Bound how long to wait for lock files in FileCache.

cachecontrol/caches/file_cache.py

@@ -67,6 +67,7 @@ def __init__(
         dirmode=0o0700,
         use_dir_lock=None,
         lock_class=None,
+        lock_timeout=30,
     ):
 
         if use_dir_lock is not None and lock_class is not None:
@@ -97,6 +98,7 @@ def __init__(
         self.filemode = filemode
         self.dirmode = dirmode
         self.lock_class = lock_class
+        self.lock_timeout = lock_timeout
 
     @staticmethod
     def encode(x):
@@ -127,7 +129,7 @@ def set(self, key, value):
         except (IOError, OSError):
             pass
 
-        with self.lock_class(name) as lock:
+        with self.lock_class(name, timeout=self.lock_timeout) as lock:
             # Write our actual file
             with _secure_open_write(lock.path, self.filemode) as fh:
                 fh.write(value)

tests/test_storage_filecache.py

@@ -12,6 +12,7 @@
 
 import pytest
 import requests
+from mock import ANY, Mock
 from cachecontrol import CacheControl
 from cachecontrol.caches import FileCache
 from lockfile import LockFile
@@ -115,6 +116,24 @@ def test_lock_class(self, tmpdir):
         assert cache.lock_class is lock_class
         cache.close()
 
+    def test_default_lock_timeout_is_passed_to_lock(self, tmpdir):
+        lock = Mock(__enter__=Mock(), __exit__=Mock())
+        lock_class = Mock(return_value=lock)
+
+        self.cache = FileCache(str(tmpdir), lock_class=lock_class)
+        self.cache.set('key', b'value')
+        lock_class.assert_called_once_with(ANY, timeout=30)
+
+    def test_lock_timeout_of_none_is_passed_to_lock(self, tmpdir):
+        lock = Mock(__enter__=Mock(), __exit__=Mock())
+        lock_class = Mock(return_value=lock)
+
+        self.cache = FileCache(str(tmpdir), lock_class=lock_class,
+                               lock_timeout=None)
+        self.cache.set('key', b'value')
+        lock_class.assert_called_once_with(ANY, timeout=None)
+        cache.close()
+
     def test_filecache_with_delete_request(self, tmpdir, sess):
         # verifies issue #155
         url = self.url + "".join(sample(string.ascii_lowercase, randint(2, 4)))