/// <summary> Commit changes resulting from delete, undeleteAll, or
/// setNorm operations
///
/// If an exception is hit, then either no changes or all
/// changes will have been committed to the index
/// (transactional semantics).
///
/// </summary>
/// <throws> IOException </throws>
public void Commit()
{
lock (this)
{
if (hasChanges)
{
if (deleter == null)
{
// In the MultiReader case, we share this deleter
// across all SegmentReaders:
SetDeleter(new IndexFileDeleter(segmentInfos, directory));
}
if (directoryOwner)
{
// Should not be necessary: no prior commit should
// have left pending files, so just defensive:
deleter.ClearPendingFiles();
System.String oldInfoFileName = segmentInfos.GetCurrentSegmentFileName();
System.String nextSegmentsFileName = segmentInfos.GetNextSegmentFileName();
// Checkpoint the state we are about to change, in
// case we have to roll back:
StartCommit();
bool success = false;
try
{
DoCommit();
segmentInfos.Write(directory);
success = true;
}
finally
{
if (!success)
{
// Rollback changes that were made to
// SegmentInfos but failed to get [fully]
// committed. This way this reader instance
// remains consistent (matched to what's
// actually in the index):
RollbackCommit();
// Erase any pending files that we were going to delete:
deleter.ClearPendingFiles();
// Remove possibly partially written next
// segments file:
deleter.DeleteFile(nextSegmentsFileName);
// Recompute deletable files & remove them (so
// partially written .del files, etc, are
// removed):
deleter.FindDeletableFiles();
deleter.DeleteFiles();
}
}
// Attempt to delete all files we just obsoleted:
deleter.DeleteFile(oldInfoFileName);
deleter.CommitPendingFiles();
if (writeLock != null)
{
writeLock.Release(); // release write lock
writeLock = null;
}
}
else
{
DoCommit();
}
}
hasChanges = false;
}
}