config: have a way to backup and restore value in config
authorPierre-Yves David <pierre-yves.david@logilab.fr>
Wed, 18 Jan 2012 16:52:26 +0100
changeset 15919 69e792cf7851
parent 15918 4f9853e7f690
child 15920 885e0c71db9b
config: have a way to backup and restore value in config This is introduce to allow temporary overwriting of a config value while being able to reinstall the old value once done. The main advantage over using ``config`` and ``setconfig`` is that backup and restore will properly restore the lack of any config. Restoring the fact that there was no value is important to allow config user to keep using meaniful default value. A more naive approach will result in the following scenario:: Before: config(section, item, my_default) --> my_default temporal overwrite old = config(section, item) … setconfig(section, item, old) After config(section, item, my_default) --> None The first user of this feature should be mq to overwriting minimal phase of future commit.
mercurial/config.py
mercurial/ui.py
--- a/mercurial/config.py	Tue Jan 17 11:08:23 2012 +0100
+++ b/mercurial/config.py	Wed Jan 18 16:52:26 2012 +0100
@@ -61,6 +61,19 @@
         self._source.update(src._source)
     def get(self, section, item, default=None):
         return self._data.get(section, {}).get(item, default)
+
+    def backup(self, section, item):
+        """return a tuple allowing restore to reinstall a previous valuesi
+
+        The main reason we need it is because it handle the "no data" case.
+        """
+        try:
+            value = self._data[section][item]
+            source = self.source(section, item)
+            return (section, item, value, source)
+        except KeyError:
+            return (section, item)
+
     def source(self, section, item):
         return self._source.get((section, item), "")
     def sections(self):
@@ -73,6 +86,20 @@
         self._data[section][item] = value
         self._source[(section, item)] = source
 
+    def restore(self, data):
+        """restore data returned by self.backup"""
+        if len(data) == 4:
+            # restore old data
+            section, item, value, source = data
+            self._data[section][item] = value
+            self._source[(section, item)] = source
+        else:
+            # no data before, remove everything
+            section, item = data
+            if section in self._data:
+                del self._data[section][item]
+            self._source.pop((section, item), None)
+
     def parse(self, src, data, sections=None, remap=None, include=None):
         sectionre = re.compile(r'\[([^\[]+)\]')
         itemre = re.compile(r'([^=\s][^=]*?)\s*=\s*(.*\S|)')
--- a/mercurial/ui.py	Tue Jan 17 11:08:23 2012 +0100
+++ b/mercurial/ui.py	Wed Jan 18 16:52:26 2012 +0100
@@ -142,6 +142,15 @@
             self._trustusers.update(self.configlist('trusted', 'users'))
             self._trustgroups.update(self.configlist('trusted', 'groups'))
 
+    def backupconfig(self, section, item):
+        return (self._ocfg.backup(section, item),
+                self._tcfg.backup(section, item),
+                self._ucfg.backup(section, item),)
+    def restoreconfig(self, data):
+        self._ocfg.restore(data[0])
+        self._tcfg.restore(data[1])
+        self._ucfg.restore(data[2])
+
     def setconfig(self, section, name, value, overlay=True):
         if overlay:
             self._ocfg.set(section, name, value)