Add experimental profiler under experiments.enable_profiling

sentry_sdk/integrations/wsgi.py

@@ -1,4 +1,5 @@
 import sys
+import sentry_sdk.profiler as profiler
 
 from sentry_sdk._functools import partial
 from sentry_sdk.hub import Hub, _should_send_default_pii
@@ -109,34 +110,35 @@ def __call__(self, environ, start_response):
         _wsgi_middleware_applied.set(True)
         try:
             hub = Hub(Hub.current)
-            with auto_session_tracking(hub, session_mode="request"):
-                with hub:
-                    with capture_internal_exceptions():
-                        with hub.configure_scope() as scope:
-                            scope.clear_breadcrumbs()
-                            scope._name = "wsgi"
-                            scope.add_event_processor(
-                                _make_wsgi_event_processor(
-                                    environ, self.use_x_forwarded_for
+            with profiler.Sampler(): # TODO: Check if profiling flag is set to True
+                with auto_session_tracking(hub, session_mode="request"):
+                    with hub:
+                        with capture_internal_exceptions():
+                            with hub.configure_scope() as scope:
+                                scope.clear_breadcrumbs()
+                                scope._name = "wsgi"
+                                scope.add_event_processor(
+                                    _make_wsgi_event_processor(
+                                        environ, self.use_x_forwarded_for
+                                    )
                                 )
-                            )
-
-                    transaction = Transaction.continue_from_environ(
-                        environ, op="http.server", name="generic WSGI request"
-                    )
-
-                    with hub.start_transaction(
-                        transaction, custom_sampling_context={"wsgi_environ": environ}
-                    ):
-                        try:
-                            rv = self.app(
-                                environ,
-                                partial(
-                                    _sentry_start_response, start_response, transaction
-                                ),
-                            )
-                        except BaseException:
-                            reraise(*_capture_exception(hub))
+
+                        transaction = Transaction.continue_from_environ(
+                            environ, op="http.server", name="generic WSGI request"
+                        )
+
+                        with hub.start_transaction(
+                            transaction, custom_sampling_context={"wsgi_environ": environ}
+                        ):
+                            try:
+                                rv = self.app(
+                                    environ,
+                                    partial(
+                                        _sentry_start_response, start_response, transaction
+                                    ),
+                                )
+                            except BaseException:
+                                reraise(*_capture_exception(hub))
         finally:
             _wsgi_middleware_applied.set(False)
 

sentry_sdk/profiler.py

@@ -0,0 +1,100 @@
+"""
+This file contains code from https://github.com/nylas/nylas-perftools, which is published under the following license:
+
+The MIT License (MIT)
+
+Copyright (c) 2014 Nylas
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+"""
+
+import atexit
+import os
+import signal
+import time
+from sentry_sdk.utils import logger
+
+def nanosecond_time():
+    return int(time.perf_counter() * 1e9)
+
+class FrameData:
+    def __init__(self, frame):
+        self._function_name = frame.f_code.co_name
+        self._module = frame.f_globals['__name__']
+
+        # Depending on Python version, frame.f_code.co_filename either stores just the file name or the entire absolute path.
+        self._file_name = os.path.basename(frame.f_code.co_filename)
+        self._abs_path = os.path.abspath(frame.f_code.co_filename) # TODO: Must verify this will give us correct absolute paths in all cases!
+        self._line_number = frame.f_lineno
+
+    def __str__(self):
+        return f'{self._function_name}({self._module}) in {self._file_name}:{self._line_number}'
+
+class StackSample:
+    def __init__(self, top_frame, profiler_start_time):
+        self._sample_time = nanosecond_time() - profiler_start_time
+        self._stack = []
+        self._add_all_frames(top_frame)
+
+    def _add_all_frames(self, top_frame):
+        frame = top_frame
+        while frame is not None:
+            self._stack.append(FrameData(frame))
+            frame = frame.f_back
+
+    def __str__(self):
+        return f'Time: {self._sample_time}; Stack: {[str(frame) for frame in reversed(self._stack)]}'
+
+class Sampler(object):
+    """
+    A simple stack sampler for low-overhead CPU profiling: samples the call
+    stack every `interval` seconds and keeps track of counts by frame. Because
+    this uses signals, it only works on the main thread.
+    """
+    def __init__(self, interval=0.01):
+        self.interval = interval
+        self._stack_samples = []
+
+    def __enter__(self):
+        self.start()
+
+    def __exit__(self, *_):
+        self.stop()
+        print(self)
+
+    def start(self):
+        self._start_time = nanosecond_time()
+        self._stack_samples = []
+        try:
+            signal.signal(signal.SIGVTALRM, self._sample)
+        except ValueError:
+            logger.warn('Profiler failed to run because it was started from a non-main thread') # TODO: Does not print anything
+            return 
+
+        signal.setitimer(signal.ITIMER_VIRTUAL, self.interval)
+        atexit.register(self.stop)
+
+    def _sample(self, signum, frame):
+        self._stack_samples.append(StackSample(frame, self._start_time))
+        #print('j')
+        signal.setitimer(signal.ITIMER_VIRTUAL, self.interval)
+
+    def _format_frame(self, frame):
+        return '{}({})'.format(frame.f_code.co_name,
+                               frame.f_globals.get('__name__'))
+
+    def samples(self):
+        return len(self._stack_samples)
+
+    def __str__(self):
+        return '\n'.join([str(sample) for sample in self._stack_samples])
+
+    def stop(self):
+        signal.setitimer(signal.ITIMER_VIRTUAL, 0)
+
+    def __del__(self):
+        self.stop()