from __future__ import annotations
import gc
import time
from collections.abc import Mapping
class GcLogger:
"""Context manager to log GC stats and overall time."""
def __enter__(self) -> GcLogger:
self.gc_start_time: float | None = 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, f"Unrecognized gc phase ({phase!r})"
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 = {
"gc_time": self.gc_time,
"gc_calls": self.gc_calls,
"gc_collected": self.gc_collected,
"gc_uncollectable": self.gc_uncollectable,
"build_time": end_time - self.start_time,
}
return result
