The first obsolescence flag is introduced to allows for fixing the "bumped"
changeset situation.
bumpedfix == 1.
Creator of new changesets intended to fix "bumped" situation should not forget
to add this flag to the marker. Otherwise the newly created changeset will be
bumped too. See inlined documentation for details.
The old name was not very good for two reasons:
- caller does not care about "cache",
- set of revision returned may not be obsolete at all.
The new name was suggested by Kevin Bullock.
People were confused by the fact `obstore.precursors` contained marker allowing
to find "precursors" and vice-versa.
This changeset changes their meaning to:
- precursors[x] -> set(markers on precursors edges of x)
- successors[x] -> set(markers on successors edges of x)
Some documentation is added to clarify the situation.
Nullid as successors create multiple issues:
- Nullid revnum is -1, confusing algorithm that use revnum unless you add
special handling in all of them.
- Nullid confuses "divergent" changeset detection and resolution. As you can't
add any successors to Nullid without being in even more troubles
Fortunately, there is no good reason to use nullid as a successor. The only
sensible meaning of "succeed by nullid" is "dropped" and this meaning is already
covered by obsolescence marker with empty successors set.
However, letting some nullid successors to slip in may cause terrible damage in
such algorithm difficult to debug. So I prefer to perform and clear detection of
of such pathological changeset. We could be much smarter by cleaning up nullid
successors on the fly but it would be much for expensive. As core Mercurial does
not create any such changeset, I think it is fine to just abort when suspicious
situation is detected.
Earlier experimental version created such changesets, so there are some out
there. The evolve extension added the necessary logic to clean up its mess.
This function is designed to be used by all code that creates new
obsolete markers in the local repository.
It is not used by debugobsolete because debugobsolete allows the
use of an unknown hash as argument.
This changeset introduces caches on the `obsstore` that keeps track of sets of
revisions meaningful for obsolescence related logics. For now they are:
- obsolete: changesets used as precursors (and not public),
- extinct: obsolete changesets with osbolete descendants only,
- unstable: non obsolete changesets with obsolete ancestors.
The cache is accessed using the `getobscache(repo, '<set-name>')` function which
builds the cache on demand. The `clearobscaches(repo)` function takes care of
clearing the caches if any.
Caches are cleared when one of these events happens:
- a new marker is added,
- a new changeset is added,
- some changesets are made public,
- some public changesets are demoted to draft or secret.
Declaration of more sets is made easy because we will have to handle at least
two other "troubles" (latecomer and conflicting).
Caches are now used by revset and changectx. It is usually not much more
expensive to compute the whole set than to check the property of a few elements.
The performance boost is welcome in case we apply obsolescence logic on a lot of
revisions. This makes the feature usable!
Obsolete markers wide-usage and propagation should be avoided by default until
the obsolete feature is more mature.
This changeset introduce the `_enable` variable and prevent the creation of
obsolete marker if the feature is set to `False` (the default).
More limitation comes in followup changesets.
Obsolete markers are now exchanged in smaller pieces that fit in a http header.
This changes is done to avoid 400 bad request error when exchanging obsolete
puskey over http.
The last key pushed is always hold by the "dump0" key to ensure an easy place to
hook for people who need it.
The function is now able to write the version header as necessary. The function
now yield bytes to be written to a stream.
This should ease later use of this function for wireprotocol based exchanged.
Prepare the public use of the writemarker by wireprotocol function.
This function yield every nodes which succeed to a group of nodes.
The first user will be checkheads who need to know if we push successors for
remote extra heads.
Marker are now written as soon as possible but within a transaction. Using a
transaction ensure a proper behavior on error and rollback compatibility.
Flush logic are not necessary anymore and are dropped from lock release.
With this changeset, the obsstore is open, written and closed for every single
added marker. This is expected to be highly inefficient and batched write should
be implemented "quickly".
Another issue is that every flush of the file will invalidate the obsstore
filecache and trigger a full re instantiation of the repo.obsstore attribute
(including, reading and parsing entry). This is also expected to be highly
inefficient and proper filecache operation should be implemented "quickly" too.
A side benefit of the filecache issue is that repo.obsstore object is properly
invalidated on transaction abortion.
This is the second step toward incremental writing of marker inside a
transaction. The obsstore file is now handled append only.
Header writing have been extracted from _writemarkers.
Because the _writemarkers method have been dropped, the push code
directly reuse the serialised content of local repo `listkeys`. This
is not very pretty, but this part of the protocol still need major
improvement anyway.
This is the first step toward incremental writing of obsolete marker within a
transaction.
For this purpose, obsstore is now given its repo sopener. This make it able to
handles read and write to the obsstore file itself. Most IO logic is removed
from localrepo and handled by obsstore object directly.
An `obsolete` boolean property is added to changeset context. Function to get
obsolete marker object from a changeset context are added to the obsolete
module.
