lib: Give TagStores item-related functions

For accessing tags by name, iterating over the collected tags, and
finding the number of tags.

Signed-off-by: Anna Schumaker <Anna@NoWheyCreamery.com>

lib/tagstore.py

@@ -10,6 +10,10 @@ class TagStore:
         self.Added = publisher.Publisher()
         self.Removed = publisher.Publisher()
 
+    def __getitem__(self, name):
+        with self.lock:
+            return self.store.get(name)
+
     def __getstate__(self):
         with self.lock:
             return { "store" : self.store }
@@ -23,6 +27,16 @@ class TagStore:
         self.Added.publish(t)
         return t
 
+    def __len__(self):
+        with self.lock:
+            return len(self.store)
+
+    def __setstate__(self, state):
+        self.store = state["store"]
+        self.lock = threading.Lock()
+        self.Added = publisher.Publisher()
+        self.Removed = publisher.Publisher()
+
     def __setstate__(self, state):
         self.store = state["store"]
         self.lock = threading.Lock()
@@ -54,3 +68,8 @@ class TagStore:
             self.store.clear()
             self.Added.reset()
             self.Removed.reset()
+
+    def tags(self):
+        with self.lock:
+            for (name, tag) in self.store.items():
+                yield tag

lib/test_tagstore.py

@@ -61,6 +61,26 @@ class TestTagStore(unittest.TestCase):
         store.remove(tag)
         self.assertNotIn("test", store.store.keys())
 
+    def test_tag_store_items(self):
+        store = tagstore.TagStore()
+        self.assertEqual(len(store), 0)
+
+        tag1 = store.add("test1", 1)
+        tag2 = store.add("test2", 2)
+        tag3 = store.add("test3", 3)
+
+        self.assertEqual(len(store), 3)
+        self.assertEqual( store["test1"], tag1)
+        self.assertEqual( store["test2"], tag2)
+        self.assertEqual( store["test3"], tag3)
+        self.assertIsNone(store["test4"])
+
+        result = [ tag for tag in store.tags() ]
+        self.assertEqual(len(result), 3)
+        self.assertIn(tag1, result)
+        self.assertIn(tag2, result)
+        self.assertIn(tag3, result)
+
     def test_tag_store_reset(self):
         store = tagstore.TagStore()
         tag = store.add("test", 1)