caches: stop warming the cache after 'localrepo.commitctx' Now that we garantee that branchmap cache are updated at the end of the transaction we can drop that one. This removes a problematic case with nested transaction where the new cache could be written on disk before the transaction is finished. The test change is harmless, since we update the cache at a later point, the dirstate have been updated in between.

caches: introduce a 'debugupdatecaches' command That command make sure caches are updated. This is based on 'localrepo.updatecaches' so when we move support for new cache in that function this command will benefit from it.

caches: call 'repo.updatecache()' in 'repo.destroyed()' Regenerating the cache after a 'strip' or a 'rollback' is useful. So we call the generic cache warming function as other caches than just branchmap will be updated there in the future. To do so, we have to make 'repo.updatecache()' able to take no arguments. In such cases, we reload all caches.

caches: introduce a function to warm cache We have multiple caches that gain from being kept up to date. For example in a server setup, we want to make sure the branchcache cache is hot for other read-only clients. Right now each cache tries to update themself in place where new data have been added. However the approach is error prone (we might miss some spot) and fragile. When nested transaction are involved, such cache updates might happen before a top level transaction is committed. Writing caches for uncommitted data on disk. Having a single entry point, run at the end of each successful transaction, helps to ensure the cache is up to date and refreshed at the right time. We start with updating the branchmap cache but other will come.

transaction: track newly introduced revisions Tracking revisions is not the data that will unlock the most new capability. However, they are the simplest thing to track and still unlock some nice improvements in regard with caching. We plug ourself at the changelog level to make sure we do not miss any revision additions. The 'revs' set is configured at the repository level because the transaction itself does not needs to know that much about the business logic.

transaction: introduce "changes" dictionary to precisely track updates The transaction is already tracking some data intended for hooks (in 'hookargs'). However, that information is minimal as we optimise for passing data to other processes through environment variables. There are multiple places were we could use more complete and lower level information locally (eg: cache update, better report of changes to hooks, etc...). For this purpose we introduces a 'changes' dictionary on the transaction. It is intended to track every changes happening to the repository (eg: new revs, bookmarks move, phases move, obs-markers, etc). For now we just adds the 'changes' dictionary. We'll adds more tracking and usages over time.