revlog: increase I/O bound to 4x the amount of data consumed This doesn't affect normal clones since they'd be bound by the CPU bound below anyway -- it does, however, improve generaldelta clones significantly. This also results in better deltaing for generaldelta clones -- in generaldelta clones, we calculate deltas with respect to the closest base if it has a higher revision number than either parent. If the base is on a significantly different branch, this can result in pointlessly massive deltas. This reduces the number of bases and hence the number of bad deltas. Empirically, for a highly branchy repository, this resulted in an improvement of around 15% to manifest size.

revlog: bound based on the length of the compressed deltas This is only relevant for generaldelta clones.

revlog: compute length of compressed deltas along with chain length In upcoming patches to the revlog, we're going to split up the notions of bounding I/O and bounding CPU.

revlog: store fulltext when compressed delta is bigger than it This is a very silly case and not particularly likely to happen in the wild, but it turns out we can hit it in a couple of places. As we tune the storage parameters we're likely to hit more such cases. The affected test cases all have smaller revlogs now.

revlog: make a predicate clearer with parens

transaction: extract backupentry registration in a dedicated function We are about to use the 'backupentry' mechanism to allow cleaning up transaction-related temporary files (such as 'changelog.i.a'). We start by extracting the entry registration into its own method for easy reuse. At that point, I would like to rename the backup-file related variable to something generic but I'm a bit short of ideas.

transaction: pass the transaction to 'postclose' callback This mirrors the API for 'pending' and 'finalize' callbacks. I do not have immediate usage planned for it, but I'm sure some callback will be happy to access transaction related data.

transaction: pass the transaction to 'finalize' callback The callback will likely need to perform some operation related to the transaction (eg: registering file update). So we better pass the current transaction as the callback argument. Otherwise callback that needs it has to rely on horrible weak reference trick. This allow already allow us to slay a wild weak reference usage.

transaction: pass the transaction to 'pending' callback The callback will likely need to perform some operation related to the transaction (eg: backing files up). So we better pass the current transaction as the callback argument. Otherwise callback that needs it has to rely on horrible weak reference trick. The first foreseen user of this is changelog._writepending. We would like it to register the temporary file it create for cleanup purpose.

transaction: gather backupjournal logic together in the __init__ The initialisation of file-backup related variable were a bit scattered, we gather them together.

transaction: handle missing file in backupentries (instead of using entries) The case where a backup of a missing file was requested was previously handled by the 'entries' list. As the 'backupentries' is about to gain ability to backup files outside of '.hg/store', we want it to be able to handle the missing file too. Reminder: using 'addbackup' on a missing file means that such file needs to be deleted if we rollback the transaction.

test-hup: use ls instead of echo Having one file entry per line makes it easier to analyse diffs.