Merge pull request #760 from zacikpa/prepend-variables

variables: Add an option to prepend child variables before parent ones

tuned/consts.py

@@ -21,6 +21,7 @@ USER_PROFILES_DIR = "/etc/tuned/profiles"
 SYSTEM_PROFILES_DIR = "/usr/lib/tuned/profiles"
 PERSISTENT_STORAGE_DIR = "/var/lib/tuned"
 PLUGIN_MAIN_UNIT_NAME = "main"
+PLUGIN_VARIABLES_UNIT_NAME = "variables"
 # Magic section header because ConfigParser does not support "headerless" config
 MAGIC_HEADER_NAME = "this_is_some_magic_section_header_because_of_compatibility"
 RECOMMEND_DIRECTORIES = ["/usr/lib/tuned/recommend.d", "/etc/tuned/recommend.d"]

tuned/profiles/loader.py

@@ -51,15 +51,9 @@ class Loader(object):
 		processed_files = []
 		self._load_profile(profile_names, profiles, processed_files)
 
-		if len(profiles) > 1:
-			final_profile = self._profile_merger.merge(profiles)
-		else:
-			final_profile = profiles[0]
-
+		final_profile = self._profile_merger.merge(profiles)
 		final_profile.name = " ".join(profile_names)
-		if "variables" in final_profile.units:
-			self._variables.add_from_cfg(final_profile.units["variables"].options)
-			del(final_profile.units["variables"])
+		self._variables.add_from_cfg(final_profile.variables)
 		# FIXME hack, do all variable expansions in one place
 		self._expand_vars_in_devices(final_profile)
 		self._expand_vars_in_regexes(final_profile)

tuned/profiles/merger.py

@@ -1,5 +1,6 @@
-import collections
+import tuned.consts as consts
 from functools import reduce
+from tuned.profiles.profile import Profile
 
 class Merger(object):
 	"""
@@ -14,7 +15,7 @@ class Merger(object):
 		Merge multiple configurations into one. If there are multiple units of the same type, option 'devices'
 		is set for each unit with respect to eliminating any duplicate devices.
 		"""
-		merged_config = reduce(self._merge_two, configs)
+		merged_config = reduce(self._merge_two, configs, Profile())
 		return merged_config
 
 	def _merge_two(self, profile_a, profile_b):
@@ -23,11 +24,22 @@ class Merger(object):
 		from the newer profile. If the 'replace' options of the newer unit is 'True', all options from the
 		older unit are dropped.
 		"""
+		if profile_a.name is None:
+			profile_a.name = profile_b.name
 
 		profile_a.options.update(profile_b.options)
 
 		for unit_name, unit in list(profile_b.units.items()):
-			if unit.replace or unit_name not in profile_a.units:
+			if unit.type == consts.PLUGIN_VARIABLES_UNIT_NAME:
+				if unit.replace:
+					profile_a.variables.clear()
+				overwritten_variables = set(profile_a.variables.keys()) & set(unit.options.keys())
+				profile_a.variables.update(unit.options)
+				if unit.prepend:
+					for variable in reversed(unit.options):
+						if variable not in overwritten_variables:
+							profile_a.variables.move_to_end(variable, last=False)
+			elif unit.replace or unit_name not in profile_a.units:
 				profile_a.units[unit_name] = unit
 			else:
 				profile_a.units[unit_name].type = unit.type

tuned/profiles/profile.py

@@ -7,10 +7,11 @@ class Profile(object):
 	Representation of a tuning profile.
 	"""
 
-	__slots__ = ["_name", "_options", "_units"]
+	__slots__ = ["_name", "_options", "_variables", "_units"]
 
-	def __init__(self, name, config):
+	def __init__(self, name=None, config={}):
 		self._name = name
+		self._variables = collections.OrderedDict()
 		self._init_options(config)
 		self._init_units(config)
 
@@ -40,6 +41,10 @@ class Profile(object):
 	def name(self, value):
 		self._name = value
 
+	@property
+	def variables(self):
+		return self._variables
+
 	@property
 	def units(self):
 		"""

tuned/profiles/unit.py

@@ -6,7 +6,7 @@ class Unit(object):
 	Unit description.
 	"""
 
-	__slots__ = [ "_name", "_priority", "_type", "_enabled", "_replace", "_drop", "_devices", "_devices_udev_regex", \
+	__slots__ = [ "_name", "_priority", "_type", "_enabled", "_replace", "_prepend", "_drop", "_devices", "_devices_udev_regex", \
 		"_cpuinfo_regex", "_uname_regex", "_script_pre", "_script_post", "_options" ]
 
 	def __init__(self, name, config):
@@ -15,6 +15,7 @@ class Unit(object):
 		self._type = config.pop("type", self._name)
 		self._enabled = config.pop("enabled", True) in [True, "True", "true", 1, "1"]
 		self._replace = config.pop("replace", False) in [True, "True", "true", 1, "1"]
+		self._prepend = config.pop("prepend", False) in [True, "True", "true", 1, "1"]
 		self._drop = config.pop("drop", None)
 		if self._drop is not None:
 			self._drop = re.split(r"\b\s*[,;]\s*", str(self._drop))
@@ -58,6 +59,10 @@ class Unit(object):
 	def replace(self):
 		return self._replace
 
+	@property
+	def prepend(self):
+		return self._prepend
+
 	@property
 	def drop(self):
 		return self._drop