MergeResult ThreeWayMerge::mergeKeySet (const KeySet & base, const KeySet & ours, const KeySet & theirs, const Key & mergeRoot)
{
Key ourkey = ours.head ().dup ();
Key theirkey = theirs.head ().dup ();
Key basekey = base.head ().dup ();
MergeResult merged = mergeKeySet (
MergeTask (BaseMergeKeys (base, basekey), OurMergeKeys (ours, ourkey), TheirMergeKeys (theirs, theirkey), mergeRoot));
return merged;
}
void MetaMergeStrategy::resolveConflict(const MergeTask& task, Key& conflictKey, MergeResult& result)
{
conflictKey.rewindMeta();
Key currentMeta;
string baseLookup = rebasePath (conflictKey, task.mergeRoot, task.baseParent);
string ourLookup = rebasePath (conflictKey, task.mergeRoot, task.ourParent);
string theirLookup = rebasePath (conflictKey, task.mergeRoot, task.theirParent);
Key baseKey = task.base.lookup(baseLookup);
Key ourKey = task.ours.lookup(ourLookup);
Key theirKey = task.theirs.lookup(theirLookup);
Key root ("user/", KEY_END);
KeySet baseMeta = getMetaKeys (baseKey);
KeySet ourMeta = getMetaKeys (ourKey);
KeySet theirMeta = getMetaKeys (theirKey);
MergeTask metaTask(BaseMergeKeys (baseMeta, root), OurMergeKeys (ourMeta, root),
TheirMergeKeys (theirMeta, root), root);
MergeResult metaResult = innerMerger.mergeKeySet(metaTask);
KeySet mergedMeta = metaResult.getMergedKeys();
Key current;
mergedMeta.rewind();
while ((current = mergedMeta.next()))
{
string metaName = current.getName().substr(string("user/").length());
conflictKey.setMeta(metaName, current.getString());
}
ConflictOperation ourOperation = getOurConflictOperation(conflictKey);
ConflictOperation theirOperation = getTheirConflictOperation(conflictKey);
if (!metaResult.hasConflicts ())
{
if (ourOperation == CONFLICT_META && theirOperation == CONFLICT_META)
{
// TODO: addConflict deletes the key content
// without this strategy restoring the value the value would be lost
// this happens only for CONFLICT_META <--> CONFLICT_META conflicts
// add a test for this behaviour
copyKeyValue(ourKey, conflictKey);
result.resolveConflict (conflictKey);
result.addMergeKey (conflictKey);
}
}
}
int MergingKDB::synchronize (KeySet & returned, Key & parentKey, ThreeWayMerge & merger)
{
try
{
// write our config
int ret = KDB::set (returned, parentKey);
// update our config (if no conflict)
KDB::get (returned, parentKey);
return ret;
}
catch (KDBException const &)
{
// a conflict occurred, see if we can solve it with the merger
// refresh the key database
KeySet theirs = returned.dup ();
KDB::get (theirs, parentKey);
// try to merge
MergeResult result = merger.mergeKeySet (MergeTask (BaseMergeKeys (base, parentKey), OurMergeKeys (returned, parentKey),
TheirMergeKeys (theirs, parentKey), parentKey));
if (!result.hasConflicts ())
{
// hurray, we solved the issue
KeySet resultKeys = result.getMergedKeys ();
int ret = KDB::set (resultKeys, parentKey);
base = resultKeys;
return ret;
}
else
{
// nothing we can do anymore
KeySet conflictSet = result.getConflictSet ();
throw MergingKDBException (parentKey, conflictSet);
}
}
}
MergeTask reverse () const
{
return MergeTask (BaseMergeKeys (base, baseParent), OurMergeKeys (theirs, theirParent), TheirMergeKeys (ours, ourParent),
mergeRoot);
}
