Recent scientific studies show that assigning a variable have no effect on
a unrelated constant. We therefore use the variable where we intended to in the
first place.
All contents includes documentation, constants, and functions, so we
gather all of those things into a single location. The diff is confusing
because it cannot understand what code is semantically moved around in this
grand migration.
When a set of revisions was empty, we were using an empty tuple. We now return an
empty frozenset to ensure the object could be used in an operation that requires a
set.
Mistakes were made while resolving rebase conflicts in 92753bcc8aa2. This led to
'date' being preserved in metadata when reading markers from a binary stream.
As a result, some known markers were seen as "new" when pulling. I noticed it
because a no-op pulls from main added about 600 duplicated markers to my
obsstore (for each pull).
I do not believe we need to perform any specific action to actively
de-duplicates existing obsstore. After this fix, duplicated markers will no be
propagated and the few affected repositories can probably deal with duplication (or
people can repull the obsstore from a clone).
As a side effect, we decode metadata only once, reducing the impact of the hack
in fm0 to store extra important data (parents and date).
This function returns the highest common version between the locally known
formats and a list of remotely known formats. This is going to be useful to
know what format should be used for exchange.
We can now read and write any known format. The list of known formats
currently has one element (0). The obsstore itself is not aware of
multiple formats yet and always uses format 0.
If we are to introduce new formats we need to be able call different
functions for different formats. Creating a function for format
version 0 is the first step.
This change is because these formats are used for version 0 of the
obsstore format. This is going to be useful in the future when we
introduce new versions of the format.
All variables involved in the obsstore format are prefixed with `_fm`.
`_fnodesize` was the exception. It is now back in line.
This is meaningful as we'll need to distinguish between multiple versions of the
obsstore format.
The mergemarkers function now returns the number of unknown markers in
the stream that have been added to the obsstore. This is similar to what
`obsstore.add` already does.
The method gains a docstring in the process.
Simple profiling of `hg log -r .` revealed ~18,000 calls to
mercurial.i18n.gettext() on the author's repository. The
culprit was 3 _() calls in util.parsedate() multiplied by
~6000 obsmarkers originating from the parsing of obsmarkers.
Changing the obsmarker code to parse the stored format of
dates instead of going through a generic path eliminates these
gettext() lookups and makes `hg log -r .` execute ~10% faster
on the author's repo. The performance gain is proportional to
the number of obsmarkers.
The author attempted to patch util.parsedate() to avoid the
gettext() lookups. However, that code is whacky and the author
is jet lagged, so the approach was not attempted.
We add a ``relevantmarkers`` method to fetch all markers that seem relevant to a
set of nodes. See function documentation about how this set is computed. This
will let us exchange only the markers that seem "relevant" to the set of
changesets related to a push or a pull.
The approach used to define "relevant" has been successfully tested in evolve
for 6 months.
We use the new `parents` field to build a dictionary of markers that touch
children of a node. This will be used to link prune markers to a set of
exchanged nodes.
We now store the `parents` field on disk. We use the same strategy as for
`date`: We stick it into the metadata. This is slow and dirty, but this is also
the only way we currently have.
At some point we'll have a new obsstore format to store this properly.
We are extracting the `date` information from the metadata at read time.
However, we failed to remove it from the metadata returned in the markers. This
is now fixed.
We need this information to build the set of relevant markers during
exchanges. This can only be done at the `createmarkers` level since
the `obsstore.create` function does not have a repo and therefore has
no access to the parent information.
This field is intended to store the parent of the precursor. This is useful to
attach pruned changesets to a set of exchanged changesets. We currently just
add the fields with a None value. None stands for "no data recorded".
The markers are now 5-item tuples (concluded by the date). The obsstore.fields
contents have been updated accordingly.
There is no change to the on-disk format yet, so the date has to be extracted
every time we read binary markers and re-injected each team we write them. This
introduces a slowdown that will be solved when a new version of the format is
added. Such a slowdown was already introduced by the evolve extension anyway.
We are going to increase the amount of data explicitly stored in obsolescence
markers. This mean we are going to have a longer tuple and some values will be
shuffled around. So we add a ``fields`` attribute to the obsstore class to
keep track of what entry is what. This will be useful for extensions and for
documentation purpose.
The date will become an official field in the markers (and ultimately
in the on-disk format). We start by making it an official argument for
the function.
We are about to add more arguments to this function (date, parents, etc).
Passing metadata as a keyword argument gives us more flexibility when adding
them.
We now have a function taking a list and marker and returning an encoded
version. This will allow obsolescence marker exchange experimentation to easily
pushkey-encode markers to be pushed after selection.
The obsstore method now have a return value. This informs caller about the
actual creation of a new markers. No new markers are created if it would have
been a duplicate.
The `metadata` argument only allow to specify metadata for all new markers. We
extension the format of the `relations` argument to support optional metadata
argument.
The first user of this should be the evolve extension who want to store parent
information of pruned changeset in extra (until we make a second version of the
format)
