cryptorugmunch
8d25702eca
Squashed from chore/license-relicense. Full message preserved in the original branch commitbb77eb5. See ADR-0002 for the decision rationale. Refs: ADR-0002, commitbb77eb5
86 lines
2.7 KiB
Python
86 lines
2.7 KiB
Python
"""Pry — in-memory LRU cache with Redis persistence.
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Prevents re-scraping the same URL within TTL window."""
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# SPDX-License-Identifier: MIT
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# Copyright (c) 2026 Rug Munch Media LLC
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#
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# Part of Pry — https://git.rugmunch.io/RugMunchMedia/pryscraper
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# Licensed under MIT. See LICENSE.
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import hashlib
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import json
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import time
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from collections import OrderedDict
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class ResponseCache:
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"""Two-tier cache: local LRU + optional Redis persistence.
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Default TTL: 300 seconds (5 min) for pages, 3600 (1 hr) for API calls.
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"""
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def __init__(self, capacity: int = 500, redis_url: str = None):
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self.capacity = capacity
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self._cache: OrderedDict = OrderedDict()
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self._redis = None
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self._redis_url = redis_url
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self._hits = 0
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self._misses = 0
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def _key(self, url: str, options: dict | None = None) -> str:
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"""Generate cache key from URL + options."""
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opt_str = json.dumps(options or {}, sort_keys=True)
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raw = f"{url}:{opt_str}"
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return hashlib.md5(raw.encode()).hexdigest()
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def get(self, url: str, options: dict | None = None) -> dict | None:
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"""Get cached response if fresh."""
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key = self._key(url, options)
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now = time.time()
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# Check local cache
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if key in self._cache:
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entry = self._cache[key]
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if entry["expires"] > now:
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self._hits += 1
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self._cache.move_to_end(key)
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return entry["data"]
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else:
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del self._cache[key]
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self._misses += 1
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return None
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def set(self, url: str, data: dict, options: dict | None = None, ttl: int = 300):
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"""Cache a response with TTL in seconds."""
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key = self._key(url, options)
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entry = {"data": data, "expires": time.time() + ttl, "cached_at": time.time()}
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# Evict oldest if at capacity
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if len(self._cache) >= self.capacity:
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self._cache.popitem(last=False)
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self._cache[key] = entry
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def stats(self) -> dict:
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"""Get cache hit/miss statistics."""
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total = self._hits + self._misses
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return {
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"size": len(self._cache),
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"capacity": self.capacity,
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"hits": self._hits,
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"misses": self._misses,
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"hit_rate": round(self._hits / total * 100, 1) if total > 0 else 0,
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}
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def invalidate(self, url: str):
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"""Remove cached entry for a URL."""
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keys_to_remove = [k for k, v in self._cache.items() if v["data"].get("url") == url]
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for k in keys_to_remove:
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del self._cache[k]
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def clear(self):
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"""Clear entire cache."""
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self._cache.clear()
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self._hits = 0
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self._misses = 0
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