http: Make logging closer to apache default format

Escape all quoted strings.
Add referrer.
Add user-agent.

caucase/http.py

@@ -93,6 +93,25 @@ class ThreadingWSGIServer(ThreadingMixIn, WSGIServer):
       self.socket.setsockopt(socket.IPPROTO_IPV6, socket.IPV6_V6ONLY, 1)
     WSGIServer.server_bind(self)
 
+def _buildQuoteCharList():
+  # All chars considered guilty
+  result = ['\\x%02x' % x for x in xrange(256)]
+  # Exception for non-printable whitespaces.
+  result[ord('\b')] = '\\b'
+  result[ord('\n')] = '\\n'
+  result[ord('\r')] = '\\r'
+  result[ord('\t')] = '\\t'
+  result[ord('\v')] = '\\v'
+  # Exception for printable chars
+  for x in xrange(0x20, 0x7f):
+    result[x] = chr(x)
+  # Exception in the exception: chars which need escapement
+  result[ord('\\')] = '\\\\'
+  result[ord('"')] = '\\"'
+  return result
+_QUOTE_LOG_LIST = _buildQuoteCharList()
+del _buildQuoteCharList
+
 class CaucaseWSGIRequestHandler(WSGIRequestHandler):
   """
   Make WSGIRequestHandler logging more apache-like.
@@ -114,6 +133,25 @@ class CaucaseWSGIRequestHandler(WSGIRequestHandler):
       '%d/' + self.monthname[now.month] + '/%Y:%H:%M:%S +0000',
     )
 
+  def log_request(self, code='-', size='-'):
+    """
+    Log request. Happens after response was sent.
+
+    Compared to python(s default (from BaseHTTPServer):
+    - log referrer
+    - log user agent
+    - escaping
+    """
+    headers = getattr(self, 'headers', {})
+    self.log_message(
+      '"%s" %s %s "%s" "%s"',
+      ''.join(_QUOTE_LOG_LIST[ord(x)] for x in self.requestline),
+      code,
+      size,
+      ''.join(_QUOTE_LOG_LIST[ord(x)] for x in headers.get('Referrer', '-')),
+      ''.join(_QUOTE_LOG_LIST[ord(x)] for x in headers.get('User-Agent', '-')),
+    )
+
 class CaucaseSSLWSGIRequestHandler(CaucaseWSGIRequestHandler):
   """
   Add SSL-specific entries to environ: