Add HTTPTransport, a Mac implementation, and an end-to-end test.

util/net/http_transport_test_server.py

Index: util/net/http_transport_test_server.py
diff --git a/util/net/http_transport_test_server.py b/util/net/http_transport_test_server.py
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index 0000000000000000000000000000000000000000..ac6c834cdba33907783f41ecd004675981951afc
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+++ b/util/net/http_transport_test_server.py
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+# coding: utf-8
+
+# Copyright 2014 The Crashpad Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+"""A one-shot testing webserver.
+
+When invoked, this server will write an integer to stdout, indiciating on which
+port the server is listening. It will then read one integer from stdin,
+indiciating the response code to set for a request. The server will process
+one HTTP request, writing it out entirely to stdout, and will then terminate.
+
+This server is written in Python since it provides a simple HTTP stack, and
+because parsing Chunked encoding is safer and easier in a memory-safe language.
+This could easily have been written in C++ instead.
+"""
+
+import BaseHTTPServer
+import struct
+import sys
+
+class BufferedReadFile(object):
+  """A File-like object that stores all read contents into a buffer."""
+
+  def __init__(self, real_file):
+    self.file = real_file
+    self.buffer = ""
+
+  def read(self, size=-1):
+    buf = self.file.read(size)
+    self.buffer += buf
+    return buf
+
+  def readline(self, size=-1):
+    buf = self.file.readline(size)
+    self.buffer += buf
+    return buf
+
+  def flush(self):
+    self.file.flush()
+
+  def close(self):
+    self.file.close()
+
+
+class RequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
+  response_code = 500
+
+  def handle_one_request(self):
+    # Wrap the rfile in the buffering file object so that the raw header block
+    # can be written to stdout after it is parsed.
+    self.rfile = BufferedReadFile(self.rfile)
+    BaseHTTPServer.BaseHTTPRequestHandler.handle_one_request(self)
+
+  def do_POST(self):
+    writer = sys.stdout
+
+    writer.write(self.rfile.buffer)
+    self.rfile.buffer = ''
+
+    if self.headers.get('Transfer-Encoding', '') == 'Chunked':
+      body = self.handle_chunked_encoding()
+    else:
+      length = int(self.headers.get('Content-Length', -1))
+      body = self.rfile.read(length)
+
+    self.send_response(self.response_code)
+    writer.write(body)
+    writer.flush()
+
+  def handle_chunked_encoding(self):
+    """This parses a "Transfer-Encoding: Chunked" body in accordance with
+    RFC 7230 §4.1. This returns the result as a string.
+    """
+    body = ''
+    chunk_size = self.read_chunk_size()
+    while chunk_size > 0:
+      # Read the body.
+      data = self.rfile.read(chunk_size)
+      chunk_size -= len(data)
+      body += data
+
+      # Finished reading this chunk.
+      if chunk_size == 0:
+        # Read through any trailer fields.
+        trailer_line = self.rfile.readline()
+        while trailer_line.strip() != '':
+          trailer_line = self.rfile.readline()
+
+        # Read the chunk size.
+        chunk_size = self.read_chunk_size()
+    return body
+
+  def read_chunk_size(self):
+    # Read the whole line, including the \r\n.
+    chunk_size_and_ext_line = self.rfile.readline()
+    # Look for a chunk extension.
+    chunk_size_end = chunk_size_and_ext_line.find(';')
+    if chunk_size_end == -1:
+      # No chunk extensions; just encounter the end of line.
+      chunk_size_end = chunk_size_and_ext_line.find('\r')
+    if chunk_size_end == -1:
+      self.send_response(400)  # Bad request.
+      return -1
+    return int(chunk_size_and_ext_line[:chunk_size_end], base=16)
+
+
+def Main():
+  # Start the server.
+  server = BaseHTTPServer.HTTPServer(('127.0.0.1', 0), RequestHandler)
+
+  # Write the port as an unsigned short to the parent process.
+  sys.stdout.write(struct.pack('=H', server.server_address[1]))
+  sys.stdout.flush()
+
+  # Read the desired test response code as an unsigned short from the parent
+  # process.
+  RequestHandler.response_code = \
+      struct.unpack('=H', sys.stdin.read(struct.calcsize('=H')))[0]
+
+  # Handle the request.
+  server.handle_request()
+
+if __name__ == '__main__':
+  Main()