Add access to read-only properties

build/android/pylib/device/device_utils.py

 # Copyright 2014 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 a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=W0613
 
@@ skipping 16 matching lines @@
 from pylib.utils import apk_helper
 from pylib.utils import device_temp_file
 from pylib.utils import host_utils
 from pylib.utils import md5sum
 from pylib.utils import parallelizer
 from pylib.utils import timeout_retry
 
 _DEFAULT_TIMEOUT = 30
 _DEFAULT_RETRIES = 3
 
+# A sentinel object for default values
+# TODO(jbudorick,perezju): revisit how default values are handled by
+# the timeout_retry decorators.
+DEFAULT = object()
+
 
 @decorators.WithExplicitTimeoutAndRetries(
     _DEFAULT_TIMEOUT, _DEFAULT_RETRIES)
 def GetAVDs():
   """Returns a list of Android Virtual Devices.
 
   Returns:
     A list containing the configured AVDs.
   """
   lines = cmd_helper.GetCmdOutput([
@@ skipping 92 matching lines @@
     Raises:
       CommandTimeoutError on timeout.
       DeviceUnreachableError on missing device.
     """
     try:
       self.RunShellCommand('ls /root', check_return=True)
       return True
     except device_errors.AdbCommandFailedError:
       return False
 
-  def NeedsSU(self, timeout=None, retries=None):
+  def NeedsSU(self, timeout=DEFAULT, retries=DEFAULT):
     """Checks whether 'su' is needed to access protected resources.
 
     Args:
       timeout: timeout in seconds
       retries: number of retries
 
     Returns:
       True if 'su' is available on the device and is needed to to access
         protected resources; False otherwise if either 'su' is not available
         (e.g. because the device has a user build), or not needed (because adbd
         already has root privileges).
 
     Raises:
       CommandTimeoutError on timeout.
       DeviceUnreachableError on missing device.
     """
     if 'needs_su' not in self._cache:
       try:
-        self.RunShellCommand('su -c ls /root && ! ls /root', check_return=True,
-                             timeout=timeout, retries=retries)
+        self.RunShellCommand(
+            'su -c ls /root && ! ls /root', check_return=True,
+            timeout=self._default_timeout if timeout is DEFAULT else timeout,
+            retries=self._default_retries if retries is DEFAULT else retries)
         self._cache['needs_su'] = True
       except device_errors.AdbCommandFailedError:
         self._cache['needs_su'] = False
     return self._cache['needs_su']
 
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def EnableRoot(self, timeout=None, retries=None):
     """Restarts adbd with root privileges.
 
@@ skipping 807 matching lines @@
 
     Returns:
       True if the device-side property changed and a restart is required as a
       result, False otherwise.
 
     Raises:
       CommandTimeoutError on timeout.
     """
     return self.old_interface.SetJavaAssertsEnabled(enabled)
 
+
+  @property
+  def build_description(self):
+    """Returns the build description of the system.
+
+    For example:
+      nakasi-user 4.4.4 KTU84P 1227136 release-keys
+    """
+    return self.GetProp('ro.build.description', cache=True)
+
+  @property
+  def build_fingerprint(self):
+    """Returns the build fingerprint of the system.
+
+    For example:
+      google/nakasi/grouper:4.4.4/KTU84P/1227136:user/release-keys
+    """
+    return self.GetProp('ro.build.fingerprint', cache=True)
+
+  @property
+  def build_id(self):
+    """Returns the build ID of the system (e.g. 'KTU84P')."""
+    return self.GetProp('ro.build.id', cache=True)
+
+  @property
+  def build_product(self):
+    """Returns the build product of the system (e.g. 'grouper')."""
+    return self.GetProp('ro.build.product', cache=True)
+
   @property
   def build_type(self):
-    """Returns the build type of the system (e.g. userdebug)."""
+    """Returns the build type of the system (e.g. 'user')."""
     return self.GetProp('ro.build.type', cache=True)
 
-  def GetProp(self, property_name, cache=False, timeout=None, retries=None):
+  @property
+  def build_version_sdk(self):
+    """Returns the build version sdk of the system as a number (e.g. 19).
+
+    For version code numbers see:
+    http://developer.android.com/reference/android/os/Build.VERSION_CODES.html
+
+    For named constants see:
+    pylib.constants.ANDROID_SDK_VERSION_CODES
+
+    Raises:
+      CommandFailedError if the build version sdk is not a number.
+    """
+    value = self.GetProp('ro.build.version.sdk', cache=True)
+    try:
+      return int(value)
+    except ValueError:
+      raise device_errors.CommandFailedError(
+          'Invalid build version sdk: %r' % value)
+
+  @property
+  def product_cpu_abi(self):
+    """Returns the product cpu abi of the device (e.g. 'armeabi-v7a')."""
+    return self.GetProp('ro.product.cpu.abi', cache=True)
+
+  @property
+  def product_model(self):
+    """Returns the name of the product model (e.g. 'Nexus 7')."""
+    return self.GetProp('ro.product.model', cache=True)
+
+  @property
+  def product_name(self):
+    """Returns the product name of the device (e.g. 'nakasi')."""
+    return self.GetProp('ro.product.name', cache=True)
+
+  def GetProp(self, property_name, cache=False, timeout=DEFAULT,
+              retries=DEFAULT):
     """Gets a property from the device.
 
     Args:
       property_name: A string containing the name of the property to get from
                      the device.
       cache: A boolean indicating whether to cache the value of this property.
       timeout: timeout in seconds
       retries: number of retries
 
     Returns:
       The value of the device's |property_name| property.
 
     Raises:
       CommandTimeoutError on timeout.
     """
     assert isinstance(property_name, basestring), (
         "property_name is not a string: %r" % property_name)
 
     cache_key = '_prop:' + property_name
     if cache and cache_key in self._cache:
       return self._cache[cache_key]
     else:
       # timeout and retries are handled down at run shell, because we don't
       # want to apply them in the other branch when reading from the cache
-      value = self.RunShellCommand(['getprop', property_name],
-                                   single_line=True, check_return=True,
-                                   timeout=timeout, retries=retries)
+      value = self.RunShellCommand(
+          ['getprop', property_name], single_line=True, check_return=True,
+          timeout=self._default_timeout if timeout is DEFAULT else timeout,
+          retries=self._default_retries if retries is DEFAULT else retries)
       if cache or cache_key in self._cache:
         self._cache[cache_key] = value
       return value
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def SetProp(self, property_name, value, check=False, timeout=None,
               retries=None):
     """Sets a property on the device.
 
     Args:
@@ skipping 150 matching lines @@
     Returns:
       A Parallelizer operating over |devices|.
     """
     if not devices:
       devices = adb_wrapper.AdbWrapper.GetDevices()
     devices = [d if isinstance(d, cls) else cls(d) for d in devices]
     if async:
       return parallelizer.Parallelizer(devices)
     else:
       return parallelizer.SyncParallelizer(devices)