Merge pull request #856 from Tenzer/RequirementsFinder-lru-cache

Add LRU cache to RequirementsFinder._get_files_from_dir

2 files changed, 24 insertions, 7 deletions

diff --git a/isort/finders.py b/isort/finders.py
index ca4cb7bd..c419bec8 100644
--- a/isort/finders.py
+++ b/isort/finders.py
@@ -35,6 +35,11 @@ try:
 except ImportError:
     Pipfile = None
 
+try:
+    from functools import lru_cache
+except ImportError:
+    from backports.functools_lru_cache import lru_cache
+
 
 KNOWN_SECTION_MAPPING = {
     'STDLIB': 'STANDARD_LIBRARY',
@@ -260,6 +265,13 @@ class RequirementsFinder(ReqsBaseFinder):
     def _get_files_from_dir(self, path):
         """Return paths to requirements files from passed dir.
         """
+        return RequirementsFinder._get_files_from_dir_cached(path)
+
+    @classmethod
+    @lru_cache(maxsize=16)
+    def _get_files_from_dir_cached(cls, path):
+        result = []
+
         for fname in os.listdir(path):
             if 'requirements' not in fname:
                 continue
@@ -268,18 +280,20 @@ class RequirementsFinder(ReqsBaseFinder):
             # *requirements*/*.{txt,in}
             if os.path.isdir(full_path):
                 for subfile_name in os.listdir(path):
-                    for ext in self.exts:
+                    for ext in cls.exts:
                         if subfile_name.endswith(ext):
-                            yield os.path.join(path, subfile_name)
+                            result.append(os.path.join(path, subfile_name))
                 continue
 
             # *requirements*.{txt,in}
             if os.path.isfile(full_path):
-                for ext in self.exts:
+                for ext in cls.exts:
                     if fname.endswith(ext):
-                        yield full_path
+                        result.append(full_path)
                         break
 
+        return result
+
     def _get_names(self, path):
         """Load required packages from path to requirements file
         """
@@ -315,8 +329,8 @@ class FindersManager(object):
         LocalFinder,
         KnownPatternFinder,
         PathFinder,
-        # PipfileFinder,
-        # RequirementsFinder,
+        PipfileFinder,
+        RequirementsFinder,
         DefaultFinder,
     )
 
diff --git a/setup.py b/setup.py
index 839ebf3c..e7795f9b 100755
--- a/setup.py
+++ b/setup.py
@@ -27,7 +27,10 @@ setup(name='isort',
           'requirements': ['pip', 'pipreqs'],
           'xdg_home': ['appdirs'],
       },
-      install_requires=['futures; python_version < "3.2"'],
+      install_requires=[
+          'futures; python_version < "3.2"',
+          'backports.functools_lru_cache; python_version < "3.2"',
+      ],
       python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
       keywords='Refactor, Python, Python2, Python3, Refactoring, Imports, Sort, Clean',
       classifiers=['Development Status :: 6 - Mature',