Added support for unix domain sockets and custom parsers.

Added the ability to use tcp sockets or unix domain sockets. Also added the
ability to specify a parser to use when processing responses from the redis
server.  To do this I had to bring back the custom connection pool, since
you need to instantiate a custom connection pool to be able to specify a
parser class.

README.rst

@@ -4,18 +4,34 @@ Redis Django Cache Backend
 
 A simple Redis cache backend for Django
 
+Changes in 0.9.0
+================
+
+Redis cache now allows you to use either a TCP connection or Unix domain
+socket to connect to you redis server.  Using a TCP connection useful for
+when you have your redis server separate from your app server and/or within
+a distributed environment.  Unix domain sockets are useful if you have your
+redis server and application running on the same machine and want the fastest
+possible connection.
+
+You can now specify (optionally) what parser class you want redis-py to use
+when parsing messages from the redis server.  redis-py will pick the best
+parser for you implicitly, but using the ``PARSER_CLASS`` setting gives you
+control and the option to roll your own parser class if you are so bold.
+
 Notes
 -----
 
-This cache backend requires the `redis-py`_ Python client library for communicating with the Redis server.
+This cache backend requires the `redis-py`_ Python client library for
+communicating with the Redis server.
 
-Redis writes to disk asynchronously so there is a slight chance 
+Redis writes to disk asynchronously so there is a slight chance
 of losing some data, but for most purposes this is acceptable.
 
 Usage
 -----
 
-1. Run ``python setup.py install`` to install, 
+1. Run ``python setup.py install`` to install,
    or place ``redis_cache`` on your Python path.
 
 2. Modify your Django settings to use ``redis_cache`` :
@@ -26,13 +42,31 @@ On Django < 1.3::
 
 On Django >= 1.3::
 
+
+    # When using TCP connections
     CACHES = {
         'default': {
             'BACKEND': 'redis_cache.RedisCache',
             'LOCATION': '<host>:<port>',
-            'OPTIONS': { # optional
+            'OPTIONS': {
+                'DB': 1,
+                'PASSWORD': 'yadayada',
+                'PARSER_CLASS': 'redis.connection.HiredisParser'
+            },
+        },
+    }
+
+    # When using unix domain sockets
+    # Note: ``LOCATION`` needs to be the same as the ``unixsocket`` setting
+    # in your redis.conf
+    CACHES = {
+        'default': {
+            'BACKEND': 'redis_cache.RedisCache',
+            'LOCATION': '/path/to/socket/file',
+            'OPTIONS': {
                 'DB': 1,
                 'PASSWORD': 'yadayada',
+                'PARSER_CLASS': 'redis.connection.HiredisParser'
             },
         },
     }

redis_cache/cache.py

@@ -1,5 +1,6 @@
 from django.core.cache.backends.base import BaseCache, InvalidCacheBackendError
 from django.core.exceptions import ImproperlyConfigured
+from django.utils import importlib
 from django.utils.encoding import smart_unicode, smart_str
 from django.utils.datastructures import SortedDict
 
@@ -13,7 +14,8 @@
 except ImportError:
     raise InvalidCacheBackendError(
         "Redis cache backend requires the 'redis-py' library")
-
+from redis.connection import UnixDomainSocketConnection, Connection
+from redis.connection import DefaultParser
 
 class CacheKey(object):
     """
@@ -35,6 +37,34 @@ def __unicode__(self):
         return smart_str(self._key)
 
 
+class CacheConnectionPool(object):
+    _connection_pool = None
+
+    def get_connection_pool(self, host='127.0.0.1', port=6379, db=1,
+        password=None, parser_class=None,
+        unix_socket_path=None):
+        if self._connection_pool is None:
+            connection_class = (
+                unix_socket_path and UnixDomainSocketConnection or Connection
+            )
+            kwargs = {
+                'db': db,
+                'password': password,
+                'connection_class': connection_class,
+                'parser_class': parser_class,
+            }
+            if unix_socket_path is None:
+                kwargs.update({
+                    'host': host,
+                    'port': port,
+                })
+            else:
+                kwargs['path'] = unix_socket_path
+            self._connection_pool = redis.ConnectionPool(**kwargs)
+        return self._connection_pool
+pool = CacheConnectionPool()
+
+
 class CacheClass(BaseCache):
     def __init__(self, server, params):
         """
@@ -44,27 +74,76 @@ def __init__(self, server, params):
 
     def _init(self, server, params):
         super(CacheClass, self).__init__(params)
-        self._initargs = { 'server': server, 'params': params }
-        options = params.get('OPTIONS', {})
-        password = params.get('password', options.get('PASSWORD', None))
-        db = params.get('db', options.get('DB', 1))
-        try:
-            db = int(db)
-        except (ValueError, TypeError):
-            raise ImproperlyConfigured("db value must be an integer")
-        if ':' in server:
-            host, port = server.split(':')
+        self._server = server
+        self._params = params
+
+        unix_socket_path = None
+        if ':' in self.server:
+            host, port = self.server.split(':')
             try:
                 port = int(port)
             except (ValueError, TypeError):
                 raise ImproperlyConfigured("port value must be an integer")
         else:
-            host = server or 'localhost'
-            port = 6379
-        self._client = redis.Redis(host=host, port=port, db=db, password=password)
+            host, port = None, None
+            unix_socket_path = self.server
+
+        kwargs = {
+            'db': self.db,
+            'password': self.password,
+            'host': host,
+            'port': port,
+            'unix_socket_path': unix_socket_path,
+        }
+        connection_pool = pool.get_connection_pool(
+            parser_class=self.parser_class,
+            **kwargs
+        )
+        self._client = redis.Redis(
+            connection_pool=connection_pool,
+            **kwargs
+        )
+
+    @property
+    def server(self):
+        return self._server or "127.0.0.1:6379"
+
+    @property
+    def params(self):
+        return self._params or {}
+
+    @property
+    def options(self):
+        return self.params.get('OPTIONS', {})
+
+    @property
+    def db(self):
+        _db = self.params.get('db', self.options.get('DB', 1))
+        try:
+            _db = int(_db)
+        except (ValueError, TypeError):
+            raise ImproperlyConfigured("db value must be an integer")
+        return _db
+
+    @property
+    def password(self):
+        return self.params.get('password', self.options.get('PASSWORD', None))
+
+    @property
+    def parser_class(self):
+        cls = self.options.get('PARSER_CLASS', None)
+        if cls is None:
+            return DefaultParser
+        mod_path, cls_name = cls.rsplit('.', 1)
+        try:
+            mod = importlib.import_module(mod_path)
+            parser_class = getattr(mod, cls_name)
+        except (AttributeError, ImportError):
+            raise ImproperlyConfigured("Could not find parser class '%s'" % parser_class)
+        return parser_class
 
     def __getstate__(self):
-        return self._initargs
+        return {'params': self._params, 'server': self._server}
 
     def __setstate__(self, state):
         self._init(**state)

runtests.py → sockettests.py

@@ -3,28 +3,32 @@
 from os.path import dirname, abspath
 from django.conf import settings
 
-if not settings.configured:
-    settings.configure(
-        DATABASES = {
-            'default': {
-                'ENGINE': 'django.db.backends.sqlite3',
-            }
-        },
-        INSTALLED_APPS = [
-            'tests.testapp',
-        ],
-        CACHES = {
-            'default': {
-                'BACKEND': 'redis_cache.RedisCache',
-                'LOCATION': '127.0.0.1:6379',
-                'OPTIONS': {
-                    'DB': 15,
-                    'PASSWORD': 'yadayada',
-                },
+
+cache_settings = {
+    'DATABASES': {
+        'default': {
+            'ENGINE': 'django.db.backends.sqlite3',
+        }
+    },
+    'INSTALLED_APPS': [
+        'tests.testapp',
+    ],
+    'ROOT_URLCONF': 'tests.urls',
+    'CACHES': {
+        'default': {
+            'BACKEND': 'redis_cache.RedisCache',
+            'LOCATION': '/tmp/redis.sock',
+            'OPTIONS': {
+                'DB': 15,
+                'PASSWORD': 'yadayada',
+                'PARSER_CLASS': 'redis.connection.HiredisParser'
             },
         },
-        ROOT_URLCONF = 'tests.urls',
-    )
+    },
+}
+
+if not settings.configured:
+    settings.configure(**cache_settings)
 
 from django.test.simple import DjangoTestSuiteRunner
 

tcptests.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+import sys
+from os.path import dirname, abspath
+from django.conf import settings
+
+
+cache_settings = {
+    'DATABASES': {
+        'default': {
+            'ENGINE': 'django.db.backends.sqlite3',
+        }
+    },
+    'INSTALLED_APPS': [
+        'tests.testapp',
+    ],
+    'ROOT_URLCONF': 'tests.urls',
+    'CACHES': {
+        'default': {
+            'BACKEND': 'redis_cache.RedisCache',
+            'LOCATION': '127.0.0.1:6379',
+            'OPTIONS': {
+                'DB': 15,
+                'PASSWORD': 'yadayada',
+                'PARSER_CLASS': 'redis.connection.HiredisParser'
+            },
+        },
+    },
+}
+
+
+if not settings.configured:
+    settings.configure(**cache_settings)
+
+from django.test.simple import DjangoTestSuiteRunner
+
+def runtests(*test_args):
+    if not test_args:
+        test_args = ['testapp']
+    parent = dirname(abspath(__file__))
+    sys.path.insert(0, parent)
+    runner = DjangoTestSuiteRunner(verbosity=1, interactive=True, failfast=False)
+    failures = runner.run_tests(test_args)
+    sys.exit(failures)
+
+if __name__ == '__main__':
+    runtests(*sys.argv[1:])

tests/settings.py

@@ -21,4 +21,4 @@
     },
 }
 
-ROOT_URLCONF = 'tests.urls'
+ROOT_URLCONF = 'tests.urls'

tests/testapp/tests.py

@@ -11,6 +11,7 @@
 from django.test import TestCase
 from models import Poll, expensive_calculation
 from redis_cache.cache import RedisCache, ImproperlyConfigured
+from redis.connection import UnixDomainSocketConnection
 
 # functions/classes for complex data type tests
 def f():
@@ -51,10 +52,15 @@ def test_bad_port_initialization(self):
 
     def test_default_initialization(self):
         self.reset_pool()
-        self.cache = self.get_cache('redis_cache.cache://127.0.0.1')
-        self.assertEqual(self.cache._client.connection_pool.connection_kwargs['host'], '127.0.0.1')
-        self.assertEqual(self.cache._client.connection_pool.connection_kwargs['db'], 1)
-        self.assertEqual(self.cache._client.connection_pool.connection_kwargs['port'], 6379)
+        if VERSION[0] == 1 and VERSION[1] < 3:
+            self.cache = self.get_cache('redis_cache.cache://')
+        elif VERSION[0] == 1 and VERSION[1] >= 3:
+            self.cache = self.get_cache('redis_cache.cache.CacheClass')
+        connection_class = self.cache._client.connection_pool.connection_class
+        if connection_class is not UnixDomainSocketConnection:
+            self.assertEqual(self.cache._client.connection_pool.connection_kwargs['host'], '127.0.0.1')
+            self.assertEqual(self.cache._client.connection_pool.connection_kwargs['port'], 6379)
+        self.assertEqual(self.cache._client.connection_pool.connection_kwargs['db'], 15)
 
     def test_simple(self):
         # Simple cache set/get works