"""
Profile test execution using cProfile.
This plugin implements :func:`startTestRun` and replaces
``event.executeTests`` with :meth:`cProfile.Profile.runcall`. It
implements :func:`beforeSummaryReport` to output profiling information
before the final test summary time. Config file options ``filename``,
``sort`` and ``restrict`` can be used to change where profiling
information is saved and how it is presented.
Load this plugin by running nose2 with the
`--plugin=nose2.plugins.prof` option and activate it
with the `--profile` option,or put the corresponding
entries (`plugin` and `always_on`) in the respective
sections of the configuration file.
"""
import cProfile
import logging
import pstats
from nose2 import events, util
log = logging.getLogger(__name__)
__unittest = True
[docs]
class Profiler(events.Plugin):
"""Profile the test run"""
configSection = "profiler"
commandLineSwitch = ("P", "profile", "Run tests under profiler")
def __init__(self):
self.pfile = self.config.as_str("filename", "")
self.sort = self.config.as_str("sort", "cumulative")
self.restrict = self.config.as_list("restrict", [])
self.fileno = None
[docs]
def startTestRun(self, event):
"""Set up the profiler"""
self.prof = cProfile.Profile()
event.executeTests = self.prof.runcall
[docs]
def beforeSummaryReport(self, event):
"""Output profiling results"""
# write prof output to stream
class Stream:
def write(self, *msg):
for m in msg:
event.stream.write(m)
event.stream.write(" ")
event.stream.flush()
stream = Stream()
prof_stats = pstats.Stats(self.prof, stream=stream)
prof_stats.sort_stats(self.sort)
event.stream.writeln(util.ln("Profiling results"))
if self.restrict:
prof_stats.print_stats(*self.restrict)
else:
prof_stats.print_stats()
if self.pfile:
prof_stats.dump_stats(self.pfile)
self.prof.disable()
event.stream.writeln("")