Support Hiredis >= 1.x only (remove packaging dependency) (#2385)

* Only set HIREDIS_AVAILABLE if Hiredis is not 0.x

* Remove compatibility code for old Hiredis versions

* Move packaging dependency to dev only

Author: akx

CHANGES

@@ -19,6 +19,7 @@
     * Fix reusing the old nodes' connections when cluster topology refresh is being done
     * Fix RedisCluster to immediately raise AuthenticationError without a retry
     * ClusterPipeline Doesn't Handle ConnectionError for Dead Hosts (#2225)
+    * Remove compatibility code for old versions of Hiredis, drop Packaging dependency
 
 * 4.1.3 (Feb 8, 2022)
     * Fix flushdb and flushall (#1926)

README.md

@@ -27,7 +27,8 @@ To install redis-py, simply:
 $ pip install redis
 ```
 
-For faster performance, install redis with hiredis support, this provides a compiled response parser, and *for most cases* requires zero code changes. By default, if hiredis is available, redis-py will attempt to use it for response parsing.
+For faster performance, install redis with hiredis support, this provides a compiled response parser, and *for most cases* requires zero code changes.
+By default, if hiredis >= 1.0 is available, redis-py will attempt to use it for response parsing.
 
 ``` bash
 $ pip install redis[hiredis]

dev_requirements.txt

@@ -4,6 +4,7 @@ flake8==4.0.1
 flynt~=0.69.0
 isort==5.10.1
 mock==4.0.3
+packaging>=20.4
 pytest==6.2.5
 pytest-timeout==2.0.1
 pytest-asyncio>=0.16.0

redis/connection.py

@@ -10,8 +10,6 @@
 from time import time
 from urllib.parse import parse_qs, unquote, urlparse
 
-from packaging.version import Version
-
 from redis.backoff import NoBackoff
 from redis.exceptions import (
     AuthenticationError,
@@ -54,16 +52,6 @@
 if HIREDIS_AVAILABLE:
     import hiredis
 
-    hiredis_version = Version(hiredis.__version__)
-    HIREDIS_SUPPORTS_CALLABLE_ERRORS = hiredis_version >= Version("0.1.3")
-    HIREDIS_SUPPORTS_BYTE_BUFFER = hiredis_version >= Version("0.1.4")
-    HIREDIS_SUPPORTS_ENCODING_ERRORS = hiredis_version >= Version("1.0.0")
-
-    HIREDIS_USE_BYTE_BUFFER = True
-    # only use byte buffer if hiredis supports it
-    if not HIREDIS_SUPPORTS_BYTE_BUFFER:
-        HIREDIS_USE_BYTE_BUFFER = False
-
 SYM_STAR = b"*"
 SYM_DOLLAR = b"$"
 SYM_CRLF = b"\r\n"
@@ -380,9 +368,7 @@ def __init__(self, socket_read_size):
         if not HIREDIS_AVAILABLE:
             raise RedisError("Hiredis is not installed")
         self.socket_read_size = socket_read_size
-
-        if HIREDIS_USE_BYTE_BUFFER:
-            self._buffer = bytearray(socket_read_size)
+        self._buffer = bytearray(socket_read_size)
 
     def __del__(self):
         try:
@@ -393,16 +379,14 @@ def __del__(self):
     def on_connect(self, connection, **kwargs):
         self._sock = connection._sock
         self._socket_timeout = connection.socket_timeout
-        kwargs = {"protocolError": InvalidResponse, "replyError": self.parse_error}
-
-        # hiredis < 0.1.3 doesn't support functions that create exceptions
-        if not HIREDIS_SUPPORTS_CALLABLE_ERRORS:
-            kwargs["replyError"] = ResponseError
+        kwargs = {
+            "protocolError": InvalidResponse,
+            "replyError": self.parse_error,
+            "errors": connection.encoder.encoding_errors,
+        }
 
         if connection.encoder.decode_responses:
             kwargs["encoding"] = connection.encoder.encoding
-        if HIREDIS_SUPPORTS_ENCODING_ERRORS:
-            kwargs["errors"] = connection.encoder.encoding_errors
         self._reader = hiredis.Reader(**kwargs)
         self._next_response = False
 
@@ -427,17 +411,10 @@ def read_from_socket(self, timeout=SENTINEL, raise_on_timeout=True):
         try:
             if custom_timeout:
                 sock.settimeout(timeout)
-            if HIREDIS_USE_BYTE_BUFFER:
-                bufflen = self._sock.recv_into(self._buffer)
-                if bufflen == 0:
-                    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
-                self._reader.feed(self._buffer, 0, bufflen)
-            else:
-                buffer = self._sock.recv(self.socket_read_size)
-                # an empty string indicates the server shutdown the socket
-                if not isinstance(buffer, bytes) or len(buffer) == 0:
-                    raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
-                self._reader.feed(buffer)
+            bufflen = self._sock.recv_into(self._buffer)
+            if bufflen == 0:
+                raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
+            self._reader.feed(self._buffer, 0, bufflen)
             # data was read from the socket and added to the buffer.
             # return True to indicate that data was read.
             return True
@@ -479,17 +456,6 @@ def read_response(self, disable_decoding=False):
                 response = self._reader.gets(False)
             else:
                 response = self._reader.gets()
-        # if an older version of hiredis is installed, we need to attempt
-        # to convert ResponseErrors to their appropriate types.
-        if not HIREDIS_SUPPORTS_CALLABLE_ERRORS:
-            if isinstance(response, ResponseError):
-                response = self.parse_error(response.args[0])
-            elif (
-                isinstance(response, list)
-                and response
-                and isinstance(response[0], ResponseError)
-            ):
-                response[0] = self.parse_error(response[0].args[0])
         # if the response is a ConnectionError or the response is a list and
         # the first item is a ConnectionError, raise it as something bad
         # happened

redis/utils.py

@@ -4,7 +4,8 @@
 try:
     import hiredis  # noqa
 
-    HIREDIS_AVAILABLE = True
+    # Only support Hiredis >= 1.0:
+    HIREDIS_AVAILABLE = not hiredis.__version__.startswith("0.")
 except ImportError:
     HIREDIS_AVAILABLE = False
 

requirements.txt

@@ -1,4 +1,3 @@
 async-timeout>=4.0.2
 deprecated>=1.2.3
-packaging>=20.4
 typing-extensions; python_version<"3.8"

setup.py

@@ -33,7 +33,6 @@
     python_requires=">=3.7",
     install_requires=[
         "deprecated>=1.2.3",
-        "packaging>=20.4",
         'importlib-metadata >= 1.0; python_version < "3.8"',
         'typing-extensions; python_version<"3.8"',
         "async-timeout>=4.0.2",