check_key disabling and performance improvements.

   *  Client() now takes a "check_key" option, which defaults to True.
      If False, it disables the checking of keys to ensure they have
      acceptable size and are composed of non-control characters.
      Suggested by Ben Hoyt.

   *  Converting control character checking of keys based on performance
      testing of alternatives by Ben Hoyt.

Author: Sean Reifschneider

ChangeLog

@@ -1,3 +1,11 @@
+   *  Client() now takes a "check_key" option, which defaults to True.
+      If False, it disables the checking of keys to ensure they have
+      acceptable size and are composed of non-control characters.
+      Suggested by Ben Hoyt.
+
+   *  Converting control character checking of keys based on performance
+      testing of alternatives by Ben Hoyt.
+
    *  Converted unicode tests from using u'', patch from Eren Güve.
 
    *  Included license file (pull request by "Philippe" pombredanne).

memcache.py

@@ -77,6 +77,8 @@ def decompress(val):
 except ImportError:
     from StringIO import StringIO
 
+invalid_key_characters = ''.join(map(chr, range(33) + [127]))
+
 
 #  Original author: Evan Martin of Danga Interactive
 __author__    = "Sean Reifschneider <jafo-memcached@tummy.com>"
@@ -161,7 +163,7 @@ def __init__(self, servers, debug=0, pickleProtocol=0,
                  server_max_key_length=SERVER_MAX_KEY_LENGTH,
                  server_max_value_length=SERVER_MAX_VALUE_LENGTH,
                  dead_retry=_DEAD_RETRY, socket_timeout=_SOCKET_TIMEOUT,
-                 cache_cas = False, flush_on_reconnect=0):
+                 cache_cas = False, flush_on_reconnect=0, check_key=True):
         """
         Create a new Client object with the given list of servers.
 
@@ -194,6 +196,8 @@ def __init__(self, servers, debug=0, pickleProtocol=0,
         back, those keys will map to it again. If it still has its data, get()s
         can read stale data that was overwritten on another server. This flag
         is off by default for backwards compatibility.
+        @param check_key: (default True) If True, the key is checked to
+        ensure it is the correct length and composed of the right characters.
         """
         local.__init__(self)
         self.debug = debug
@@ -204,6 +208,7 @@ def __init__(self, servers, debug=0, pickleProtocol=0,
         self.stats = {}
         self.cache_cas = cache_cas
         self.reset_cas()
+        self.do_check_key = check_key
 
         # Allow users to modify pickling/unpickling behavior
         self.pickleProtocol = pickleProtocol
@@ -430,7 +435,8 @@ def delete(self, key, time=0):
         should fail. Defaults to None for no delay.
         @rtype: int
         '''
-        self.check_key(key)
+        if self.do_check_key:
+            self.check_key(key)
         server, key = self._get_server(key)
         if not server:
             return 0
@@ -490,7 +496,8 @@ def decr(self, key, delta=1):
         return self._incrdecr("decr", key, delta)
 
     def _incrdecr(self, cmd, key, delta):
-        self.check_key(key)
+        if self.do_check_key:
+            self.check_key(key)
         server, key = self._get_server(key)
         if not server:
             return None
@@ -615,7 +622,7 @@ def _map_and_prefix_keys(self, key_iterable, key_prefix):
         """
         # Check it just once ...
         key_extra_len=len(key_prefix)
-        if key_prefix:
+        if key_prefix and self.do_check_key:
             self.check_key(key_prefix)
 
         # server (_Host) -> list of unprefixed server keys in mapping
@@ -634,7 +641,8 @@ def _map_and_prefix_keys(self, key_iterable, key_prefix):
                 server, key = self._get_server(key_prefix + str_orig_key)
 
             # Now check to make sure key length is proper ...
-            self.check_key(str_orig_key, key_extra_len=key_extra_len)
+            if self.do_check_key:
+                self.check_key(str_orig_key, key_extra_len=key_extra_len)
 
             if not server:
                 continue
@@ -781,7 +789,8 @@ def _val_to_store_info(self, val, min_compress_len):
         return (flags, len(val), val)
 
     def _set(self, cmd, key, val, time, min_compress_len = 0):
-        self.check_key(key)
+        if self.do_check_key:
+            self.check_key(key)
         server, key = self._get_server(key)
         if not server:
             return 0
@@ -823,7 +832,8 @@ def _unsafe_set():
             return 0
 
     def _get(self, cmd, key):
-        self.check_key(key)
+        if self.do_check_key:
+            self.check_key(key)
         server, key = self._get_server(key)
         if not server:
             return None
@@ -1036,10 +1046,9 @@ def check_key(self, key, key_extra_len=0):
                 len(key) + key_extra_len > self.server_max_key_length:
                 raise Client.MemcachedKeyLengthError("Key length is > %s"
                          % self.server_max_key_length)
-            for char in key:
-                if ord(char) < 33 or ord(char) == 127:
-                    raise Client.MemcachedKeyCharacterError(
-                            "Control characters not allowed")
+            if len(key) != len(key.translate(None, invalid_key_characters)):
+                raise Client.MemcachedKeyCharacterError(
+                        "Control characters not allowed")
 
 
 class _Host(object):