feat: valkey first-class store support

Adds support for Valkey as a store option, alternative to Redis.

litestar/stores/valkey.py

@@ -0,0 +1,210 @@
+from __future__ import annotations
+
+from datetime import timedelta
+from typing import TYPE_CHECKING, cast
+
+from valkey.asyncio import Valkey
+from valkey.asyncio.connection import ConnectionPool
+
+from litestar.exceptions import ImproperlyConfiguredException
+from litestar.types import Empty, EmptyType
+from litestar.utils.empty import value_or_default
+
+from .base import NamespacedStore
+
+if TYPE_CHECKING:
+    from types import TracebackType
+
+
+__all__ = ("ValkeyStore",)
+
+
+class ValkeyStore(NamespacedStore):
+    """Valkey based, thread and process safe asynchronous key/value store."""
+
+    __slots__ = (
+        "_delete_all_script",
+        "_get_and_renew_script",
+        "_valkey",
+        "handle_client_shutdown",
+    )
+
+    def __init__(
+        self, valkey: Valkey, namespace: str | None | EmptyType = Empty, handle_client_shutdown: bool = False
+    ) -> None:
+        """Initialize :class:`ValkeyStore`
+
+        Args:
+            valkey: An :class:`valkey.asyncio.Valkey` instance
+            namespace: A key prefix to simulate a namespace in valkey. If not given,
+                defaults to ``LITESTAR``. Namespacing can be explicitly disabled by passing
+                ``None``. This will make :meth:`.delete_all` unavailable.
+            handle_client_shutdown: If ``True``, handle the shutdown of the `valkey` instance automatically during the store's lifespan. Should be set to `True` unless the shutdown is handled externally
+        """
+        self._valkey = valkey
+        self.namespace: str | None = value_or_default(namespace, "LITESTAR")
+        self.handle_client_shutdown = handle_client_shutdown
+
+        # script to get and renew a key in one atomic step
+        self._get_and_renew_script = self._valkey.register_script(
+            b"""
+        local key = KEYS[1]
+        local renew = tonumber(ARGV[1])
+
+        local data = server.call('GET', key)
+        local ttl = server.call('TTL', key)
+
+        if ttl > 0 then
+            server.call('EXPIRE', key, renew)
+        end
+
+        return data
+        """
+        )
+
+        # script to delete all keys in the namespace
+        self._delete_all_script = self._valkey.register_script(
+            b"""
+        local cursor = 0
+
+        repeat
+            local result = server.call('SCAN', cursor, 'MATCH', ARGV[1])
+            for _,key in ipairs(result[2]) do
+                server.call('UNLINK', key)
+            end
+            cursor = tonumber(result[1])
+        until cursor == 0
+        """
+        )
+
+    async def _shutdown(self) -> None:
+        if self.handle_client_shutdown:
+            await self._valkey.aclose(close_connection_pool=True)
+
+    async def __aexit__(
+        self,
+        exc_type: type[BaseException] | None,
+        exc_val: BaseException | None,
+        exc_tb: TracebackType | None,
+    ) -> None:
+        await self._shutdown()
+
+    @classmethod
+    def with_client(
+        cls,
+        url: str = "valkey://localhost:6379",
+        *,
+        db: int | None = None,
+        port: int | None = None,
+        username: str | None = None,
+        password: str | None = None,
+        namespace: str | None | EmptyType = Empty,
+    ) -> ValkeyStore:
+        """Initialize a :class:`ValkeyStore` instance with a new class:`valkey.asyncio.Valkey` instance.
+
+        Args:
+            url: Valkey URL to connect to
+            db: Valkey database to use
+            port: Valkey port to use
+            username: Valkey username to use
+            password: Valkey password to use
+            namespace: Virtual key namespace to use
+        """
+        pool: ConnectionPool = ConnectionPool.from_url(
+            url=url,
+            db=db,
+            decode_responses=False,
+            port=port,
+            username=username,
+            password=password,
+        )
+        return cls(
+            valkey=Valkey(connection_pool=pool),
+            namespace=namespace,
+            handle_client_shutdown=True,
+        )
+
+    def with_namespace(self, namespace: str) -> ValkeyStore:
+        """Return a new :class:`ValkeyStore` with a nested virtual key namespace.
+        The current instances namespace will serve as a prefix for the namespace, so it
+        can be considered the parent namespace.
+        """
+        return type(self)(
+            valkey=self._valkey,
+            namespace=f"{self.namespace}_{namespace}" if self.namespace else namespace,
+            handle_client_shutdown=self.handle_client_shutdown,
+        )
+
+    def _make_key(self, key: str) -> str:
+        prefix = f"{self.namespace}:" if self.namespace else ""
+        return prefix + key
+
+    async def set(self, key: str, value: str | bytes, expires_in: int | timedelta | None = None) -> None:
+        """Set a value.
+
+        Args:
+            key: Key to associate the value with
+            value: Value to store
+            expires_in: Time in seconds before the key is considered expired
+
+        Returns:
+            ``None``
+        """
+        if isinstance(value, str):
+            value = value.encode("utf-8")
+        await self._valkey.set(self._make_key(key), value, ex=expires_in)
+
+    async def get(self, key: str, renew_for: int | timedelta | None = None) -> bytes | None:
+        """Get a value.
+
+        Args:
+            key: Key associated with the value
+            renew_for: If given and the value had an initial expiry time set, renew the
+                expiry time for ``renew_for`` seconds. If the value has not been set
+                with an expiry time this is a no-op. Atomicity of this step is guaranteed
+                by using a lua script to execute fetch and renewal. If ``renew_for`` is
+                not given, the script will be bypassed so no overhead will occur
+
+        Returns:
+            The value associated with ``key`` if it exists and is not expired, else
+            ``None``
+        """
+        key = self._make_key(key)
+        if renew_for:
+            if isinstance(renew_for, timedelta):
+                renew_for = renew_for.seconds
+            data = await self._get_and_renew_script(keys=[key], args=[renew_for])
+            return cast("bytes | None", data)
+        return await self._valkey.get(key)  # type: ignore[no-any-return]
+
+    async def delete(self, key: str) -> None:
+        """Delete a value.
+
+        If no such key exists, this is a no-op.
+
+        Args:
+            key: Key of the value to delete
+        """
+        await self._valkey.delete(self._make_key(key))
+
+    async def delete_all(self) -> None:
+        """Delete all stored values in the virtual key namespace.
+
+        Raises:
+            ImproperlyConfiguredException: If no namespace was configured
+        """
+        if not self.namespace:
+            raise ImproperlyConfiguredException("Cannot perform delete operation: No namespace configured")
+
+        await self._delete_all_script(keys=[], args=[f"{self.namespace}*:*"])
+
+    async def exists(self, key: str) -> bool:
+        """Check if a given ``key`` exists."""
+        return await self._valkey.exists(self._make_key(key)) == 1  # type: ignore[no-any-return]
+
+    async def expires_in(self, key: str) -> int | None:
+        """Get the time in seconds ``key`` expires in. If no such ``key`` exists or no
+        expiry time was set, return ``None``.
+        """
+        ttl = await self._valkey.ttl(self._make_key(key))
+        return None if ttl == -2 else ttl

pyproject.toml

@@ -83,7 +83,7 @@ brotli = ["brotli"]
 cli = ["jsbeautifier", "uvicorn[standard]", "uvloop>=0.18.0; sys_platform != 'win32'"]
 cryptography = ["cryptography"]
 full = [
-  "litestar[annotated-types,attrs,brotli,cli,cryptography,jinja,jwt,mako,minijinja,opentelemetry,piccolo,picologging,prometheus,pydantic,redis,sqlalchemy,standard,structlog]",
+  "litestar[annotated-types,attrs,brotli,cli,cryptography,jinja,jwt,mako,minijinja,opentelemetry,piccolo,picologging,prometheus,pydantic,redis,sqlalchemy,standard,structlog,valkey]",
 ]
 jinja = ["jinja2>=3.1.2"]
 jwt = [
@@ -98,6 +98,7 @@ picologging = ["picologging"]
 prometheus = ["prometheus-client"]
 pydantic = ["pydantic", "email-validator", "pydantic-extra-types"]
 redis = ["redis[hiredis]>=4.4.4"]
+valkey = ["valkey[libvalkey]>=6.0.2"]
 sqlalchemy = ["advanced-alchemy>=0.2.2"]
 standard = ["jinja2", "jsbeautifier", "uvicorn[standard]", "uvloop>=0.18.0; sys_platform != 'win32'", "fast-query-parsers>=1.0.2"]
 structlog = ["structlog"]