branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
== New Features ==
* `hg mv -A` can now be used with `--at-rev`. It behaves just like
`hg cp -A --at-rev`, i.e. it marks the destination as a copy of the
source whether or not the source still exists (but the source must
exist in the parent revision).
* New revset predicate `diffcontains(pattern)` for filtering revisions
in the same way as `hg grep --diff pattern`.
* The memory footprint per changeset and per file during pull/unbundle
operations has been significantly reduced.
== New Experimental Features ==
== Bug Fixes ==
== Backwards Compatibility Changes ==
== Internal API Changes ==
* `merge.update()` is now private (renamed to `_update()`). Hopefully
the higher-level functions available in the same module cover your
use cases.
* `phases.registernew` now takes a set of revisions instead of a list
of nodes. `phases.advanceboundary` takes an optional set of revisions
in addition to the list of nodes. The corresponeding members of the
`phasecache` class follow this change.
* The `addgroup` member of `revlog` classes no longer keeps a list of
all found nodes. It now returns True iff a node was found in the group.
An optional callback for duplicated nodes can be used by callers to keep
track of all nodes themselve.
* The `_chaininfocache` of `revlog` classes has been changed from a dict
to a LRU cache.