Раис Юсупалиев
117 lines
4.1 KiB
Python
117 lines
4.1 KiB
Python
"""Redis-backed cache repository."""
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from dataclasses import asdict, is_dataclass
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from decimal import Decimal
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from enum import Enum
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import json
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from typing import Any, Callable, Protocol
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from pydantic import BaseModel
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from app.config import RepositoryConfig
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class RedisClientProtocol(Protocol):
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async def get(self, key: str) -> bytes | str | None: ...
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async def set(self, key: str, value: str, ex: int | None = None) -> Any: ...
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async def delete(self, key: str) -> Any: ...
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class PriceCacheRepositoryError(RuntimeError):
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"""Deterministic repository error raised on Redis operation failures."""
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class PriceCache:
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"""Repository for cached provider payloads."""
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def __init__(self, redis_client: RedisClientProtocol, *, ttl_seconds: int) -> None:
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self._redis_client = redis_client
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self._ttl_seconds = ttl_seconds
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@classmethod
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def from_repository_config(
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cls,
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repository_config: RepositoryConfig,
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*,
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client_factory: Callable[[str], RedisClientProtocol] | None = None,
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) -> "PriceCache":
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resolved_factory = client_factory or _default_redis_client_factory
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redis_client = resolved_factory(repository_config.redis_dsn)
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return cls(
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redis_client=redis_client,
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ttl_seconds=repository_config.price_cache_ttl_seconds,
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)
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async def get(self, key: str) -> Any | None:
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try:
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payload = await self._redis_client.get(key)
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except Exception as exc:
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raise PriceCacheRepositoryError("Redis cache read failed.") from exc
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if payload is None:
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return None
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if isinstance(payload, bytes):
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serialized_payload = payload.decode("utf-8")
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elif isinstance(payload, str):
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serialized_payload = payload
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else:
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raise TypeError("Redis cache payload must be bytes or str.")
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return json.loads(serialized_payload)
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async def set(self, key: str, value: Any, ttl: int | None = None) -> None:
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serialized_payload = _serialize(value)
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resolved_ttl = self._ttl_seconds if ttl is None else ttl
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try:
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await self._redis_client.set(key, serialized_payload, ex=resolved_ttl)
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except Exception as exc:
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raise PriceCacheRepositoryError("Redis cache write failed.") from exc
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async def invalidate(self, key: str) -> None:
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try:
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await self._redis_client.delete(key)
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except Exception as exc:
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raise PriceCacheRepositoryError("Redis cache invalidate failed.") from exc
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def _default_redis_client_factory(redis_dsn: str) -> RedisClientProtocol:
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"""Create async Redis client from DSN."""
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try:
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from aioredis import from_url as aioredis_from_url # type: ignore
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except ModuleNotFoundError:
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try:
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import redis.asyncio as redis_asyncio # type: ignore[import-not-found]
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except ModuleNotFoundError as exc:
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raise RuntimeError(
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"No async Redis client implementation is available."
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) from exc
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return redis_asyncio.from_url(redis_dsn, encoding="utf-8", decode_responses=False)
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return aioredis_from_url(redis_dsn, encoding="utf-8", decode_responses=False)
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def _serialize(value: Any) -> str:
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normalized = _normalize_for_json(value)
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return json.dumps(normalized, ensure_ascii=True, sort_keys=True, separators=(",", ":"))
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def _normalize_for_json(value: Any) -> Any:
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if isinstance(value, BaseModel):
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return _normalize_for_json(value.model_dump(mode="json"))
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if is_dataclass(value):
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return _normalize_for_json(asdict(value))
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if isinstance(value, Enum):
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return _normalize_for_json(value.value)
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if isinstance(value, Decimal):
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return str(value)
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if isinstance(value, dict):
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return {str(key): _normalize_for_json(item) for key, item in value.items()}
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if isinstance(value, (list, tuple)):
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return [_normalize_for_json(item) for item in value]
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if value is None or isinstance(value, (str, int, float, bool)):
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return value
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raise TypeError(f"Unsupported cache payload type: {type(value)!r}")
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