Add --silent flag to observatory_tool.py

tools/observatory_tool.py

 #!/usr/bin/env python
 # Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 """Helper for building and deploying Observatory"""
 
 import argparse
 import os
 import shutil
 import subprocess
@@ skipping 15 matching lines @@
 
 usage = """obs_tool.py [options]"""
 
 def BuildArguments():
   result = argparse.ArgumentParser(usage=usage)
   result.add_argument("--package-root", help="package root", default=None)
   result.add_argument("--dart-executable", help="dart executable", default=None)
   result.add_argument("--pub-executable", help="pub executable", default=None)
   result.add_argument("--directory", help="observatory root", default=None)
   result.add_argument("--command", help="[get, build, deploy]", default=None)
+  result.add_argument("--silent", help="silence all output", default=False)
   return result
 
 def ProcessOptions(options, args):
   # Required options.
   if (options.command == None) or (options.directory == None):
     return False
   # If we have a pub executable, we are running from the dart-sdk.
   if (options.pub_executable != None):
     return True
   # Otherwise, we need a dart executable and a package root.
   return ((options.package_root != None) and
           (options.dart_executable != None))
 
 def ChangeDirectory(directory):
   os.chdir(directory);
 
-def PubGet(dart_executable, pub_executable, pkg_root):
+def PubGet(dart_executable, pub_executable, pkg_root, silent):
   # Always remove pubspec.lock before running 'pub get'.
   try:
     os.remove('pubspec.lock');
   except OSError as e:
     pass
-  if (pub_executable != None):
-    return subprocess.call([pub_executable,
-                            'get',
-                            '--offline'])
-  else:
-    return subprocess.call(['python',
-                            RUN_PUB,
-                            '--package-root=' + pkg_root,
-                            '--dart-executable=' + dart_executable,
-                            'get',
-                            '--offline'])
+  with open(os.devnull, 'wb') as silent_sink:
+    if (pub_executable != None):
+      return subprocess.call([pub_executable,
+                              'get',
+                              '--offline'],
+                              stdout=silent_sink if silent else None,
+                              stderr=silent_sink if silent else None)
+    else:
+      return subprocess.call(['python',
+                              RUN_PUB,
+                              '--package-root=' + pkg_root,
+                              '--dart-executable=' + dart_executable,
+                              'get',
+                              '--offline'],
+                              stdout=silent_sink if silent else None,
+                              stderr=silent_sink if silent else None,)
 
-def PubBuild(dart_executable, pub_executable, pkg_root, output_dir):
-  if (pub_executable != None):
-    return subprocess.call([pub_executable,
-                            'build',
-                            '--output',
-                            output_dir])
-  else:
-    return subprocess.call(['python',
-                            RUN_PUB,
-                            '--package-root=' + pkg_root,
-                            '--dart-executable=' + dart_executable,
-                            'build',
-                            '--output',
-                            output_dir])
+def PubBuild(dart_executable, pub_executable, pkg_root, silent, output_dir):
+  with open(os.devnull, 'wb') as silent_sink:
+    if (pub_executable != None):
+      return subprocess.call([pub_executable,
+                              'build',
+                              '--output',
+                              output_dir],
+                              stdout=silent_sink if silent else None,
+                              stderr=silent_sink if silent else None,)
+    else:
+      return subprocess.call(['python',
+                              RUN_PUB,
+                              '--package-root=' + pkg_root,
+                              '--dart-executable=' + dart_executable,
+                              'build',
+                              '--output',
+                              output_dir],
+                              stdout=silent_sink if silent else None,
+                              stderr=silent_sink if silent else None,)
 
 def Deploy(input_dir, output_dir):
   shutil.rmtree(output_dir)
   shutil.copytree(input_dir, output_dir, ignore=IGNORE_PATTERNS)
   return 0
 
 def RewritePubSpec(input_path, output_path, search, replace):
   with open(input_path, 'rb') as input_file:
     input_data = input_file.read()
     input_data = input_data.replace(search, replace)
     with open(output_path, 'wb+') as output_file:
       output_file.write(input_data)
 
 def ExecuteCommand(options, args):
   cmd = options.command
   if (cmd == 'get'):
     return PubGet(options.dart_executable,
                   options.pub_executable,
-                  options.package_root)
+                  options.package_root,
+                  options.silent)
   elif (cmd == 'build'):
     return PubBuild(options.dart_executable,
                     options.pub_executable,
                     options.package_root,
+                    options.silent,
                     args[0])
   elif (cmd == 'deploy'):
     Deploy('build', 'deployed')
   elif (cmd == 'rewrite'):
     RewritePubSpec(args[0], args[1], args[2], args[3])
   else:
     print >> sys.stderr, ('ERROR: command "%s" not supported') % (cmd)
     return -1;
 
 def main():
@@ skipping 13 matching lines @@
   if (options.pub_executable != None):
     options.pub_executable = os.path.abspath(options.pub_executable)
   if len(args) == 1:
     args[0] = os.path.abspath(args[0])
   # Pub must be run from the project's root directory.
   ChangeDirectory(options.directory)
   return ExecuteCommand(options, args)
 
 if __name__ == '__main__':
   sys.exit(main());