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Differential D9475

upgrade: move optimisation to something more declarative
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Authored by marmoute on Dec 1 2020, 4:54 AM.

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Reviewers
mharbison72
Group Reviewers
hg-reviewers
Commits
rHG32dcd783a985: upgrade: move optimisation to something more declarative
Summary

This is not great yet, but still better than the previous state. This get use
one step closer to having all the possible "actions" clearly declared and moved
in a dedicated module.

Diff Detail

Repository
rHG Mercurial
Branch
default
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Event Timeline

marmoute created this revision.Dec 1 2020, 4:54 AM
mharbison72 accepted this revision.Dec 1 2020, 11:37 PM
mharbison72 added a subscriber: mharbison72.

Queued these 3, thanks. D9468 LGTM, but I'll leave it for @pulkit25 to make sure he's happy with it. The later ones generate merge conflicts without it, so stopping here.

This revision is now accepted and ready to land.Dec 1 2020, 11:37 PM

Revision Contents
Changeset List

PathPackages
Mmercurial/upgrade.py (176 lines)

Diff 23900

mercurial/upgrade.py

# backward compatibility for a while. # backward compatibility for a while.
legacy_opts_map = { legacy_opts_map = {
b'redeltaparent': b're-delta-parent', b'redeltaparent': b're-delta-parent',
b'redeltamultibase': b're-delta-multibase', b'redeltamultibase': b're-delta-multibase',
b'redeltaall': b're-delta-all', b'redeltaall': b're-delta-all',
b'redeltafulladd': b're-delta-fulladd', b'redeltafulladd': b're-delta-fulladd',
} }
ALL_OPTIMISATIONS = []
def findoptimizations(repo):
"""Determine optimisation that could be used during upgrade"""
# These are unconditionally added. There is logic later that figures out
# which ones to apply.
optimizations = []
optimizations.append( def register_optimization(obj):
ALL_OPTIMISATIONS.append(obj)
return obj
register_optimization(
improvement( improvement(
name=b're-delta-parent', name=b're-delta-parent',
type=OPTIMISATION, type=OPTIMISATION,
description=_( description=_(
b'deltas within internal storage will be recalculated to ' b'deltas within internal storage will be recalculated to '
b'choose an optimal base revision where this was not ' b'choose an optimal base revision where this was not '
b'already done; the size of the repository may shrink and ' b'already done; the size of the repository may shrink and '
b'various operations may become faster; the first time ' b'various operations may become faster; the first time '
b'this optimization is performed could slow down upgrade ' b'this optimization is performed could slow down upgrade '
b'execution considerably; subsequent invocations should ' b'execution considerably; subsequent invocations should '
b'not run noticeably slower' b'not run noticeably slower'
), ),
upgrademessage=_( upgrademessage=_(
b'deltas within internal storage will choose a new ' b'deltas within internal storage will choose a new '
b'base revision if needed' b'base revision if needed'
), ),
) )
) )
optimizations.append( register_optimization(
improvement( improvement(
name=b're-delta-multibase', name=b're-delta-multibase',
type=OPTIMISATION, type=OPTIMISATION,
description=_( description=_(
b'deltas within internal storage will be recalculated ' b'deltas within internal storage will be recalculated '
b'against multiple base revision and the smallest ' b'against multiple base revision and the smallest '
b'difference will be used; the size of the repository may ' b'difference will be used; the size of the repository may '
b'shrink significantly when there are many merges; this ' b'shrink significantly when there are many merges; this '
b'optimization will slow down execution in proportion to ' b'optimization will slow down execution in proportion to '
b'the number of merges in the repository and the amount ' b'the number of merges in the repository and the amount '
b'of files in the repository; this slow down should not ' b'of files in the repository; this slow down should not '
b'be significant unless there are tens of thousands of ' b'be significant unless there are tens of thousands of '
b'files and thousands of merges' b'files and thousands of merges'
), ),
upgrademessage=_( upgrademessage=_(
b'deltas within internal storage will choose an ' b'deltas within internal storage will choose an '
b'optimal delta by computing deltas against multiple ' b'optimal delta by computing deltas against multiple '
b'parents; may slow down execution time ' b'parents; may slow down execution time '
b'significantly' b'significantly'
), ),
) )
) )
optimizations.append( register_optimization(
improvement( improvement(
name=b're-delta-all', name=b're-delta-all',
type=OPTIMISATION, type=OPTIMISATION,
description=_( description=_(
b'deltas within internal storage will always be ' b'deltas within internal storage will always be '
b'recalculated without reusing prior deltas; this will ' b'recalculated without reusing prior deltas; this will '
b'likely make execution run several times slower; this ' b'likely make execution run several times slower; this '
b'optimization is typically not needed' b'optimization is typically not needed'
), ),
upgrademessage=_( upgrademessage=_(
b'deltas within internal storage will be fully ' b'deltas within internal storage will be fully '
b'recomputed; this will likely drastically slow down ' b'recomputed; this will likely drastically slow down '
b'execution time' b'execution time'
), ),
) )
) )
optimizations.append( register_optimization(
improvement( improvement(
name=b're-delta-fulladd', name=b're-delta-fulladd',
type=OPTIMISATION, type=OPTIMISATION,
description=_( description=_(
b'every revision will be re-added as if it was new ' b'every revision will be re-added as if it was new '
b'content. It will go through the full storage ' b'content. It will go through the full storage '
b'mechanism giving extensions a chance to process it ' b'mechanism giving extensions a chance to process it '
b'(eg. lfs). This is similar to "re-delta-all" but even ' b'(eg. lfs). This is similar to "re-delta-all" but even '
b'slower since more logic is involved.' b'slower since more logic is involved.'
), ),
upgrademessage=_( upgrademessage=_(
b'each revision will be added as new content to the ' b'each revision will be added as new content to the '
b'internal storage; this will likely drastically slow ' b'internal storage; this will likely drastically slow '
b'down execution time, but some extensions might need ' b'down execution time, but some extensions might need '
b'it' b'it'
), ),
) )
) )
return optimizations
def findoptimizations(repo):
"""Determine optimisation that could be used during upgrade"""
# These are unconditionally added. There is logic later that figures out
# which ones to apply.
return list(ALL_OPTIMISATIONS)
def determineactions(repo, deficiencies, sourcereqs, destreqs): def determineactions(repo, deficiencies, sourcereqs, destreqs):
"""Determine upgrade actions that will be performed. """Determine upgrade actions that will be performed.
Given a list of improvements as returned by ``finddeficiencies`` and Given a list of improvements as returned by ``finddeficiencies`` and
``findoptimizations``, determine the list of upgrade actions that ``findoptimizations``, determine the list of upgrade actions that
will be performed. will be performed.