dirstate-tree: Add tree traversal/iteration
Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.
Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.
This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.
Differential Revision: https://phab.mercurial-scm.org/D10370
Require a destination
$ cat >> $HGRCPATH <<EOF
> [extensions]
> rebase =
> [commands]
> rebase.requiredest = True
> EOF
$ hg init repo
$ cd repo
$ echo a >> a
$ hg commit -qAm aa
$ echo b >> b
$ hg commit -qAm bb
$ hg up ".^"
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo c >> c
$ hg commit -qAm cc
$ hg rebase
abort: you must specify a destination
(use: hg rebase -d REV)
[10]
$ hg rebase -d 1
rebasing 2:5db65b93a12b tip "cc"
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/5db65b93a12b-4fb789ec-rebase.hg
$ hg rebase -d 0 -r . -q
$ HGPLAIN=1 hg rebase
rebasing 2:889b0bc6a730 tip "cc"
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/889b0bc6a730-41ec4f81-rebase.hg
$ hg rebase -d 0 -r . -q
$ hg --config commands.rebase.requiredest=False rebase
rebasing 2:279de9495438 tip "cc"
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/279de9495438-ab0a5128-rebase.hg
Requiring dest should not break continue or other rebase options
$ hg up 1 -q
$ echo d >> c
$ hg commit -qAm dc
$ hg log -G -T '{rev} {desc}'
@ 3 dc
|
| o 2 cc
|/
o 1 bb
|
o 0 aa
$ hg rebase -d 2
rebasing 3:0537f6b50def tip "dc"
merging c
warning: conflicts while merging c! (edit, then use 'hg resolve --mark')
unresolved conflicts (see 'hg resolve', then 'hg rebase --continue')
[240]
$ echo d > c
$ hg resolve --mark --all
(no more unresolved files)
continue: hg rebase --continue
$ hg rebase --continue
rebasing 3:0537f6b50def tip "dc"
saved backup bundle to $TESTTMP/repo/.hg/strip-backup/0537f6b50def-be4c7386-rebase.hg
$ cd ..
Check rebase.requiredest interaction with pull --rebase
$ hg clone repo clone
updating to branch default
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd repo
$ echo e > e
$ hg commit -qAm ee
$ cd ..
$ cd clone
$ echo f > f
$ hg commit -qAm ff
$ hg pull --rebase
abort: rebase destination required by configuration
(use hg pull followed by hg rebase -d DEST)
[10]
Setup rebase with multiple destinations
$ cd $TESTTMP
$ cat >> $TESTTMP/maprevset.py <<EOF
> from __future__ import absolute_import
> from mercurial import registrar, revset, revsetlang, smartset
> revsetpredicate = registrar.revsetpredicate()
> cache = {}
> @revsetpredicate(b'map')
> def map(repo, subset, x):
> """(set, mapping)"""
> setarg, maparg = revsetlang.getargs(x, 2, 2, b'')
> rset = revset.getset(repo, smartset.fullreposet(repo), setarg)
> mapstr = revsetlang.getstring(maparg, b'')
> map = dict(a.split(b':') for a in mapstr.split(b','))
> rev = rset.first()
> desc = repo[rev].description()
> newdesc = map.get(desc)
> if newdesc == b'null':
> revs = [-1]
> else:
> query = revsetlang.formatspec(b'desc(%s)', newdesc)
> revs = repo.revs(query)
> return smartset.baseset(revs)
> EOF
$ cat >> $HGRCPATH <<EOF
> [ui]
> allowemptycommit=1
> [extensions]
> drawdag=$TESTDIR/drawdag.py
> [phases]
> publish=False
> [alias]
> tglog = log -G --template "{rev}: {node|short} {desc} {instabilities}" -r 'sort(all(), topo)'
> [extensions]
> maprevset=$TESTTMP/maprevset.py
> [experimental]
> evolution=true
> EOF
$ rebasewithdag() {
> N=`"$PYTHON" -c "print($N+1)"`
> hg init repo$N && cd repo$N
> hg debugdrawdag
> hg rebase "$@" > _rebasetmp
> r=$?
> grep -v 'saved backup bundle' _rebasetmp
> [ $r -eq 0 ] && rm -f .hg/localtags && hg tglog
> cd ..
> return $r
> }
Destination resolves to an empty set:
$ rebasewithdag -s B -d 'SRC - SRC' <<'EOS'
> C
> |
> B
> |
> A
> EOS
nothing to rebase - empty destination
[1]
Multiple destinations and --collapse are not compatible:
$ rebasewithdag -s C+E -d 'SRC^^' --collapse <<'EOS'
> C F
> | |
> B E
> | |
> A D
> EOS
abort: --collapse does not work with multiple destinations
[10]
Multiple destinations cannot be used with --base:
$ rebasewithdag -b B -b E -d 'SRC^^' --collapse <<'EOS'
> B E
> | |
> A D
> EOS
abort: unknown revision 'SRC'
[255]
Rebase to null should work:
$ rebasewithdag -r A+C+D -d 'null' <<'EOS'
> C D
> | |
> A B
> EOS
already rebased 0:426bada5c675 A "A"
already rebased 2:dc0947a82db8 C "C"
rebasing 3:004dc1679908 D tip "D"
o 4: d8d8601abd5e D
o 2: dc0947a82db8 C
|
| o 1: fc2b737bb2e5 B
|
o 0: 426bada5c675 A
Destination resolves to multiple changesets:
$ rebasewithdag -s B -d 'ALLSRC+SRC' <<'EOS'
> C
> |
> B
> |
> Z
> EOS
abort: rebase destination for f0a671a46792 is not unique
[10]
Destination is an ancestor of source:
$ rebasewithdag -s B -d 'SRC' <<'EOS'
> C
> |
> B
> |
> Z
> EOS
abort: source and destination form a cycle
[10]
BUG: cycles aren't flagged correctly when --dry-run is set:
$ rebasewithdag -s B -d 'SRC' --dry-run <<'EOS'
> C
> |
> B
> |
> Z
> EOS
abort: source and destination form a cycle
starting dry-run rebase; repository will not be changed
[10]
Switch roots:
$ rebasewithdag -s 'all() - roots(all())' -d 'roots(all()) - ::SRC' <<'EOS'
> C F
> | |
> B E
> | |
> A D
> EOS
rebasing 2:112478962961 B "B"
rebasing 4:26805aba1e60 C "C"
rebasing 3:cd488e83d208 E "E"
rebasing 5:0069ba24938a F tip "F"
o 9: d150ff263fc8 F
|
o 8: 66f30a1a2eab E
|
| o 7: 93db94ffae0e C
| |
| o 6: d0071c3b0c88 B
| |
| o 1: 058c1e1fb10a D
|
o 0: 426bada5c675 A
Different destinations for merge changesets with a same root:
$ rebasewithdag -s B -d '((parents(SRC)-B-A)::) - (::ALLSRC)' <<'EOS'
> C G
> |\|
> | F
> |
> B E
> |\|
> A D
> EOS
rebasing 3:a4256619d830 B "B"
rebasing 6:8e139e245220 C tip "C"
o 8: d7d1169e9b1c C
|\
| o 7: 2ed0c8546285 B
| |\
o | | 5: 8fdb2c1feb20 G
| | |
| | o 4: cd488e83d208 E
| | |
o | | 2: a6661b868de9 F
/ /
| o 1: 058c1e1fb10a D
|
o 0: 426bada5c675 A
Move to a previous parent:
$ rebasewithdag -s E -s F -s G -d 'SRC^^' <<'EOS'
> H
> |
> D G
> |/
> C F
> |/
> B E # E will be ignored, since E^^ is empty
> |/
> A
> EOS
rebasing 4:33441538d4aa F "F"
rebasing 6:cf43ad9da869 G "G"
rebasing 7:eef94f3b5f03 H tip "H"
o 10: b3d84c6666cf H
|
| o 5: f585351a92f8 D
|/
o 3: 26805aba1e60 C
|
| o 9: f7c28a1a15e2 G
|/
o 1: 112478962961 B
|
| o 8: 02aa697facf7 F
|/
| o 2: 7fb047a69f22 E
|/
o 0: 426bada5c675 A
Source overlaps with destination:
$ rebasewithdag -s 'B+C+D' -d 'map(SRC, "B:C,C:D")' <<'EOS'
> B C D
> \|/
> A
> EOS
rebasing 2:dc0947a82db8 C "C"
rebasing 1:112478962961 B "B"
o 5: 5fe9935d5222 B
|
o 4: 12d20731b9e0 C
|
o 3: b18e25de2cf5 D
|
o 0: 426bada5c675 A
Detect cycles early:
$ rebasewithdag -r 'all()-Z' -d 'map(SRC, "A:B,B:C,C:D,D:B")' <<'EOS'
> A B C
> \|/
> | D
> |/
> Z
> EOS
abort: source and destination form a cycle
[10]
Detect source is ancestor of dest in runtime:
$ rebasewithdag -r 'C+B' -d 'map(SRC, "C:B,B:D")' -q <<'EOS'
> D
> |
> B C
> \|
> A
> EOS
abort: source is ancestor of destination
[10]
"Already rebased" fast path still works:
$ rebasewithdag -r 'all()' -d 'SRC^' <<'EOS'
> E F
> /| |
> B C D
> \|/
> A
> EOS
already rebased 1:112478962961 B "B"
already rebased 2:dc0947a82db8 C "C"
already rebased 3:b18e25de2cf5 D "D"
already rebased 4:312782b8f06e E "E"
already rebased 5:ad6717a6a58e F tip "F"
o 5: ad6717a6a58e F
|
o 3: b18e25de2cf5 D
|
| o 4: 312782b8f06e E
| |\
+---o 2: dc0947a82db8 C
| |
| o 1: 112478962961 B
|/
o 0: 426bada5c675 A
Massively rewrite the DAG:
$ rebasewithdag -r 'all()' -d 'map(SRC, "A:I,I:null,H:A,B:J,J:C,C:H,D:E,F:G,G:K,K:D,E:B")' <<'EOS'
> D G K
> | | |
> C F J
> | | |
> B E I
> \| |
> A H
> EOS
rebasing 4:701514e1408d I "I"
rebasing 0:426bada5c675 A "A"
rebasing 1:e7050b6e5048 H "H"
rebasing 5:26805aba1e60 C "C"
rebasing 7:cf89f86b485b J "J"
rebasing 2:112478962961 B "B"
rebasing 3:7fb047a69f22 E "E"
rebasing 8:f585351a92f8 D "D"
rebasing 10:ae41898d7875 K tip "K"
rebasing 9:711f53bbef0b G "G"
rebasing 6:64a8289d2492 F "F"
o 21: 3735afb3713a F
|
o 20: 07698142d7a7 G
|
o 19: 33aba52e7e72 K
|
o 18: 9fdae89dc5a1 D
|
o 17: 277dda9a65ee E
|
o 16: 9c74fd8657ad B
|
o 15: 6527eb0688bb J
|
o 14: e94d655b928d C
|
o 13: 620d6d349459 H
|
o 12: a569a116758f A
|
o 11: 2bf1302f5c18 I
Resolve instability:
$ rebasewithdag <<'EOF' -r 'orphan()-obsolete()' -d 'max((successors(max(roots(ALLSRC) & ::SRC)^)-obsolete())::)'
> F2
> |
> J E E2
> | |/
> I2 I | E3
> \| |/
> H | G
> | | |
> B2 D F
> | |/ # rebase: B -> B2
> N C # amend: E -> E2
> | | # amend: E2 -> E3
> M B # rebase: F -> F2
> \| # amend: I -> I2
> A
> EOF
6 new orphan changesets
rebasing 16:5c432343bf59 J tip "J"
rebasing 3:26805aba1e60 C "C"
rebasing 6:f585351a92f8 D "D"
rebasing 10:ffebc37c5d0b E3 "E3"
rebasing 13:fb184bcfeee8 F2 "F2"
rebasing 11:dc838ab4c0da G "G"
o 22: 174f63d574a8 G
|
o 21: c9d9fbe76705 F2
|
o 20: 0a03c2ede755 E3
|
o 19: 228d9d2541b1 D
|
o 18: cd856b400c95 C
|
o 17: 9148200c858c J
|
o 15: eb74780f5094 I2
|
o 12: 78309edd643f H
|
o 5: 4b4531bd8e1d B2
|
o 4: 337c285c272b N
|
o 2: 699bc4b6fa22 M
|
o 0: 426bada5c675 A