From 77731440f3488c5c113ea410b81aa86c7fecbc23 Mon Sep 17 00:00:00 2001
From: Toshio Kuratomi <toshio@fedoraproject.org>
Date: Wed, 18 Feb 2015 08:12:01 -0800
Subject: [PATCH] Optimize the plugin loader.

We have been caching the paths to the plugins but before we would only
cache the specific plugin that we were looking for.  This meant that we
might search through all of the plugin directories before finding the
specific module we were interested in.  The next plugin we needed we
might again search through all the plugin directories before finding the
plugin we wanted.

This new code will cache all the potential plugins in each directory
searched.  For a play that only uses one plugin we'll only search
through directories until we encounter the directory that has the proper
plugin.  For a large playbook with many plugins used we'll search
through each directory at most once each.

From v1: 68e86de26fd5eac8a0a177528d7ffec0ed78ce4f
         730c2ba40352ef4248461a10f560d10b08b9db35
---
 v2/ansible/plugins/__init__.py | 36 +++++++++++++++++++++++++++-------
 1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/v2/ansible/plugins/__init__.py b/v2/ansible/plugins/__init__.py
index 78586372c9..2aa3360bcd 100644
--- a/v2/ansible/plugins/__init__.py
+++ b/v2/ansible/plugins/__init__.py
@@ -69,6 +69,7 @@ class PluginLoader:
         self._plugin_path_cache = PLUGIN_PATH_CACHE[class_name]
 
         self._extra_dirs = []
+        self._searched_paths = set()
 
     def print_paths(self):
         ''' Returns a string suitable for printing of the search path '''
@@ -171,16 +172,37 @@ class PluginLoader:
                 else:
                     suffixes = ['.py', '']
 
-        for suffix in suffixes:
-            full_name = '%s%s' % (name, suffix)
+        potential_names = frozenset('%s%s' % (name, s) for s in suffixes)
+        for full_name in potential_names:
             if full_name in self._plugin_path_cache:
                 return self._plugin_path_cache[full_name]
 
-            for i in self._get_paths():
-                path = os.path.join(i, full_name)
-                if os.path.isfile(path):
-                    self._plugin_path_cache[full_name] = path
-                    return path
+        found = None
+        for path in [p for p in self._get_paths() if p not in self._searched_paths]:
+            if os.path.isdir(path):
+                for potential_file in os.listdir(path):
+                    for suffix in suffixes:
+                        if potential_file.endswith(suffix):
+                            full_path = os.path.join(path, potential_file)
+                            full_name = os.path.basename(full_path)
+                            break
+                    else: # Yes, this is a for-else: http://bit.ly/1ElPkyg
+                        continue
+    
+                    if full_name not in self._plugin_path_cache:
+                        self._plugin_path_cache[full_name] = full_path
+    
+            self._searched_paths.add(path)
+            for full_name in potential_names:
+                if full_name in self._plugin_path_cache:
+                    return self._plugin_path_cache[full_name]
+
+        # if nothing is found, try finding alias/deprecated
+        if not name.startswith('_'):
+            for alias_name in ('_%s' % n for n in potential_names):
+                # We've already cached all the paths at this point
+                if alias_name in self._plugin_path_cache:
+                    return self._plugin_path_cache[alias_name]
 
         return None