59 lines
1.5 KiB
Python
59 lines
1.5 KiB
Python
"""磁盘缓存：SQLite 持久化，重启不丢"""
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import json
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from datetime import datetime, timedelta
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from typing import Optional
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from database import get_connection
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def get_cache(key: str) -> Optional[str]:
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"""获取缓存，过期或不存在返回 None"""
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now = datetime.now().isoformat()
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conn = get_connection()
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try:
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row = conn.execute(
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"SELECT value FROM cache WHERE key = ? AND expires_at > ?",
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(key, now),
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).fetchone()
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if row:
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return row["value"]
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return None
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finally:
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conn.close()
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def set_cache(key: str, value: str, ttl_hours: int = 6):
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"""写入缓存，过期时间 = now + ttl_hours"""
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expires_at = (datetime.now() + timedelta(hours=ttl_hours)).isoformat()
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conn = get_connection()
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try:
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conn.execute(
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"INSERT OR REPLACE INTO cache (key, value, expires_at) VALUES (?, ?, ?)",
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(key, value, expires_at),
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)
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conn.commit()
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finally:
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conn.close()
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def del_cache(key: str):
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"""删除指定缓存"""
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conn = get_connection()
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try:
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conn.execute("DELETE FROM cache WHERE key = ?", (key,))
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conn.commit()
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finally:
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conn.close()
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def clean_expired():
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"""清理已过期的缓存（可在启动时调用一次）"""
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now = datetime.now().isoformat()
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conn = get_connection()
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try:
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conn.execute("DELETE FROM cache WHERE expires_at <= ?", (now,))
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conn.commit()
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finally:
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conn.close()
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