[android] Instumentation tests determine whether to install test apk based on Md5Sum.

build/android/pylib/android_commands.py

 # Copyright (c) 2012 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.
 
 """Provides an interface to communicate with the device via the adb command.
 
 Assumes adb binary is currently on system path.
 """
 
 import collections
@@ skipping 390 matching lines @@
 
     self._LogShell(install_cmd)
     return self._adb.SendCommand(install_cmd,
                                  timeout_time=2 * 60,
                                  retry_count=0)
 
   def ManagedInstall(self, apk_path, keep_data=False, package_name=None,
                      reboots_on_failure=2):
     """Installs specified package and reboots device on timeouts.
 
+    If package_name is supplied, checks if the package is already installed and
+    doesn't reinstall if the apk md5sums match.
+
     Args:
       apk_path: Path to .apk file to install.
       keep_data: Reinstalls instead of uninstalling first, preserving the
         application data.
       package_name: Package name (only needed if keep_data=False).
       reboots_on_failure: number of time to reboot if package manager is frozen.
-
-    Returns:
-      A status string returned by adb install
     """
+    # Check if package is already installed and up to date.
+    if package_name:
+      installed_apk_path = self.GetApplicationPath(package_name)
+      if installed_apk_path and self.CheckMd5Sum(apk_path, installed_apk_path):
+        logging.info('Skipped install: identical %s APK already installed' %
+            package_name)
+        return
+    # Install.
     reboots_left = reboots_on_failure
     while True:
       try:
         if not keep_data:
           assert package_name
           self.Uninstall(package_name)
         install_status = self.Install(apk_path, reinstall=keep_data)
         if 'Success' in install_status:
-          return install_status
+          return
       except errors.WaitForResponseTimedOutError:
         print '@@@STEP_WARNINGS@@@'
         logging.info('Timeout on installing %s on device %s', apk_path,
                      self._device)
 
       if reboots_left <= 0:
         raise Exception('Install failure')
 
       # Force a hard reboot on last attempt
       self.Reboot(full_reboot=(reboots_left == 1))
@@ skipping 286 matching lines @@
       self.RunShellCommand('pm clear ' + package)
 
   def SendKeyEvent(self, keycode):
     """Sends keycode to the device.
 
     Args:
       keycode: Numeric keycode to send (see "enum" at top of file).
     """
     self.RunShellCommand('input keyevent %d' % keycode)
 
-  def CheckMd5Sum(self, local_path, device_path, ignore_paths=False):
+  def CheckMd5Sum(self, local_path, device_path):
     """Compares the md5sum of a local path against a device path.
 
     Args:
       local_path: Path (file or directory) on the host.
       device_path: Path on the device.
-      ignore_paths: If False, both the md5sum and the relative paths/names of
-          files must match. If True, only the md5sum must match.
 
     Returns:
       True if the md5sums match.
     """
     if not self._md5sum_build_dir:
       default_build_type = os.environ.get('BUILD_TYPE', 'Debug')
       build_dir = '%s/%s/' % (
           cmd_helper.OutDirectory().get(), default_build_type)
       md5sum_dist_path = '%s/md5sum_dist' % build_dir
       if not os.path.exists(md5sum_dist_path):
@@ skipping 715 matching lines @@
   """
   def __init__(self, output):
     self._output = output
 
   def write(self, data):
     data = data.replace('\r\r\n', '\n')
     self._output.write(data)
 
   def flush(self):
     self._output.flush()