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a721dfa 2eec8c3 a721dfa 2eec8c3 a721dfa 2eec8c3 a721dfa 2eec8c3 a721dfa 2eec8c3 a721dfa | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 | from __future__ import annotations
import asyncio
import json
import os
import sqlite3
import time
from typing import Any, Callable, Dict, Optional, Protocol, Tuple
from backend.runtime_utils import clone_cache_payload
class LoggerLike(Protocol):
def error(self, msg: str, *args: Any, **kwargs: Any) -> None: ...
def info(self, msg: str, *args: Any, **kwargs: Any) -> None: ...
class PersistentCache:
"""SQLite-based persistent cache layer."""
def __init__(
self,
db_path: str,
cache_version_getter: Callable[[], str],
logger: LoggerLike,
) -> None:
self.db_path = db_path
self._cache_version_getter = cache_version_getter
self._logger = logger
db_dir = os.path.dirname(os.path.abspath(self.db_path))
os.makedirs(db_dir, exist_ok=True)
self._init_db()
def _init_db(self) -> None:
with sqlite3.connect(self.db_path) as conn:
conn.execute(
"""
CREATE TABLE IF NOT EXISTS cache (
key TEXT PRIMARY KEY,
payload BLOB,
expiry REAL,
version TEXT
)
"""
)
conn.execute("CREATE INDEX IF NOT EXISTS idx_expiry ON cache(expiry)")
def get(self, key: str) -> Optional[Any]:
try:
cache_version = self._cache_version_getter()
with sqlite3.connect(self.db_path) as conn:
cur = conn.execute(
"SELECT payload, expiry, version FROM cache WHERE key = ?",
(key,),
)
row = cur.fetchone()
if row:
payload, expiry, version = row
if time.time() < expiry and version == cache_version:
return json.loads(payload)
conn.execute("DELETE FROM cache WHERE key = ?", (key,))
except Exception as ex:
self._logger.error("[Persistence] Read error: %s", ex)
return None
def set(self, key: str, payload: Any, ttl: int) -> None:
cached_payload = clone_cache_payload(payload)
if hasattr(self, "_queue"):
self._queue.put_nowait((key, cached_payload, ttl))
return
self._write_sync(key, cached_payload, ttl)
def _write_sync(self, key: str, payload: Any, ttl: int) -> None:
try:
with sqlite3.connect(self.db_path) as conn:
conn.execute(
"INSERT OR REPLACE INTO cache (key, payload, expiry, version) VALUES (?, ?, ?, ?)",
(key, json.dumps(payload), time.time() + ttl, self._cache_version_getter()),
)
except Exception as ex:
self._logger.error("[Persistence] Sync write error: %s", ex)
async def start_writer(self) -> None:
self._queue: asyncio.Queue[Tuple[str, Any, int]] = asyncio.Queue()
self._logger.info("[Persistence] Async writer started.")
while True:
key, payload, ttl = await self._queue.get()
try:
await asyncio.to_thread(self._write_sync, key, payload, ttl)
except Exception as ex:
self._logger.error("[Persistence] Writer loop error: %s", ex)
finally:
self._queue.task_done()
def evict(self) -> None:
try:
with sqlite3.connect(self.db_path) as conn:
conn.execute("DELETE FROM cache WHERE expiry < ?", (time.time(),))
except Exception as ex:
self._logger.error("[Persistence] Eviction error: %s", ex)
class TTLCache:
def __init__(self) -> None:
self._store: Dict[str, Tuple[float, Any]] = {}
def get(self, key: str) -> Optional[Any]:
entry = self._store.get(key)
if entry is None:
return None
exp, payload = entry
if time.time() > exp:
self._store.pop(key, None)
return None
return clone_cache_payload(payload)
def set(self, key: str, payload: Any, ttl_seconds: int) -> None:
self._store[key] = (time.time() + ttl_seconds, clone_cache_payload(payload))
def delete(self, key: str) -> bool:
return self._store.pop(key, None) is not None
def delete_by_prefix(self, prefix: str) -> int:
victims = [k for k in list(self._store) if k.startswith(prefix)]
for key in victims:
self._store.pop(key, None)
return len(victims)
def clear(self) -> int:
count = len(self._store)
self._store.clear()
return count
def evict_expired(self) -> int:
now = time.time()
expired = [key for key, (exp, _) in self._store.items() if now > exp]
for key in expired:
self._store.pop(key, None)
return len(expired)
def stats(self) -> Dict[str, Any]:
now = time.time()
alive = sum(1 for exp, _ in self._store.values() if now <= exp)
return {
"total_keys": len(self._store),
"alive_keys": alive,
"expired_keys": len(self._store) - alive,
}
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