[Android] Add ring_buffer option to adb.Logcat

build/android/pylib/device/adb_wrapper.py

 # Copyright 2013 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.
 
 """This module wraps Android's adb tool.
 
 This is a thin wrapper around the adb interface. Any additional complexity
 should be delegated to a higher level (ex. DeviceUtils).
 """
 
@@ skipping 282 matching lines @@
     lines = self._RunDeviceAdbCmd(
         cmd, timeout=timeout, retries=retries).splitlines()
     if lines:
       return [ParseLine(line) for line in lines]
     else:
       raise device_errors.AdbCommandFailedError(
           cmd, 'path does not specify an accessible directory in the device',
           device_serial=self._device_serial)
 
   def Logcat(self, clear=False, dump=False, filter_specs=None,
-             logcat_format=None, timeout=None, retries=_DEFAULT_RETRIES):
+             logcat_format=None, ring_buffer=None, timeout=None,
+             retries=_DEFAULT_RETRIES):
     """Get an iterable over the logcat output.
 
     Args:
       clear: If true, clear the logcat.
       dump: If true, dump the current logcat contents.
       filter_specs: If set, a list of specs to filter the logcat.
       logcat_format: If set, the format in which the logcat should be output.
         Options include "brief", "process", "tag", "thread", "raw", "time",
         "threadtime", and "long"
+      ring_buffer: If set, a list of alternate ring buffers to request.
+        Options include "main", "system", "radio", "events", "crash" or "all".
+        The default is equivalent to ["main", "system", "crash"].
       timeout: (optional) If set, timeout per try in seconds. If clear or dump
         is set, defaults to _DEFAULT_TIMEOUT.
       retries: (optional) If clear or dump is set, the number of retries to
         attempt. Otherwise, does nothing.
 
     Yields:
       logcat output line by line.
     """
     cmd = ['logcat']
     use_iter = True
     if clear:
       cmd.append('-c')
       use_iter = False
     if dump:
       cmd.append('-d')
       use_iter = False
     if logcat_format:
       cmd.extend(['-v', logcat_format])
+    if ring_buffer:

[jbudorick, 2015/03/18 16:53:01]

optional nit: could do

  for buffer_name in ring_buffer or []:
    cmd.extend(['-b', buffer_name])

+      for buffer_name in ring_buffer:
+        cmd.extend(['-b', buffer_name])
     if filter_specs:
       cmd.extend(filter_specs)
 
     if use_iter:
       return self._IterRunDeviceAdbCmd(cmd, timeout)
     else:
       timeout = timeout if timeout is not None else _DEFAULT_TIMEOUT
       return self._RunDeviceAdbCmd(cmd, timeout, retries).splitlines()
 
   def Forward(self, local, remote, timeout=_DEFAULT_TIMEOUT,
@@ skipping 175 matching lines @@
     """Restarts the adbd daemon with root permissions, if possible.
 
     Args:
       timeout: (optional) Timeout per try in seconds.
       retries: (optional) Number of retries to attempt.
     """
     output = self._RunDeviceAdbCmd(['root'], timeout, retries)
     if 'cannot' in output:
       raise device_errors.AdbCommandFailedError(
           ['root'], output, device_serial=self._device_serial)