--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/piecrust/serving/util.py	Sat Aug 08 22:01:47 2015 -0700
@@ -0,0 +1,60 @@
+import re
+import os.path
+import hashlib
+import logging
+import datetime
+from werkzeug.wrappers import Response
+from werkzeug.wsgi import wrap_file
+
+
+logger = logging.getLogger(__name__)
+
+
+def load_mimetype_map():
+    mimetype_map = {}
+    sep_re = re.compile(r'\s+')
+    path = os.path.join(os.path.dirname(__file__), 'mime.types')
+    with open(path, 'r') as f:
+        for line in f:
+            tokens = sep_re.split(line)
+            if len(tokens) > 1:
+                for t in tokens[1:]:
+                    mimetype_map[t] = tokens[0]
+    return mimetype_map
+
+
+def make_wrapped_file_response(environ, request, path):
+    logger.debug("Serving %s" % path)
+
+    # Check if we can return a 304 status code.
+    mtime = os.path.getmtime(path)
+    etag_str = '%s$$%s' % (path, mtime)
+    etag = hashlib.md5(etag_str.encode('utf8')).hexdigest()
+    if etag in request.if_none_match:
+        response = Response()
+        response.status_code = 304
+        return response
+
+    wrapper = wrap_file(environ, open(path, 'rb'))
+    response = Response(wrapper)
+    _, ext = os.path.splitext(path)
+    response.set_etag(etag)
+    response.last_modified = datetime.datetime.fromtimestamp(mtime)
+    response.mimetype = mimetype_map.get(
+            ext.lstrip('.'), 'text/plain')
+    response.direct_passthrough = True
+    return response
+
+
+mimetype_map = load_mimetype_map()
+content_type_map = {
+        'html': 'text/html',
+        'xml': 'text/xml',
+        'txt': 'text/plain',
+        'text': 'text/plain',
+        'css': 'text/css',
+        'xhtml': 'application/xhtml+xml',
+        'atom': 'application/atom+xml',  # or 'text/xml'?
+        'rss': 'application/rss+xml',    # or 'text/xml'?
+        'json': 'application/json'}
+