blob: 39acd7bd76c70ddf29f71ceaef0f66bb248a58e9 [file] [log] [blame]
"""Raw data collector for Coverage."""
import os, sys
from coverage.misc import CoverageException
from coverage.pytracer import PyTracer
try:
# Use the C extension code when we can, for speed.
from coverage.tracer import CTracer # pylint: disable=no-name-in-module
except ImportError:
# Couldn't import the C extension, maybe it isn't built.
if os.getenv('COVERAGE_TEST_TRACER') == 'c':
# During testing, we use the COVERAGE_TEST_TRACER env var to indicate
# that we've fiddled with the environment to test this fallback code.
# If we thought we had a C tracer, but couldn't import it, then exit
# quickly and clearly instead of dribbling confusing errors. I'm using
# sys.exit here instead of an exception because an exception here
# causes all sorts of other noise in unittest.
sys.stderr.write(
"*** COVERAGE_TEST_TRACER is 'c' but can't import CTracer!\n"
)
sys.exit(1)
CTracer = None
try:
import __pypy__
except ImportError:
__pypy__ = None
class Collector(object):
"""Collects trace data.
Creates a Tracer object for each thread, since they track stack
information. Each Tracer points to the same shared data, contributing
traced data points.
When the Collector is started, it creates a Tracer for the current thread,
and installs a function to create Tracers for each new thread started.
When the Collector is stopped, all active Tracers are stopped.
Threads started while the Collector is stopped will never have Tracers
associated with them.
"""
# The stack of active Collectors. Collectors are added here when started,
# and popped when stopped. Collectors on the stack are paused when not
# the top, and resumed when they become the top again.
_collectors = []
def __init__(self,
should_trace, check_include, timid, branch, warn, concurrency,
):
"""Create a collector.
`should_trace` is a function, taking a filename, and returning a
canonicalized filename, or None depending on whether the file should
be traced or not.
TODO: `check_include`
If `timid` is true, then a slower simpler trace function will be
used. This is important for some environments where manipulation of
tracing functions make the faster more sophisticated trace function not
operate properly.
If `branch` is true, then branches will be measured. This involves
collecting data on which statements followed each other (arcs). Use
`get_arc_data` to get the arc data.
`warn` is a warning function, taking a single string message argument,
to be used if a warning needs to be issued.
`concurrency` is a string indicating the concurrency library in use.
Valid values are "greenlet", "eventlet", "gevent", or "thread" (the
default).
"""
self.should_trace = should_trace
self.check_include = check_include
self.warn = warn
self.branch = branch
self.threading = None
self.concurrency = concurrency
self.concur_id_func = None
try:
if concurrency == "greenlet":
import greenlet # pylint: disable=import-error
self.concur_id_func = greenlet.getcurrent
elif concurrency == "eventlet":
import eventlet.greenthread # pylint: disable=import-error
self.concur_id_func = eventlet.greenthread.getcurrent
elif concurrency == "gevent":
import gevent # pylint: disable=import-error
self.concur_id_func = gevent.getcurrent
elif concurrency == "thread" or not concurrency:
# It's important to import threading only if we need it. If
# it's imported early, and the program being measured uses
# gevent, then gevent's monkey-patching won't work properly.
import threading
self.threading = threading
else:
raise CoverageException(
"Don't understand concurrency=%s" % concurrency
)
except ImportError:
raise CoverageException(
"Couldn't trace with concurrency=%s, "
"the module isn't installed." % concurrency
)
self.reset()
if timid:
# Being timid: use the simple Python trace function.
self._trace_class = PyTracer
else:
# Being fast: use the C Tracer if it is available, else the Python
# trace function.
self._trace_class = CTracer or PyTracer
def __repr__(self):
return "<Collector at 0x%x>" % id(self)
def tracer_name(self):
"""Return the class name of the tracer we're using."""
return self._trace_class.__name__
def reset(self):
"""Clear collected data, and prepare to collect more."""
# A dictionary mapping filenames to dicts with line number keys,
# or mapping filenames to dicts with line number pairs as keys.
self.data = {}
self.plugin_data = {}
# A cache of the results from should_trace, the decision about whether
# to trace execution in a file. A dict of filename to (filename or
# None).
if __pypy__ is not None:
# Alex Gaynor said:
# should_trace_cache is a strictly growing key: once a key is in
# it, it never changes. Further, the keys used to access it are
# generally constant, given sufficient context. That is to say, at
# any given point _trace() is called, pypy is able to know the key.
# This is because the key is determined by the physical source code
# line, and that's invariant with the call site.
#
# This property of a dict with immutable keys, combined with
# call-site-constant keys is a match for PyPy's module dict,
# which is optimized for such workloads.
#
# This gives a 20% benefit on the workload described at
# https://bitbucket.org/pypy/pypy/issue/1871/10x-slower-than-cpython-under-coverage
self.should_trace_cache = __pypy__.newdict("module")
else:
self.should_trace_cache = {}
# Our active Tracers.
self.tracers = []
def _start_tracer(self):
"""Start a new Tracer object, and store it in self.tracers."""
tracer = self._trace_class()
tracer.data = self.data
tracer.arcs = self.branch
tracer.should_trace = self.should_trace
tracer.should_trace_cache = self.should_trace_cache
tracer.warn = self.warn
if hasattr(tracer, 'concur_id_func'):
tracer.concur_id_func = self.concur_id_func
elif self.concur_id_func:
raise CoverageException(
"Can't support concurrency=%s with %s, "
"only threads are supported" % (
self.concurrency, self.tracer_name(),
)
)
if hasattr(tracer, 'plugin_data'):
tracer.plugin_data = self.plugin_data
if hasattr(tracer, 'threading'):
tracer.threading = self.threading
if hasattr(tracer, 'check_include'):
tracer.check_include = self.check_include
fn = tracer.start()
self.tracers.append(tracer)
return fn
# The trace function has to be set individually on each thread before
# execution begins. Ironically, the only support the threading module has
# for running code before the thread main is the tracing function. So we
# install this as a trace function, and the first time it's called, it does
# the real trace installation.
def _installation_trace(self, frame_unused, event_unused, arg_unused):
"""Called on new threads, installs the real tracer."""
# Remove ourselves as the trace function
sys.settrace(None)
# Install the real tracer.
fn = self._start_tracer()
# Invoke the real trace function with the current event, to be sure
# not to lose an event.
if fn:
fn = fn(frame_unused, event_unused, arg_unused)
# Return the new trace function to continue tracing in this scope.
return fn
def start(self):
"""Start collecting trace information."""
if self._collectors:
self._collectors[-1].pause()
self._collectors.append(self)
# Check to see whether we had a fullcoverage tracer installed.
traces0 = []
fn0 = sys.gettrace()
if fn0:
tracer0 = getattr(fn0, '__self__', None)
if tracer0:
traces0 = getattr(tracer0, 'traces', [])
# Install the tracer on this thread.
fn = self._start_tracer()
# Replay all the events from fullcoverage into the new trace function.
for args in traces0:
(frame, event, arg), lineno = args
try:
fn(frame, event, arg, lineno=lineno)
except TypeError:
raise Exception(
"fullcoverage must be run with the C trace function."
)
# Install our installation tracer in threading, to jump start other
# threads.
if self.threading:
self.threading.settrace(self._installation_trace)
def stop(self):
"""Stop collecting trace information."""
assert self._collectors
assert self._collectors[-1] is self
self.pause()
self.tracers = []
# Remove this Collector from the stack, and resume the one underneath
# (if any).
self._collectors.pop()
if self._collectors:
self._collectors[-1].resume()
def pause(self):
"""Pause tracing, but be prepared to `resume`."""
for tracer in self.tracers:
tracer.stop()
stats = tracer.get_stats()
if stats:
print("\nCoverage.py tracer stats:")
for k in sorted(stats.keys()):
print("%16s: %s" % (k, stats[k]))
if self.threading:
self.threading.settrace(None)
def resume(self):
"""Resume tracing after a `pause`."""
for tracer in self.tracers:
tracer.start()
if self.threading:
self.threading.settrace(self._installation_trace)
else:
self._start_tracer()
def get_line_data(self):
"""Return the line data collected.
Data is { filename: { lineno: None, ...}, ...}
"""
if self.branch:
# If we were measuring branches, then we have to re-build the dict
# to show line data.
line_data = {}
for f, arcs in self.data.items():
line_data[f] = dict((l1, None) for l1, _ in arcs.keys() if l1)
return line_data
else:
return self.data
def get_arc_data(self):
"""Return the arc data collected.
Data is { filename: { (l1, l2): None, ...}, ...}
Note that no data is collected or returned if the Collector wasn't
created with `branch` true.
"""
if self.branch:
return self.data
else:
return {}
def get_plugin_data(self):
return self.plugin_data