Added optional length argument to get_hexdigest utility.

compressor/base.py

@@ -63,16 +63,14 @@ class Compressor(object):
 
     @cached_property
     def mtimes(self):
-        for kind, value, elem in self.split_contents():
-            if kind == 'file':
-                yield str(get_mtime(value))
+        return [str(get_mtime(value))
+                for kind, value, _ in self.split_contents() if kind == 'file']
 
     @cached_property
     def cachekey(self):
-        cachestr = "".join(
-            chain([self.content], self.mtimes)).encode(self.charset)
-        return "django_compressor.%s.%s" % (socket.gethostname(),
-                                            get_hexdigest(cachestr)[:12])
+        key = get_hexdigest(''.join(
+            [self.content] + self.mtimes).encode(self.charset), 12)
+        return "django_compressor.%s.%s" % (socket.gethostname(), key)
 
     @cached_property
     def hunks(self):

compressor/cache.py

@@ -8,8 +8,11 @@ from django.utils.hashcompat import sha_constructor
 from compressor.conf import settings
 
 
-def get_hexdigest(plaintext):
-    return sha_constructor(plaintext).hexdigest()
+def get_hexdigest(plaintext, length=None):
+    digest = sha_constructor(plaintext).hexdigest()
+    if length:
+        return digest[:length]
+    return digest
 
 
 def get_mtime_cachekey(filename):
@@ -37,7 +40,7 @@ def get_mtime(filename):
 def get_hashed_mtime(filename, length=12):
     filename = os.path.realpath(filename)
     mtime = str(int(get_mtime(filename)))
-    return get_hexdigest(mtime)[:length]
+    return get_hexdigest(mtime, length)
 
 
 cache = get_cache(settings.COMPRESS_CACHE_BACKEND)