adds profiler

Author: David Erb

src/dls_utilpack/profiler.py

@@ -0,0 +1,89 @@
+import logging
+import threading
+import time
+from typing import Optional
+
+logger = logging.getLogger(__name__)
+
+
+class Profile:
+    """
+    Class that holds the total execution time and call count of potentially multiple executions of the same label.
+    Reports its contents as a single-line string.
+
+    TODO: Make profiles nestable by accumulating them at the context close.
+    """
+
+    def __init__(self, label):
+        self.__label = label
+        self.__start_time = 0
+        self.__seconds = 0.0
+        self.__count = 0
+
+    def __enter__(self):
+        self.__start_time = time.time()
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.__seconds = time.time() - self.__start_time
+        self.__count += 1
+
+    def __str__(self):
+        if self.__count == 0:
+            average = 0.0
+        else:
+            average = self.__seconds / self.__count
+
+        return (
+            f"{self.__label} called {self.__count} times"
+            f" for average of {'%0.3f' % average} seconds"
+        )
+
+
+class Profiler:
+    """
+    Class that accumulates multiple profiles.
+    Reports its results as a multi-line string.
+    """
+
+    def __init__(self):
+        self.__profiles = {}
+
+    def profile(self, label: str) -> Profile:
+        """
+        Return the profile for the given label.  Uses previously existing profile, if any, or makes a new instance.
+
+        Args:
+            label (str): label identifying the profile
+
+        Returns:
+            Profile: a new profile object, or previously existing one
+        """
+        profile = self.__profiles.get(label)
+        if profile is None:
+            profile = Profile(label)
+            self.__profiles[label] = profile
+
+        return profile
+
+    def __str__(self) -> str:
+        lines = []
+        for profile in self.__profiles.values():
+            lines.append(str(profile))
+
+        return "\n".join(lines)
+
+
+# A global instance for convenience.
+__profiler: Optional[Profiler] = None
+
+__global_lock = threading.RLock()
+
+
+def dls_utilpack_global_profiler() -> Profiler:
+    global __profiler
+    global __global_lock
+
+    with __global_lock:
+        if __profiler is None:
+            __profiler = Profiler()
+    return __profiler

tests/test_profiler.py

@@ -0,0 +1,32 @@
+import asyncio
+import logging
+
+from dls_utilpack.profiler import dls_utilpack_global_profiler
+
+# Base class for the tester.
+from tests.base_tester import BaseTester
+
+logger = logging.getLogger(__name__)
+
+
+# ----------------------------------------------------------------------------------------
+class TestProfiler(BaseTester):
+    def test(self, constants, logging_setup, output_directory):
+        """ """
+
+        self.main(constants, output_directory)
+
+    # ----------------------------------------------------------------------------------------
+    async def _main_coroutine(
+        self,
+        constants,
+        output_directory,
+    ):
+        """ """
+
+        profiler = dls_utilpack_global_profiler()
+
+        with profiler.profile("loop1"):
+            await asyncio.sleep(0.1)
+
+        logger.debug(f"profile\n{profiler}")