dirstate-tree: Make Rust DirstateMap bindings go through a trait object
This changeset starts a series that adds an experiment to make status faster
by changing the dirstate (first only in memory and later also on disk) to
be shaped as a tree matching the directory structure, instead of the current
flat collection of entries. The status algorithm can then traverse this tree
dirstate at the same time as it traverses the filesystem.
We (Octobus) have made prototypes that show promising results but are prone
to bitrot. We would like to start upstreaming some experimental Rust code that
goes in this direction, but to avoid disrupting users it should only be
enabled by some run-time opt-in while keeping the existing dirstate structure
and status algorithm as-is.
The `DirstateMap` type and `status` function look like the appropriate
boundary. This adds a new trait that abstracts everything Python bindings need
and makes those bindings go through a `dyn` trait object. Later we’ll have two
implementations of this trait, and the same bindings can use either.
Differential Revision: https://phab.mercurial-scm.org/D10362
#testcases abortcommand abortflag
#if abortflag
$ cat >> $HGRCPATH <<EOF
> [alias]
> abort = merge --abort
> EOF
#endif
$ addcommit () {
> echo $1 > $1
> hg add $1
> hg commit -d "${2} 0" -m $1
> }
$ commit () {
> hg commit -d "${2} 0" -m $1
> }
$ hg init a
$ cd a
$ addcommit "A" 0
$ addcommit "B" 1
$ echo "C" >> A
$ commit "C" 2
$ hg update -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo "D" >> A
$ commit "D" 3
created new head
State before the merge
$ hg status
$ hg id
e45016d2b3d3 tip
$ hg summary
parent: 3:e45016d2b3d3 tip
D
branch: default
commit: (clean)
update: 2 new changesets, 2 branch heads (merge)
phases: 4 draft
Testing the abort functionality first in case of conflicts
$ hg abort
abort: no merge in progress (abortflag !)
abort: no operation in progress (abortcommand !)
[20]
$ hg merge
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg merge --abort e4501
abort: cannot specify a node with --abort
[10]
$ hg merge --abort --rev e4501
abort: cannot specify both --abort and --rev
[10]
#if abortcommand
when in dry-run mode
$ hg abort --dry-run
merge in progress, will be aborted
#endif
$ hg abort
aborting the merge, updating back to e45016d2b3d3
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
Checking that we got back in the same state
$ hg status
? A.orig
$ hg id
e45016d2b3d3 tip
$ hg summary
parent: 3:e45016d2b3d3 tip
D
branch: default
commit: 1 unknown (clean)
update: 2 new changesets, 2 branch heads (merge)
phases: 4 draft
Merging a conflict araises
$ hg merge
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
Correct the conflict without marking the file as resolved
$ echo "ABCD" > A
$ hg commit -m "Merged"
abort: unresolved merge conflicts (see 'hg help resolve')
[20]
Mark the conflict as resolved and commit
$ hg resolve -m A
(no more unresolved files)
$ hg commit -m "Merged"
Test that if a file is removed but not marked resolved, the commit still fails
(issue4972)
$ hg up ".^"
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg merge 2
merging A
warning: conflicts while merging A! (edit, then use 'hg resolve --mark')
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
$ hg rm --force A
$ hg commit -m merged
abort: unresolved merge conflicts (see 'hg help resolve')
[20]
$ hg resolve -ma
(no more unresolved files)
$ hg commit -m merged
created new head
Testing the abort functionality in case of no conflicts
$ hg update -C 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ addcommit "E" 4
created new head
$ hg id
68352a18a7c4 tip
$ hg merge -r 4
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg merge --preview --abort
abort: cannot specify both --abort and --preview
[10]
$ hg abort
aborting the merge, updating back to 68352a18a7c4
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg id
68352a18a7c4 tip
$ cd ..