Docserver: refactor the Handler/ServerInstance relationship into a servlet

chrome/common/extensions/docs/server2/servlet.py

+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+class Request(object):
+  '''Request data.
+  '''
+  def __init__(self, path, headers):
+    self.path = path
+    self.headers = headers
+
+class _ContentBuilder(object):
+  '''Builds the response content.
+  '''
+  def __init__(self):
+    self._buf = []
+
+  def Append(self, content):
+    if isinstance(content, unicode):
+      content = content.encode('utf-8', 'replace')
+    self._buf.append(content)
+
+  def ToString(self):
+    self._Collapse()
+    return self._buf[0]
+
+  def __str__(self):
+    return self.ToString()
+
+  def __len__(self):
+    return len(self.ToString())
+
+  def _Collapse(self):
+    self._buf = [''.join(self._buf)]
+
+class Response(object):
+  '''The response from Get().
+  '''
+  def __init__(self, content=None, headers=None, status=None):
+    self.content = _ContentBuilder()
+    if content is not None:
+      self.content.Append(content)
+    self.headers = {}
+    if headers is not None:
+      self.headers.update(headers)
+    self.status = status
+
+  @staticmethod
+  def Ok(content, headers=None):
+    '''Returns an OK (200) response.
+    '''
+    return Response(content=content, headers=headers, status=200)
+
+  @staticmethod
+  def Redirect(url, permanent=False):
+    '''Returns a redirect (301 or 302) response.
+    '''
+    if not url.startswith('/'):
+      url = '/%s' % url
+    status = 301 if permanent else 302
+    return Response(headers={'Location': url}, status=status)
+
+  @staticmethod
+  def NotFound(content, headers=None):
+    '''Returns a not found (404) response.
+    '''
+    return Response(content=content, headers=headers, status=404)
+
+  @staticmethod
+  def InternalError(content, headers=None):
+    '''Returns an internal error (500) response.
+    '''
+    return Response(content=content, headers=headers, status=500)
+
+  def Append(self, content):
+    '''Appends |content| to the response content.
+    '''
+    self.content.append(content)
+
+  def AddHeader(self, key, value):
+    '''Adds a header to the response.
+    '''
+    self.headers[key] = value
+
+  def AddHeaders(self, headers):
+    '''Adds several headers to the response.
+    '''
+    self.headers.update(headers)
+
+  def SetStatus(self, status):
+    self.status = status
+
+  def __repr__(self):
+    return '{content: %s bytes, status: %s, headers: %s entries}' % (
+        len(self.content), self.status, len(self.headers.keys()))
+
+class Servlet(object):
+  def __init__(self, request):
+    self._request = request
+
+  def Get(self):
+    '''Returns a Response.
+    '''
+    raise NotImplemented()