revlog: skeleton support for version 2 revlogs
There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.
It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.
This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.
An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.
To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.
Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.
There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> hg init r
> cd r
> for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> }
$ initrepo
log before edit
$ hg log --graph
@ changeset: 5:652413bf663e
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
show the edit commands offered
$ HGEDITOR=cat hg histedit 177f92b77385
pick 177f92b77385 2 c
pick 055a42cdd887 3 d
pick e860deea161a 4 e
pick 652413bf663e 5 f
# Edit history between 177f92b77385 and 652413bf663e
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
edit the history
(use a hacky editor to check histedit-last-edit.txt backup)
$ EDITED="$TESTTMP/editedhistory"
$ cat > $EDITED <<EOF
> edit 177f92b77385 c
> pick e860deea161a e
> pick 652413bf663e f
> pick 055a42cdd887 d
> EOF
$ HGEDITOR="cat \"$EDITED\" > " hg histedit 177f92b77385 2>&1 | fixbundle
0 files updated, 0 files merged, 4 files removed, 0 files unresolved
Editing (177f92b77385), you may commit or record as needed now.
(hg histedit --continue to resume)
rules should end up in .hg/histedit-last-edit.txt:
$ cat .hg/histedit-last-edit.txt
edit 177f92b77385 c
pick e860deea161a e
pick 652413bf663e f
pick 055a42cdd887 d
$ hg histedit --abort
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cat > $EDITED <<EOF
> pick 177f92b77385 c
> pick e860deea161a e
> pick 652413bf663e f
> pick 055a42cdd887 d
> EOF
$ HGEDITOR="cat \"$EDITED\" > " hg histedit 177f92b77385 2>&1 | fixbundle
log after edit
$ hg log --graph
@ changeset: 5:07114f51870f
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 4:8ade9693061e
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 3:d8249471110a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
put things back
$ hg histedit 177f92b77385 --commands - 2>&1 << EOF | fixbundle
> pick 177f92b77385 c
> pick 07114f51870f d
> pick d8249471110a e
> pick 8ade9693061e f
> EOF
$ hg log --graph
@ changeset: 5:7eca9b5b1148
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:915da888f2de
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:10517e47bbbb
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
slightly different this time
$ hg histedit 177f92b77385 --commands - << EOF 2>&1 | fixbundle
> pick 10517e47bbbb d
> pick 7eca9b5b1148 f
> pick 915da888f2de e
> pick 177f92b77385 c
> EOF
$ hg log --graph
@ changeset: 5:38b92f448761
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 4:de71b079d9ce
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:be9ae3a309c6
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:799205341b6b
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
keep prevents stripping dead revs
$ hg histedit 799205341b6b --keep --commands - 2>&1 << EOF | fixbundle
> pick 799205341b6b d
> pick be9ae3a309c6 f
> pick 38b92f448761 c
> pick de71b079d9ce e
> EOF
$ hg log --graph
@ changeset: 7:803ef1c6fcfd
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 6:ece0b8d93dda
| parent: 3:be9ae3a309c6
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
| o changeset: 5:38b92f448761
| | user: test
| | date: Thu Jan 01 00:00:00 1970 +0000
| | summary: c
| |
| o changeset: 4:de71b079d9ce
|/ user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:be9ae3a309c6
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:799205341b6b
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
try with --rev
$ hg histedit --commands - --rev -2 2>&1 <<EOF | fixbundle
> pick de71b079d9ce e
> pick 38b92f448761 c
> EOF
hg: parse error: pick "de71b079d9ce" changeset was not a candidate
(only use listed changesets)
$ hg log --graph
@ changeset: 7:803ef1c6fcfd
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 6:ece0b8d93dda
| parent: 3:be9ae3a309c6
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
| o changeset: 5:38b92f448761
| | user: test
| | date: Thu Jan 01 00:00:00 1970 +0000
| | summary: c
| |
| o changeset: 4:de71b079d9ce
|/ user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:be9ae3a309c6
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 2:799205341b6b
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Verify that revsetalias entries work with histedit:
$ cat >> $HGRCPATH <<EOF
> [revsetalias]
> grandparent(ARG) = p1(p1(ARG))
> EOF
$ echo extra commit >> c
$ hg ci -m 'extra commit to c'
$ HGEDITOR=cat hg histedit 'grandparent(.)'
pick ece0b8d93dda 6 c
pick 803ef1c6fcfd 7 e
pick 9c863c565126 8 extra commit to c
# Edit history between ece0b8d93dda and 9c863c565126
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
should also work if a commit message is missing
$ BUNDLE="$TESTDIR/missing-comment.hg"
$ hg init missing
$ cd missing
$ hg unbundle $BUNDLE
adding changesets
adding manifests
adding file changes
added 3 changesets with 3 changes to 1 files
(run 'hg update' to get a working copy)
$ hg co tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log --graph
@ changeset: 2:bd22688093b3
| tag: tip
| user: Robert Altman <robert.altman@telventDTN.com>
| date: Mon Nov 28 16:40:04 2011 +0000
| summary: Update file.
|
o changeset: 1:3b3e956f9171
| user: Robert Altman <robert.altman@telventDTN.com>
| date: Mon Nov 28 16:37:57 2011 +0000
|
o changeset: 0:141947992243
user: Robert Altman <robert.altman@telventDTN.com>
date: Mon Nov 28 16:35:28 2011 +0000
summary: Checked in text file
$ hg histedit 0
$ cd ..
$ cd ..
Test to make sure folding renames doesn't cause bogus conflicts (issue4251):
$ hg init issue4251
$ cd issue4251
$ mkdir initial-dir
$ echo foo > initial-dir/initial-file
$ hg add initial-dir/initial-file
$ hg commit -m "initial commit"
Move the file to a new directory, and in the same commit, change its content:
$ mkdir another-dir
$ hg mv initial-dir/initial-file another-dir/
$ echo changed > another-dir/initial-file
$ hg commit -m "moved and changed"
Rename the file:
$ hg mv another-dir/initial-file another-dir/renamed-file
$ hg commit -m "renamed"
Now, let's try to fold the second commit into the first:
$ cat > editor.sh <<EOF
> #!/bin/sh
> cat > \$1 <<ENDOF
> pick b0f4233702ca 0 initial commit
> fold 5e8704a8f2d2 1 moved and changed
> pick 40e7299e8fa7 2 renamed
> ENDOF
> EOF
$ HGEDITOR="sh ./editor.sh" hg histedit 0
saved backup bundle to $TESTTMP/issue4251/.hg/strip-backup/*-backup.hg (glob)
saved backup bundle to $TESTTMP/issue4251/.hg/strip-backup/*-backup.hg (glob)
$ hg --config diff.git=yes export 0
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID fffadc26f8f85623ce60b028a3f1ccc3730f8530
# Parent 0000000000000000000000000000000000000000
pick b0f4233702ca 0 initial commit
fold 5e8704a8f2d2 1 moved and changed
pick 40e7299e8fa7 2 renamed
diff --git a/another-dir/initial-file b/another-dir/initial-file
new file mode 100644
--- /dev/null
+++ b/another-dir/initial-file
@@ -0,0 +1,1 @@
+changed
$ hg --config diff.git=yes export 1
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID 9b730d82b00af8a2766facebfa47cc124405a118
# Parent fffadc26f8f85623ce60b028a3f1ccc3730f8530
renamed
diff --git a/another-dir/initial-file b/another-dir/renamed-file
rename from another-dir/initial-file
rename to another-dir/renamed-file
$ cd ..