init

.venv/lib/python3.8/site-packages/mypy/gclogger.py

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+import gc
+import time
+
+from typing import Mapping, Optional
+
+
+class GcLogger:
+    """Context manager to log GC stats and overall time."""
+
+    def __enter__(self) -> 'GcLogger':
+        self.gc_start_time: Optional[float] = None
+        self.gc_time = 0.0
+        self.gc_calls = 0
+        self.gc_collected = 0
+        self.gc_uncollectable = 0
+        gc.callbacks.append(self.gc_callback)
+        self.start_time = time.time()
+        return self
+
+    def gc_callback(self, phase: str, info: Mapping[str, int]) -> None:
+        if phase == 'start':
+            assert self.gc_start_time is None, "Start phase out of sequence"
+            self.gc_start_time = time.time()
+        elif phase == 'stop':
+            assert self.gc_start_time is not None, "Stop phase out of sequence"
+            self.gc_calls += 1
+            self.gc_time += time.time() - self.gc_start_time
+            self.gc_start_time = None
+            self.gc_collected += info['collected']
+            self.gc_uncollectable += info['uncollectable']
+        else:
+            assert False, "Unrecognized gc phase (%r)" % (phase,)
+
+    def __exit__(self, *args: object) -> None:
+        while self.gc_callback in gc.callbacks:
+            gc.callbacks.remove(self.gc_callback)
+
+    def get_stats(self) -> Mapping[str, float]:
+        end_time = time.time()
+        result = {}
+        result['gc_time'] = self.gc_time
+        result['gc_calls'] = self.gc_calls
+        result['gc_collected'] = self.gc_collected
+        result['gc_uncollectable'] = self.gc_uncollectable
+        result['build_time'] = end_time - self.start_time
+        return result