Create HTTP-based GM results viewer.

gm/rebaseline_server/server.py

+#!/usr/bin/python
+
+'''
+Copyright 2013 Google Inc.
+
+Use of this source code is governed by a BSD-style license that can be
+found in the LICENSE file.
+'''
+
+'''
+HTTP server for our HTML rebaseline viewer.
+'''
+
+# System-level imports
+import argparse
+import BaseHTTPServer
+import json
+import os
+import posixpath
+import re
+import shutil
+import sys
+
+# Imports from within Skia
+#
+# We need to add the 'tools' directory, so that we can import svn.py within
+# that directory.
+# Make sure that the 'tools' dir is in the PYTHONPATH, but add it at the *end*
+# so any dirs that are already in the PYTHONPATH will be preferred.
+TRUNK_DIRECTORY = os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.realpath(__file__))))
+TOOLS_DIRECTORY = os.path.join(TRUNK_DIRECTORY, 'tools')
+if TOOLS_DIRECTORY not in sys.path:
+  sys.path.append(TOOLS_DIRECTORY)
+import svn
+
+# Imports from local dir
+import results
+
+ACTUALS_SVN_REPO = 'http://skia-autogen.googlecode.com/svn/gm-actual'
+PATHSPLIT_RE = re.compile('/([^/]+)/(.+)')
+TRUNK_DIRECTORY = os.path.dirname(os.path.dirname(os.path.dirname(
+    os.path.realpath(__file__))))
+
+# A simple dictionary of file name extensions to MIME types. The empty string
+# entry is used as the default when no extension was given or if the extension
+# has no entry in this dictionary.
+MIME_TYPE_MAP = {'': 'application/octet-stream',
+                 'html': 'text/html',
+                 'css': 'text/css',
+                 'png': 'image/png',
+                 'js': 'application/javascript',
+                 'json': 'application/json'
+                 }
+
+DEFAULT_ACTUALS_DIR = '.gm-actuals'
+DEFAULT_EXPECTATIONS_DIR = os.path.join(TRUNK_DIRECTORY, 'expectations', 'gm')
+DEFAULT_PORT = 8888
+
+_SERVER = None   # This gets filled in by main()
+
+class Server(object):
+  """ HTTP server for our HTML rebaseline viewer.
+
+  params:
+    actuals_dir: directory under which we will check out the latest actual
+                 GM results
+    expectations_dir: directory under which to find GM expectations (they
+                      must already be in that directory)
+    port: which TCP port to listen on for HTTP requests
+    export: whether to allow HTTP clients on other hosts to access this server
+  """
+  def __init__(self,
+               actuals_dir=DEFAULT_ACTUALS_DIR,
+               expectations_dir=DEFAULT_EXPECTATIONS_DIR,
+               port=DEFAULT_PORT, export=False):
+    self._actuals_dir = actuals_dir
+    self._expectations_dir = expectations_dir
+    self._port = port
+    self._export = export
+
+  def fetch_results(self):
+    """ Create self.results, based on the expectations in
+    self._expectations_dir and the latest actuals from skia-autogen.
+
+    TODO(epoger): Add a new --browseonly mode setting.  In that mode,
+    the gm-actuals and expectations will automatically be updated every few
+    minutes.  See discussion in https://codereview.chromium.org/24274003/ .
+    """
+    print 'Checking out latest actual GM results from %s into %s ...' % (
+        ACTUALS_SVN_REPO, self._actuals_dir)
+    actuals_repo = svn.Svn(self._actuals_dir)
+    if not os.path.isdir(self._actuals_dir):
+      os.makedirs(self._actuals_dir)
+      actuals_repo.Checkout(ACTUALS_SVN_REPO, '.')

[borenet, 2013/09/26 19:02:01]

Does this just check out into '.'?  We haven't chdir'd to self._actuals_dir...

[epoger, 2013/09/26 21:22:21]

The svn.Svn() constructor takes care of this for us.

I have just checked the directory where I am running the server to confirm. 
Yes, it checked out into .gm_actuals.

+    else:
+      actuals_repo.Update('.')

[epoger, 2013/09/26 17:26:51]

Now updates the gm-actuals we checked out last time, if they're still around,
rather than checking them out from scratch every time.

And added --actuals-dir flag, so the user can determine where these files are
kept.

[borenet, 2013/09/26 19:02:01]

Same question here as above: do we need to os.chdir(self._actuals_dir) in order
to use '.'?

[epoger, 2013/09/26 21:22:21]

See above.  It works as-is.

+    print 'Parsing results from actuals in %s and expectations in %s ...' % (
+        self._actuals_dir, self._expectations_dir)
+    self.results = results.Results(
+      actuals_root=self._actuals_dir,
+      expected_root=self._expectations_dir)
+
+  def run(self):
+    self.fetch_results()
+    if self._export:
+      server_address = ('', self._port)
+      print ('WARNING: Running in "export" mode. Users on other machines will '
+             'be able to modify your GM expectations!')
+    else:
+      server_address = ('127.0.0.1', self._port)
+    http_server = BaseHTTPServer.HTTPServer(server_address, HTTPRequestHandler)
+    print 'Ready for requests on http://%s:%d' % (
+        http_server.server_name, http_server.server_port)
+    http_server.serve_forever()
+
+
+class HTTPRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):
+  """ HTTP request handlers for various types of queries this server knows
+      how to handle (static HTML and Javascript, expected/actual results, etc.)
+  """
+  def do_GET(self):
+    """ Handles all GET requests, forwarding them to the appropriate
+        do_GET_* dispatcher. """
+    if self.path == '' or self.path == '/' or self.path == '/index.html' :
+      self.redirect_to('/static/view.html')
+      return
+    if self.path == '/favicon.ico' :
+      self.redirect_to('/static/favicon.ico')
+      return
+
+    # All requests must be of this form:
+    #   /dispatcher/remainder
+    # where "dispatcher" indicates which do_GET_* dispatcher to run
+    # and "remainder" is the remaining path sent to that dispatcher.
+    normpath = posixpath.normpath(self.path)
+    (dispatcher_name, remainder) = PATHSPLIT_RE.match(normpath).groups()
+    dispatchers = {
+      'results': self.do_GET_results,
+      'static': self.do_GET_static,
+    }
+    dispatcher = dispatchers[dispatcher_name]
+    dispatcher(remainder)
+
+  def do_GET_results(self, result_type):
+    """ Handle a GET request for GM results.
+    For now, we ignore the remaining path info, because we only know how to

[epoger, 2013/09/26 17:26:51]

This is a little funny... the client now requests /results/all instead of
/results/$type .  So we have this "vestigial" subpath which is currently unused.

[borenet, 2013/09/26 19:02:01]

Looks like I could request /results/pleasenoresults and still get "all".  Is
there a plan to add back result types, or can we go ahead and remove the
subpath?

[epoger, 2013/09/26 21:22:21]

Again, I file this under "we don't know yet, let's let this develop a bit and
see."  I added a TODO here.

+    return all results. """
+    print 'do_GET_results: sending results of type "%s"' % result_type
+    response_dict = _SERVER.results.GetAll()
+    if response_dict:
+      self.send_json_dict(response_dict)
+    else:
+      self.send_error(404)
+
+  def do_GET_static(self, path):
+    """ Handle a GET request for a file under the 'static' directory. """
+    print 'do_GET_static: sending file "%s"' % path
+    self.send_file(posixpath.join('static', path))
+
+  def redirect_to(self, url):
+    """ Redirect the HTTP client to a different url. """
+    self.send_response(301)
+    self.send_header('Location', url)
+    self.end_headers()
+
+  def send_file(self, path):
+    """ Send the contents of the file at this path, with a mimetype based
+        on the filename extension. """
+    # Grab the extension if there is one
+    extension = os.path.splitext(path)[1]
+    if len(extension) >= 1:
+      extension = extension[1:]
+
+    # Determine the MIME type of the file from its extension
+    mime_type = MIME_TYPE_MAP.get(extension, MIME_TYPE_MAP[''])
+
+    # Open the file and send it over HTTP
+    if os.path.isfile(path):
+      with open(path, 'rb') as sending_file:
+        self.send_response(200)
+        self.send_header('Content-type', mime_type)
+        self.end_headers()
+        self.wfile.write(sending_file.read())
+    else:
+      self.send_error(404)
+
+  def send_json_dict(self, json_dict):
+    """ Send the contents of this dictionary in JSON format, with a JSON
+        mimetype. """
+    self.send_response(200)
+    self.send_header('Content-type', 'application/json')
+    self.end_headers()
+    json.dump(json_dict, self.wfile)
+
+
+def main():
+  parser = argparse.ArgumentParser()
+  parser.add_argument('--actuals-dir',
+                    help=('Directory into which we will check out the latest '
+                          'actual GM results. If this directory does not '
+                          'exist, it will be created. Defaults to %(default)s'),
+                    default=DEFAULT_ACTUALS_DIR)
+  parser.add_argument('--expectations-dir',
+                    help=('Directory under which to find GM expectations; '
+                          'defaults to %(default)s .'),

[borenet, 2013/09/26 19:02:01]

I think adding the period here will be confusing...

[epoger, 2013/09/26 21:22:21]

Removed all trailing periods from the command-line option descriptions.  My high
school English teachers will be disappointed, but my co-workers will probably be
happier.  Seems like a reasonable tradeoff.

+                    default=DEFAULT_EXPECTATIONS_DIR)
+  parser.add_argument('--export', action='store_true',
+                      help=('Instead of only allowing access from HTTP clients '
+                            'on localhost, allow HTTP clients on other hosts '
+                            'to access this server.  WARNING: doing so will '
+                            'allow users on other hosts to modify your '
+                            'GM expectations!'))
+  parser.add_argument('--port',
+                    help=('Which TCP port to listen on for HTTP requests; '
+                          'defaults to %(default)s .'),
+                    default=DEFAULT_PORT)
+  args = parser.parse_args()
+  global _SERVER
+  _SERVER = Server(expectations_dir=args.expectations_dir,
+                   port=args.port, export=args.export)
+  _SERVER.run()
+
+if __name__ == '__main__':
+  main()