mercurial/upgrade_utils/actions.py

47315:825d5a5907b4

FORMAT_VARIANT = b'deficiency'
OPTIMISATION = b'optimization'


class improvement(object):
    """Represents an improvement that can be made as part of an upgrade.

    The following attributes are defined on each instance:

    name
       Machine-readable string uniquely identifying this improvement. It
       will be mapped to an action later in the upgrade process.

    type
       Either ``FORMAT_VARIANT`` or ``OPTIMISATION``.
       A format variant is where we change the storage format. Not all format
       variant changes are an obvious problem.
       An optimization is an action (sometimes optional) that
       can be taken to further improve the state of the repository.

    description
       Message intended for humans explaining the improvement in more detail,
       including the implications of it. For ``FORMAT_VARIANT`` types, should be
       worded in the present tense. For ``OPTIMISATION`` types, should be
       worded in the future tense.

    upgrademessage
       Message intended for humans explaining what an upgrade addressing this
       issue will do. Should be worded in the future tense.

    postupgrademessage
       Message intended for humans which will be shown post an upgrade
       operation when the improvement will be added

    postdowngrademessage
       Message intended for humans which will be shown post an upgrade
       operation in which this improvement was removed

    touches_filelogs (bool)
        Whether this improvement touches filelogs

    touches_manifests (bool)
        Whether this improvement touches manifests

    touches_changelog (bool)
        Whether this improvement touches changelog

    touches_requirements (bool)
        Whether this improvement changes repository requirements
    """

    def __init__(self, name, type, description, upgrademessage):
        self.name = name
        self.type = type
        self.description = description
        self.upgrademessage = upgrademessage
        self.postupgrademessage = None
        self.postdowngrademessage = None
        # By default for now, we assume every improvement touches
        # all the things
        self.touches_filelogs = True
        self.touches_manifests = True
        self.touches_changelog = True
        self.touches_requirements = True

    def __eq__(self, other):
        if not isinstance(other, improvement):
            # This is what python tell use to do
            return NotImplemented
        return self.name == other.name

    def __ne__(self, other):
        return not (self == other)

    def __hash__(self):
        return hash(self.name)


allformatvariant = []  # type: List[Type['formatvariant']]


def registerformatvariant(cls):
    allformatvariant.append(cls)
    return cls


class formatvariant(improvement):
    """an improvement subclass dedicated to repository format"""

    type = FORMAT_VARIANT
    ### The following attributes should be defined for each class:

    # machine-readable string uniquely identifying this improvement. it will be
    # mapped to an action later in the upgrade process.
    name = None

    # Message intended for humans which will be shown post an upgrade
    # operation in which this improvement was removed
    postdowngrademessage = None

    # By default for now, we assume every improvement touches all the things
    touches_filelogs = True
    touches_manifests = True
    touches_changelog = True
    touches_requirements = True

    def __init__(self):
        raise NotImplementedError()

    @staticmethod
    def fromrepo(repo):
        """current value of the variant in the repository"""
        raise NotImplementedError()

def register_optimization(obj):
    ALL_OPTIMISATIONS.append(obj)
    return obj


register_optimization(
    improvement(
        name=b're-delta-parent',
        type=OPTIMISATION,
        description=_(
            b'deltas within internal storage will be recalculated to '
            b'choose an optimal base revision where this was not '
            b'already done; the size of the repository may shrink and '
            b'various operations may become faster; the first time '
            b'this optimization is performed could slow down upgrade '
            b'execution considerably; subsequent invocations should '
            b'not run noticeably slower'
        ),
        upgrademessage=_(
            b'deltas within internal storage will choose a new '
            b'base revision if needed'
        ),
    )
)

register_optimization(
    improvement(
        name=b're-delta-multibase',
        type=OPTIMISATION,
        description=_(
            b'deltas within internal storage will be recalculated '
            b'against multiple base revision and the smallest '
            b'difference will be used; the size of the repository may '
            b'shrink significantly when there are many merges; this '
            b'optimization will slow down execution in proportion to '
            b'the number of merges in the repository and the amount '
            b'of files in the repository; this slow down should not '
            b'be significant unless there are tens of thousands of '
            b'files and thousands of merges'
        ),
        upgrademessage=_(
            b'deltas within internal storage will choose an '
            b'optimal delta by computing deltas against multiple '
            b'parents; may slow down execution time '
            b'significantly'
        ),
    )
)

register_optimization(
    improvement(
        name=b're-delta-all',
        type=OPTIMISATION,
        description=_(
            b'deltas within internal storage will always be '
            b'recalculated without reusing prior deltas; this will '
            b'likely make execution run several times slower; this '
            b'optimization is typically not needed'
        ),
        upgrademessage=_(
            b'deltas within internal storage will be fully '
            b'recomputed; this will likely drastically slow down '
            b'execution time'
        ),
    )
)

register_optimization(
    improvement(
        name=b're-delta-fulladd',
        type=OPTIMISATION,
        description=_(
            b'every revision will be re-added as if it was new '
            b'content. It will go through the full storage '
            b'mechanism giving extensions a chance to process it '
            b'(eg. lfs). This is similar to "re-delta-all" but even '
            b'slower since more logic is involved.'
        ),
        upgrademessage=_(
            b'each revision will be added as new content to the '
            b'internal storage; this will likely drastically slow '
            b'down execution time, but some extensions might need '
            b'it'
        ),
    )
)


def findoptimizations(repo):
    """Determine optimisation that could be used during upgrade"""
    # These are unconditionally added. There is logic later that figures out

47319:e985a36c2aa3

FORMAT_VARIANT = b'deficiency'
OPTIMISATION = b'optimization'


class improvement(object):
    """Represents an improvement that can be made as part of an upgrade."""

    ### The following attributes should be defined for each subclass:

    # Either ``FORMAT_VARIANT`` or ``OPTIMISATION``.
    # A format variant is where we change the storage format. Not all format
    # variant changes are an obvious problem.
    # An optimization is an action (sometimes optional) that
    # can be taken to further improve the state of the repository.
    type = None

    # machine-readable string uniquely identifying this improvement. it will be
    # mapped to an action later in the upgrade process.
    name = None

    # Message intended for humans which will be shown post an upgrade
    # operation in which this improvement was removed
    postdowngrademessage = None

    # By default for now, we assume every improvement touches all the things

    # Whether this improvement touches filelogs
    touches_filelogs = True

    # Whether this improvement touches manifests
    touches_manifests = True

    # Whether this improvement touches changelog
    touches_changelog = True

    # Whether this improvement changes repository requirements
    touches_requirements = True


allformatvariant = []  # type: List[Type['formatvariant']]


def registerformatvariant(cls):
    allformatvariant.append(cls)
    return cls


class formatvariant(improvement):
    """an improvement subclass dedicated to repository format"""

    type = FORMAT_VARIANT

    @staticmethod
    def fromrepo(repo):
        """current value of the variant in the repository"""
        raise NotImplementedError()

def register_optimization(obj):
    ALL_OPTIMISATIONS.append(obj)
    return obj


class optimization(improvement):
    """an improvement subclass dedicated to optimizations"""

    type = OPTIMISATION


@register_optimization
class redeltaparents(optimization):
    name = b're-delta-parent'

    type = OPTIMISATION

    description = _(
        b'deltas within internal storage will be recalculated to '
        b'choose an optimal base revision where this was not '
        b'already done; the size of the repository may shrink and '
        b'various operations may become faster; the first time '
        b'this optimization is performed could slow down upgrade '
        b'execution considerably; subsequent invocations should '
        b'not run noticeably slower'
    )

    upgrademessage = _(
        b'deltas within internal storage will choose a new '
        b'base revision if needed'
    )


@register_optimization
class redeltamultibase(optimization):
    name = b're-delta-multibase'

    type = OPTIMISATION

    description = _(
        b'deltas within internal storage will be recalculated '
        b'against multiple base revision and the smallest '
        b'difference will be used; the size of the repository may '
        b'shrink significantly when there are many merges; this '
        b'optimization will slow down execution in proportion to '
        b'the number of merges in the repository and the amount '
        b'of files in the repository; this slow down should not '
        b'be significant unless there are tens of thousands of '
        b'files and thousands of merges'
    )

    upgrademessage = _(
        b'deltas within internal storage will choose an '
        b'optimal delta by computing deltas against multiple '
        b'parents; may slow down execution time '
        b'significantly'
    )


@register_optimization
class redeltaall(optimization):
    name = b're-delta-all'

    type = OPTIMISATION

    description = _(
        b'deltas within internal storage will always be '
        b'recalculated without reusing prior deltas; this will '
        b'likely make execution run several times slower; this '
        b'optimization is typically not needed'
    )

    upgrademessage = _(
        b'deltas within internal storage will be fully '
        b'recomputed; this will likely drastically slow down '
        b'execution time'
    )


@register_optimization
class redeltafulladd(optimization):
    name = b're-delta-fulladd'

    type = OPTIMISATION

    description = _(
        b'every revision will be re-added as if it was new '
        b'content. It will go through the full storage '
        b'mechanism giving extensions a chance to process it '
        b'(eg. lfs). This is similar to "re-delta-all" but even '
        b'slower since more logic is involved.'
    )

    upgrademessage = _(
        b'each revision will be added as new content to the '
        b'internal storage; this will likely drastically slow '
        b'down execution time, but some extensions might need '
        b'it'
    )


def findoptimizations(repo):
    """Determine optimisation that could be used during upgrade"""
    # These are unconditionally added. There is logic later that figures out