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Differential D4037

lookup: add option to disambiguate prefix within revset
ClosedPublic

Authored by martinvonz on Aug 1 2018, 5:57 PM.

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rHG503f936489dd: lookup: add option to disambiguate prefix within revset
Summary

When resolving a nodeid prefix that is not unique within the repo and
the user has configured a revset that they want to disambiguate
within, we now try to look up within that revset before we fail. If
there is a unique match within the revset, we use that.

This is of course most effective at allowing a short prefix if the
revset contains few nodes. For most of our internal users at Google,
"not public()" is sufficiently small that a hex digit or two is
enough.

The implementation is currently pretty slow, but good enough for small
revsets (which is the expected use case). The scan in the revset is
linear. We may want to use a prefix tree if we want to allow users to
use a larger revset.

Credit for the idea goes to Kyle Lippincott.

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.Aug 1 2018, 5:57 PM
Closed by commit rHG503f936489dd: lookup: add option to disambiguate prefix within revset (authored by martinvonz). · Explain WhyAug 3 2018, 11:11 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/configitems.py (3 lines)
Mmercurial/scmutil.py (23 lines)
AMtests/test-revisions.t (37 lines)

Diff 9876

mercurial/configitems.py

default=False, default=False,
) )
coreconfigitem('experimental', 'removeemptydirs', coreconfigitem('experimental', 'removeemptydirs',
default=True, default=True,
) )
coreconfigitem('experimental', 'revlogv2', coreconfigitem('experimental', 'revlogv2',
default=None, default=None,
) )
coreconfigitem('experimental', 'revisions.disambiguatewithin',
default=None,
)
coreconfigitem('experimental', 'single-head-per-branch', coreconfigitem('experimental', 'single-head-per-branch',
default=False, default=False,
) )
coreconfigitem('experimental', 'sshserver.support-v2', coreconfigitem('experimental', 'sshserver.support-v2',
default=False, default=False,
) )
coreconfigitem('experimental', 'spacemovesdown', coreconfigitem('experimental', 'spacemovesdown',
default=False, default=False,

mercurial/scmutil.py

"""Format given revision and node depending on the current verbosity""" """Format given revision and node depending on the current verbosity"""
if ui.debugflag: if ui.debugflag:
hexfunc = hex hexfunc = hex
else: else:
hexfunc = short hexfunc = short
return '%d:%s' % (rev, hexfunc(node)) return '%d:%s' % (rev, hexfunc(node))
def resolvehexnodeidprefix(repo, prefix): def resolvehexnodeidprefix(repo, prefix):
try:
# Uses unfiltered repo because it's faster when prefix is ambiguous/ # Uses unfiltered repo because it's faster when prefix is ambiguous/
# This matches the shortesthexnodeidprefix() function below. # This matches the shortesthexnodeidprefix() function below.
node = repo.unfiltered().changelog._partialmatch(prefix) node = repo.unfiltered().changelog._partialmatch(prefix)
except error.AmbiguousPrefixLookupError:
revset = repo.ui.config('experimental', 'revisions.disambiguatewithin')
if revset:
# Clear config to avoid infinite recursion
configoverrides = {('experimental',
'revisions.disambiguatewithin'): None}
with repo.ui.configoverride(configoverrides):
revs = repo.anyrevs([revset], user=True)
matches = []
for rev in revs:
node = repo.changelog.node(rev)
if hex(node).startswith(prefix):
matches.append(node)
if len(matches) == 1:
return matches[0]
raise
if node is None: if node is None:
return return
repo.changelog.rev(node) # make sure node isn't filtered repo.changelog.rev(node) # make sure node isn't filtered
return node return node
def shortesthexnodeidprefix(repo, node, minlength=1): def shortesthexnodeidprefix(repo, node, minlength=1):
"""Find the shortest unambiguous prefix that matches hexnode.""" """Find the shortest unambiguous prefix that matches hexnode."""
# _partialmatch() of filtered changelog could take O(len(repo)) time, # _partialmatch() of filtered changelog could take O(len(repo)) time,

tests/test-revisions.t

  • This file was added.
$ hg init repo
$ cd repo
$ echo 0 > a
$ hg ci -qAm 0
$ for i in 5 8 14 43; do
> hg up -q 0
> echo $i > a
> hg ci -qm $i
> done
$ cat <<EOF >> .hg/hgrc
> [alias]
> l = log -T '{rev}:{shortest(node,1)}\n'
> EOF
$ hg l
4:7ba5d
3:7ba57
2:72
1:9
0:b
$ cat <<EOF >> .hg/hgrc
> [experimental]
> revisions.disambiguatewithin=:3
> EOF
9 was unambiguous and still is
$ hg l -r 9
1:9
7 was ambiguous and still is
$ hg l -r 7
abort: 00changelog.i@7: ambiguous identifier!
[255]
7b is no longer ambiguous
$ hg l -r 7b
3:7ba57
$ cd ..