Mercurial > hg
view mercurial/error.py @ 32697:19b9fc40cc51
revlog: skeleton support for version 2 revlogs
There are a number of improvements we want to make to revlogs
that will require a new version - version 2. It is unclear what the
full set of improvements will be or when we'll be done with them.
What I do know is that the process will likely take longer than a
single release, will require input from various stakeholders to
evaluate changes, and will have many contentious debates and
bikeshedding.
It is unrealistic to develop revlog version 2 up front: there
are just too many uncertainties that we won't know until things
are implemented and experiments are run. Some changes will also
be invasive and prone to bit rot, so sitting on dozens of patches
is not practical.
This commit introduces skeleton support for version 2 revlogs in
a way that is flexible and not bound by backwards compatibility
concerns.
An experimental repo requirement for denoting revlog v2 has been
added. The requirement string has a sub-version component to it.
This will allow us to declare multiple requirements in the course
of developing revlog v2. Whenever we change the in-development
revlog v2 format, we can tweak the string, creating a new
requirement and locking out old clients. This will allow us to
make as many backwards incompatible changes and experiments to
revlog v2 as we want. In other words, we can land code and make
meaningful progress towards revlog v2 while still maintaining
extreme format flexibility up until the point we freeze the
format and remove the experimental labels.
To enable the new repo requirement, you must supply an experimental
and undocumented config option. But not just any boolean flag
will do: you need to explicitly use a value that no sane person
should ever type. This is an additional guard against enabling
revlog v2 on an installation it shouldn't be enabled on. The
specific scenario I'm trying to prevent is say a user with a
4.4 client with a frozen format enabling the option but then
downgrading to 4.3 and accidentally creating repos with an
outdated and unsupported repo format. Requiring a "challenge"
string should prevent this.
Because the format is not yet finalized and I don't want to take
any chances, revlog v2's version is currently 0xDEAD. I figure
squatting on a value we're likely never to use as an actual revlog
version to mean "internal testing only" is acceptable. And
"dead" is easily recognized as something meaningful.
There is a bunch of cleanup that is needed before work on revlog
v2 begins in earnest. I plan on doing that work once this patch
is accepted and we're comfortable with the idea of starting down
this path.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 May 2017 20:29:11 -0700 |
parents | 6df193b5c437 |
children | 61714510220d |
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# error.py - Mercurial exceptions # # Copyright 2005-2008 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Mercurial exceptions. This allows us to catch exceptions at higher levels without forcing imports. """ from __future__ import absolute_import # Do not import anything but pycompat here, please from . import pycompat def _tobytes(exc): """Byte-stringify exception in the same way as BaseException_str()""" if not exc.args: return b'' if len(exc.args) == 1: return pycompat.bytestr(exc.args[0]) return b'(%s)' % b', '.join(b"'%s'" % pycompat.bytestr(a) for a in exc.args) class Hint(object): """Mix-in to provide a hint of an error This should come first in the inheritance list to consume a hint and pass remaining arguments to the exception class. """ def __init__(self, *args, **kw): self.hint = kw.pop(r'hint', None) super(Hint, self).__init__(*args, **kw) class RevlogError(Hint, Exception): __bytes__ = _tobytes class FilteredIndexError(IndexError): __bytes__ = _tobytes class LookupError(RevlogError, KeyError): def __init__(self, name, index, message): self.name = name self.index = index # this can't be called 'message' because at least some installs of # Python 2.6+ complain about the 'message' property being deprecated self.lookupmessage = message if isinstance(name, str) and len(name) == 20: from .node import short name = short(name) RevlogError.__init__(self, '%s@%s: %s' % (index, name, message)) def __bytes__(self): return RevlogError.__bytes__(self) def __str__(self): return RevlogError.__str__(self) class FilteredLookupError(LookupError): pass class ManifestLookupError(LookupError): pass class CommandError(Exception): """Exception raised on errors in parsing the command line.""" __bytes__ = _tobytes class InterventionRequired(Hint, Exception): """Exception raised when a command requires human intervention.""" __bytes__ = _tobytes class Abort(Hint, Exception): """Raised if a command needs to print an error and exit.""" __bytes__ = _tobytes class HookLoadError(Abort): """raised when loading a hook fails, aborting an operation Exists to allow more specialized catching.""" class HookAbort(Abort): """raised when a validation hook fails, aborting an operation Exists to allow more specialized catching.""" class ConfigError(Abort): """Exception raised when parsing config files""" class UpdateAbort(Abort): """Raised when an update is aborted for destination issue""" class MergeDestAbort(Abort): """Raised when an update is aborted for destination issues""" class NoMergeDestAbort(MergeDestAbort): """Raised when an update is aborted because there is nothing to merge""" class ManyMergeDestAbort(MergeDestAbort): """Raised when an update is aborted because destination is ambiguous""" class ResponseExpected(Abort): """Raised when an EOF is received for a prompt""" def __init__(self): from .i18n import _ Abort.__init__(self, _('response expected')) class OutOfBandError(Hint, Exception): """Exception raised when a remote repo reports failure""" __bytes__ = _tobytes class ParseError(Hint, Exception): """Raised when parsing config files and {rev,file}sets (msg[, pos])""" __bytes__ = _tobytes class UnknownIdentifier(ParseError): """Exception raised when a {rev,file}set references an unknown identifier""" def __init__(self, function, symbols): from .i18n import _ ParseError.__init__(self, _("unknown identifier: %s") % function) self.function = function self.symbols = symbols class RepoError(Hint, Exception): __bytes__ = _tobytes class RepoLookupError(RepoError): pass class FilteredRepoLookupError(RepoLookupError): pass class CapabilityError(RepoError): pass class RequirementError(RepoError): """Exception raised if .hg/requires has an unknown entry.""" class StdioError(IOError): """Raised if I/O to stdout or stderr fails""" def __init__(self, err): IOError.__init__(self, err.errno, err.strerror) # no __bytes__() because error message is derived from the standard IOError class UnsupportedMergeRecords(Abort): def __init__(self, recordtypes): from .i18n import _ self.recordtypes = sorted(recordtypes) s = ' '.join(self.recordtypes) Abort.__init__( self, _('unsupported merge state records: %s') % s, hint=_('see https://mercurial-scm.org/wiki/MergeStateRecords for ' 'more information')) class UnknownVersion(Abort): """generic exception for aborting from an encounter with an unknown version """ def __init__(self, msg, hint=None, version=None): self.version = version super(UnknownVersion, self).__init__(msg, hint=hint) class LockError(IOError): def __init__(self, errno, strerror, filename, desc): IOError.__init__(self, errno, strerror, filename) self.desc = desc # no __bytes__() because error message is derived from the standard IOError class LockHeld(LockError): def __init__(self, errno, filename, desc, locker): LockError.__init__(self, errno, 'Lock held', filename, desc) self.locker = locker class LockUnavailable(LockError): pass # LockError is for errors while acquiring the lock -- this is unrelated class LockInheritanceContractViolation(RuntimeError): __bytes__ = _tobytes class ResponseError(Exception): """Raised to print an error with part of output and exit.""" __bytes__ = _tobytes class UnknownCommand(Exception): """Exception raised if command is not in the command table.""" __bytes__ = _tobytes class AmbiguousCommand(Exception): """Exception raised if command shortcut matches more than one command.""" __bytes__ = _tobytes # derived from KeyboardInterrupt to simplify some breakout code class SignalInterrupt(KeyboardInterrupt): """Exception raised on SIGTERM and SIGHUP.""" class SignatureError(Exception): __bytes__ = _tobytes class PushRaced(RuntimeError): """An exception raised during unbundling that indicate a push race""" __bytes__ = _tobytes class ProgrammingError(Hint, RuntimeError): """Raised if a mercurial (core or extension) developer made a mistake""" __bytes__ = _tobytes class WdirUnsupported(Exception): """An exception which is raised when 'wdir()' is not supported""" __bytes__ = _tobytes # bundle2 related errors class BundleValueError(ValueError): """error raised when bundle2 cannot be processed""" __bytes__ = _tobytes class BundleUnknownFeatureError(BundleValueError): def __init__(self, parttype=None, params=(), values=()): self.parttype = parttype self.params = params self.values = values if self.parttype is None: msg = 'Stream Parameter' else: msg = parttype entries = self.params if self.params and self.values: assert len(self.params) == len(self.values) entries = [] for idx, par in enumerate(self.params): val = self.values[idx] if val is None: entries.append(val) else: entries.append("%s=%r" % (par, val)) if entries: msg = '%s - %s' % (msg, ', '.join(entries)) ValueError.__init__(self, msg) class ReadOnlyPartError(RuntimeError): """error raised when code tries to alter a part being generated""" __bytes__ = _tobytes class PushkeyFailed(Abort): """error raised when a pushkey part failed to update a value""" def __init__(self, partid, namespace=None, key=None, new=None, old=None, ret=None): self.partid = partid self.namespace = namespace self.key = key self.new = new self.old = old self.ret = ret # no i18n expected to be processed into a better message Abort.__init__(self, 'failed to update value for "%s/%s"' % (namespace, key)) class CensoredNodeError(RevlogError): """error raised when content verification fails on a censored node Also contains the tombstone data substituted for the uncensored data. """ def __init__(self, filename, node, tombstone): from .node import short RevlogError.__init__(self, '%s:%s' % (filename, short(node))) self.tombstone = tombstone class CensoredBaseError(RevlogError): """error raised when a delta is rejected because its base is censored A delta based on a censored revision must be formed as single patch operation which replaces the entire base with new content. This ensures the delta may be applied by clones which have not censored the base. """ class InvalidBundleSpecification(Exception): """error raised when a bundle specification is invalid. This is used for syntax errors as opposed to support errors. """ __bytes__ = _tobytes class UnsupportedBundleSpecification(Exception): """error raised when a bundle specification is not supported.""" __bytes__ = _tobytes class CorruptedState(Exception): """error raised when a command is not able to read its state from file""" __bytes__ = _tobytes class PeerTransportError(Abort): """Transport-level I/O error when communicating with a peer repo."""