Implemented cache helper file

src/searchly/__init__.py

@@ -55,3 +55,8 @@
 CONTEXT_SIZE = 7
 DOWN_SAMPLING = 1e-1
 NEIGHBOURHOOD_AMOUNT = API_SONG_SIMILARITY_LIMIT * 10
+
+# Cache settings
+CACHE_MAX_LENGTH = 256
+CACHE_MAX_AGE = 5 * 60  # 5 minutes
+CACHE_DICT_FORMAT = '{}:{}'

src/searchly/helper/cache.py

@@ -0,0 +1,27 @@
+from expiringdict import ExpiringDict
+
+from src.searchly import CACHE_MAX_LENGTH, CACHE_MAX_AGE, CACHE_DICT_FORMAT
+
+
+__cache = ExpiringDict(max_len=CACHE_MAX_LENGTH, max_age_seconds=CACHE_MAX_AGE)  # 5 minutes expiration
+
+
+def get(method, key):
+    """
+    Get object from the cache given a method and key.
+    :param method: Method.
+    :param key: Key.
+    :return: Cached object if found, None otherwise.
+    """
+    return __cache.get(CACHE_DICT_FORMAT.format(method, key))
+
+
+def refresh(method, key, refreshed_element):
+    """
+    Refresh object in cache.
+    :param method: Method.
+    :param key: Key.
+    :param refreshed_element: Object to refresh.
+    :return: Object refreshed.
+    """
+    __cache[CACHE_DICT_FORMAT.format(method, key)] = refreshed_element