extension: expose _find_entry_points as list_entry_points

Having the ability to list the entry points without loading them can be quite
useful. Expose the internal method externally to help with that.

Change-Id: Id675f335957a95fcfce61934dfbfbb2c64af761a

2 files changed, 21 insertions, 6 deletions

diff --git a/stevedore/extension.py b/stevedore/extension.py
index 4029b65..cdd53d2 100644
--- a/stevedore/extension.py
+++ b/stevedore/extension.py
@@ -156,16 +156,22 @@ class ExtensionManager(object):
 
     ENTRY_POINT_CACHE = {}
 
-    def _find_entry_points(self, namespace):
-        if namespace not in self.ENTRY_POINT_CACHE:
-            eps = list(pkg_resources.iter_entry_points(namespace))
-            self.ENTRY_POINT_CACHE[namespace] = eps
-        return self.ENTRY_POINT_CACHE[namespace]
+    def list_entry_points(self):
+        """Return the list of entry points for this namespace.
+
+        The entry points are not actually loaded, their list is just read and
+        returned.
+
+        """
+        if self.namespace not in self.ENTRY_POINT_CACHE:
+            eps = list(pkg_resources.iter_entry_points(self.namespace))
+            self.ENTRY_POINT_CACHE[self.namespace] = eps
+        return self.ENTRY_POINT_CACHE[self.namespace]
 
     def _load_plugins(self, invoke_on_load, invoke_args, invoke_kwds,
                       verify_requirements):
         extensions = []
-        for ep in self._find_entry_points(self.namespace):
+        for ep in self.list_entry_points():
             LOG.debug('found extension %r', ep)
             try:
                 ext = self._load_one_plugin(ep,
diff --git a/stevedore/tests/test_extension.py b/stevedore/tests/test_extension.py
index 7d695ef..a84c2df 100644
--- a/stevedore/tests/test_extension.py
+++ b/stevedore/tests/test_extension.py
@@ -13,6 +13,8 @@
 """Tests for stevedore.extension
 """
 
+import operator
+
 import mock
 
 from stevedore import exception
@@ -49,6 +51,13 @@ class TestCallback(utils.TestCase):
         e = em['t1']
         self.assertEqual(e.name, 't1')
 
+    def test_list_entry_points(self):
+        em = extension.ExtensionManager('stevedore.test.extension')
+        n = em.list_entry_points()
+        self.assertEqual(set(['e1', 'e2', 't1', 't2']),
+                         set(map(operator.attrgetter("name"), n)))
+        self.assertEqual(4, len(n))
+
     def test_contains_by_name(self):
         em = extension.ExtensionManager('stevedore.test.extension')
         self.assertEqual('t1' in em, True)