# Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 # For details: https://bitbucket.org/ned/coveragepy/src/default/NOTICE.txt """Raw data collector for coverage.py.""" import os import sys from coverage import env from coverage.backward import iitems from coverage.files import abs_file from coverage.misc import CoverageException, isolate_module from coverage.pytracer import PyTracer os = isolate_module(os) try: # Use the C extension code when we can, for speed. from coverage.tracer import CTracer, CFileDisposition # 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 environment variable # 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 class FileDisposition(object): """A simple value type for recording what to do with a file.""" pass 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 file name, and returning a `coverage.FileDisposition object`. `check_include` is a function taking a file name and a frame. It returns a boolean: True if the file should be traced, False if not. 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 self.concur_id_func = greenlet.getcurrent elif concurrency == "eventlet": import eventlet.greenthread # pylint: disable=import-error,useless-suppression self.concur_id_func = eventlet.greenthread.getcurrent elif concurrency == "gevent": import gevent # pylint: disable=import-error,useless-suppression 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 if self._trace_class is CTracer: self.file_disposition_class = CFileDisposition self.supports_plugins = True else: self.file_disposition_class = FileDisposition self.supports_plugins = False def __repr__(self): return "" % (id(self), self.tracer_name()) 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 file names to dicts with line number keys (if not # branch coverage), or mapping file names to dicts with line number # pairs as keys (if branch coverage). self.data = {} # A dictionary mapping file names to file tracer plugin names that will # handle them. self.file_tracers = {} # The .should_trace_cache attribute is a cache from file names to # coverage.FileDisposition objects, or None. When a file is first # considered for tracing, a FileDisposition is obtained from # Coverage.should_trace. Its .trace attribute indicates whether the # file should be traced or not. If it should be, a plugin with dynamic # file names can decide not to trace it based on the dynamic file name # being excluded by the inclusion rules, in which case the # FileDisposition will be replaced by None in the cache. if env.PYPY: import __pypy__ # pylint: disable=import-error # 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.trace_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, 'file_tracers'): tracer.file_tracers = self.file_tracers 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, event, arg): """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, event, arg) # 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() # Check to see whether we had a fullcoverage tracer installed. If so, # get the stack frames it stashed away for us. traces0 = [] fn0 = sys.gettrace() if fn0: tracer0 = getattr(fn0, '__self__', None) if tracer0: traces0 = getattr(tracer0, 'traces', []) try: # Install the tracer on this thread. fn = self._start_tracer() except: if self._collectors: self._collectors[-1].resume() raise # If _start_tracer succeeded, then we add ourselves to the global # stack of collectors. self._collectors.append(self) # 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, ( "Expected current collector to be %r, but it's %r" % (self, self._collectors[-1]) ) 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 save_data(self, covdata): """Save the collected data to a `CoverageData`. Also resets the collector. """ def abs_file_dict(d): """Return a dict like d, but with keys modified by `abs_file`.""" return dict((abs_file(k), v) for k, v in iitems(d)) if self.branch: covdata.add_arcs(abs_file_dict(self.data)) else: covdata.add_lines(abs_file_dict(self.data)) covdata.add_file_tracers(abs_file_dict(self.file_tracers)) self.reset()