[android] Switch test scripts to use last modified time instead of md5sum when checking dependencie…

build/android/pylib/android_commands.py

Index: build/android/pylib/android_commands.py
diff --git a/build/android/pylib/android_commands.py b/build/android/pylib/android_commands.py
index f260639352cb073fa6674acbf979f0a307361f44..9dc9d364b9d14cc4e2478bca22ad04e8a0841d92 100644
--- a/build/android/pylib/android_commands.py
+++ b/build/android/pylib/android_commands.py
@@ -61,9 +61,9 @@ KEYCODE_DPAD_RIGHT = 22
 KEYCODE_ENTER = 66
 KEYCODE_MENU = 82
 
-MD5SUM_DEVICE_FOLDER = constants.TEST_EXECUTABLE_DIR + '/md5sum/'
-MD5SUM_DEVICE_PATH = MD5SUM_DEVICE_FOLDER + 'md5sum_bin'
-MD5SUM_LD_LIBRARY_PATH = 'LD_LIBRARY_PATH=%s' % MD5SUM_DEVICE_FOLDER
+TIMEMODIFIED_DEVICE_FOLDER = constants.TEST_EXECUTABLE_DIR + '/timemodified/'

[frankf, 2013/06/20 22:52:38]

If these are only used in one function, let's move them there.

[frankf, 2013/06/20 22:52:38]

FOLDER -> DIRECTORY

[craigdh, 2013/07/02 17:26:12]

Done.

[craigdh, 2013/07/02 17:26:12]

Done.

+TIMEMODIFIED_DEVICE_PATH = TIMEMODIFIED_DEVICE_FOLDER + 'timemodified_bin'
+TIMEMODIFIED_LD_LIBRARY_PATH = 'LD_LIBRARY_PATH=%s' % TIMEMODIFIED_DEVICE_FOLDER
 
 def GetEmulators():
   """Returns a list of emulators.  Does not filter by status (e.g. offline).
@@ -171,9 +171,9 @@ def _GetFilesFromRecursiveLsOutput(path, ls_output, re_file, utc_offset=None):
   return files
 
 
-def _ComputeFileListHash(md5sum_output):
-  """Returns a list of MD5 strings from the provided md5sum output."""
-  return [line.split('  ')[0] for line in md5sum_output]
+def _ComputeFileListTimesModified(timemodified_output):
+  """Returns a list of time strings from the provided timemodified output."""
+  return [line.split('  ')[0] for line in timemodified_output]
 
 
 def _HasAdbPushSucceeded(command_output):
@@ -220,7 +220,7 @@ class AndroidCommands(object):
     self._logcat_tmpoutfile = None
     self._pushed_files = []
     self._device_utc_offset = self.RunShellCommand('date +%z')[0]
-    self._md5sum_build_dir = ''
+    self._timemodified_build_dir = ''
     self._external_storage = ''
     self._util_wrapper = ''
 
@@ -696,57 +696,68 @@ class AndroidCommands(object):
     """
     self.RunShellCommand('input keyevent %d' % keycode)
 
-  def CheckMd5Sum(self, local_path, device_path, ignore_paths=False):
-    """Compares the md5sum of a local path against a device path.
+  def CheckTimesModified(self, local_path, device_path, ignore_paths=False):

[frankf, 2013/06/20 22:52:38]

I would rename this to something like FileOutOfSync()

[craigdh, 2013/07/02 17:26:12]

Done.

[craigdh, 2013/07/02 17:26:12]

Done.

+    """Compares the time modified 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.
+      ignore_paths: If False, both the time modified and the relative
+          paths/names of files must match. If True, only the time modified
+          must match.
 
     Returns:
-      True if the md5sums match.
+      True if the time the files were modified match or are more recent.
     """
     assert os.path.exists(local_path), 'Local path not found %s' % local_path
 
-    if not self._md5sum_build_dir:
+    if not self._timemodified_build_dir:
       default_build_type = os.environ.get('BUILD_TYPE', 'Debug')
       build_dir = '%s/%s/' % (
           cmd_helper.OutDirectory().get(), default_build_type)

[frankf, 2013/06/20 22:52:38]

We should really set the out directory once instead of figuring it out multiple
times.

[craigdh, 2013/07/02 17:26:12]

Why? It's not a very heavy call.

-      md5sum_dist_path = '%s/md5sum_dist' % build_dir
-      if not os.path.exists(md5sum_dist_path):
+      timemodified_dist_path = '%s/timemodified_dist' % build_dir

[frankf, 2013/06/20 22:52:38]

let's have 'host'/'device' in the variable names to make this more readable.

[craigdh, 2013/07/02 17:26:12]

Done.

+      if not os.path.exists(timemodified_dist_path):
         build_dir = '%s/Release/' % cmd_helper.OutDirectory().get()
-        md5sum_dist_path = '%s/md5sum_dist' % build_dir
-        assert os.path.exists(md5sum_dist_path), 'Please build md5sum.'
-      command = 'push %s %s' % (md5sum_dist_path, MD5SUM_DEVICE_FOLDER)
+        timemodified_dist_path = '%s/timemodified_dist' % build_dir
+        assert os.path.exists(timemodified_dist_path), 'Build timemodified.'
+      command = 'push %s %s' % (timemodified_dist_path,
+                                TIMEMODIFIED_DEVICE_FOLDER)
       assert _HasAdbPushSucceeded(self._adb.SendCommand(command))
-      self._md5sum_build_dir = build_dir
+      self._timemodified_build_dir = build_dir
 
     self._pushed_files.append(device_path)
-    hashes_on_device = _ComputeFileListHash(
-        self.RunShellCommand(MD5SUM_LD_LIBRARY_PATH + ' ' + self._util_wrapper +
-            ' ' + MD5SUM_DEVICE_PATH + ' ' + device_path))
+    hashes_on_device = _ComputeFileListTimesModified(
+        self.RunShellCommand(TIMEMODIFIED_LD_LIBRARY_PATH + ' ' +
+            self._util_wrapper + ' ' + TIMEMODIFIED_DEVICE_PATH + ' ' +
+            device_path))
     assert os.path.exists(local_path), 'Local path not found %s' % local_path
-    md5sum_output = cmd_helper.GetCmdOutput(
-        ['%s/md5sum_bin_host' % self._md5sum_build_dir, local_path])
-    hashes_on_host = _ComputeFileListHash(md5sum_output.splitlines())
+    timemodified_output = cmd_helper.GetCmdOutput(
+        ['%s/timemodified_bin_host' % self._timemodified_build_dir, local_path])
+    hashes_on_host = _ComputeFileListTimesModified(
+        timemodified_output.splitlines())
 
+    #TODO(craigdh): This doesn't appear to have any effect.

[frankf, 2013/06/20 22:52:38]

What's the deal here? If not used, can we remove it?

[craigdh, 2013/07/02 17:26:12]

Done.

     if ignore_paths:
       hashes_on_device = [h.split()[0] for h in hashes_on_device]
       hashes_on_host = [h.split()[0] for h in hashes_on_host]
 
-    return hashes_on_device == hashes_on_host
+    if len(hashes_on_device) != len(hashes_on_host):
+      return False
+    hashes_on_device.sort()
+    hashes_on_host.sort()
+    return all(int(dtime) >= int(htime) for dtime, htime in
+        zip(hashes_on_device, hashes_on_host))
 
   def PushIfNeeded(self, local_path, device_path):
     """Pushes |local_path| to |device_path|.
 
     Works for files and directories. This method skips copying any paths in
-    |test_data_paths| that already exist on the device with the same hash.
+    |test_data_paths| that already exist on the device with the same modified
+    time.
 
     All pushed files can be removed by calling RemovePushedFiles().
     """
-    if self.CheckMd5Sum(local_path, device_path):
+    if self.CheckTimesModified(local_path, device_path):
       return
 
     # They don't match, so remove everything first and then create it.
@@ -1274,7 +1285,7 @@ class AndroidCommands(object):
 
   def SetUtilWrapper(self, util_wrapper):
     """Sets a wrapper prefix to be used when running a locally-built
-    binary on the device (ex.: md5sum_bin).
+    binary on the device (ex.: timemodified_bin).
     """
     self._util_wrapper = util_wrapper