Add Etag header on HEAD requests for StaticFileHandler.

diff --git a/tornado/web.py b/tornado/web.py
index 78267b3aeb4062853980ea2fe085295b27cc0082..86447bdc43662f958754c80365d850b046f318cf 100644 (file)
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -1485,6 +1485,10 @@ class StaticFileHandler(RequestHandler):
 
         if not include_body:
             self.set_header("Content-Length", os.path.getsize(abspath))
+            with open(abspath, "rb") as file:
+                hasher = hashlib.sha1()
+                hasher.update(file.read())
+                self.set_header("Etag", '"%s"' % hasher.hexdigest())
             return
         file = open(abspath, "rb")
         try: