Added a locl digest command to the client to execute the XXH3 locally rather than asking the server for it

Author: dmaier-redislabs

pyproject.toml

@@ -28,7 +28,10 @@ classifiers = [
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
 ]
-dependencies = ['async-timeout>=4.0.3; python_full_version<"3.11.3"']
+dependencies = [
+    'async-timeout>=4.0.3; python_full_version<"3.11.3"',
+    'xxhash~=3.6.0',
+]
 
 [project.optional-dependencies]
 hiredis = [

redis/commands/core.py

@@ -2,6 +2,7 @@
 
 import datetime
 import hashlib
+import xxhash
 import warnings
 from enum import Enum
 from typing import (
@@ -23,6 +24,7 @@
     Union,
 )
 
+from docs.conf import version
 from redis.exceptions import ConnectionError, DataError, NoScriptError, RedisError
 from redis.typing import (
     AbsExpiryT,
@@ -1888,6 +1890,27 @@ def expiretime(self, key: str) -> int:
         """
         return self.execute_command("EXPIRETIME", key)
 
+    @experimental_method()
+    def digest_local(self, value: Union[bytes, str]) -> str:
+        """
+        Compute the hexadecimal digest of the value locally, without sending it to the server.
+
+        This is useful for conditional operations like IFDEQ/IFDNE where you need to
+        compute the digest client-side before sending a command.
+
+        Warning:
+        **Experimental** - This API may change or be removed without notice.
+
+        Arguments:
+          - value: Union[bytes, str] - the value to compute the digest of.
+
+        Returns:
+          - (str) the XXH3 digest of the value as a hex string (16 hex characters)
+
+        For more information, see https://redis.io/commands/digest
+        """
+        return xxhash.xxh3_64(value).hexdigest()
+
     @experimental_method()
     def digest(self, name: KeyT) -> Optional[str]:
         """

tests/test_commands.py

@@ -2575,6 +2575,9 @@ def test_set_ifdeq_and_ifdne(self, r, val):
         d = self._server_xxh3_digest(r, "k")
         assert d is not None
 
+        # sanity check: local digest matches server's
+        assert d == r.digest_local(val)
+
         # IFDEQ must match to set; if key missing => won't create
         assert r.set("k", b"X", ifdeq=d) is True
         assert r.get("k") == b"X"