Adding the first set of remote test cases and associated framework.

remoting/tools/remote_test_helper/jsonrpclib.py

Index: remoting/tools/remote_test_helper/jsonrpclib.py
diff --git a/remoting/tools/remote_test_helper/jsonrpclib.py b/remoting/tools/remote_test_helper/jsonrpclib.py
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+# Copyright 2014 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.
+"""Module to implement the JSON-RPC protocol.
+
+This module uses xmlrpclib as the base and only overrides those
+portions that implement the XML-RPC protocol. These portions are rewritten
+to use the JSON-RPC protocol instead.
+
+When large portions of code need to be rewritten the original code and
+comments are preserved. The intention here is to keep the amount of code
+change to a minimum.
+
+This module only depends on default Python modules. No third party code is
+required to use this module.
+"""
+import json
+import urllib
+import xmlrpclib as _base
+
+gzip_encode = _base.gzip_encode
+
+
+class Error(Exception):
+
+  def __str__(self):
+    return repr(self)
+
+
+class ProtocolError(Error):
+  """Indicates a JSON protocol error."""
+
+  def __init__(self, url, errcode, errmsg, headers):
+    Error.__init__(self)
+    self.url = url
+    self.errcode = errcode
+    self.errmsg = errmsg
+    self.headers = headers
+
+  def __repr__(self):
+    return (
+        '<ProtocolError for %s: %s %s>' %
+        (self.url, self.errcode, self.errmsg))
+
+
+class ResponseError(Error):
+  """Indicates a broken response package."""
+  pass
+
+
+class Fault(Error):
+  """Indicates an JSON-RPC fault package."""
+
+  def __init__(self, code, message):
+    Error.__init__(self)
+    if not isinstance(code, int):
+      raise ProtocolError('Fault code must be an integer.')
+    self.code = code
+    self.message = message
+
+  def __repr__(self):
+      return (
+          '<Fault %s: %s>' %
+          (self.code, repr(self.message))
+          )
+
+
+def CreateRequest(methodname, params, ident=''):
+  """Create a valid JSON-RPC request.
+
+  Args:
+    methodname: The name of the remote method to invoke.
+    params: The parameters to pass to the remote method. This should be a
+        list or tuple and able to be encoded by the default JSON parser.
+
+  Returns:
+    A valid JSON-RPC request object.
+  """
+  request = {
+    'jsonrpc': '2.0',
+    'method': methodname,
+    'params': params,
+    'id': ident
+    }
+
+  return request
+
+
+def CreateRequestString(methodname, params, ident=''):
+  """Create a valid JSON-RPC request string.
+
+  Args:
+    methodname: The name of the remote method to invoke.
+    params: The parameters to pass to the remote method.
+        These parameters need to be encode-able by the default JSON parser.
+    ident: The request identifier.
+
+  Returns:
+    A valid JSON-RPC request string.
+  """
+  return json.dumps(CreateRequest(methodname, params, ident))
+
+def CreateResponse(data, ident):
+  """Create a JSON-RPC response.
+
+  Args:
+    data: The data to return.
+    ident: The response identifier.
+
+  Returns:
+    A valid JSON-RPC response object.
+  """
+  if isinstance(data, Fault):
+    response = {
+    'jsonrpc': '2.0',
+    'error': {
+        'code': data.code,
+        'message': data.message},
+    'id': ident
+        }

[andrewrs, 2014/12/18 19:10:32]

This trailing brace doesn't look quite aligned in the review tool.

[Mike Meade, 2015/01/05 23:18:58]

Actually this whole block was badly formatted. Thats what I get for letting
Eclipse decide what my indents should be.

Done.

+  else:
+    response = {
+      'jsonrpc': '2.0',
+      'response': data,
+      'id': ident
+      }
+
+  return response
+
+
+def CreateResponseString(data, ident):
+  """Create a JSON-RPC response string.
+
+  Args:
+    data: The data to return.
+    ident: The response identifier.
+
+  Returns:
+    A valid JSON-RPC response object.
+  """
+  return json.dumps(CreateResponse(data, ident))
+
+
+def ParseHTTPResponse(response):
+  """Parse an HTTP response object and return the JSON object.
+
+  Args:
+    response: An HTTP response object.
+
+  Returns:
+    The returned JSON-RPC object.
+
+  Raises:
+    ProtocolError: if the object format is not correct.
+    Fault: If a Fault error is returned from the server.
+  """
+  # Check for new http response object, else it is a file object
+  if hasattr(response, 'getheader'):
+    if response.getheader('Content-Encoding', '') == 'gzip':
+      stream = _base.GzipDecodedResponse(response)
+    else:
+      stream = response
+  else:
+    stream = response
+
+  data = ''
+  while 1:
+    chunk = stream.read(1024)
+    if not chunk:
+      break
+    data += chunk
+
+  response = json.loads(data)
+  ValidateBasicJSONRPCData(response)
+
+  if 'response' in response:
+    ValidateResponse(response)
+    return response['response']
+  elif 'error' in response:
+    ValidateError(response)
+    code = response['error']['code']
+    message = response['error']['message']
+    raise Fault(code, message)
+  else:
+    raise ProtocolError('No valid JSON returned')
+
+
+def ValidateRequest(data):
+  """Validate a JSON-RPC request object.
+
+  Args:
+    data: The JSON-RPC object (dict).
+
+  Raises:
+    ProtocolError: if the object format is not correct.
+  """
+  ValidateBasicJSONRPCData(data)
+  if 'method' not in data or 'params' not in data:
+    raise ProtocolError('JSON is not a valid request')
+
+
+def ValidateResponse(data):
+  """Validate a JSON-RPC response object.
+
+  Args:
+    data: The JSON-RPC object (dict).
+
+  Raises:
+    ProtocolError: if the object format is not correct.
+  """
+  ValidateBasicJSONRPCData(data)
+  if 'response' not in data:
+    raise ProtocolError('JSON is not a valid response')
+
+
+def ValidateError(data):
+  """Validate a JSON-RPC error object.
+
+  Args:
+    data: The JSON-RPC object (dict).
+
+  Raises:
+    ProtocolError: if the object format is not correct.
+  """
+  ValidateBasicJSONRPCData(data)
+  if ('error' not in data or
+      'code' not in data['error'] or
+      'message' not in data['error']):
+    raise ProtocolError('JSON is not a valid error response')
+
+
+def ValidateBasicJSONRPCData(data):
+  """Validate a basic JSON-RPC object.
+
+  Args:
+    data: The JSON-RPC object (dict).
+
+  Raises:
+    ProtocolError: if the object format is not correct.
+  """
+  error = None
+  if not isinstance(data, dict):
+    error = 'JSON data is not a dictionary'
+  elif 'jsonrpc' not in data or data['jsonrpc'] != '2.0':
+    error = 'JSON is not a valid JSON RPC 2.0 message'
+  elif 'id' not in data:
+    error = 'JSON data missing required id entry'
+  if error:
+    raise ProtocolError(error)
+
+
+class Transport(_base.Transport):
+  """RPC transport class.
+
+  This class extends the functionality of xmlrpclib.Transport and only
+  overrides the operations needed to change the protocol from XML-RPC to
+  JSON-RPC.
+  """
+

[andrewrs, 2014/12/18 19:10:32]

What do you think about setting Transport.user_agent for these classes?

[Mike Meade, 2015/01/05 23:18:58]

Done.

+  def single_request(self, host, handler, request_body, verbose=0):
+    """Issue a single JSON-RPC request."""
+
+    h = self.make_connection(host)
+    if verbose:
+      h.set_debuglevel(1)
+    try:
+      self.send_request(h, handler, request_body)
+      self.send_host(h, host)
+      self.send_user_agent(h)
+      self.send_content(h, request_body)

[andrewrs, 2014/12/18 19:10:32]

Looking at the default implementation of xmlrpclib, it appears that send_content
is setting a Content-Type: text/xml header. Would you want to override that
behavior to set Content-Type: application/json?

[Mike Meade, 2015/01/05 23:18:58]

Good catch on that one. Done.

+
+      response = h.getresponse(buffering=True)
+      if response.status == 200:
+        self.verbose = verbose
+
+        return self.parse_response(response)
+
+    except Fault:
+      raise
+    except Exception:
+      # All unexpected errors leave connection in
+      # a strange state, so we clear it.
+      self.close()
+      raise
+
+    # discard any response data and raise exception
+    if response.getheader('content-length', 0):
+      response.read()
+    raise ProtocolError(
+        host + handler,
+        response.status, response.reason,
+        response.msg,
+        )
+
+  def parse_response(self, response):
+    """Parse the HTTP resoponse from the server."""
+    return ParseHTTPResponse(response)
+
+
+class SafeTransport(_base.SafeTransport):
+  """Transport class for HTTPS servers.
+
+  This class extends the functionality of xmlrpclib.SafeTransport and only
+  overrides the operations needed to change the protocol from XML-RPC to
+  JSON-RPC.
+  """
+
+  def parse_response(self, response):
+    return ParseHTTPResponse(response)
+
+
+class ServerProxy(_base.ServerProxy):
+  """Proxy class to the RPC server.
+
+  This class extends the functionality of xmlrpclib.ServerProxy and only
+  overrides the operations needed to change the protocol from XML-RPC to
+  JSON-RPC.
+  """
+
+  def __init__(self, uri, transport=None, encoding=None, verbose=0,
+               allow_none=0, use_datetime=0):
+    urltype, _ = urllib.splittype(uri)
+    if urltype not in ('http', 'https'):
+      raise IOError('unsupported JSON-RPC protocol')
+
+    _base.ServerProxy.__init__(self, uri, transport, encoding, verbose,
+                               allow_none, use_datetime)
+
+    if transport is None:
+      if type == 'https':
+        transport = SafeTransport(use_datetime=use_datetime)
+      else:
+        transport = Transport(use_datetime=use_datetime)
+    self.__transport = transport
+
+  def __request(self, methodname, params):
+    """Call a method on the remote server."""
+    request = CreateRequestString(methodname, params)
+
+    response = self.__transport.request(
+        self.__host,
+        self.__handler,
+        request,
+        verbose=self.__verbose
+        )
+
+    return response