Adding support for non-decodable commands

Some commands (i.e DUMP) should never have their response decoded, as they return binaries, not encoded blobs

fixes #1254

Author: chayim

redis/client.py

@@ -27,6 +27,9 @@
 SYM_EMPTY = b''
 EMPTY_RESPONSE = 'EMPTY_RESPONSE'
 
+# some responses (ie. dump) are binary, and just meant to never be decoded
+NEVER_DECODE = 'NEVER_DECODE'
+
 
 def timestamp_to_datetime(response):
     "Converts a unix timestamp to a Python datetime object"
@@ -1081,7 +1084,10 @@ def execute_command(self, *args, **options):
     def parse_response(self, connection, command_name, **options):
         "Parses a response from the Redis server"
         try:
-            response = connection.read_response()
+            if NEVER_DECODE in options:
+                response = connection.read_response(disable_decoding=True)
+            else:
+                response = connection.read_response()
         except ResponseError:
             if EMPTY_RESPONSE in options:
                 return options[EMPTY_RESPONSE]

redis/commands/core.py

@@ -801,7 +801,10 @@ def dump(self, name):
         Return a serialized version of the value stored at the specified key.
         If key does not exist a nil bulk reply is returned.
         """
-        return self.execute_command('DUMP', name)
+        from redis.client import NEVER_DECODE
+        options = {}
+        options[NEVER_DECODE] = []
+        return self.execute_command('DUMP', name, **options)
 
     def exists(self, *names):
         "Returns the number of ``names`` that exist"

redis/connection.py

@@ -314,7 +314,7 @@ def on_disconnect(self):
     def can_read(self, timeout):
         return self._buffer and self._buffer.can_read(timeout)
 
-    def read_response(self):
+    def read_response(self, disable_decoding=False):
         raw = self._buffer.readline()
         if not raw:
             raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
@@ -354,8 +354,9 @@ def read_response(self):
             length = int(response)
             if length == -1:
                 return None
-            response = [self.read_response() for i in range(length)]
-        if isinstance(response, bytes):
+            response = [self.read_response(disable_decoding=disable_decoding)
+                        for i in range(length)]
+        if isinstance(response, bytes) and disable_decoding is False:
             response = self.encoder.decode(response)
         return response
 
@@ -449,7 +450,7 @@ def read_from_socket(self, timeout=SENTINEL, raise_on_timeout=True):
             if custom_timeout:
                 sock.settimeout(self._socket_timeout)
 
-    def read_response(self):
+    def read_response(self, disable_decoding=False):
         if not self._reader:
             raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR)
 
@@ -742,10 +743,12 @@ def can_read(self, timeout=0):
             self.connect()
         return self._parser.can_read(timeout)
 
-    def read_response(self):
+    def read_response(self, disable_decoding=False):
         """Read the response from a previously sent command"""
         try:
-            response = self._parser.read_response()
+            response = self._parser.read_response(
+                disable_decoding=disable_decoding
+            )
         except socket.timeout:
             self.disconnect()
             raise TimeoutError("Timeout reading from %s:%s" %

redis/sentinel.py

@@ -51,9 +51,9 @@ def connect(self):
                     continue
             raise SlaveNotFoundError  # Never be here
 
-    def read_response(self):
+    def read_response(self, disable_decoding=False):
         try:
-            return super().read_response()
+            return super().read_response(disable_decoding=disable_decoding)
         except ReadOnlyError:
             if self.connection_pool.is_master:
                 # When talking to a master, a ReadOnlyError when likely