stablerange: log time spent updating the stable range

cache: track time spend updating various cache This produce more useful blackbox log.

obshashrange: adds blackbox usage in tests This will help track the validation of the cache.

obshashrange: test behavior in case of rollback The cache should be properly invalidated.

obshashrange: extend tests We test more situations.

dualsourcecache: add a cache name This will be used to automatically log message for blackbox

obscache: stop definition of the empty key

obshashrange: keep value fetched from sql in memory This will reduce the number of roundtrip to the data base we need.

obshashrange: stop inheriting from 'dict' A simple dictionary attribute seems more simpler.

merge with stable

obshashrange: to not overwrite the list with the set We reusing the list variable lower in the code.

obshashrange: properly break out of the two loops Otherwise we would continue to iterate even after we reseted the cache.

obshashrange: fix reset conditional If the revision is in "revs" we should not reset the cache. The old code was wrong (Thanks goes to new tests for catching this).

cache: ensure we warm stablerange cache before the obshashrange cache I've been seeing traceback that seems to be happening because of issues in this area.

evolve: fixing obscache invalidation This was missing a call to the parent's destroyed(), such that any transaction after stripping some nodes would result in a crash (by attempting to read nodes which were stripped).

obshashrange: warm the cache at the end of each transaction This will help having warmed cache for read only client. The warming is still imperfect in case of markers that trigger a reset, but we are in a better place than what we used to be.

obshashrange: warm cache outside of loops The performance impact will be lower

obshashrange: "update" the cache on each transaction close Right now the "update" does not really file the cache, but it will detect invalid situation and clean them.

obshashrange: properly invalidate the cache on destroyed Copy paste is the scurge of code source.

obshashrange: properly drop the current connection on clear

obshashrange: exit early if nothing to write

obshashrange: use the dualsourcecache as a base for the cache This will easily open the way to incrementally updated obshashrange cache. Small update are needed to the data base schema so be bump the version Currently the update function is not warming the cache (but details case where it is invalidated).

obscache: makes dualsourcecache compatible with obshashrange cache needs The goal of the abstract method is to be reusable. So we make sure it is reusable.

readme: add a changelog entry about the more efficient obscache

obscache: extract a data agnostic class We now have an independent class that we can reuse for other purpose (eg: obshashrange cache)

obscache: extract the actual data update in a dedicated function This will help extract a data agnostic class.

obscache: move an assert to a lower level

obscache: use 'nullid' as the hash of an empty obsstore This align this result with what we use for 'emptykey'

obcache: move empty on the class We'll extract a smaller data agnostic class but we need to gather all method on it first.

obcache: move _checkkey on the class We'll extract a smaller data agnostic class but we need to gather all method on it first.

obcache: move updateneeded on the class We'll extract a smaller data agnostic class but we need to gather all method on it first.

obshistory: only display each revision once in debugobshistory When using a revision range, the same precursor could have been displayed more than once. Use a cache to display each revision only once. It's a fix until we found the nicest way to display obs history.