Add optional support for unicode keys

memcached's ASCII protocol supports unicode keys, so lets support them
as well. Since using unicode keys for memcache is uncommon and to
preserve the previous behavior disable support by default.

README.rst

@@ -123,3 +123,4 @@ Credits
 * `Ernest W. Durbin III <https://github.com/ewdurbin>`_
 * `Remco van Oosterhout <https://github.com/Vhab>`_
 * `Nicholas Charriere <https://github.com/nichochar>`_
+* `Joe Gordon <https://github.com/jogo>`_

docs/getting_started.rst

@@ -63,8 +63,11 @@ This client implements the ASCII protocol of memcached. This means keys should n
 contain any of the following illegal characters:
 > Keys cannot have spaces, new lines, carriage returns, or null characters.
 We suggest that if you have unicode characters, or long keys, you use an effective
-hashing mechanism before calling this client. At Pinterest, we have found that murmur3 hash is a
+hashing mechanism before calling this client. At Pinterest, we have found that
-great candidate for this.
+murmur3 hash is a great candidate for this. Alternatively you can
+set `allow_unicode_keys` to support unicode keys, but beware of
+what unicode encoding you use to make sure multiple clients can find the
+same key.
 
 
 Best Practices

pymemcache/client/base.py

@@ -81,9 +81,12 @@ STAT_TYPES = {
 # Common helper functions.
 
 
-def _check_key(key, key_prefix=b''):
+def _check_key(key, allow_unicode_keys, key_prefix=b''):
     """Checks key and add key_prefix."""
-    if isinstance(key, VALID_STRING_TYPES):
+    if allow_unicode_keys:
+        if isinstance(key, six.text_type):
+            key = key.encode('utf8')
+    elif isinstance(key, VALID_STRING_TYPES):
         try:
             key = key.encode('ascii')
         except (UnicodeEncodeError, UnicodeDecodeError):
@@ -177,7 +180,8 @@ class Client(object):
                  ignore_exc=False,
                  socket_module=socket,
                  key_prefix=b'',
-                 default_noreply=True):
+                 default_noreply=True,
+                 allow_unicode_keys=False):
         """
         Constructor.
 
@@ -203,6 +207,7 @@ class Client(object):
           default_noreply: bool, the default value for 'noreply' as passed to
             store commands (except from cas, incr, and decr, which default to
             False).
+          allow_unicode_keys: bool, support unicode (utf8) keys
 
         Notes:
           The constructor does not make a connection to memcached. The first
@@ -223,10 +228,11 @@ class Client(object):
             raise TypeError("key_prefix should be bytes.")
         self.key_prefix = key_prefix
         self.default_noreply = default_noreply
+        self.allow_unicode_keys = allow_unicode_keys
 
     def check_key(self, key):
         """Checks key and add key_prefix."""
-        return _check_key(key, key_prefix=self.key_prefix)
+        return _check_key(key, allow_unicode_keys=self.allow_unicode_keys, key_prefix=self.key_prefix)
 
     def _connect(self):
         sock = self.socket_module.socket(self.socket_module.AF_INET,
@@ -841,7 +847,8 @@ class PooledClient(object):
                  key_prefix=b'',
                  max_pool_size=None,
                  lock_generator=None,
-                 default_noreply=True):
+                 default_noreply=True,
+                 allow_unicode_keys=False):
         self.server = server
         self.serializer = serializer
         self.deserializer = deserializer
@@ -851,6 +858,7 @@ class PooledClient(object):
         self.ignore_exc = ignore_exc
         self.socket_module = socket_module
         self.default_noreply = default_noreply
+        self.allow_unicode_keys = allow_unicode_keys
         if isinstance(key_prefix, six.text_type):
             key_prefix = key_prefix.encode('ascii')
         if not isinstance(key_prefix, bytes):
@@ -864,7 +872,7 @@ class PooledClient(object):
 
     def check_key(self, key):
         """Checks key and add key_prefix."""
-        return _check_key(key, key_prefix=self.key_prefix)
+        return _check_key(key, allow_unicode_keys=self.allow_unicode_keys, key_prefix=self.key_prefix)
 
     def _create_client(self):
         client = Client(self.server,
@@ -878,7 +886,8 @@ class PooledClient(object):
                         ignore_exc=False,
                         socket_module=self.socket_module,
                         key_prefix=self.key_prefix,
-                        default_noreply=self.default_noreply)
+                        default_noreply=self.default_noreply,
+                        allow_unicode_keys=self.allow_unicode_keys)
         return client
 
     def close(self):

pymemcache/client/hash.py

@@ -30,6 +30,7 @@ class HashClient(object):
         dead_timeout=60,
         use_pooling=False,
         ignore_exc=False,
+        allow_unicode_keys=False
     ):
         """
         Constructor.
@@ -66,6 +67,7 @@ class HashClient(object):
         self.use_pooling = use_pooling
         self.key_prefix = key_prefix
         self.ignore_exc = ignore_exc
+        self.allow_unicode_keys = allow_unicode_keys
         self._failed_clients = {}
         self._dead_clients = {}
         self._last_dead_check_time = time.time()
@@ -80,6 +82,7 @@ class HashClient(object):
             'key_prefix': key_prefix,
             'serializer': serializer,
             'deserializer': deserializer,
+            'allow_unicode_keys': allow_unicode_keys,
         }
 
         if use_pooling is True:
@@ -113,7 +116,7 @@ class HashClient(object):
         self.hasher.remove_node(key)
 
     def _get_client(self, key):
-        _check_key(key, self.key_prefix)
+        _check_key(key, self.allow_unicode_keys, self.key_prefix)
         if len(self._dead_clients) > 0:
             current_time = time.time()
             ldc = self._last_dead_check_time

pymemcache/client/rendezvous.py

@@ -36,7 +36,7 @@ class RendezvousHash(object):
 
         for node in self.nodes:
             score = self.hash_function(
-                "%s-%s" % (str(node), str(key)))
+                "%s-%s" % (node, key))
 
             if score > high_score:
                 (high_score, winner) = (score, node)

pymemcache/test/test_client.py

@@ -1,4 +1,5 @@
 # Copyright 2012 Pinterest.com
+# -*- coding: utf-8 -*-
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -92,6 +93,18 @@ class ClientTestMixin(object):
         with pytest.raises(MemcacheIllegalInputError):
             _set()
 
+    def test_set_unicode_key_ok(self):
+        client = self.make_client([b'STORED\r\n'], allow_unicode_keys=True)
+
+        result = client.set(u'\u0FFF', b'value', noreply=False)
+        assert result is True
+
+    def test_set_unicode_key_ok_snowman(self):
+        client = self.make_client([b'STORED\r\n'], allow_unicode_keys=True)
+
+        result = client.set('my☃', b'value', noreply=False)
+        assert result is True
+
     def test_set_unicode_char_in_middle_of_key(self):
         client = self.make_client([b'STORED\r\n'])
 
@@ -101,6 +114,15 @@ class ClientTestMixin(object):
         with pytest.raises(MemcacheIllegalInputError):
             _set()
 
+    def test_set_unicode_char_in_middle_of_key_snowman(self):
+        client = self.make_client([b'STORED\r\n'])
+
+        def _set():
+            client.set('my☃', b'value', noreply=False)
+
+        with pytest.raises(MemcacheIllegalInputError):
+            _set()
+
     def test_set_unicode_value(self):
         client = self.make_client([b''])
 
@@ -110,6 +132,12 @@ class ClientTestMixin(object):
         with pytest.raises(MemcacheIllegalInputError):
             _set()
 
+    def test_set_unicode_char_in_middle_of_key_ok(self):
+        client = self.make_client([b'STORED\r\n'], allow_unicode_keys=True)
+
+        result = client.set('helloworld_\xb1901520_%c3', b'value', noreply=False)
+        assert result is True
+
     def test_set_noreply(self):
         client = self.make_client([])
         result = client.set(b'key', b'value', noreply=True)
@@ -626,6 +654,15 @@ class TestClient(ClientTestMixin, unittest.TestCase):
         with pytest.raises(MemcacheClientError):
             client.get(b'x' * 251)
 
+    def test_too_long_unicode_key(self):
+        client = self.make_client([b'STORED\r\n'], allow_unicode_keys=True)
+
+        with pytest.raises(MemcacheClientError):
+            client.get('my☃'*150)
+
+        with pytest.raises(MemcacheClientError):
+            client.get(u'\u0FFF'*150)
+
     def test_key_contains_spae(self):
         client = self.make_client([b'END\r\n'])
         with pytest.raises(MemcacheClientError):

pymemcache/test/test_client_hash.py

@@ -12,8 +12,8 @@ import socket
 
 class TestHashClient(ClientTestMixin, unittest.TestCase):
 
-    def make_client_pool(self, hostname, mock_socket_values, serializer=None):
+    def make_client_pool(self, hostname, mock_socket_values, serializer=None, **kwargs):
-        mock_client = Client(hostname, serializer=serializer)
+        mock_client = Client(hostname, serializer=serializer, **kwargs)
         mock_client.sock = MockSocket(mock_socket_values)
         client = PooledClient(hostname, serializer=serializer)
         client.client_pool = pool.ObjectPool(lambda: mock_client)
@@ -28,7 +28,8 @@ class TestHashClient(ClientTestMixin, unittest.TestCase):
             s = '%s:%s' % (ip, current_port)
             c = self.make_client_pool(
                 (ip, current_port),
-                vals
+                vals,
+                **kwargs
             )
             client.clients[s] = c
             client.hasher.add_node(s)

pymemcache/test/test_integration.py

@@ -1,4 +1,5 @@
 # Copyright 2012 Pinterest.com
+# -*- coding: utf-8 -*-
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -23,27 +24,47 @@ from pymemcache.exceptions import (
 )
 
 
+def get_set_helper(client, key, value, key2, value2):
+    result = client.get(key)
+    assert result is None
+
+    client.set(key, value, noreply=False)
+    result = client.get(key)
+    assert result == value
+
+    client.set(key2, value2, noreply=True)
+    result = client.get(key2)
+    assert result == value2
+
+    result = client.get_many([key, key2])
+    assert result == {key: value, key2: value2}
+
+    result = client.get_many([])
+    assert result == {}
+
+
 @pytest.mark.integration()
 def test_get_set(client_class, host, port, socket_module):
     client = client_class((host, port), socket_module=socket_module)
     client.flush_all()
 
-    result = client.get('key')
+    key = b'key'
-    assert result is None
+    value = b'value'
+    key2 = b'key2'
+    value2 = b'value2'
+    get_set_helper(client, key, value, key2, value2)
 
-    client.set(b'key', b'value', noreply=False)
-    result = client.get(b'key')
-    assert result == b'value'
 
-    client.set(b'key2', b'value2', noreply=True)
+@pytest.mark.integration()
-    result = client.get(b'key2')
+def test_get_set_unicode_key(client_class, host, port, socket_module):
-    assert result == b'value2'
+    client = client_class((host, port), socket_module=socket_module, allow_unicode_keys=True)
+    client.flush_all()
 
-    result = client.get_many([b'key', b'key2'])
+    key = u"こんにちは"
-    assert result == {b'key': b'value', b'key2': b'value2'}
+    value = b'hello'
-
+    key2 = 'my☃'
-    result = client.get_many([])
+    value2 = b'value2'
-    assert result == {}
+    get_set_helper(client, key, value, key2, value2)
 
 
 @pytest.mark.integration()

pymemcache/test/utils.py

@@ -26,12 +26,14 @@ class MockMemcacheClient(object):
                  timeout=None,
                  no_delay=False,
                  ignore_exc=False,
-                 default_noreply=True):
+                 default_noreply=True,
+                 allow_unicode_keys=False):
 
         self._contents = {}
 
         self.serializer = serializer
         self.deserializer = deserializer
+        self.allow_unicode_keys = allow_unicode_keys
 
         # Unused, but present for interface compatibility
         self.server = server
@@ -41,13 +43,14 @@ class MockMemcacheClient(object):
         self.ignore_exc = ignore_exc
 
     def get(self, key, default=None):
-        if isinstance(key, six.text_type):
+        if not self.allow_unicode_keys:
-            raise MemcacheIllegalInputError(key)
+            if isinstance(key, six.text_type):
-        if isinstance(key, six.string_types):
+                raise MemcacheIllegalInputError(key)
-            try:
+            if isinstance(key, six.string_types):
-                key = key.encode('ascii')
+                try:
-            except (UnicodeEncodeError, UnicodeDecodeError):
+                    key = key.encode('ascii')
-                raise MemcacheIllegalInputError
+                except (UnicodeEncodeError, UnicodeDecodeError):
+                    raise MemcacheIllegalInputError
 
         if key not in self._contents:
             return default
@@ -72,15 +75,16 @@ class MockMemcacheClient(object):
     get_multi = get_many
 
     def set(self, key, value, expire=0, noreply=True):
-        if isinstance(key, six.text_type):
+        if not self.allow_unicode_keys:
-            raise MemcacheIllegalInputError(key)
+            if isinstance(key, six.text_type):
+                raise MemcacheIllegalInputError(key)
+            if isinstance(key, six.string_types):
+                try:
+                    key = key.encode('ascii')
+                except (UnicodeEncodeError, UnicodeDecodeError):
+                    raise MemcacheIllegalInputError
         if isinstance(value, six.text_type):
             raise MemcacheIllegalInputError(value)
-        if isinstance(key, six.string_types):
-            try:
-                key = key.encode('ascii')
-            except (UnicodeEncodeError, UnicodeDecodeError):
-                raise MemcacheIllegalInputError
         if isinstance(value, six.string_types):
             try:
                 value = value.encode('ascii')