Author: andar
Revision: 5323
Log:
Modify the Config class to version the config files now.
Add ability to register converter functions for config files to convert them to
newer versions.
Diff:
Modified: trunk/deluge/config.py
===================================================================
--- trunk/deluge/config.py 2009-05-28 19:16:58 UTC (rev 5322)
+++ trunk/deluge/config.py 2009-05-28 23:43:45 UTC (rev 5323)
@@ -36,6 +36,35 @@
"""
Deluge Config Module
+
+This module is used for loading and saving of configuration files.. or anything
+really.
+
+The format of the config file is as follows:
+
+<format version as int>
+<config file version as int>
+<content>
+
+The format version is controlled by the Config class. It should only be
changed
+when anything below it is changed directly by the Config class. An example of
+this would be if we changed the serializer for the content to something
different.
+
+The config file version is changed by the 'owner' of the config file. This is
+to signify that there is a change in the naming of some config keys or
something
+similar along those lines.
+
+The content is simply the dict to be saved and will be serialized before being
+written.
+
+Converting
+
+Since the format of the config could change, there needs to be a way to have
+the Config object convert to newer formats. To do this, you will need to
+register conversion functions for various versions of the config file. Note
that
+this can only be done for the 'config file version' and not for the 'format'
+version as this will be done internally.
+
"""
import cPickle as pickle
@@ -74,6 +103,11 @@
self.__config = {}
self.__set_functions = {}
self.__change_callback = None
+
+ # These hold the version numbers and they will be set when loaded
+ self.__format_version = None
+ self.__file_version = None
+
# This will get set with a reactor.callLater whenever a config option
# is set.
self.__save_timer = None
@@ -247,16 +281,40 @@
"""
if not filename:
filename = self.__config_file
+ data = open(filename, "rb")
try:
- self.__config.update(json.load(open(filename, "rb")))
+ self.__format_version = int(data.readline())
+ except ValueError:
+ pass
+
+ try:
+ self.__file_version = int(data.readline())
+ except ValueError:
+ pass
+
+
+ if not self.__format_version:
+ data.seek(0)
+ self.__format_version = 1
+ self.__file_version = 1
+
+ fdata = data.read()
+ data.close()
+
+ try:
+ self.__config.update(json.loads(fdata))
except Exception, e:
try:
- self.__config.update(pickle.load(open(filename, "rb")))
+ self.__config.update(pickle.loads(fdata))
except Exception, e:
+ log.exception(e)
log.warning("Unable to load config file: %s", filename)
- log.debug("Config %s loaded: %s", filename, self.__config)
+
+ log.debug("Config %s version: %s.%s loaded: %s", filename,
+ self.__format_version, self.__file_version, self.__config)
+
def save(self, filename=None):
"""
Save configuration to disk
@@ -271,7 +329,11 @@
# Check to see if the current config differs from the one on disk
# We will only write a new config file if there is a difference
try:
- if self.__config == json.load(open(filename, "rb")):
+ data = open(filename, "rb")
+ data.seek(2)
+ loaded_data = json.load(data)
+ data.close()
+ if self.__config == loaded_data:
# The config has not changed so lets just return
self.__save_timer = None
return
@@ -284,6 +346,8 @@
try:
log.debug("Saving new config file %s", filename + ".new")
f = open(filename + ".new", "wb")
+ f.write(str(self.__format_version) + "\n")
+ f.write(str(self.__file_version) + "\n")
json.dump(self.__config, f, indent=2)
f.flush()
os.fsync(f.fileno())
@@ -309,7 +373,40 @@
return False
else:
return True
-
+
+ def run_converter(self, input_range, output_version, func):
+ """
+ Runs a function that will convert file versions in the
`:param:input_range`
+ to the `:param:output_version`.
+
+ :param input_range: tuple, (int, int) the range of input versions this
+ function will accept
+ :param output_version: int, the version this function will return
+ :param func: func, the function that will do the conversion, it will
take
+ the config dict as an argument and return the augmented dict
+
+ :raises ValueError: if the output_version is less than the input_range
+
+ """
+ if output_version in input_range or output_version <= max(input_range):
+ raise ValueError("output_version needs to be greater than
input_range")
+
+ if self.__file_version not in input_range:
+ log.debug("File version %s is not in input_range %s, ignoring
converter function..",
+ self.__file_version, input_range)
+ return
+
+ try:
+ self.__config = func(self.__config)
+ except Exception, e:
+ log.exception(e)
+ log.error("There was an exception try to convert config file %s %s
to %s",
+ self.__config_file, self.__file_version, output_version)
+ raise e
+ else:
+ self.__file_version = output_version
+ self.save()
+
@property
def config_file(self):
return self.__config_file
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"deluge-commit" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/deluge-commit?hl=en
-~----------~----~----~----~------~----~------~--~---
