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Differential D805

alias: make alias command lazily resolved
ClosedPublic

Authored by quark on Sep 23 2017, 4:57 PM.

Details

Reviewers
yuja
Group Reviewers
hg-reviewers
Commits
rHGbd50aa1aa035: alias: make alias command lazily resolved
Summary

With many aliases, resolving them could have some visible overhead. Below is
part of traceprof [1] output of hg bookmark --hidden:

(time unit: ms)
37  \ addaliases                             dispatch.py:526
37   | __init__ (60 times)                   dispatch.py:402
33   | findcmd (108 times)                   cmdutil.py:721
16   | findpossible (49 times)               cmdutil.py:683

It may get better by optimizing findcmd to do a bisect, but we don't
really need to resolve an alias if it's not used, so let's make those
command entries lazy.

After this patch, addalias takes less than 1ms.

.. perf:: improved performance when many aliases are defined

[1]: https://bitbucket.org/facebook/hg-experimental/src/9aca0dbdbdfc48457e5d2581ca2d6e662fced2e6/hgext3rd/traceprof.pyx

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

quark created this revision.Sep 23 2017, 4:57 PM
quark edited the summary of this revision. (Show Details)Sep 23 2017, 5:00 PM
quark updated this revision to Diff 2050.Sep 23 2017, 5:34 PM
quark updated this revision to Diff 2052.Sep 23 2017, 5:41 PM
yuja accepted this revision.Sep 25 2017, 10:48 AM
yuja added a subscriber: yuja.

Looks okay. Queued, thanks.

mercurial/dispatch.py
539

A slice operation would be unlikely for alias commands, so this
should be fine.

This revision is now accepted and ready to land.Sep 25 2017, 10:48 AM
Closed by commit rHGbd50aa1aa035: alias: make alias command lazily resolved (authored by quark). · Explain WhySep 25 2017, 11:02 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mmercurial/dispatch.py (37 lines)

Diff 2065

mercurial/dispatch.py

else: else:
try: try:
return util.checksignature(self.fn)(ui, *args, **opts) return util.checksignature(self.fn)(ui, *args, **opts)
except error.SignatureError: except error.SignatureError:
args = ' '.join([self.cmdname] + self.args) args = ' '.join([self.cmdname] + self.args)
ui.debug("alias '%s' expands to '%s'\n" % (self.name, args)) ui.debug("alias '%s' expands to '%s'\n" % (self.name, args))
raise raise
class lazyaliasentry(object):
"""like a typical command entry (func, opts, help), but is lazy"""
def __init__(self, name, definition, cmdtable, source):
self.name = name
self.definition = definition
self.cmdtable = cmdtable.copy()
self.source = source
@util.propertycache
def _aliasdef(self):
return cmdalias(self.name, self.definition, self.cmdtable, self.source)
def __getitem__(self, n):
yujaUnsubmitted
Not Done

A slice operation would be unlikely for alias commands, so this
should be fine.

yuja: A slice operation would be unlikely for alias commands, so this should be fine.
aliasdef = self._aliasdef
if n == 0:
return aliasdef
elif n == 1:
return aliasdef.opts
elif n == 2:
return aliasdef.help
else:
raise IndexError
def __iter__(self):
for i in range(3):
yield self[i]
def __len__(self):
return 3
def addaliases(ui, cmdtable): def addaliases(ui, cmdtable):
# aliases are processed after extensions have been loaded, so they # aliases are processed after extensions have been loaded, so they
# may use extension commands. Aliases can also use other alias definitions, # may use extension commands. Aliases can also use other alias definitions,
# but only if they have been defined prior to the current definition. # but only if they have been defined prior to the current definition.
for alias, definition in ui.configitems('alias'): for alias, definition in ui.configitems('alias'):
try: try:
if cmdtable[alias][0].definition == definition: if cmdtable[alias].definition == definition:
continue continue
except (KeyError, AttributeError): except (KeyError, AttributeError):
# definition might not exist or it might not be a cmdalias # definition might not exist or it might not be a cmdalias
pass pass
source = ui.configsource('alias', alias) source = ui.configsource('alias', alias)
aliasdef = cmdalias(alias, definition, cmdtable, source) entry = lazyaliasentry(alias, definition, cmdtable, source)
cmdtable[aliasdef.name] = (aliasdef, aliasdef.opts, aliasdef.help) cmdtable[alias] = entry
def _parse(ui, args): def _parse(ui, args):
options = {} options = {}
cmdoptions = {} cmdoptions = {}
try: try:
args = fancyopts.fancyopts(args, commands.globalopts, options) args = fancyopts.fancyopts(args, commands.globalopts, options)
except getopt.GetoptError as inst: except getopt.GetoptError as inst: