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Cache Stampede Prevention with SingleFlight in Python

Implements a SingleFlight pattern in Python to deduplicate concurrent cache-miss computations and prevent cache stampede.

caching concurrency singleflight

Python

import threading
import time
from functools import wraps


class SingleFlight:
    def __init__(self):
        self._lock = threading.Lock()
        self._inflight = None

    def do(self, key, fn):
        with self._lock:
            if self._inflight is not None:
                return self._inflight[1]
           …

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