The git.git repo seems to have lots of merges from far back in the
history into newer history. That results in `jj log -r 'git_refs()'`
being completely useless because of the number of such edges. For
example, v2.31.0 has almost 600 edges going out of it and presumably
merging (forking) back into various different previous versions. Git,
unlike Mercurial, seems to remove an edge from the graph if the edge
can also be reached via a longer path. This commit makes it so we also
do that (i.e. the filtered graph is a transitive reduction of the
graph before filtering).
This slows down `jj log -r ,,v2.0.0 -T ""` by about 2%. That's still
small enough that it doesn't seem worth it to have a separate iterator
for contiguous ranges (which would be an option).
When rendering a non-contiguous subset of the commits, we want to
still show the connections between the commits in the graph, even
though they're not directly connected. This commit introduces an
adaptor for the revset iterators that also yield the edges to show in
such a simplified graph.
This has no measurable impact on `jj log -r ,,v2.0.0` in the git.git
repo.
The output of `jj log -r 'v1.0.0 | v2.0.0'` now looks like this:
```
o e156455ea491 e156455ea491 gitster@pobox.com 2014-05-28 11:04:19.000 -07:00 refs/tags/v2.0.0
:\ Git 2.0
: ~
o c2f3bf071ee9 c2f3bf071ee9 junkio@cox.net 2005-12-21 00:01:00.000 -08:00 refs/tags/v1.0.0
~ GIT 1.0.0
```
Before this commit, it looked like this:
```
o e156455ea491 e156455ea491 gitster@pobox.com 2014-05-28 11:04:19.000 -07:00 refs/tags/v2.0.0
| Git 2.0
| o c2f3bf071ee9 c2f3bf071ee9 junkio@cox.net 2005-12-21 00:01:00.000 -08:00 refs/tags/v1.0.0
| |\ GIT 1.0.0
```
The output of `jj log -r 'git_refs()'` in the git.git repo is still
completely useless (it's >350k lines and >500MB of data). I think
that's because we don't filter out edges to ancestors that we have
transitive edges to. Mercurial also doesn't filter out such edges, but
Git (with `--simplify-by-decoration`) seems to filter them out. I'll
change it soon so we filter them out.
This adds a `git_refs()` revset that includes all commits pointed to
by a git ref. It's not very useful yet because the graph log doesn't
use the right type of edges for non-contiguous commits.
I've often missed not having the timestamp there. It gets too long
with both email and timestamp for both author and committer, so I
removed the committer email to make room for the author timestamp.
Merging is currently done with line-level granularity, so it makes
sense to have newlines after the markers. That makes them easier to
edit out when resolving conflicts.
This lets you use the same operator as we currently have for ancestors
and descendants (`,,`) to also specify a DAG range. That's what
Mercurial uses the `::` operator for and what Git has `git log
--ancestry-path` for.
It seems clearer to let the parsed `RevsetExpression`s have only root
and head expression instead of adding the ancestors when building the
expression tree.
I really liked the idea of having the operators for parents and
ancestors (etc.) look similar, but that turned out to be problematic
when we want to add an infix operator for a DAG range (hg's `::`
revset operator and git's `--ancestry-path` flag). Let's say we chose
`:*:` as the operator. Part of the problem is how to parse `foo:*:bar`
without eagerly parsing the `foo:`. It would also be nicer to use
exactly the same operator as prefix, postfix, and infix. Since the
"parents" operator can be repeated, we can't have it be just `:` and
the "ancestors" operator be `::`. We could make the "ancestors"
operator be something like `*:*` (or anything symmetric with the `:`
symbol on the inside). However, at that point, the operator is getting
ugly and hard to type. Another option would be to use `:` for
ancestors and `::` for parents, but that is counterintuitive and get
annoying if you want to repeat it. So it seems that the best option is
to simply pick different symbols for parents/children and
ancestors/descendants/range.
This patch changes the ancestors/descendants operators to both be
`,,`. I'm not at all attached to that particular symbol. I suspect
we'll change it later.
Now that expressions may contain literal strings, we can simply have
functions accept only expressions arguments. That simplifies both the
grammar and the code.
A small drawback is that `description((foo), bar)` is now allowed and
does a search for the string "foo" (not "(foo)"). That seems
unlikely to trip up users.
Git refs with names containing e.g "-" are currently not accepted
symbol names, and I don't plan to change the grammar to accept
them. Instead, let's have the user quote symbol names containing
unusual characters. That way we can keep these symbols reserved for
revset operators.
With this patch the user can do e.g. `jj diff -r '"v2.9.0-rc2"'`.
This adds `children(<set>)` and `<set>:` for the children of the given
set, and `descendants(<set>)` and `<set>:*` for the descendants of the
given set. The children and descendants are filtered to be among
ancestors of non-obsolete commits. I haven't added a way of overriding
that yet.
This is especially important now that we leak the rule names into the
`SyntaxError` message. For example, the error message when doing `jj
diff -r :` will now mention "expected parents_op, ancestors_op, or
primary". It seems much clearer with the "_op" suffixes there. Longer
term, we should think more about how we can best surface syntax errors
from the library crate.
The tests don't need any complex set up (no repo necessary), so they
can be in the `revset` module itself. I'm sure we'll need to split up
that module later (at least separate out the parsing), but that's a
separate problem.
I don't know why I made it walk by generation number to start
with. Walking by position is better in at least two ways: 1) revsets
now depend on the walks to be by descending index position (though
they could equally well depend on the walks to be by generation number
-- it just needs to be consistent), and 2) the log output gets less
interleaved.
This commit makes the number of bytes in the graphlog output in the
git.git repo drop by ~40% due to the reduced amount of
interleaving. Also, it reduces the time of `jj bench walkrevs v1.0.0
v2.0.0` in the git.git repo by 32% (9.4ms -> 6.4ms) and `jj bench
walkrevs v2.0.0 v1.0.0` by 33% (7.7ms -> 5.1ms).
This teaches `jj log` a new `-r` option with a default of
`*:non_obsolete_heads()`. It also removes the `--all` option since
that's not used very frequently and can now be achieved with `jj log
-r '*:all_heads()'`.
This change adds a `non_obsolete_heads(<set>)` revset, which walks up
ancestors of the input set until it gets to a non-obsolete and
non-pruned commit. That's what we do by default in `jj log`
(i.e. without `--all`). Now we can make `jj log` use revsets and teach
it a `-r` option!
When removing uninteresting heads, we had a check for explicitly
keeping the checkout (working copy) commit. I'm pretty sure that is a
leftover from before we had the "pruned" flag on commits; the working
copy should never be pruned or obsolete.
This adds `parents(foo)` and `ancestors(foo)` as alternative ways of
writing `:foo` and `*:foo`.
I haven't added support for for whitespace yet; the parsing is very
strict. The error messages will also need to be improved later.
