Added MemcacheCacheHandler (#1042)

* Added MemcacheCacheHandler

* Import MemcacheError where used

* Update index.rst

---------

Co-authored-by: Stéphane Bruckert <stephane.bruckert@gmail.com>

CHANGELOG.md

@@ -8,7 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## Unreleased
 
 ### Added
-
+- Added `MemcacheCacheHandler`, a cache handler that stores the token info using pymemcache.
 - Added support for audiobook endpoints: get_audiobook, get_audiobooks, and get_audiobook_chapters.
 - Added integration tests for audiobook endpoints.
 - Removed `python 2.7` from GitHub Actions CI workflow. Python v2.7 reached end of life support and is no longer supported by Ubuntu 20.04.

docs/index.rst

@@ -185,14 +185,17 @@ cache handler ``CacheHandler``. The default cache handler ``CacheFileHandler`` i
 An instance of that new class can then be passed as a parameter when
 creating ``SpotifyOAuth``, ``SpotifyPKCE`` or ``SpotifyImplicitGrant``.
 The following handlers are available and defined in the URL above.
+
   - ``CacheFileHandler``
   - ``MemoryCacheHandler``
   - ``DjangoSessionCacheHandler``
   - ``FlaskSessionCacheHandler``
   - ``RedisCacheHandler``
+  - ``MemcacheCacheHandler``: install with dependency using ``pip install "spotipy[pymemcache]"``
 
 Feel free to contribute new cache handlers to the repo.
 
+
 Examples
 =======================
  

setup.py

@@ -7,8 +7,13 @@ test_reqs = [
     'mock==2.0.0'
 ]
 
+memcache_cache_reqs = [
+    'pymemcache>=3.5.2'
+]
+
 extra_reqs = {
-    'test': test_reqs
+    'test': test_reqs,
+    'memcache': memcache_cache_reqs
 }
 
 setup(
@@ -25,7 +30,7 @@ setup(
     },
     python_requires='>3.8',
     install_requires=[
-        "redis>=3.5.3",
+        "redis>=3.5.3",  # TODO: Move to extras_require in v3
         "requests>=2.25.0",
         "urllib3>=1.26.0"
     ],

spotipy/cache_handler.py

@@ -4,7 +4,8 @@ __all__ = [
     'DjangoSessionCacheHandler',
     'FlaskSessionCacheHandler',
     'MemoryCacheHandler',
-    'RedisCacheHandler']
+    'RedisCacheHandler',
+    'MemcacheCacheHandler']
 
 import errno
 import json
@@ -208,3 +209,34 @@ class RedisCacheHandler(CacheHandler):
             self.redis.set(self.key, json.dumps(token_info))
         except RedisError as e:
             logger.warning('Error saving token to cache: ' + str(e))
+
+
+class MemcacheCacheHandler(CacheHandler):
+    """A Cache handler that stores the token info in Memcache using the pymemcache client
+    """
+    def __init__(self, memcache, key=None) -> None:
+        """
+        Parameters:
+            * memcache: memcache client object provided by pymemcache
+            (https://pymemcache.readthedocs.io/en/latest/getting_started.html)
+            * key: May be supplied, will otherwise be generated
+                   (takes precedence over `token_info`)
+        """
+        self.memcache = memcache
+        self.key = key if key else 'token_info'
+
+    def get_cached_token(self):
+        from pymemcache import MemcacheError
+        try:
+            token_info = self.memcache.get(self.key)
+            if token_info:
+                return json.loads(token_info.decode())
+        except MemcacheError as e:
+            logger.warning('Error getting token from cache' + str(e))
+
+    def save_token_to_cache(self, token_info):
+        from pymemcache import MemcacheError
+        try:
+            self.memcache.set(self.key, json.dumps(token_info))
+        except MemcacheError as e:
+            logger.warning('Error saving token to cache' + str(e))