Move wm_flow off of views and onto Sky

sky/tools/skypy/skyserver.py

+# 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.
+
+import socket
+import subprocess
+import logging
+import os.path
+
+class SkyServer(object):
+    def __init__(self, paths, port, configuration, root):
+        self.paths = paths
+        self.port = port
+        self.configuration = configuration
+        self.root = root
+        self.server = None
+
+    @staticmethod
+    def _port_in_use(port):
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        return sock.connect_ex(('localhost', port)) == 0
+
+    @staticmethod
+    def _download_server_if_necessary(paths):
+        subprocess.call(os.path.join(paths.sky_tools_directory,
+            'download_sky_server'))
+        return os.path.join(paths.src_root, 'out', 'downloads', 'sky_server')
+
+    def __enter__(self):
+        if self._port_in_use(self.port):
+            logging.warn(
+                'Port %s already in use, assuming custom sky_server started.' %
+                self.port)
+            return
+
+        server_path = self._download_server_if_necessary(self.paths)
+        server_command = [
+            server_path,
+            '-t', self.configuration,
+            self.root,
+            str(self.port),
+        ]
+        self.server = subprocess.Popen(server_command)
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        if self.server:
+            self.server.terminate()
+
+    def path_as_url(self, path):
+        return self.url_for_path(self.port, self.root, path)
+
+    @staticmethod
+    def url_for_path(port, root, path):
+        relative_path = os.path.relpath(path, root)
+        return 'http://localhost:%s/%s' % (port, relative_path)