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Differential D2876

rebase: allow in-memory merge of the working copy parent
ClosedPublic

Authored by martinvonz on Mar 15 2018, 4:20 PM.

Details

Reviewers
phillco
pulkit
Group Reviewers
hg-reviewers
Commits
rHG795eb53f1d3e: rebase: allow in-memory merge of the working copy parent
Summary

Before this patch and when the rebase involved the working copy parent
(and thus the working copy too), we would not do in-memory rebase even
if requested to. The in-code comment explains that the reason had
something to do with avoiding an extra update, but I don't know which
update that refers to. Perhaps an earlier version of the code used to
update to the destination before rebasing even if in-memory rebase was
requested? That seems to not be done at least since aa660c1203a9
(rebase: do not bail on uncomitted changes if rebasing in-memory,
2017-12-07).

To see if this still made it slower, I create a single tiny commit on
top of one branch of the mozilla-unified repo (commit a1098c82 to be
exact) and rebased it to another branch (commit d4e9a7be). Before this
patch that took 11.8s and after this patch it took 8.6s (I only did
two runs each, but the timings were very consistent).

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

martinvonz created this revision.Mar 15 2018, 4:20 PM
phillco accepted this revision.Mar 15 2018, 4:40 PM
pulkit accepted this revision.Mar 17 2018, 2:05 PM
Closed by commit rHG795eb53f1d3e: rebase: allow in-memory merge of the working copy parent (authored by martinvonz). · Explain WhyMar 17 2018, 3:08 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mhgext/rebase.py (15 lines)
Mtests/test-rebase-inmemory.t (5 lines)

Diff 7093

hgext/rebase.py

**pycompat.strkwargs(opts)) **pycompat.strkwargs(opts))
# restore original working directory # restore original working directory
# (we do this before stripping) # (we do this before stripping)
newwd = self.state.get(self.originalwd, self.originalwd) newwd = self.state.get(self.originalwd, self.originalwd)
if newwd < 0: if newwd < 0:
# original directory is a parent of rebase set root or ignored # original directory is a parent of rebase set root or ignored
newwd = self.originalwd newwd = self.originalwd
if (newwd not in [c.rev() for c in repo[None].parents()] and if newwd not in [c.rev() for c in repo[None].parents()]:
not self.inmemory):
ui.note(_("update back to initial working directory parent\n")) ui.note(_("update back to initial working directory parent\n"))
hg.updaterepo(repo, newwd, False) hg.updaterepo(repo, newwd, False)
collapsedas = None collapsedas = None
if self.collapsef and not self.keepf: if self.collapsef and not self.keepf:
collapsedas = newnode collapsedas = newnode
clearrebased(ui, repo, self.destmap, self.state, self.skipped, clearrebased(ui, repo, self.destmap, self.state, self.skipped,
collapsedas, self.keepf, fm=fm) collapsedas, self.keepf, fm=fm)
else: else:
ui.status(_('nothing to rebase - working ' ui.status(_('nothing to rebase - working '
'directory parent is already an ' 'directory parent is already an '
'ancestor of destination %s\n') % dest) 'ancestor of destination %s\n') % dest)
else: # can it happen? else: # can it happen?
ui.status(_('nothing to rebase from %s to %s\n') % ui.status(_('nothing to rebase from %s to %s\n') %
('+'.join(bytes(repo[r]) for r in base), dest)) ('+'.join(bytes(repo[r]) for r in base), dest))
return None return None
# If rebasing the working copy parent, force in-memory merge to be off.
#
# This is because the extra work of checking out the newly rebased commit
# outweights the benefits of rebasing in-memory, and executing an extra
# update command adds a bit of overhead, so better to just do it on disk. In
# all other cases leave it on.
#
# Note that there are cases where this isn't true -- e.g., rebasing large
# stacks that include the WCP. However, I'm not yet sure where the cutoff
# is.
rebasingwcp = repo['.'].rev() in rebaseset rebasingwcp = repo['.'].rev() in rebaseset
ui.log("rebase", "", rebase_rebasing_wcp=rebasingwcp) ui.log("rebase", "", rebase_rebasing_wcp=rebasingwcp)
if rbsrt.inmemory and rebasingwcp: if rbsrt.inmemory and rebasingwcp:
rbsrt.inmemory = False
# Check these since we did not before. # Check these since we did not before.
cmdutil.checkunfinished(repo) cmdutil.checkunfinished(repo)
cmdutil.bailifchanged(repo) cmdutil.bailifchanged(repo)
if not destf: if not destf:
dest = repo[_destrebase(repo, rebaseset, destspace=destspace)] dest = repo[_destrebase(repo, rebaseset, destspace=destspace)]
destf = bytes(dest) destf = bytes(dest)

tests/test-rebase-inmemory.t

Ensure symlink and executable files were rebased properly: Ensure symlink and executable files were rebased properly:
$ hg up -Cq 3 $ hg up -Cq 3
$ readlink.py e $ readlink.py e
e -> somefile e -> somefile
$ ls -l f | cut -c -10 $ ls -l f | cut -c -10
-rwxr-xr-x -rwxr-xr-x
Rebase the working copy parent, which should default to an on-disk merge even if Rebase the working copy parent
we requested in-memory.
$ hg up -C 3 $ hg up -C 3
0 files updated, 0 files merged, 0 files removed, 0 files unresolved 0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg rebase -r 3 -d 0 --debug | grep rebasing $ hg rebase -r 3 -d 0 --debug | grep rebasing
rebasing on disk rebasing in-memory
rebasing 3:753feb6fd12a "c" (tip) rebasing 3:753feb6fd12a "c" (tip)
$ hg tglog $ hg tglog
@ 3: 844a7de3e617 'c' @ 3: 844a7de3e617 'c'
| |
| o 2: 09c044d2cb43 'd' | o 2: 09c044d2cb43 'd'
| | | |
| o 1: fc055c3b4d33 'b' | o 1: fc055c3b4d33 'b'
|/ |/
o 0: b173517d0057 'a' o 0: b173517d0057 'a'