allow to use xxhash as digestmod #344

Readme.md

@@ -139,7 +139,8 @@ This backend uses [pickle](https://docs.python.org/3/library/pickle.html) module
 values, but the cashes can store values with md5-keyed hash.
 
 Use `secret` and `digestmod` parameters to protect your application from security vulnerabilities.
-The `digestmod` is a hashing algorithm that can be used: `sum`, `md5` (default), `sha1` and `sha256`
+The `digestmod` is a hashing algorithm that can be used: `sum`, `md5` (default), `sha1` and `sha256`.
+To use [xxhash](https://pypi.org/project/xxhash/) algorithms (digestmods: `xxh3_64`, `xxh3_128`, `xxh32` and `xxh64`) install `xxhash` package or setup cashews with speedup requirements (`pip install cashews[speedup]`))
 The `secret` is a salt for a hash.
 
 Pickle can't serialize any type of object. In case you need to store more complex types

cashews/exceptions.py

@@ -14,6 +14,10 @@ class UnsupportedPicklerError(CacheError):
     """Unknown or unsupported pickle type."""
 
 
+class UnsupportedDigestmod(CacheError):
+    """Unknown or unsupported digestmod type."""
+
+
 class UnsupportedCompressorError(CacheError):
     """Unknown or unsupported compress type."""
 

cashews/serialize.py

@@ -6,26 +6,58 @@
 from typing import TYPE_CHECKING
 
 from .compresors import Compressor, CompressType, get_compressor
-from .exceptions import DecompressionError, SignIsMissingError, UnSecureDataError
+from .exceptions import DecompressionError, SignIsMissingError, UnSecureDataError, UnsupportedDigestmod
 from .picklers import Pickler, PicklerType, get_pickler
 
+try:
+    import xxhash
+except ImportError:
+    _XXHASH = False
+else:
+    _XXHASH = True
+
+
 if TYPE_CHECKING:  # pragma: no cover
     from ._typing import ICustomDecoder, ICustomEncoder, Key, Value
     from .backends.interface import Backend
 
 
 def _seal(digestmod):
-    def sign(key: bytes, value: bytes) -> bytes:
-        return hmac.new(key, value, digestmod).hexdigest().encode()
+    def sign(secret: bytes, value: bytes) -> bytes:
+        return hmac.new(secret, value, digestmod).hexdigest().encode()
 
     return sign
 
 
-def simple_sign(key: bytes, value: bytes) -> bytes:
-    s = sum(key) + sum(value)
+def simple_sign(secret: bytes, value: bytes) -> bytes:
+    s = sum(secret) + sum(value)
     return f"{s:x}".encode()
 
 
+def _xxhash_xxh32_sign(secret: bytes, value: bytes) -> bytes:
+    if not _XXHASH:
+        raise UnsupportedDigestmod("xxhash is not installed")
+    return xxhash.xxh32_hexdigest(secret + value).encode()
+
+
+def _xxhash_xxh64_sign(secret: bytes, value: bytes) -> bytes:
+    if not _XXHASH:
+        raise UnsupportedDigestmod("xxhash is not installed")
+    return xxhash.xxh64_hexdigest(secret + value).encode()
+
+
+def _xxhash_xxh3_64_sign(secret: bytes, value: bytes) -> bytes:
+    if not _XXHASH:
+        raise UnsupportedDigestmod("xxhash is not installed")
+    return xxhash.xxh3_64_hexdigest(secret + value).encode()
+
+
+def _xxhash_xxh3_128_sign(secret: bytes, value: bytes) -> bytes:
+    if not _XXHASH:
+        raise UnsupportedDigestmod("xxhash is not installed")
+    return xxhash.xxh3_128_hexdigest(secret + value).encode()
+
+
 def _to_bytes(value: str | bytes) -> bytes:
     if isinstance(value, str):
         value = value.encode()
@@ -46,11 +78,17 @@ class HashSigner(Signer):
         b"md5": _seal(hashlib.md5),
         b"sha256": _seal(hashlib.sha256),
         b"sum": simple_sign,
+        b"xxh32": _xxhash_xxh32_sign,
+        b"xxh64": _xxhash_xxh64_sign,
+        b"xxh3_64": _xxhash_xxh3_64_sign,
+        b"xxh3_128": _xxhash_xxh3_128_sign,
     }
 
     def __init__(self, secret: str | bytes, digestmod: str | bytes = b"md5"):
         self._secret = _to_bytes(secret)
         self._digestmod = _to_bytes(digestmod)
+        if self._digestmod in (b"xxh32", b"xxh64") and not _XXHASH:
+            raise UnsupportedDigestmod()
 
     def sign(self, key: Key, value: bytes) -> bytes:
         sign = self._gen_sign(key, value, self._digestmod)