Feat: implement direct storage access

Closes #258

docs/usage.rst

@@ -551,6 +551,14 @@ To modify the default storage for all ``TinyDB`` instances, set the
 
 >>> TinyDB.DEFAULT_STORAGE = MemoryStorage
 
+In case you need to access the storage instance directly, you can use the
+``storage`` property of your TinyDB instance. This may be useful to call
+method directly on the storage or middleware:
+
+>>> db = TinyDB(storage=CachingMiddleware(MemoryStorage))
+<tinydb.middlewares.CachingMiddleware at 0x10991def0>
+>>> db.storage.flush()
+
 Middleware
 ..........
 

tests/test_tinydb.py

@@ -5,7 +5,7 @@
 import pytest
 
 from tinydb import TinyDB, where
-from tinydb.middlewares import Middleware
+from tinydb.middlewares import Middleware, CachingMiddleware
 from tinydb.storages import MemoryStorage
 
 
@@ -785,3 +785,10 @@ def test_insert_multiple_with_single_dict(db):
         d = {'first': 'John', 'last': 'smith'}
         db.insert_multiple(d)
         db.close()
+
+
+def test_access_storage():
+    assert isinstance(TinyDB(storage=MemoryStorage).storage,
+                      MemoryStorage)
+    assert isinstance(TinyDB(storage=CachingMiddleware(MemoryStorage)).storage,
+                      CachingMiddleware)

tinydb/database.py

@@ -230,6 +230,15 @@ def purge_table(self, name):
         proxy = StorageProxy(self._storage, name)
         proxy.purge_table()
 
+    @property
+    def storage(self):
+        """
+        Access the storage used for this TinyDB instance.
+
+        :return: This instance's storage
+        """
+        return self._storage
+
     def close(self):
         """
         Close the database.