is printed to
`stream` instead.
For the exact meaning of `sort_by` and `restrictions` consult the
:mod:`profile` documentation.
.. versionadded:: 0.9
Added support for `restrictions` and `profile_dir`.
:param app: the WSGI application to profile.
:param stream: the stream for the profiled stats. defaults to stderr.
:param sort_by: a tuple of columns to sort the result by.
:param restrictions: a tuple of profiling strictions, not used if dumping
to `profile_dir`.
:param profile_dir: directory name to save pstat files
"""
def __init__(self, app, stream=None,
sort_by=('time', 'calls'), restrictions=(), profile_dir=None):
if not available:
raise RuntimeError('the profiler is not available because '
'profile or pstat is not installed.')
self._app = app
self._stream = stream or sys.stdout
self._sort_by = sort_by
self._restrictions = restrictions
self._profile_dir = profile_dir
def __call__(self, environ, start_response):
response_body = []
def catching_start_response(status, headers, exc_info=None):
start_response(status, headers, exc_info)
return response_body.append
def runapp():
appiter = self._app(environ, catching_start_response)
response_body.extend(appiter)
if hasattr(appiter, 'close'):
appiter.close()
p = Profile()
start = time.time()
p.runcall(runapp)
body = b''.join(response_body)
elapsed = time.time() - start
if self._profile_dir is not None:
prof_filename = os.path.join(self._profile_dir,
'%s.%s.%06dms.%d.prof' % (
environ['REQUEST_METHOD'],
environ.get('PATH_INFO').strip(
'/').replace('/', '.') or 'root',
elapsed * 1000.0,
time.time()
))
p.dump_stats(prof_filename)
else:
stats = Stats(p, stream=self._stream)
stats.sort_stats(*self._sort_by)
self._stream.write('-' * 80)
self._stream.write('\nPATH: %r\n' % environ.get('PATH_INFO'))
stats.print_stats(*self._restrictions)
self._stream.write('-' * 80 + '\n\n')
return [body]
def make_action(app_factory, hostname='localhost', port=5000,
threaded=False, processes=1, stream=None,
sort_by=('time', 'calls'), restrictions=()):
"""Return a new callback for :mod:`werkzeug.script` that starts a local
server with the profiler enabled.
::
from werkzeug.contrib import profiler
action_profile = profiler.make_action(make_app)
"""
def action(hostname=('h', hostname), port=('p', port),
threaded=threaded, processes=processes):
"""Start a new development server."""
from werkzeug.serving import run_simple
app = ProfilerMiddleware(app_factory(), stream, sort_by, restrictions)
run_simple(hostname, port, app, False, None, threaded, processes)
return action
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