error: introduce StorageError

Errors in revlogs are often represented by RevlogError. It's fine
for revlogs to raise a revlog-specific exception. But in the context
of multiple storage backends, it doesn't make sense to be throwing or
catching an exception with "revlog" in its name when revlogs may not
even be in play.

This commit introduces a new generic StorageError type for representing
errors in the storage layer.

RevlogError is an instance of this type.

Interface documentation and tests referencing RevlogError has been
updated to specify StorageError should be used.

.. api::

   ``error.StorageError`` has been introduced to represent errors in
   storage. It should be used in place of ``error.RevlogError`` unless
   the error is known to come from a revlog.

Differential Revision: https://phab.mercurial-scm.org/D4654

mercurial/error.py

@@ -1,329 +1,336
 # error.py - Mercurial exceptions
 #
 # Copyright 2005-2008 Matt Mackall <[e-mail]>
 #
 # 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):
+class StorageError(Hint, Exception):
+    """Raised when an error occurs in a storage layer.
+
+    Usually subclassed by a storage-specific exception.
+    """
+    __bytes__ = _tobytes
+
+class RevlogError(StorageError):
     __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, bytes) 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 AmbiguousPrefixLookupError(LookupError):
     pass
 
 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 PatchError(Exception):
     __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"""
 
     def __init__(self, msg, *args, **kwargs):
         # On Python 3, turn the message back into a string since this is
         # an internal-only error that won't be printed except in a
         # stack traces.
         msg = pycompat.sysstr(msg)
         super(ProgrammingError, self).__init__(msg, *args, **kwargs)
 
     __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, pycompat.maybebytestr(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."""
 
 class InMemoryMergeConflictsError(Exception):
     """Exception raised when merge conflicts arose during an in-memory merge."""
     __bytes__ = _tobytes
 
 class WireprotoCommandError(Exception):
     """Represents an error during execution of a wire protocol command.
 
     Should only be thrown by wire protocol version 2 commands.
 
     The error is a formatter string and an optional iterable of arguments.
     """
     def __init__(self, message, args=None):
         self.message = message
         self.messageargs = args

mercurial/repository.py

@@ -1,1585 +1,1585
 # repository.py - Interfaces and base classes for repositories and peers.
 #
 # Copyright 2017 Gregory Szorc <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 from .i18n import _
 from . import (
     error,
 )
 from .utils import (
     interfaceutil,
 )
 
 # When narrowing is finalized and no longer subject to format changes,
 # we should move this to just "narrow" or similar.
 NARROW_REQUIREMENT = 'narrowhg-experimental'
 
 class ipeerconnection(interfaceutil.Interface):
     """Represents a "connection" to a repository.
 
     This is the base interface for representing a connection to a repository.
     It holds basic properties and methods applicable to all peer types.
 
     This is not a complete interface definition and should not be used
     outside of this module.
     """
     ui = interfaceutil.Attribute("""ui.ui instance""")
 
     def url():
         """Returns a URL string representing this peer.
 
         Currently, implementations expose the raw URL used to construct the
         instance. It may contain credentials as part of the URL. The
         expectations of the value aren't well-defined and this could lead to
         data leakage.
 
         TODO audit/clean consumers and more clearly define the contents of this
         value.
         """
 
     def local():
         """Returns a local repository instance.
 
         If the peer represents a local repository, returns an object that
         can be used to interface with it. Otherwise returns ``None``.
         """
 
     def peer():
         """Returns an object conforming to this interface.
 
         Most implementations will ``return self``.
         """
 
     def canpush():
         """Returns a boolean indicating if this peer can be pushed to."""
 
     def close():
         """Close the connection to this peer.
 
         This is called when the peer will no longer be used. Resources
         associated with the peer should be cleaned up.
         """
 
 class ipeercapabilities(interfaceutil.Interface):
     """Peer sub-interface related to capabilities."""
 
     def capable(name):
         """Determine support for a named capability.
 
         Returns ``False`` if capability not supported.
 
         Returns ``True`` if boolean capability is supported. Returns a string
         if capability support is non-boolean.
 
         Capability strings may or may not map to wire protocol capabilities.
         """
 
     def requirecap(name, purpose):
         """Require a capability to be present.
 
         Raises a ``CapabilityError`` if the capability isn't present.
         """
 
 class ipeercommands(interfaceutil.Interface):
     """Client-side interface for communicating over the wire protocol.
 
     This interface is used as a gateway to the Mercurial wire protocol.
     methods commonly call wire protocol commands of the same name.
     """
 
     def branchmap():
         """Obtain heads in named branches.
 
         Returns a dict mapping branch name to an iterable of nodes that are
         heads on that branch.
         """
 
     def capabilities():
         """Obtain capabilities of the peer.
 
         Returns a set of string capabilities.
         """
 
     def clonebundles():
         """Obtains the clone bundles manifest for the repo.
 
         Returns the manifest as unparsed bytes.
         """
 
     def debugwireargs(one, two, three=None, four=None, five=None):
         """Used to facilitate debugging of arguments passed over the wire."""
 
     def getbundle(source, **kwargs):
         """Obtain remote repository data as a bundle.
 
         This command is how the bulk of repository data is transferred from
         the peer to the local repository
 
         Returns a generator of bundle data.
         """
 
     def heads():
         """Determine all known head revisions in the peer.
 
         Returns an iterable of binary nodes.
         """
 
     def known(nodes):
         """Determine whether multiple nodes are known.
 
         Accepts an iterable of nodes whose presence to check for.
 
         Returns an iterable of booleans indicating of the corresponding node
         at that index is known to the peer.
         """
 
     def listkeys(namespace):
         """Obtain all keys in a pushkey namespace.
 
         Returns an iterable of key names.
         """
 
     def lookup(key):
         """Resolve a value to a known revision.
 
         Returns a binary node of the resolved revision on success.
         """
 
     def pushkey(namespace, key, old, new):
         """Set a value using the ``pushkey`` protocol.
 
         Arguments correspond to the pushkey namespace and key to operate on and
         the old and new values for that key.
 
         Returns a string with the peer result. The value inside varies by the
         namespace.
         """
 
     def stream_out():
         """Obtain streaming clone data.
 
         Successful result should be a generator of data chunks.
         """
 
     def unbundle(bundle, heads, url):
         """Transfer repository data to the peer.
 
         This is how the bulk of data during a push is transferred.
 
         Returns the integer number of heads added to the peer.
         """
 
 class ipeerlegacycommands(interfaceutil.Interface):
     """Interface for implementing support for legacy wire protocol commands.
 
     Wire protocol commands transition to legacy status when they are no longer
     used by modern clients. To facilitate identifying which commands are
     legacy, the interfaces are split.
     """
 
     def between(pairs):
         """Obtain nodes between pairs of nodes.
 
         ``pairs`` is an iterable of node pairs.
 
         Returns an iterable of iterables of nodes corresponding to each
         requested pair.
         """
 
     def branches(nodes):
         """Obtain ancestor changesets of specific nodes back to a branch point.
 
         For each requested node, the peer finds the first ancestor node that is
         a DAG root or is a merge.
 
         Returns an iterable of iterables with the resolved values for each node.
         """
 
     def changegroup(nodes, source):
         """Obtain a changegroup with data for descendants of specified nodes."""
 
     def changegroupsubset(bases, heads, source):
         pass
 
 class ipeercommandexecutor(interfaceutil.Interface):
     """Represents a mechanism to execute remote commands.
 
     This is the primary interface for requesting that wire protocol commands
     be executed. Instances of this interface are active in a context manager
     and have a well-defined lifetime. When the context manager exits, all
     outstanding requests are waited on.
     """
 
     def callcommand(name, args):
         """Request that a named command be executed.
 
         Receives the command name and a dictionary of command arguments.
 
         Returns a ``concurrent.futures.Future`` that will resolve to the
         result of that command request. That exact value is left up to
         the implementation and possibly varies by command.
 
         Not all commands can coexist with other commands in an executor
         instance: it depends on the underlying wire protocol transport being
         used and the command itself.
 
         Implementations MAY call ``sendcommands()`` automatically if the
         requested command can not coexist with other commands in this executor.
 
         Implementations MAY call ``sendcommands()`` automatically when the
         future's ``result()`` is called. So, consumers using multiple
         commands with an executor MUST ensure that ``result()`` is not called
         until all command requests have been issued.
         """
 
     def sendcommands():
         """Trigger submission of queued command requests.
 
         Not all transports submit commands as soon as they are requested to
         run. When called, this method forces queued command requests to be
         issued. It will no-op if all commands have already been sent.
 
         When called, no more new commands may be issued with this executor.
         """
 
     def close():
         """Signal that this command request is finished.
 
         When called, no more new commands may be issued. All outstanding
         commands that have previously been issued are waited on before
         returning. This not only includes waiting for the futures to resolve,
         but also waiting for all response data to arrive. In other words,
         calling this waits for all on-wire state for issued command requests
         to finish.
 
         When used as a context manager, this method is called when exiting the
         context manager.
 
         This method may call ``sendcommands()`` if there are buffered commands.
         """
 
 class ipeerrequests(interfaceutil.Interface):
     """Interface for executing commands on a peer."""
 
     def commandexecutor():
         """A context manager that resolves to an ipeercommandexecutor.
 
         The object this resolves to can be used to issue command requests
         to the peer.
 
         Callers should call its ``callcommand`` method to issue command
         requests.
 
         A new executor should be obtained for each distinct set of commands
         (possibly just a single command) that the consumer wants to execute
         as part of a single operation or round trip. This is because some
         peers are half-duplex and/or don't support persistent connections.
         e.g. in the case of HTTP peers, commands sent to an executor represent
         a single HTTP request. While some peers may support multiple command
         sends over the wire per executor, consumers need to code to the least
         capable peer. So it should be assumed that command executors buffer
         called commands until they are told to send them and that each
         command executor could result in a new connection or wire-level request
         being issued.
         """
 
 class ipeerbase(ipeerconnection, ipeercapabilities, ipeerrequests):
     """Unified interface for peer repositories.
 
     All peer instances must conform to this interface.
     """
 
 @interfaceutil.implementer(ipeerbase)
 class peer(object):
     """Base class for peer repositories."""
 
     def capable(self, name):
         caps = self.capabilities()
         if name in caps:
             return True
 
         name = '%s=' % name
         for cap in caps:
             if cap.startswith(name):
                 return cap[len(name):]
 
         return False
 
     def requirecap(self, name, purpose):
         if self.capable(name):
             return
 
         raise error.CapabilityError(
             _('cannot %s; remote repository does not support the %r '
               'capability') % (purpose, name))
 
 class irevisiondelta(interfaceutil.Interface):
     """Represents a delta between one revision and another.
 
     Instances convey enough information to allow a revision to be exchanged
     with another repository.
 
     Instances represent the fulltext revision data or a delta against
     another revision. Therefore the ``revision`` and ``delta`` attributes
     are mutually exclusive.
 
     Typically used for changegroup generation.
     """
 
     node = interfaceutil.Attribute(
         """20 byte node of this revision.""")
 
     p1node = interfaceutil.Attribute(
         """20 byte node of 1st parent of this revision.""")
 
     p2node = interfaceutil.Attribute(
         """20 byte node of 2nd parent of this revision.""")
 
     linknode = interfaceutil.Attribute(
         """20 byte node of the changelog revision this node is linked to.""")
 
     flags = interfaceutil.Attribute(
         """2 bytes of integer flags that apply to this revision.""")
 
     basenode = interfaceutil.Attribute(
         """20 byte node of the revision this data is a delta against.
 
         ``nullid`` indicates that the revision is a full revision and not
         a delta.
         """)
 
     baserevisionsize = interfaceutil.Attribute(
         """Size of base revision this delta is against.
 
         May be ``None`` if ``basenode`` is ``nullid``.
         """)
 
     revision = interfaceutil.Attribute(
         """Raw fulltext of revision data for this node.""")
 
     delta = interfaceutil.Attribute(
         """Delta between ``basenode`` and ``node``.
 
         Stored in the bdiff delta format.
         """)
 
 class irevisiondeltarequest(interfaceutil.Interface):
     """Represents a request to generate an ``irevisiondelta``."""
 
     node = interfaceutil.Attribute(
         """20 byte node of revision being requested.""")
 
     p1node = interfaceutil.Attribute(
         """20 byte node of 1st parent of revision.""")
 
     p2node = interfaceutil.Attribute(
         """20 byte node of 2nd parent of revision.""")
 
     linknode = interfaceutil.Attribute(
         """20 byte node to store in ``linknode`` attribute.""")
 
     basenode = interfaceutil.Attribute(
         """Base revision that delta should be generated against.
 
         If ``nullid``, the derived ``irevisiondelta`` should have its
         ``revision`` field populated and no delta should be generated.
 
         If ``None``, the delta may be generated against any revision that
         is an ancestor of this revision. Or a full revision may be used.
 
         If any other value, the delta should be produced against that
         revision.
         """)
 
     ellipsis = interfaceutil.Attribute(
         """Boolean on whether the ellipsis flag should be set.""")
 
 class ifilerevisionssequence(interfaceutil.Interface):
     """Contains index data for all revisions of a file.
 
     Types implementing this behave like lists of tuples. The index
     in the list corresponds to the revision number. The values contain
     index metadata.
 
     The *null* revision (revision number -1) is always the last item
     in the index.
     """
 
     def __len__():
         """The total number of revisions."""
 
     def __getitem__(rev):
         """Returns the object having a specific revision number.
 
         Returns an 8-tuple with the following fields:
 
         offset+flags
            Contains the offset and flags for the revision. 64-bit unsigned
            integer where first 6 bytes are the offset and the next 2 bytes
            are flags. The offset can be 0 if it is not used by the store.
         compressed size
             Size of the revision data in the store. It can be 0 if it isn't
             needed by the store.
         uncompressed size
             Fulltext size. It can be 0 if it isn't needed by the store.
         base revision
             Revision number of revision the delta for storage is encoded
             against. -1 indicates not encoded against a base revision.
         link revision
             Revision number of changelog revision this entry is related to.
         p1 revision
             Revision number of 1st parent. -1 if no 1st parent.
         p2 revision
             Revision number of 2nd parent. -1 if no 1st parent.
         node
             Binary node value for this revision number.
 
         Negative values should index off the end of the sequence. ``-1``
         should return the null revision. ``-2`` should return the most
         recent revision.
         """
 
     def __contains__(rev):
         """Whether a revision number exists."""
 
     def insert(self, i, entry):
         """Add an item to the index at specific revision."""
 
 class ifileindex(interfaceutil.Interface):
     """Storage interface for index data of a single file.
 
     File storage data is divided into index metadata and data storage.
     This interface defines the index portion of the interface.
 
     The index logically consists of:
 
     * A mapping between revision numbers and nodes.
     * DAG data (storing and querying the relationship between nodes).
     * Metadata to facilitate storage.
     """
     index = interfaceutil.Attribute(
         """An ``ifilerevisionssequence`` instance.""")
 
     def __len__():
         """Obtain the number of revisions stored for this file."""
 
     def __iter__():
         """Iterate over revision numbers for this file."""
 
     def revs(start=0, stop=None):
         """Iterate over revision numbers for this file, with control."""
 
     def parents(node):
         """Returns a 2-tuple of parent nodes for a revision.
 
         Values will be ``nullid`` if the parent is empty.
         """
 
     def parentrevs(rev):
         """Like parents() but operates on revision numbers."""
 
     def rev(node):
         """Obtain the revision number given a node.
 
         Raises ``error.LookupError`` if the node is not known.
         """
 
     def node(rev):
         """Obtain the node value given a revision number.
 
         Raises ``IndexError`` if the node is not known.
         """
 
     def lookup(node):
         """Attempt to resolve a value to a node.
 
         Value can be a binary node, hex node, revision number, or a string
         that can be converted to an integer.
 
         Raises ``error.LookupError`` if a node could not be resolved.
         """
 
     def linkrev(rev):
         """Obtain the changeset revision number a revision is linked to."""
 
     def flags(rev):
         """Obtain flags used to affect storage of a revision."""
 
     def iscensored(rev):
         """Return whether a revision's content has been censored."""
 
     def commonancestorsheads(node1, node2):
         """Obtain an iterable of nodes containing heads of common ancestors.
 
         See ``ancestor.commonancestorsheads()``.
         """
 
     def descendants(revs):
         """Obtain descendant revision numbers for a set of revision numbers.
 
         If ``nullrev`` is in the set, this is equivalent to ``revs()``.
         """
 
     def headrevs():
         """Obtain a list of revision numbers that are DAG heads.
 
         The list is sorted oldest to newest.
 
         TODO determine if sorting is required.
         """
 
     def heads(start=None, stop=None):
         """Obtain a list of nodes that are DAG heads, with control.
 
         The set of revisions examined can be limited by specifying
         ``start`` and ``stop``. ``start`` is a node. ``stop`` is an
         iterable of nodes. DAG traversal starts at earlier revision
         ``start`` and iterates forward until any node in ``stop`` is
         encountered.
         """
 
     def children(node):
         """Obtain nodes that are children of a node.
 
         Returns a list of nodes.
         """
 
     def deltaparent(rev):
         """"Return the revision that is a suitable parent to delta against."""
 
 class ifiledata(interfaceutil.Interface):
     """Storage interface for data storage of a specific file.
 
     This complements ``ifileindex`` and provides an interface for accessing
     data for a tracked file.
     """
     def rawsize(rev):
         """The size of the fulltext data for a revision as stored."""
 
     def size(rev):
         """Obtain the fulltext size of file data.
 
         Any metadata is excluded from size measurements. Use ``rawsize()`` if
         metadata size is important.
         """
 
     def checkhash(fulltext, node, p1=None, p2=None, rev=None):
         """Validate the stored hash of a given fulltext and node.
 
-        Raises ``error.RevlogError`` is hash validation fails.
+        Raises ``error.StorageError`` is hash validation fails.
         """
 
     def revision(node, raw=False):
         """"Obtain fulltext data for a node.
 
         By default, any storage transformations are applied before the data
         is returned. If ``raw`` is True, non-raw storage transformations
         are not applied.
 
         The fulltext data may contain a header containing metadata. Most
         consumers should use ``read()`` to obtain the actual file data.
         """
 
     def read(node):
         """Resolve file fulltext data.
 
         This is similar to ``revision()`` except any metadata in the data
         headers is stripped.
         """
 
     def renamed(node):
         """Obtain copy metadata for a node.
 
         Returns ``False`` if no copy metadata is stored or a 2-tuple of
         (path, node) from which this revision was copied.
         """
 
     def cmp(node, fulltext):
         """Compare fulltext to another revision.
 
         Returns True if the fulltext is different from what is stored.
 
         This takes copy metadata into account.
 
         TODO better document the copy metadata and censoring logic.
         """
 
     def revdiff(rev1, rev2):
         """Obtain a delta between two revision numbers.
 
         Operates on raw data in the store (``revision(node, raw=True)``).
 
         The returned data is the result of ``bdiff.bdiff`` on the raw
         revision data.
         """
 
     def emitrevisiondeltas(requests):
         """Produce ``irevisiondelta`` from ``irevisiondeltarequest``s.
 
         Given an iterable of objects conforming to the ``irevisiondeltarequest``
         interface, emits objects conforming to the ``irevisiondelta``
         interface.
 
         This method is a generator.
 
         ``irevisiondelta`` should be emitted in the same order of
         ``irevisiondeltarequest`` that was passed in.
 
         The emitted objects MUST conform by the results of
         ``irevisiondeltarequest``. Namely, they must respect any requests
         for building a delta from a specific ``basenode`` if defined.
 
         When sending deltas, implementations must take into account whether
         the client has the base delta before encoding a delta against that
         revision. A revision encountered previously in ``requests`` is
         always a suitable base revision. An example of a bad delta is a delta
         against a non-ancestor revision. Another example of a bad delta is a
         delta against a censored revision.
         """
 
 class ifilemutation(interfaceutil.Interface):
     """Storage interface for mutation events of a tracked file."""
 
     def add(filedata, meta, transaction, linkrev, p1, p2):
         """Add a new revision to the store.
 
         Takes file data, dictionary of metadata, a transaction, linkrev,
         and parent nodes.
 
         Returns the node that was added.
 
         May no-op if a revision matching the supplied data is already stored.
         """
 
     def addrevision(revisiondata, transaction, linkrev, p1, p2, node=None,
                     flags=0, cachedelta=None):
         """Add a new revision to the store.
 
         This is similar to ``add()`` except it operates at a lower level.
 
         The data passed in already contains a metadata header, if any.
 
         ``node`` and ``flags`` can be used to define the expected node and
         the flags to use with storage.
 
         ``add()`` is usually called when adding files from e.g. the working
         directory. ``addrevision()`` is often called by ``add()`` and for
         scenarios where revision data has already been computed, such as when
         applying raw data from a peer repo.
         """
 
     def addgroup(deltas, linkmapper, transaction, addrevisioncb=None):
         """Process a series of deltas for storage.
 
         ``deltas`` is an iterable of 7-tuples of
         (node, p1, p2, linknode, deltabase, delta, flags) defining revisions
         to add.
 
         The ``delta`` field contains ``mpatch`` data to apply to a base
         revision, identified by ``deltabase``. The base node can be
         ``nullid``, in which case the header from the delta can be ignored
         and the delta used as the fulltext.
 
         ``addrevisioncb`` should be called for each node as it is committed.
 
         Returns a list of nodes that were processed. A node will be in the list
         even if it existed in the store previously.
         """
 
     def getstrippoint(minlink):
         """Find the minimum revision that must be stripped to strip a linkrev.
 
         Returns a 2-tuple containing the minimum revision number and a set
         of all revisions numbers that would be broken by this strip.
 
         TODO this is highly revlog centric and should be abstracted into
         a higher-level deletion API. ``repair.strip()`` relies on this.
         """
 
     def strip(minlink, transaction):
         """Remove storage of items starting at a linkrev.
 
         This uses ``getstrippoint()`` to determine the first node to remove.
         Then it effectively truncates storage for all revisions after that.
 
         TODO this is highly revlog centric and should be abstracted into a
         higher-level deletion API.
         """
 
 class ifilestorage(ifileindex, ifiledata, ifilemutation):
     """Complete storage interface for a single tracked file."""
 
     version = interfaceutil.Attribute(
         """Version number of storage.
 
         TODO this feels revlog centric and could likely be removed.
         """)
 
     _generaldelta = interfaceutil.Attribute(
         """Whether deltas can be against any parent revision.
 
         TODO this is used by changegroup code and it could probably be
         folded into another API.
         """)
 
     def files():
         """Obtain paths that are backing storage for this file.
 
         TODO this is used heavily by verify code and there should probably
         be a better API for that.
         """
 
     def checksize():
         """Obtain the expected sizes of backing files.
 
         TODO this is used by verify and it should not be part of the interface.
         """
 
 class idirs(interfaceutil.Interface):
     """Interface representing a collection of directories from paths.
 
     This interface is essentially a derived data structure representing
     directories from a collection of paths.
     """
 
     def addpath(path):
         """Add a path to the collection.
 
         All directories in the path will be added to the collection.
         """
 
     def delpath(path):
         """Remove a path from the collection.
 
         If the removal was the last path in a particular directory, the
         directory is removed from the collection.
         """
 
     def __iter__():
         """Iterate over the directories in this collection of paths."""
 
     def __contains__(path):
         """Whether a specific directory is in this collection."""
 
 class imanifestdict(interfaceutil.Interface):
     """Interface representing a manifest data structure.
 
     A manifest is effectively a dict mapping paths to entries. Each entry
     consists of a binary node and extra flags affecting that entry.
     """
 
     def __getitem__(path):
         """Returns the binary node value for a path in the manifest.
 
         Raises ``KeyError`` if the path does not exist in the manifest.
 
         Equivalent to ``self.find(path)[0]``.
         """
 
     def find(path):
         """Returns the entry for a path in the manifest.
 
         Returns a 2-tuple of (node, flags).
 
         Raises ``KeyError`` if the path does not exist in the manifest.
         """
 
     def __len__():
         """Return the number of entries in the manifest."""
 
     def __nonzero__():
         """Returns True if the manifest has entries, False otherwise."""
 
     __bool__ = __nonzero__
 
     def __setitem__(path, node):
         """Define the node value for a path in the manifest.
 
         If the path is already in the manifest, its flags will be copied to
         the new entry.
         """
 
     def __contains__(path):
         """Whether a path exists in the manifest."""
 
     def __delitem__(path):
         """Remove a path from the manifest.
 
         Raises ``KeyError`` if the path is not in the manifest.
         """
 
     def __iter__():
         """Iterate over paths in the manifest."""
 
     def iterkeys():
         """Iterate over paths in the manifest."""
 
     def keys():
         """Obtain a list of paths in the manifest."""
 
     def filesnotin(other, match=None):
         """Obtain the set of paths in this manifest but not in another.
 
         ``match`` is an optional matcher function to be applied to both
         manifests.
 
         Returns a set of paths.
         """
 
     def dirs():
         """Returns an object implementing the ``idirs`` interface."""
 
     def hasdir(dir):
         """Returns a bool indicating if a directory is in this manifest."""
 
     def matches(match):
         """Generate a new manifest filtered through a matcher.
 
         Returns an object conforming to the ``imanifestdict`` interface.
         """
 
     def walk(match):
         """Generator of paths in manifest satisfying a matcher.
 
         This is equivalent to ``self.matches(match).iterkeys()`` except a new
         manifest object is not created.
 
         If the matcher has explicit files listed and they don't exist in
         the manifest, ``match.bad()`` is called for each missing file.
         """
 
     def diff(other, match=None, clean=False):
         """Find differences between this manifest and another.
 
         This manifest is compared to ``other``.
 
         If ``match`` is provided, the two manifests are filtered against this
         matcher and only entries satisfying the matcher are compared.
 
         If ``clean`` is True, unchanged files are included in the returned
         object.
 
         Returns a dict with paths as keys and values of 2-tuples of 2-tuples of
         the form ``((node1, flag1), (node2, flag2))`` where ``(node1, flag1)``
         represents the node and flags for this manifest and ``(node2, flag2)``
         are the same for the other manifest.
         """
 
     def setflag(path, flag):
         """Set the flag value for a given path.
 
         Raises ``KeyError`` if the path is not already in the manifest.
         """
 
     def get(path, default=None):
         """Obtain the node value for a path or a default value if missing."""
 
     def flags(path, default=''):
         """Return the flags value for a path or a default value if missing."""
 
     def copy():
         """Return a copy of this manifest."""
 
     def items():
         """Returns an iterable of (path, node) for items in this manifest."""
 
     def iteritems():
         """Identical to items()."""
 
     def iterentries():
         """Returns an iterable of (path, node, flags) for this manifest.
 
         Similar to ``iteritems()`` except items are a 3-tuple and include
         flags.
         """
 
     def text():
         """Obtain the raw data representation for this manifest.
 
         Result is used to create a manifest revision.
         """
 
     def fastdelta(base, changes):
         """Obtain a delta between this manifest and another given changes.
 
         ``base`` in the raw data representation for another manifest.
 
         ``changes`` is an iterable of ``(path, to_delete)``.
 
         Returns a 2-tuple containing ``bytearray(self.text())`` and the
         delta between ``base`` and this manifest.
         """
 
 class imanifestrevisionbase(interfaceutil.Interface):
     """Base interface representing a single revision of a manifest.
 
     Should not be used as a primary interface: should always be inherited
     as part of a larger interface.
     """
 
     def new():
         """Obtain a new manifest instance.
 
         Returns an object conforming to the ``imanifestrevisionwritable``
         interface. The instance will be associated with the same
         ``imanifestlog`` collection as this instance.
         """
 
     def copy():
         """Obtain a copy of this manifest instance.
 
         Returns an object conforming to the ``imanifestrevisionwritable``
         interface. The instance will be associated with the same
         ``imanifestlog`` collection as this instance.
         """
 
     def read():
         """Obtain the parsed manifest data structure.
 
         The returned object conforms to the ``imanifestdict`` interface.
         """
 
 class imanifestrevisionstored(imanifestrevisionbase):
     """Interface representing a manifest revision committed to storage."""
 
     def node():
         """The binary node for this manifest."""
 
     parents = interfaceutil.Attribute(
         """List of binary nodes that are parents for this manifest revision."""
     )
 
     def readdelta(shallow=False):
         """Obtain the manifest data structure representing changes from parent.
 
         This manifest is compared to its 1st parent. A new manifest representing
         those differences is constructed.
 
         The returned object conforms to the ``imanifestdict`` interface.
         """
 
     def readfast(shallow=False):
         """Calls either ``read()`` or ``readdelta()``.
 
         The faster of the two options is called.
         """
 
     def find(key):
         """Calls self.read().find(key)``.
 
         Returns a 2-tuple of ``(node, flags)`` or raises ``KeyError``.
         """
 
 class imanifestrevisionwritable(imanifestrevisionbase):
     """Interface representing a manifest revision that can be committed."""
 
     def write(transaction, linkrev, p1node, p2node, added, removed, match=None):
         """Add this revision to storage.
 
         Takes a transaction object, the changeset revision number it will
         be associated with, its parent nodes, and lists of added and
         removed paths.
 
         If match is provided, storage can choose not to inspect or write out
         items that do not match. Storage is still required to be able to provide
         the full manifest in the future for any directories written (these
         manifests should not be "narrowed on disk").
 
         Returns the binary node of the created revision.
         """
 
 class imanifeststorage(interfaceutil.Interface):
     """Storage interface for manifest data."""
 
     tree = interfaceutil.Attribute(
         """The path to the directory this manifest tracks.
 
         The empty bytestring represents the root manifest.
         """)
 
     index = interfaceutil.Attribute(
         """An ``ifilerevisionssequence`` instance.""")
 
     indexfile = interfaceutil.Attribute(
         """Path of revlog index file.
 
         TODO this is revlog specific and should not be exposed.
         """)
 
     opener = interfaceutil.Attribute(
         """VFS opener to use to access underlying files used for storage.
 
         TODO this is revlog specific and should not be exposed.
         """)
 
     version = interfaceutil.Attribute(
         """Revlog version number.
 
         TODO this is revlog specific and should not be exposed.
         """)
 
     _generaldelta = interfaceutil.Attribute(
         """Whether generaldelta storage is being used.
 
         TODO this is revlog specific and should not be exposed.
         """)
 
     fulltextcache = interfaceutil.Attribute(
         """Dict with cache of fulltexts.
 
         TODO this doesn't feel appropriate for the storage interface.
         """)
 
     def __len__():
         """Obtain the number of revisions stored for this manifest."""
 
     def __iter__():
         """Iterate over revision numbers for this manifest."""
 
     def rev(node):
         """Obtain the revision number given a binary node.
 
         Raises ``error.LookupError`` if the node is not known.
         """
 
     def node(rev):
         """Obtain the node value given a revision number.
 
         Raises ``error.LookupError`` if the revision is not known.
         """
 
     def lookup(value):
         """Attempt to resolve a value to a node.
 
         Value can be a binary node, hex node, revision number, or a bytes
         that can be converted to an integer.
 
         Raises ``error.LookupError`` if a ndoe could not be resolved.
 
         TODO this is only used by debug* commands and can probably be deleted
         easily.
         """
 
     def parents(node):
         """Returns a 2-tuple of parent nodes for a node.
 
         Values will be ``nullid`` if the parent is empty.
         """
 
     def parentrevs(rev):
         """Like parents() but operates on revision numbers."""
 
     def linkrev(rev):
         """Obtain the changeset revision number a revision is linked to."""
 
     def revision(node, _df=None, raw=False):
         """Obtain fulltext data for a node."""
 
     def revdiff(rev1, rev2):
         """Obtain a delta between two revision numbers.
 
         The returned data is the result of ``bdiff.bdiff()`` on the raw
         revision data.
         """
 
     def cmp(node, fulltext):
         """Compare fulltext to another revision.
 
         Returns True if the fulltext is different from what is stored.
         """
 
     def emitrevisiondeltas(requests):
         """Produce ``irevisiondelta`` from ``irevisiondeltarequest``s.
 
         See the documentation for ``ifiledata`` for more.
         """
 
     def addgroup(deltas, linkmapper, transaction, addrevisioncb=None):
         """Process a series of deltas for storage.
 
         See the documentation in ``ifilemutation`` for more.
         """
 
     def getstrippoint(minlink):
         """Find minimum revision that must be stripped to strip a linkrev.
 
         See the documentation in ``ifilemutation`` for more.
         """
 
     def strip(minlink, transaction):
         """Remove storage of items starting at a linkrev.
 
         See the documentation in ``ifilemutation`` for more.
         """
 
     def checksize():
         """Obtain the expected sizes of backing files.
 
         TODO this is used by verify and it should not be part of the interface.
         """
 
     def files():
         """Obtain paths that are backing storage for this manifest.
 
         TODO this is used by verify and there should probably be a better API
         for this functionality.
         """
 
     def deltaparent(rev):
         """Obtain the revision that a revision is delta'd against.
 
         TODO delta encoding is an implementation detail of storage and should
         not be exposed to the storage interface.
         """
 
     def clone(tr, dest, **kwargs):
         """Clone this instance to another."""
 
     def clearcaches(clear_persisted_data=False):
         """Clear any caches associated with this instance."""
 
     def dirlog(d):
         """Obtain a manifest storage instance for a tree."""
 
     def add(m, transaction, link, p1, p2, added, removed, readtree=None,
             match=None):
         """Add a revision to storage.
 
         ``m`` is an object conforming to ``imanifestdict``.
 
         ``link`` is the linkrev revision number.
 
         ``p1`` and ``p2`` are the parent revision numbers.
 
         ``added`` and ``removed`` are iterables of added and removed paths,
         respectively.
 
         ``readtree`` is a function that can be used to read the child tree(s)
         when recursively writing the full tree structure when using
         treemanifets.
 
         ``match`` is a matcher that can be used to hint to storage that not all
         paths must be inspected; this is an optimization and can be safely
         ignored. Note that the storage must still be able to reproduce a full
         manifest including files that did not match.
         """
 
 class imanifestlog(interfaceutil.Interface):
     """Interface representing a collection of manifest snapshots.
 
     Represents the root manifest in a repository.
 
     Also serves as a means to access nested tree manifests and to cache
     tree manifests.
     """
 
     def __getitem__(node):
         """Obtain a manifest instance for a given binary node.
 
         Equivalent to calling ``self.get('', node)``.
 
         The returned object conforms to the ``imanifestrevisionstored``
         interface.
         """
 
     def get(tree, node, verify=True):
         """Retrieve the manifest instance for a given directory and binary node.
 
         ``node`` always refers to the node of the root manifest (which will be
         the only manifest if flat manifests are being used).
 
         If ``tree`` is the empty string, the root manifest is returned.
         Otherwise the manifest for the specified directory will be returned
         (requires tree manifests).
 
         If ``verify`` is True, ``LookupError`` is raised if the node is not
         known.
 
         The returned object conforms to the ``imanifestrevisionstored``
         interface.
         """
 
     def getstorage(tree):
         """Retrieve an interface to storage for a particular tree.
 
         If ``tree`` is the empty bytestring, storage for the root manifest will
         be returned. Otherwise storage for a tree manifest is returned.
 
         TODO formalize interface for returned object.
         """
 
     def clearcaches():
         """Clear caches associated with this collection."""
 
     def rev(node):
         """Obtain the revision number for a binary node.
 
         Raises ``error.LookupError`` if the node is not known.
         """
 
 class ilocalrepositoryfilestorage(interfaceutil.Interface):
     """Local repository sub-interface providing access to tracked file storage.
 
     This interface defines how a repository accesses storage for a single
     tracked file path.
     """
 
     def file(f):
         """Obtain a filelog for a tracked path.
 
         The returned type conforms to the ``ifilestorage`` interface.
         """
 
 class ilocalrepositorymain(interfaceutil.Interface):
     """Main interface for local repositories.
 
     This currently captures the reality of things - not how things should be.
     """
 
     supportedformats = interfaceutil.Attribute(
         """Set of requirements that apply to stream clone.
 
         This is actually a class attribute and is shared among all instances.
         """)
 
     supported = interfaceutil.Attribute(
         """Set of requirements that this repo is capable of opening.""")
 
     requirements = interfaceutil.Attribute(
         """Set of requirements this repo uses.""")
 
     filtername = interfaceutil.Attribute(
         """Name of the repoview that is active on this repo.""")
 
     wvfs = interfaceutil.Attribute(
         """VFS used to access the working directory.""")
 
     vfs = interfaceutil.Attribute(
         """VFS rooted at the .hg directory.
 
         Used to access repository data not in the store.
         """)
 
     svfs = interfaceutil.Attribute(
         """VFS rooted at the store.
 
         Used to access repository data in the store. Typically .hg/store.
         But can point elsewhere if the store is shared.
         """)
 
     root = interfaceutil.Attribute(
         """Path to the root of the working directory.""")
 
     path = interfaceutil.Attribute(
         """Path to the .hg directory.""")
 
     origroot = interfaceutil.Attribute(
         """The filesystem path that was used to construct the repo.""")
 
     auditor = interfaceutil.Attribute(
         """A pathauditor for the working directory.
 
         This checks if a path refers to a nested repository.
 
         Operates on the filesystem.
         """)
 
     nofsauditor = interfaceutil.Attribute(
         """A pathauditor for the working directory.
 
         This is like ``auditor`` except it doesn't do filesystem checks.
         """)
 
     baseui = interfaceutil.Attribute(
         """Original ui instance passed into constructor.""")
 
     ui = interfaceutil.Attribute(
         """Main ui instance for this instance.""")
 
     sharedpath = interfaceutil.Attribute(
         """Path to the .hg directory of the repo this repo was shared from.""")
 
     store = interfaceutil.Attribute(
         """A store instance.""")
 
     spath = interfaceutil.Attribute(
         """Path to the store.""")
 
     sjoin = interfaceutil.Attribute(
         """Alias to self.store.join.""")
 
     cachevfs = interfaceutil.Attribute(
         """A VFS used to access the cache directory.
 
         Typically .hg/cache.
         """)
 
     filteredrevcache = interfaceutil.Attribute(
         """Holds sets of revisions to be filtered.""")
 
     names = interfaceutil.Attribute(
         """A ``namespaces`` instance.""")
 
     def close():
         """Close the handle on this repository."""
 
     def peer():
         """Obtain an object conforming to the ``peer`` interface."""
 
     def unfiltered():
         """Obtain an unfiltered/raw view of this repo."""
 
     def filtered(name, visibilityexceptions=None):
         """Obtain a named view of this repository."""
 
     obsstore = interfaceutil.Attribute(
         """A store of obsolescence data.""")
 
     changelog = interfaceutil.Attribute(
         """A handle on the changelog revlog.""")
 
     manifestlog = interfaceutil.Attribute(
         """An instance conforming to the ``imanifestlog`` interface.
 
         Provides access to manifests for the repository.
         """)
 
     dirstate = interfaceutil.Attribute(
         """Working directory state.""")
 
     narrowpats = interfaceutil.Attribute(
         """Matcher patterns for this repository's narrowspec.""")
 
     def narrowmatch():
         """Obtain a matcher for the narrowspec."""
 
     def setnarrowpats(newincludes, newexcludes):
         """Define the narrowspec for this repository."""
 
     def __getitem__(changeid):
         """Try to resolve a changectx."""
 
     def __contains__(changeid):
         """Whether a changeset exists."""
 
     def __nonzero__():
         """Always returns True."""
         return True
 
     __bool__ = __nonzero__
 
     def __len__():
         """Returns the number of changesets in the repo."""
 
     def __iter__():
         """Iterate over revisions in the changelog."""
 
     def revs(expr, *args):
         """Evaluate a revset.
 
         Emits revisions.
         """
 
     def set(expr, *args):
         """Evaluate a revset.
 
         Emits changectx instances.
         """
 
     def anyrevs(specs, user=False, localalias=None):
         """Find revisions matching one of the given revsets."""
 
     def url():
         """Returns a string representing the location of this repo."""
 
     def hook(name, throw=False, **args):
         """Call a hook."""
 
     def tags():
         """Return a mapping of tag to node."""
 
     def tagtype(tagname):
         """Return the type of a given tag."""
 
     def tagslist():
         """Return a list of tags ordered by revision."""
 
     def nodetags(node):
         """Return the tags associated with a node."""
 
     def nodebookmarks(node):
         """Return the list of bookmarks pointing to the specified node."""
 
     def branchmap():
         """Return a mapping of branch to heads in that branch."""
 
     def revbranchcache():
         pass
 
     def branchtip(branchtip, ignoremissing=False):
         """Return the tip node for a given branch."""
 
     def lookup(key):
         """Resolve the node for a revision."""
 
     def lookupbranch(key):
         """Look up the branch name of the given revision or branch name."""
 
     def known(nodes):
         """Determine whether a series of nodes is known.
 
         Returns a list of bools.
         """
 
     def local():
         """Whether the repository is local."""
         return True
 
     def publishing():
         """Whether the repository is a publishing repository."""
 
     def cancopy():
         pass
 
     def shared():
         """The type of shared repository or None."""
 
     def wjoin(f, *insidef):
         """Calls self.vfs.reljoin(self.root, f, *insidef)"""
 
     def setparents(p1, p2):
         """Set the parent nodes of the working directory."""
 
     def filectx(path, changeid=None, fileid=None):
         """Obtain a filectx for the given file revision."""
 
     def getcwd():
         """Obtain the current working directory from the dirstate."""
 
     def pathto(f, cwd=None):
         """Obtain the relative path to a file."""
 
     def adddatafilter(name, fltr):
         pass
 
     def wread(filename):
         """Read a file from wvfs, using data filters."""
 
     def wwrite(filename, data, flags, backgroundclose=False, **kwargs):
         """Write data to a file in the wvfs, using data filters."""
 
     def wwritedata(filename, data):
         """Resolve data for writing to the wvfs, using data filters."""
 
     def currenttransaction():
         """Obtain the current transaction instance or None."""
 
     def transaction(desc, report=None):
         """Open a new transaction to write to the repository."""
 
     def undofiles():
         """Returns a list of (vfs, path) for files to undo transactions."""
 
     def recover():
         """Roll back an interrupted transaction."""
 
     def rollback(dryrun=False, force=False):
         """Undo the last transaction.
 
         DANGEROUS.
         """
 
     def updatecaches(tr=None, full=False):
         """Warm repo caches."""
 
     def invalidatecaches():
         """Invalidate cached data due to the repository mutating."""
 
     def invalidatevolatilesets():
         pass
 
     def invalidatedirstate():
         """Invalidate the dirstate."""
 
     def invalidate(clearfilecache=False):
         pass
 
     def invalidateall():
         pass
 
     def lock(wait=True):
         """Lock the repository store and return a lock instance."""
 
     def wlock(wait=True):
         """Lock the non-store parts of the repository."""
 
     def currentwlock():
         """Return the wlock if it's held or None."""
 
     def checkcommitpatterns(wctx, vdirs, match, status, fail):
         pass
 
     def commit(text='', user=None, date=None, match=None, force=False,
                editor=False, extra=None):
         """Add a new revision to the repository."""
 
     def commitctx(ctx, error=False):
         """Commit a commitctx instance to the repository."""
 
     def destroying():
         """Inform the repository that nodes are about to be destroyed."""
 
     def destroyed():
         """Inform the repository that nodes have been destroyed."""
 
     def status(node1='.', node2=None, match=None, ignored=False,
                clean=False, unknown=False, listsubrepos=False):
         """Convenience method to call repo[x].status()."""
 
     def addpostdsstatus(ps):
         pass
 
     def postdsstatus():
         pass
 
     def clearpostdsstatus():
         pass
 
     def heads(start=None):
         """Obtain list of nodes that are DAG heads."""
 
     def branchheads(branch=None, start=None, closed=False):
         pass
 
     def branches(nodes):
         pass
 
     def between(pairs):
         pass
 
     def checkpush(pushop):
         pass
 
     prepushoutgoinghooks = interfaceutil.Attribute(
         """util.hooks instance.""")
 
     def pushkey(namespace, key, old, new):
         pass
 
     def listkeys(namespace):
         pass
 
     def debugwireargs(one, two, three=None, four=None, five=None):
         pass
 
     def savecommitmessage(text):
         pass
 
 class completelocalrepository(ilocalrepositorymain,
                               ilocalrepositoryfilestorage):
     """Complete interface for a local repository."""

mercurial/testing/storage.py

@@ -1,984 +1,984
 # storage.py - Testing of storage primitives.
 #
 # Copyright 2018 Gregory Szorc <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import unittest
 
 from ..node import (
     hex,
     nullid,
     nullrev,
 )
 from .. import (
     error,
     mdiff,
     revlog,
 )
 
 class basetestcase(unittest.TestCase):
     if not getattr(unittest.TestCase, r'assertRaisesRegex', False):
         assertRaisesRegex = (# camelcase-required
             unittest.TestCase.assertRaisesRegexp)
 
 class revisiondeltarequest(object):
     def __init__(self, node, p1, p2, linknode, basenode, ellipsis):
         self.node = node
         self.p1node = p1
         self.p2node = p2
         self.linknode = linknode
         self.basenode = basenode
         self.ellipsis = ellipsis
 
 class ifileindextests(basetestcase):
     """Generic tests for the ifileindex interface.
 
     All file storage backends for index data should conform to the tests in this
     class.
 
     Use ``makeifileindextests()`` to create an instance of this type.
     """
     def testempty(self):
         f = self._makefilefn()
         self.assertEqual(len(f), 0, 'new file store has 0 length by default')
         self.assertEqual(list(f), [], 'iter yields nothing by default')
 
         gen = iter(f)
         with self.assertRaises(StopIteration):
             next(gen)
 
         # revs() should evaluate to an empty list.
         self.assertEqual(list(f.revs()), [])
 
         revs = iter(f.revs())
         with self.assertRaises(StopIteration):
             next(revs)
 
         self.assertEqual(list(f.revs(start=20)), [])
 
         # parents() and parentrevs() work with nullid/nullrev.
         self.assertEqual(f.parents(nullid), (nullid, nullid))
         self.assertEqual(f.parentrevs(nullrev), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
             f.parents(b'\x01' * 20)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.parentrevs(i)
 
         # nullid/nullrev lookup always works.
         self.assertEqual(f.rev(nullid), nullrev)
         self.assertEqual(f.node(nullrev), nullid)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.node(i)
 
         self.assertEqual(f.lookup(nullid), nullid)
         self.assertEqual(f.lookup(nullrev), nullid)
         self.assertEqual(f.lookup(hex(nullid)), nullid)
 
         # String converted to integer doesn't work for nullrev.
         with self.assertRaises(error.LookupError):
             f.lookup(b'%d' % nullrev)
 
         self.assertEqual(f.linkrev(nullrev), nullrev)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.linkrev(i)
 
         self.assertEqual(f.flags(nullrev), 0)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.flags(i)
 
         self.assertFalse(f.iscensored(nullrev))
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.iscensored(i)
 
         self.assertEqual(list(f.commonancestorsheads(nullid, nullid)), [])
 
         with self.assertRaises(ValueError):
             self.assertEqual(list(f.descendants([])), [])
 
         self.assertEqual(list(f.descendants([nullrev])), [])
 
         self.assertEqual(f.headrevs(), [nullrev])
         self.assertEqual(f.heads(), [nullid])
         self.assertEqual(f.heads(nullid), [nullid])
         self.assertEqual(f.heads(None, [nullid]), [nullid])
         self.assertEqual(f.heads(nullid, [nullid]), [nullid])
 
         self.assertEqual(f.children(nullid), [])
 
         with self.assertRaises(error.LookupError):
             f.children(b'\x01' * 20)
 
         self.assertEqual(f.deltaparent(nullrev), nullrev)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.deltaparent(i)
 
     def testsinglerevision(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node = f.add(b'initial', None, tr, 0, nullid, nullid)
 
         self.assertEqual(len(f), 1)
         self.assertEqual(list(f), [0])
 
         gen = iter(f)
         self.assertEqual(next(gen), 0)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         self.assertEqual(list(f.revs()), [0])
         self.assertEqual(list(f.revs(start=1)), [])
         self.assertEqual(list(f.revs(start=0)), [0])
         self.assertEqual(list(f.revs(stop=0)), [0])
         self.assertEqual(list(f.revs(stop=1)), [0])
         self.assertEqual(list(f.revs(1, 1)), [])
         # TODO buggy
         self.assertEqual(list(f.revs(1, 0)), [1, 0])
         self.assertEqual(list(f.revs(2, 0)), [2, 1, 0])
 
         self.assertEqual(f.parents(node), (nullid, nullid))
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
 
         with self.assertRaises(error.LookupError):
             f.parents(b'\x01' * 20)
 
         with self.assertRaises(IndexError):
             f.parentrevs(1)
 
         self.assertEqual(f.rev(node), 0)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
 
         self.assertEqual(f.node(0), node)
 
         with self.assertRaises(IndexError):
             f.node(1)
 
         self.assertEqual(f.lookup(node), node)
         self.assertEqual(f.lookup(0), node)
         self.assertEqual(f.lookup(b'0'), node)
         self.assertEqual(f.lookup(hex(node)), node)
 
         self.assertEqual(f.linkrev(0), 0)
 
         with self.assertRaises(IndexError):
             f.linkrev(1)
 
         self.assertEqual(f.flags(0), 0)
 
         with self.assertRaises(IndexError):
             f.flags(1)
 
         self.assertFalse(f.iscensored(0))
 
         with self.assertRaises(IndexError):
             f.iscensored(1)
 
         self.assertEqual(list(f.descendants([0])), [])
 
         self.assertEqual(f.headrevs(), [0])
 
         self.assertEqual(f.heads(), [node])
         self.assertEqual(f.heads(node), [node])
         self.assertEqual(f.heads(stop=[node]), [node])
 
         with self.assertRaises(error.LookupError):
             f.heads(stop=[b'\x01' * 20])
 
         self.assertEqual(f.children(node), [])
 
         self.assertEqual(f.deltaparent(0), nullrev)
 
     def testmultiplerevisions(self):
         fulltext0 = b'x' * 1024
         fulltext1 = fulltext0 + b'y'
         fulltext2 = b'y' + fulltext0 + b'z'
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
             node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
 
         self.assertEqual(len(f), 3)
         self.assertEqual(list(f), [0, 1, 2])
 
         gen = iter(f)
         self.assertEqual(next(gen), 0)
         self.assertEqual(next(gen), 1)
         self.assertEqual(next(gen), 2)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         self.assertEqual(list(f.revs()), [0, 1, 2])
         self.assertEqual(list(f.revs(0)), [0, 1, 2])
         self.assertEqual(list(f.revs(1)), [1, 2])
         self.assertEqual(list(f.revs(2)), [2])
         self.assertEqual(list(f.revs(3)), [])
         self.assertEqual(list(f.revs(stop=1)), [0, 1])
         self.assertEqual(list(f.revs(stop=2)), [0, 1, 2])
         self.assertEqual(list(f.revs(stop=3)), [0, 1, 2])
         self.assertEqual(list(f.revs(2, 0)), [2, 1, 0])
         self.assertEqual(list(f.revs(2, 1)), [2, 1])
         # TODO this is wrong
         self.assertEqual(list(f.revs(3, 2)), [3, 2])
 
         self.assertEqual(f.parents(node0), (nullid, nullid))
         self.assertEqual(f.parents(node1), (node0, nullid))
         self.assertEqual(f.parents(node2), (node1, nullid))
 
         self.assertEqual(f.parentrevs(0), (nullrev, nullrev))
         self.assertEqual(f.parentrevs(1), (0, nullrev))
         self.assertEqual(f.parentrevs(2), (1, nullrev))
 
         self.assertEqual(f.rev(node0), 0)
         self.assertEqual(f.rev(node1), 1)
         self.assertEqual(f.rev(node2), 2)
 
         with self.assertRaises(error.LookupError):
             f.rev(b'\x01' * 20)
 
         self.assertEqual(f.node(0), node0)
         self.assertEqual(f.node(1), node1)
         self.assertEqual(f.node(2), node2)
 
         with self.assertRaises(IndexError):
             f.node(3)
 
         self.assertEqual(f.lookup(node0), node0)
         self.assertEqual(f.lookup(0), node0)
         self.assertEqual(f.lookup(b'0'), node0)
         self.assertEqual(f.lookup(hex(node0)), node0)
 
         self.assertEqual(f.lookup(node1), node1)
         self.assertEqual(f.lookup(1), node1)
         self.assertEqual(f.lookup(b'1'), node1)
         self.assertEqual(f.lookup(hex(node1)), node1)
 
         self.assertEqual(f.linkrev(0), 0)
         self.assertEqual(f.linkrev(1), 1)
         self.assertEqual(f.linkrev(2), 3)
 
         with self.assertRaises(IndexError):
             f.linkrev(3)
 
         self.assertEqual(f.flags(0), 0)
         self.assertEqual(f.flags(1), 0)
         self.assertEqual(f.flags(2), 0)
 
         with self.assertRaises(IndexError):
             f.flags(3)
 
         self.assertFalse(f.iscensored(0))
         self.assertFalse(f.iscensored(1))
         self.assertFalse(f.iscensored(2))
 
         with self.assertRaises(IndexError):
             f.iscensored(3)
 
         self.assertEqual(f.commonancestorsheads(node1, nullid), [])
         self.assertEqual(f.commonancestorsheads(node1, node0), [node0])
         self.assertEqual(f.commonancestorsheads(node1, node1), [node1])
         self.assertEqual(f.commonancestorsheads(node0, node1), [node0])
         self.assertEqual(f.commonancestorsheads(node1, node2), [node1])
         self.assertEqual(f.commonancestorsheads(node2, node1), [node1])
 
         self.assertEqual(list(f.descendants([0])), [1, 2])
         self.assertEqual(list(f.descendants([1])), [2])
         self.assertEqual(list(f.descendants([0, 1])), [1, 2])
 
         self.assertEqual(f.headrevs(), [2])
 
         self.assertEqual(f.heads(), [node2])
         self.assertEqual(f.heads(node0), [node2])
         self.assertEqual(f.heads(node1), [node2])
         self.assertEqual(f.heads(node2), [node2])
 
         # TODO this behavior seems wonky. Is it correct? If so, the
         # docstring for heads() should be updated to reflect desired
         # behavior.
         self.assertEqual(f.heads(stop=[node1]), [node1, node2])
         self.assertEqual(f.heads(stop=[node0]), [node0, node2])
         self.assertEqual(f.heads(stop=[node1, node2]), [node1, node2])
 
         with self.assertRaises(error.LookupError):
             f.heads(stop=[b'\x01' * 20])
 
         self.assertEqual(f.children(node0), [node1])
         self.assertEqual(f.children(node1), [node2])
         self.assertEqual(f.children(node2), [])
 
         self.assertEqual(f.deltaparent(0), nullrev)
         self.assertEqual(f.deltaparent(1), 0)
         self.assertEqual(f.deltaparent(2), 1)
 
     def testmultipleheads(self):
         f = self._makefilefn()
 
         with self._maketransactionfn() as tr:
             node0 = f.add(b'0', None, tr, 0, nullid, nullid)
             node1 = f.add(b'1', None, tr, 1, node0, nullid)
             node2 = f.add(b'2', None, tr, 2, node1, nullid)
             node3 = f.add(b'3', None, tr, 3, node0, nullid)
             node4 = f.add(b'4', None, tr, 4, node3, nullid)
             node5 = f.add(b'5', None, tr, 5, node0, nullid)
 
         self.assertEqual(len(f), 6)
 
         self.assertEqual(list(f.descendants([0])), [1, 2, 3, 4, 5])
         self.assertEqual(list(f.descendants([1])), [2])
         self.assertEqual(list(f.descendants([2])), [])
         self.assertEqual(list(f.descendants([3])), [4])
         self.assertEqual(list(f.descendants([0, 1])), [1, 2, 3, 4, 5])
         self.assertEqual(list(f.descendants([1, 3])), [2, 4])
 
         self.assertEqual(f.headrevs(), [2, 4, 5])
 
         self.assertEqual(f.heads(), [node2, node4, node5])
         self.assertEqual(f.heads(node0), [node2, node4, node5])
         self.assertEqual(f.heads(node1), [node2])
         self.assertEqual(f.heads(node2), [node2])
         self.assertEqual(f.heads(node3), [node4])
         self.assertEqual(f.heads(node4), [node4])
         self.assertEqual(f.heads(node5), [node5])
 
         # TODO this seems wrong.
         self.assertEqual(f.heads(stop=[node0]), [node0, node2, node4, node5])
         self.assertEqual(f.heads(stop=[node1]), [node1, node2, node4, node5])
 
         self.assertEqual(f.children(node0), [node1, node3, node5])
         self.assertEqual(f.children(node1), [node2])
         self.assertEqual(f.children(node2), [])
         self.assertEqual(f.children(node3), [node4])
         self.assertEqual(f.children(node4), [])
         self.assertEqual(f.children(node5), [])
 
 class ifiledatatests(basetestcase):
     """Generic tests for the ifiledata interface.
 
     All file storage backends for data should conform to the tests in this
     class.
 
     Use ``makeifiledatatests()`` to create an instance of this type.
     """
     def testempty(self):
         f = self._makefilefn()
 
         self.assertEqual(f.rawsize(nullrev), 0)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.rawsize(i)
 
         self.assertEqual(f.size(nullrev), 0)
 
         for i in range(-5, 5):
             if i == nullrev:
                 continue
 
             with self.assertRaises(IndexError):
                 f.size(i)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(b'', nullid)
 
         with self.assertRaises(error.LookupError):
             f.checkhash(b'', b'\x01' * 20)
 
         self.assertEqual(f.revision(nullid), b'')
         self.assertEqual(f.revision(nullid, raw=True), b'')
 
         with self.assertRaises(error.LookupError):
             f.revision(b'\x01' * 20)
 
         self.assertEqual(f.read(nullid), b'')
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
         self.assertFalse(f.renamed(nullid))
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
         self.assertTrue(f.cmp(nullid, b''))
         self.assertTrue(f.cmp(nullid, b'foo'))
 
         with self.assertRaises(error.LookupError):
             f.cmp(b'\x01' * 20, b'irrelevant')
 
         self.assertEqual(f.revdiff(nullrev, nullrev), b'')
 
         with self.assertRaises(IndexError):
             f.revdiff(0, nullrev)
 
         with self.assertRaises(IndexError):
             f.revdiff(nullrev, 0)
 
         with self.assertRaises(IndexError):
             f.revdiff(0, 0)
 
         gen = f.emitrevisiondeltas([])
         with self.assertRaises(StopIteration):
             next(gen)
 
         requests = [
             revisiondeltarequest(nullid, nullid, nullid, nullid, nullid, False),
         ]
         gen = f.emitrevisiondeltas(requests)
 
         delta = next(gen)
 
         self.assertEqual(delta.node, nullid)
         self.assertEqual(delta.p1node, nullid)
         self.assertEqual(delta.p2node, nullid)
         self.assertEqual(delta.linknode, nullid)
         self.assertEqual(delta.basenode, nullid)
         self.assertIsNone(delta.baserevisionsize)
         self.assertEqual(delta.revision, b'')
         self.assertIsNone(delta.delta)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
         requests = [
             revisiondeltarequest(nullid, nullid, nullid, nullid, nullid, False),
             revisiondeltarequest(nullid, b'\x01' * 20, b'\x02' * 20,
                                  b'\x03' * 20, nullid, False)
         ]
 
         gen = f.emitrevisiondeltas(requests)
 
         next(gen)
         delta = next(gen)
 
         self.assertEqual(delta.node, nullid)
         self.assertEqual(delta.p1node, b'\x01' * 20)
         self.assertEqual(delta.p2node, b'\x02' * 20)
         self.assertEqual(delta.linknode, b'\x03' * 20)
         self.assertEqual(delta.basenode, nullid)
         self.assertIsNone(delta.baserevisionsize)
         self.assertEqual(delta.revision, b'')
         self.assertIsNone(delta.delta)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
     def testsinglerevision(self):
         fulltext = b'initial'
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node = f.add(fulltext, None, tr, 0, nullid, nullid)
 
         self.assertEqual(f.rawsize(0), len(fulltext))
 
         with self.assertRaises(IndexError):
             f.rawsize(1)
 
         self.assertEqual(f.size(0), len(fulltext))
 
         with self.assertRaises(IndexError):
             f.size(1)
 
         f.checkhash(fulltext, node)
         f.checkhash(fulltext, node, nullid, nullid)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(fulltext + b'extra', node)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(fulltext, node, b'\x01' * 20, nullid)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(fulltext, node, nullid, b'\x01' * 20)
 
         self.assertEqual(f.revision(node), fulltext)
         self.assertEqual(f.revision(node, raw=True), fulltext)
 
         self.assertEqual(f.read(node), fulltext)
 
         self.assertFalse(f.renamed(node))
 
         self.assertFalse(f.cmp(node, fulltext))
         self.assertTrue(f.cmp(node, fulltext + b'extra'))
 
         self.assertEqual(f.revdiff(0, 0), b'')
         self.assertEqual(f.revdiff(nullrev, 0),
                          b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x07%s' %
                          fulltext)
 
         self.assertEqual(f.revdiff(0, nullrev),
                          b'\x00\x00\x00\x00\x00\x00\x00\x07\x00\x00\x00\x00')
 
         requests = [
             revisiondeltarequest(node, nullid, nullid, nullid, nullid, False),
         ]
         gen = f.emitrevisiondeltas(requests)
 
         delta = next(gen)
 
         self.assertEqual(delta.node, node)
         self.assertEqual(delta.p1node, nullid)
         self.assertEqual(delta.p2node, nullid)
         self.assertEqual(delta.linknode, nullid)
         self.assertEqual(delta.basenode, nullid)
         self.assertIsNone(delta.baserevisionsize)
         self.assertEqual(delta.revision, fulltext)
         self.assertIsNone(delta.delta)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
     def testmultiplerevisions(self):
         fulltext0 = b'x' * 1024
         fulltext1 = fulltext0 + b'y'
         fulltext2 = b'y' + fulltext0 + b'z'
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, None, tr, 1, node0, nullid)
             node2 = f.add(fulltext2, None, tr, 3, node1, nullid)
 
         self.assertEqual(f.rawsize(0), len(fulltext0))
         self.assertEqual(f.rawsize(1), len(fulltext1))
         self.assertEqual(f.rawsize(2), len(fulltext2))
 
         with self.assertRaises(IndexError):
             f.rawsize(3)
 
         self.assertEqual(f.size(0), len(fulltext0))
         self.assertEqual(f.size(1), len(fulltext1))
         self.assertEqual(f.size(2), len(fulltext2))
 
         with self.assertRaises(IndexError):
             f.size(3)
 
         f.checkhash(fulltext0, node0)
         f.checkhash(fulltext1, node1)
         f.checkhash(fulltext1, node1, node0, nullid)
         f.checkhash(fulltext2, node2, node1, nullid)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(fulltext1, b'\x01' * 20)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(fulltext1 + b'extra', node1, node0, nullid)
 
-        with self.assertRaises(error.RevlogError):
+        with self.assertRaises(error.StorageError):
             f.checkhash(fulltext1, node1, node0, node0)
 
         self.assertEqual(f.revision(node0), fulltext0)
         self.assertEqual(f.revision(node0, raw=True), fulltext0)
         self.assertEqual(f.revision(node1), fulltext1)
         self.assertEqual(f.revision(node1, raw=True), fulltext1)
         self.assertEqual(f.revision(node2), fulltext2)
         self.assertEqual(f.revision(node2, raw=True), fulltext2)
 
         with self.assertRaises(error.LookupError):
             f.revision(b'\x01' * 20)
 
         self.assertEqual(f.read(node0), fulltext0)
         self.assertEqual(f.read(node1), fulltext1)
         self.assertEqual(f.read(node2), fulltext2)
 
         with self.assertRaises(error.LookupError):
             f.read(b'\x01' * 20)
 
         self.assertFalse(f.renamed(node0))
         self.assertFalse(f.renamed(node1))
         self.assertFalse(f.renamed(node2))
 
         with self.assertRaises(error.LookupError):
             f.renamed(b'\x01' * 20)
 
         self.assertFalse(f.cmp(node0, fulltext0))
         self.assertFalse(f.cmp(node1, fulltext1))
         self.assertFalse(f.cmp(node2, fulltext2))
 
         self.assertTrue(f.cmp(node1, fulltext0))
         self.assertTrue(f.cmp(node2, fulltext1))
 
         with self.assertRaises(error.LookupError):
             f.cmp(b'\x01' * 20, b'irrelevant')
 
         self.assertEqual(f.revdiff(0, 1),
                          b'\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04\x01' +
                          fulltext1)
 
         self.assertEqual(f.revdiff(0, 2),
                          b'\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04\x02' +
                          fulltext2)
 
         requests = [
             revisiondeltarequest(node0, nullid, nullid, b'\x01' * 20, nullid,
                                  False),
             revisiondeltarequest(node1, node0, nullid, b'\x02' * 20, node0,
                                  False),
             revisiondeltarequest(node2, node1, nullid, b'\x03' * 20, node1,
                                  False),
         ]
         gen = f.emitrevisiondeltas(requests)
 
         delta = next(gen)
 
         self.assertEqual(delta.node, node0)
         self.assertEqual(delta.p1node, nullid)
         self.assertEqual(delta.p2node, nullid)
         self.assertEqual(delta.linknode, b'\x01' * 20)
         self.assertEqual(delta.basenode, nullid)
         self.assertIsNone(delta.baserevisionsize)
         self.assertEqual(delta.revision, fulltext0)
         self.assertIsNone(delta.delta)
 
         delta = next(gen)
 
         self.assertEqual(delta.node, node1)
         self.assertEqual(delta.p1node, node0)
         self.assertEqual(delta.p2node, nullid)
         self.assertEqual(delta.linknode, b'\x02' * 20)
         self.assertEqual(delta.basenode, node0)
         self.assertIsNone(delta.baserevisionsize)
         self.assertIsNone(delta.revision)
         self.assertEqual(delta.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x00\x00\x00\x04\x01' +
                          fulltext1)
 
         delta = next(gen)
 
         self.assertEqual(delta.node, node2)
         self.assertEqual(delta.p1node, node1)
         self.assertEqual(delta.p2node, nullid)
         self.assertEqual(delta.linknode, b'\x03' * 20)
         self.assertEqual(delta.basenode, node1)
         self.assertIsNone(delta.baserevisionsize)
         self.assertIsNone(delta.revision)
         self.assertEqual(delta.delta,
                          b'\x00\x00\x00\x00\x00\x00\x04\x01\x00\x00\x04\x02' +
                          fulltext2)
 
         with self.assertRaises(StopIteration):
             next(gen)
 
     def testrenamed(self):
         fulltext0 = b'foo'
         fulltext1 = b'bar'
         fulltext2 = b'baz'
 
         meta1 = {
             b'copy': b'source0',
             b'copyrev': b'a' * 40,
         }
 
         meta2 = {
             b'copy': b'source1',
             b'copyrev': b'b' * 40,
         }
 
         stored1 = b''.join([
             b'\x01\ncopy: source0\n',
             b'copyrev: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n\x01\n',
             fulltext1,
         ])
 
         stored2 = b''.join([
             b'\x01\ncopy: source1\n',
             b'copyrev: bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb\n\x01\n',
             fulltext2,
         ])
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, meta1, tr, 1, node0, nullid)
             node2 = f.add(fulltext2, meta2, tr, 2, nullid, nullid)
 
         self.assertEqual(f.rawsize(1), len(stored1))
         self.assertEqual(f.rawsize(2), len(stored2))
 
         # Metadata header isn't recognized when parent isn't nullid.
         self.assertEqual(f.size(1), len(stored1))
         self.assertEqual(f.size(2), len(fulltext2))
 
         self.assertEqual(f.revision(node1), stored1)
         self.assertEqual(f.revision(node1, raw=True), stored1)
         self.assertEqual(f.revision(node2), stored2)
         self.assertEqual(f.revision(node2, raw=True), stored2)
 
         self.assertEqual(f.read(node1), fulltext1)
         self.assertEqual(f.read(node2), fulltext2)
 
         # Returns False when first parent is set.
         self.assertFalse(f.renamed(node1))
         self.assertEqual(f.renamed(node2), (b'source1', b'\xbb' * 20))
 
         self.assertTrue(f.cmp(node1, fulltext1))
         self.assertTrue(f.cmp(node1, stored1))
         self.assertFalse(f.cmp(node2, fulltext2))
         self.assertTrue(f.cmp(node2, stored2))
 
     def testmetadataprefix(self):
         # Content with metadata prefix has extra prefix inserted in storage.
         fulltext0 = b'\x01\nfoo'
         stored0 = b'\x01\n\x01\n\x01\nfoo'
 
         fulltext1 = b'\x01\nbar'
         meta1 = {
             b'copy': b'source0',
             b'copyrev': b'b' * 40,
         }
         stored1 = b''.join([
             b'\x01\ncopy: source0\n',
             b'copyrev: %s\n' % (b'b' * 40),
             b'\x01\n\x01\nbar',
         ])
 
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(fulltext0, {}, tr, 0, nullid, nullid)
             node1 = f.add(fulltext1, meta1, tr, 1, nullid, nullid)
 
         self.assertEqual(f.rawsize(0), len(stored0))
         self.assertEqual(f.rawsize(1), len(stored1))
 
         # TODO this is buggy.
         self.assertEqual(f.size(0), len(fulltext0) + 4)
 
         self.assertEqual(f.size(1), len(fulltext1))
 
         self.assertEqual(f.revision(node0), stored0)
         self.assertEqual(f.revision(node0, raw=True), stored0)
 
         self.assertEqual(f.revision(node1), stored1)
         self.assertEqual(f.revision(node1, raw=True), stored1)
 
         self.assertEqual(f.read(node0), fulltext0)
         self.assertEqual(f.read(node1), fulltext1)
 
         self.assertFalse(f.cmp(node0, fulltext0))
         self.assertTrue(f.cmp(node0, stored0))
 
         self.assertFalse(f.cmp(node1, fulltext1))
         self.assertTrue(f.cmp(node1, stored0))
 
     def testcensored(self):
         f = self._makefilefn()
 
         stored1 = revlog.packmeta({
             b'censored': b'tombstone',
         }, b'')
 
         # TODO tests are incomplete because we need the node to be
         # different due to presence of censor metadata. But we can't
         # do this with addrevision().
         with self._maketransactionfn() as tr:
             node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
             f.addrevision(stored1, tr, 1, node0, nullid,
                           flags=revlog.REVIDX_ISCENSORED)
 
         self.assertEqual(f.flags(1), revlog.REVIDX_ISCENSORED)
         self.assertTrue(f.iscensored(1))
 
         self.assertEqual(f.revision(1), stored1)
         self.assertEqual(f.revision(1, raw=True), stored1)
 
         self.assertEqual(f.read(1), b'')
 
 class ifilemutationtests(basetestcase):
     """Generic tests for the ifilemutation interface.
 
     All file storage backends that support writing should conform to this
     interface.
 
     Use ``makeifilemutationtests()`` to create an instance of this type.
     """
     def testaddnoop(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             node0 = f.add(b'foo', None, tr, 0, nullid, nullid)
             node1 = f.add(b'foo', None, tr, 0, nullid, nullid)
             # Varying by linkrev shouldn't impact hash.
             node2 = f.add(b'foo', None, tr, 1, nullid, nullid)
 
         self.assertEqual(node1, node0)
         self.assertEqual(node2, node0)
         self.assertEqual(len(f), 1)
 
     def testaddrevisionbadnode(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             # Adding a revision with bad node value fails.
-            with self.assertRaises(error.RevlogError):
+            with self.assertRaises(error.StorageError):
                 f.addrevision(b'foo', tr, 0, nullid, nullid, node=b'\x01' * 20)
 
     def testaddrevisionunknownflag(self):
         f = self._makefilefn()
         with self._maketransactionfn() as tr:
             for i in range(15, 0, -1):
                 if (1 << i) & ~revlog.REVIDX_KNOWN_FLAGS:
                     flags = 1 << i
                     break
 
-            with self.assertRaises(error.RevlogError):
+            with self.assertRaises(error.StorageError):
                 f.addrevision(b'foo', tr, 0, nullid, nullid, flags=flags)
 
     def testaddgroupsimple(self):
         f = self._makefilefn()
 
         callbackargs = []
         def cb(*args, **kwargs):
             callbackargs.append((args, kwargs))
 
         def linkmapper(node):
             return 0
 
         with self._maketransactionfn() as tr:
             nodes = f.addgroup([], None, tr, addrevisioncb=cb)
 
         self.assertEqual(nodes, [])
         self.assertEqual(callbackargs, [])
         self.assertEqual(len(f), 0)
 
         fulltext0 = b'foo'
         delta0 = mdiff.trivialdiffheader(len(fulltext0)) + fulltext0
 
         deltas = [
             (b'\x01' * 20, nullid, nullid, nullid, nullid, delta0, 0),
         ]
 
         with self._maketransactionfn() as tr:
-            with self.assertRaises(error.RevlogError):
+            with self.assertRaises(error.StorageError):
                 f.addgroup(deltas, linkmapper, tr, addrevisioncb=cb)
 
             node0 = f.add(fulltext0, None, tr, 0, nullid, nullid)
 
         f = self._makefilefn()
 
         deltas = [
             (node0, nullid, nullid, nullid, nullid, delta0, 0),
         ]
 
         with self._maketransactionfn() as tr:
             nodes = f.addgroup(deltas, linkmapper, tr, addrevisioncb=cb)
 
         self.assertEqual(nodes, [
             b'\x49\xd8\xcb\xb1\x5c\xe2\x57\x92\x04\x47'
             b'\x00\x6b\x46\x97\x8b\x7a\xf9\x80\xa9\x79'])
 
         self.assertEqual(len(callbackargs), 1)
         self.assertEqual(callbackargs[0][0][1], nodes[0])
 
         self.assertEqual(list(f.revs()), [0])
         self.assertEqual(f.rev(nodes[0]), 0)
         self.assertEqual(f.node(0), nodes[0])
 
     def testaddgroupmultiple(self):
         f = self._makefilefn()
 
         fulltexts = [
             b'foo',
             b'bar',
             b'x' * 1024,
         ]
 
         nodes = []
         with self._maketransactionfn() as tr:
             for fulltext in fulltexts:
                 nodes.append(f.add(fulltext, None, tr, 0, nullid, nullid))
 
         f = self._makefilefn()
         deltas = []
         for i, fulltext in enumerate(fulltexts):
             delta = mdiff.trivialdiffheader(len(fulltext)) + fulltext
 
             deltas.append((nodes[i], nullid, nullid, nullid, nullid, delta, 0))
 
         with self._maketransactionfn() as tr:
             self.assertEqual(f.addgroup(deltas, lambda x: 0, tr), nodes)
 
         self.assertEqual(len(f), len(deltas))
         self.assertEqual(list(f.revs()), [0, 1, 2])
         self.assertEqual(f.rev(nodes[0]), 0)
         self.assertEqual(f.rev(nodes[1]), 1)
         self.assertEqual(f.rev(nodes[2]), 2)
         self.assertEqual(f.node(0), nodes[0])
         self.assertEqual(f.node(1), nodes[1])
         self.assertEqual(f.node(2), nodes[2])
 
 def makeifileindextests(makefilefn, maketransactionfn):
     """Create a unittest.TestCase class suitable for testing file storage.
 
     ``makefilefn`` is a callable which receives the test case as an
     argument and returns an object implementing the ``ifilestorage`` interface.
 
     ``maketransactionfn`` is a callable which receives the test case as an
     argument and returns a transaction object.
 
     Returns a type that is a ``unittest.TestCase`` that can be used for
     testing the object implementing the file storage interface. Simply
     assign the returned value to a module-level attribute and a test loader
     should find and run it automatically.
     """
     d = {
         r'_makefilefn': makefilefn,
         r'_maketransactionfn': maketransactionfn,
     }
     return type(r'ifileindextests', (ifileindextests,), d)
 
 def makeifiledatatests(makefilefn, maketransactionfn):
     d = {
         r'_makefilefn': makefilefn,
         r'_maketransactionfn': maketransactionfn,
     }
     return type(r'ifiledatatests', (ifiledatatests,), d)
 
 def makeifilemutationtests(makefilefn, maketransactionfn):
     d = {
         r'_makefilefn': makefilefn,
         r'_maketransactionfn': maketransactionfn,
     }
     return type(r'ifilemutationtests', (ifilemutationtests,), d)