Add super-primitive shelldb

This is basically skydb v2, except only for android.

I revisited some of the architecture decisions I made
in writing skydb.  I also separated skyserver.py from
dependency on skypy/paths.py since it wasn't really adding
any value.

We could make this way fancier, but this should at least
make working with SkyDemo.apk easier for now.

R=abarth@chromium.org

Review URL: https://codereview.chromium.org/960233007

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 subprocess
+import sys
+import urllib
+import urlparse
+
+SKY_TOOLS_DIR = os.path.dirname(__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,
+    'third_party/android_tools/sdk/platform-tools/adb')
+
+
+PID_FILE_PATH = "/tmp/skydemo.pids"
+PID_FILE_KEYS = frozenset([
+    'remote_sky_server_port',
+    'sky_server_pid',
+    'sky_server_port',
+    'sky_server_root',
+    'build_dir',
+])
+
+# This 'strict dictionary' approach is useful for catching typos.
+class Pids(object):
+    def __init__(self, known_keys, contents=None):
+        self._known_keys = known_keys
+        self._dict = contents if contents is not None else {}
+
+    def __len__(self):
+        return len(self._dict)
+
+    def __getitem__(self, key):
+        assert key in self._known_keys, '%s not in known_keys' % key
+        return self._dict[key]
+
+    def __setitem__(self, key, value):
+        assert key in self._known_keys, '%s not in known_keys' % key
+        self._dict[key] = value
+
+    def __delitem__(self, key):
+        assert key in self._known_keys, '%s not in known_keys' % key
+        del self._dict[key]
+
+    def __iter__(self):
+        return iter(self._dict)
+
+    def __contains__(self, key):
+        assert key in self._known_keys, '%s not in allowed_keys' % key
+        return key in self._dict
+
+    def clear():
+        self._dict = {}
+
+    @classmethod
+    def read_from(cls, path, known_keys):
+        contents = {}
+        try:
+            with open(path, 'r') as pid_file:
+                contents = json.load(pid_file)
+        except:
+            if os.path.exists(path):
+                logging.warn('Failed to read pid file: %s' % path)
+        return cls(known_keys, contents)
+
+    def write_to(self, path):
+        try:
+            with open(path, 'w') as pid_file:
+                json.dump(self._dict, pid_file, indent=2, sort_keys=True)
+        except:
+            logging.warn('Failed to write pid file: %s' % path)
+
+
+def _convert_to_sky_url(url):
+    result = urllib.parse.urlsplit(url)
+    result.scheme = 'sky'
+    return urllib.parse.urlunsplit(result)
+
+
+# A free function for possible future sharing with a 'load' command.
+def _url_from_args(args):
+    if urlparse.urlparse(args.url_or_path).scheme:
+        return args.url_or_path
+    # The load happens on the remote device, use the remote port.
+    remote_sky_server_port = self.pids.get('remote_sky_server_port',
+        self.pids['sky_server_port'])
+    url = SkyServer.url_for_path(remote_sky_server_port,
+        self.pids['sky_server_root'], args.url_or_path)
+    return _convert_to_sky_url(url)
+
+
+class StartSky(object):
+    def add_subparser(self, subparsers):
+        start_parser = subparsers.add_parser('start',
+            help='launch SKyShell.apk on the device')
+        start_parser.add_argument('build_dir', type=str)
+        start_parser.add_argument('url_or_path', nargs='?', type=str,
+            default=DEFAULT_URL)
+        start_parser.set_defaults(func=self.run)
+
+    def _server_root_for_url(self, url_or_path):
+        path = os.path.abspath(url_or_path)
+        if os.path.commonprefix([path, SRC_ROOT]) == SRC_ROOT:
+            server_root = SRC_ROOT
+        else:
+            server_root = os.path.dirname(path)
+            logging.warn(
+                '%s is outside of mojo root, using %s as server root' %
+                (path, server_root))
+        return server_root
+
+    def _sky_server_for_args(self, args):
+        # FIXME: This is a hack.  sky_server should just take a build_dir
+        # not a magical "configuration" name.
+        configuration = os.path.basename(os.path.normpath(args.build_dir))
+        server_root = self._server_root_for_url(args.url_or_path)
+        sky_server = SkyServer(SKY_SERVER_PORT, configuration, server_root)
+        return sky_server
+
+    def run(self, args, pids):
+        apk_path = os.path.join(args.build_dir, 'apks', APK_NAME)
+        if not os.path.exists(apk_path):
+            print "'%s' does not exist?" % apk_path
+            return 2
+
+        sky_server = self._sky_server_for_args(args)
+        pids['sky_server_pid'] = sky_server.start()
+        pids['sky_server_port'] = sky_server.port
+        pids['sky_server_root'] = sky_server.root
+
+        pids['build_dir'] = args.build_dir
+
+        subprocess.check_call([ADB_PATH, 'install', '-r', apk_path])
+
+        port_string = 'tcp:%s' % sky_server.port
+        subprocess.check_call([
+            ADB_PATH, 'reverse', port_string, port_string
+        ])
+        pids['remote_sky_server_port'] = sky_server.port
+
+        subprocess.check_call([ADB_PATH, 'shell',
+            'am', 'start',
+            '-a', 'android.intent.action.VIEW',
+            '-d', _url_from_args(args)])
+
+
+class StopSky(object):
+    def add_subparser(self, subparsers):
+        stop_parser = subparsers.add_parser('stop',
+            help=('kill all running SkyShell.apk processes'))
+        stop_parser.set_defaults(func=self.run)
+
+    def _kill_if_exists(self, pids, key, name):
+        pid = pids.pop(key, None)
+        if not pid:
+            logging.info('No pid for %s, nothing to do.' % name)
+            return
+        logging.info('Killing %s (%d).' % (name, pid))
+        try:
+            os.kill(pid, signal.SIGTERM)
+        except OSError:
+            logging.info('%s (%d) already gone.' % (name, pid))
+
+    def run(self, args, pids):
+        self._kill_if_exists(pids, 'sky_server_pid', 'sky_server')
+
+        if 'remote_sky_server_port' in self.pids:
+            port_string = 'tcp:%s' % self.pids['remote_sky_server_port']
+            subprocess.call([ADB_PATH, 'reverse', '--remove', port_string])
+
+        subprocess.call([
+            ADB_PATH, 'shell', 'am', 'force-stop', ANDROID_PACKAGE])
+
+        pids.clear()
+
+
+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()]:
+            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()

tools/skydb

@@ -144,8 +144,7 @@ class SkyDebugger(object):
         # not a magical "configuration" name.
         configuration = os.path.basename(os.path.normpath(self.paths.build_dir))
         server_root = self._server_root_for_url(args.url_or_path)
-        sky_server = SkyServer(self.paths, SKY_SERVER_PORT,
-            configuration, server_root)
+        sky_server = SkyServer(SKY_SERVER_PORT, configuration, server_root)
         return sky_server
 
     def _create_paths_for_build_dir(self, build_dir):

tools/skypy/skyserver.py

@@ -7,9 +7,13 @@ import subprocess
 import logging
 import os.path
 
+SKYPY_PATH = os.path.dirname(__file__)
+SKY_TOOLS_PATH = os.path.dirname(SKYPY_PATH)
+SKY_ROOT = os.path.dirname(SKY_TOOLS_PATH)
+SRC_ROOT = os.path.dirname(SKY_ROOT)
+
 class SkyServer(object):
-    def __init__(self, paths, port, configuration, root):
-        self.paths = paths
+    def __init__(self, port, configuration, root):
         self.port = port
         self.configuration = configuration
         self.root = root
@@ -21,10 +25,9 @@ class SkyServer(object):
         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 _download_server_if_necessary():
+        subprocess.call(os.path.join(SKY_TOOLS_PATH, 'download_sky_server'))
+        return os.path.join(SRC_ROOT, 'out', 'downloads', 'sky_server')
 
     def start(self):
         if self._port_in_use(self.port):
@@ -33,7 +36,7 @@ class SkyServer(object):
                 self.port)
             return
 
-        server_path = self._download_server_if_necessary(self.paths)
+        server_path = self._download_server_if_necessary()
         server_command = [
             server_path,
             '-t', self.configuration,