Enable tracing in SkyShell

sky/tools/shelldb

 #!/usr/bin/env python
 # Copyright 2015 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.
 
 from skypy.skyserver import SkyServer
 import argparse
 import json
 import logging
 import os
+import re
 import subprocess
 import sys
+import time
 import urlparse
 
 SKY_TOOLS_DIR = os.path.dirname(os.path.abspath(__file__))
 SKY_ROOT = os.path.dirname(SKY_TOOLS_DIR)
 SRC_ROOT = os.path.dirname(SKY_ROOT)
 
 SKY_SERVER_PORT = 9888
 DEFAULT_URL = "sky://domokit.github.io/home"
 APK_NAME = 'SkyDemo.apk'
 ADB_PATH = os.path.join(SRC_ROOT,
@@ skipping 198 matching lines @@
         mojo_core_path = os.path.join(SRC_ROOT, 'mojo/public/dart/core.dart')
         analyzer_args = [ANALYZER_PATH,
             "--url-mapping=dart:sky,%s" % dart_sky_path,
             "--url-mapping=dart:sky_builtin,%s" % sky_builtin_path,
             "--url-mapping=dart:mojo.bindings,%s" % mojo_bindings_path,
             "--url-mapping=dart:mojo.core,%s" % mojo_core_path,
             args.app_path
         ]
         subprocess.call(analyzer_args)
 
+class StartTracing(object):
+    def add_subparser(self, subparsers):
+        start_tracing_parser = subparsers.add_parser('start_tracing',
+            help=('start tracing a running sky instance'))
+        start_tracing_parser.set_defaults(func=self.run)
+
+    def run(self, args, pids):
+        subprocess.check_output([ADB_PATH, 'shell',
+            'am', 'broadcast',
+            '-a', 'org.domokit.sky.demo.TRACING_START'])
+
+
+TRACE_COMPLETE_REGEXP = re.compile('Trace complete')
+TRACE_FILE_REGEXP = re.compile(r'Saving trace to (?P<path>\S+)')
+
+class StopTracing(object):
+    def add_subparser(self, subparsers):
+        stop_tracing_parser = subparsers.add_parser('stop_tracing',
+            help=('stop tracing a running sky instance'))
+        stop_tracing_parser.set_defaults(func=self.run)
+
+    def run(self, args, pids):
+        subprocess.check_output([ADB_PATH, 'logcat', '-c'])
+        subprocess.check_output([ADB_PATH, 'shell',
+            'am', 'broadcast',
+            '-a', 'org.domokit.sky.demo.TRACING_STOP'])
+        device_path = None
+        is_complete = False
+        while not is_complete:
+            time.sleep(0.2)
+            log = subprocess.check_output([ADB_PATH, 'logcat', '-d'])
+            if device_path is None:
+                result = TRACE_FILE_REGEXP.search(log)
+                if result:
+                    device_path = result.group('path')
+            is_complete = TRACE_COMPLETE_REGEXP.search(log) is not None
+
+        print 'Downloading trace %s ...' % os.path.basename(device_path)
+
+        if device_path:
+            subprocess.check_output([ADB_PATH, 'pull', device_path])
+            subprocess.check_output([ADB_PATH, 'shell', 'rm', device_path])
+
 
 class SkyShellRunner(object):
     def main(self):
         logging.basicConfig(level=logging.WARNING)
 
         parser = argparse.ArgumentParser(description='Sky Shell Runner')
         subparsers = parser.add_subparsers(help='sub-command help')
 
-        for command in [StartSky(), StopSky(), Analyze()]:
+        commands = [
+            StartSky(),
+            StopSky(),
+            Analyze(),
+            StartTracing(),
+            StopTracing(),
+        ]
+
+        for command in commands:
             command.add_subparser(subparsers)
 
         args = parser.parse_args()
         pids = Pids.read_from(PID_FILE_PATH, PID_FILE_KEYS)
         exit_code = args.func(args, pids)
         # We could do this with an at-exit handler instead?
         pids.write_to(PID_FILE_PATH)
         sys.exit(exit_code)
 
 
 if __name__ == '__main__':
     SkyShellRunner().main()