Coverage for python/lsst/dax/apdb/timer.py: 20%
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1# This file is part of dax_apdb.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
22"""Module with methods to return timing information.
24This was developed as a part of a prototype for performance studies. It
25could probably be removed in the production system.
26"""
29import logging
30import resource
31import time
34_LOG = logging.getLogger(__name__.partition(".")[2]) # strip leading "lsst."
37class Timer(object):
38 """
39 Instance of this class can be used to track consumed time.
41 This class is also a context manager and can be used in
42 a `with` statement. By default it prints consumed CPU time
43 and real time spent in a context.
45 Example:
47 with Timer('SelectTimer'):
48 engine.execute('SELECT ...')
50 """
51 def __init__(self, name="", doPrint=True):
52 """
53 @param name: Time name, will be printed together with statistics
54 @param doPrint: if True then print statistics on exist from context
55 """
56 self._name = name
57 self._print = doPrint
59 self._startReal = None
60 self._startUser = None
61 self._startSys = None
62 self._sumReal = 0.
63 self._sumUser = 0.
64 self._sumSys = 0.
66 def start(self):
67 """
68 Start timer.
69 """
70 self._startReal = time.time()
71 ru = resource.getrusage(resource.RUSAGE_SELF)
72 self._startUser = ru.ru_utime
73 self._startSys = ru.ru_stime
74 return self
76 def stop(self):
77 """
78 Stop timer.
79 """
80 if self._startReal is not None:
81 self._sumReal += time.time() - self._startReal
82 ru = resource.getrusage(resource.RUSAGE_SELF)
83 self._sumUser += ru.ru_utime - self._startUser
84 self._sumSys += ru.ru_stime - self._startSys
85 self._startReal = None
86 self._startUser = None
87 self._startSys = None
88 return self
90 def dump(self):
91 """
92 Dump timer statistics
93 """
94 _LOG.info("%s", self)
95 return self
97 def __str__(self):
98 real = self._sumReal
99 user = self._sumUser
100 sys = self._sumSys
101 if self._startReal is not None:
102 real += time.time() - self._startReal
103 ru = resource.getrusage(resource.RUSAGE_SELF)
104 user += ru.ru_utime - self._startUser
105 sys += ru.ru_stime - self._startSys
106 info = "real=%.3f user=%.3f sys=%.3f" % (real, user, sys)
107 if self._name:
108 info = self._name + ": " + info
109 return info
111 def __enter__(self):
112 """
113 Enter context, start timer
114 """
115 self.start()
116 return self
118 def __exit__(self, exc_type, exc_val, exc_tb):
119 """
120 Exit context, stop and dump timer
121 """
122 if exc_type is None:
123 self.stop()
124 if self._print:
125 self.dump()
126 return False