~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2006 Canonical

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""Exceptions for bzr, and reporting of them.

There are 3 different classes of error:

 * KeyboardInterrupt, and OSError with EPIPE - the program terminates 

   with an appropriate short message

 * User errors, indicating a problem caused by the user such as a bad URL.

   These are printed in a short form.

 * Internal unexpected errors, including most Python builtin errors

   and some raised from inside bzr.  These are printed with a full 

   traceback and an invitation to report the bug.

Exceptions are caught at a high level to report errors to the user, and

might also be caught inside the program.  Therefore it needs to be

possible to convert them to a meaningful string, and also for them to be

interrogated by the program.

Exceptions are defined such that the arguments given to the constructor

are stored in the object as properties of the same name.  When the

object is printed as a string, the doc string of the class is used as

a format string with the property dictionary available to it.

This means that exceptions can used like this:

>>> import sys

>>> try:

...   raise NotBranchError(path='/foo/bar')

... except:

...   print '%s.%s' % (sys.exc_type.__module__, sys.exc_type.__name__)

...   print sys.exc_value

...   path = getattr(sys.exc_value, 'path', None)

...   if path is not None:

...     print path

bzrlib.errors.NotBranchError

Not a branch: /foo/bar

/foo/bar

Therefore:

 * create a new exception class for any class of error that can be

   usefully distinguished.  If no callers are likely to want to catch

   one but not another, don't worry about them.

 * the __str__ method should generate something useful; BzrError provides

   a good default implementation

Exception strings should start with a capital letter and should not have a

final fullstop.

"""

from warnings import warn

from bzrlib.patches import (PatchSyntax, 

                            PatchConflict, 

                            MalformedPatchHeader,

                            MalformedHunkHeader,

                            MalformedLine,)

# based on Scott James Remnant's hct error classes

# TODO: is there any value in providing the .args field used by standard

# python exceptions?   A list of values with no names seems less useful 

# to me.

# TODO: Perhaps convert the exception to a string at the moment it's 

# constructed to make sure it will succeed.  But that says nothing about

# exceptions that are never raised.

# TODO: Convert all the other error classes here to BzrNewError, and eliminate

# the old one.

# TODO: The pattern (from hct) of using classes docstrings as message

# templates is cute but maybe not such a great idea - perhaps should have a

# separate static message_template.

class BzrError(StandardError):

    is_user_error = True

    def __str__(self):

        # XXX: Should we show the exception class in 

        # exceptions that don't provide their own message?  

        # maybe it should be done at a higher level

        ## n = self.__class__.__name__ + ': '

        n = ''

        if len(self.args) == 1:

            return str(self.args[0])

        elif len(self.args) == 2:

            # further explanation or suggestions

            try:

                return n + '\n  '.join([self.args[0]] + self.args[1])

            except TypeError:

                return n + "%r" % self

        else:

            return n + `self.args`

class BzrNewError(BzrError):

    """bzr error"""

    # base classes should override the docstring with their human-

    # readable explanation

    def __init__(self, *args, **kwds):

        # XXX: Use the underlying BzrError to always generate the args attribute

        # if it doesn't exist.  We can't use super here, because exceptions are

        # old-style classes in python2.4 (but new in 2.5).  --bmc, 20060426

        BzrError.__init__(self, *args)

        for key, value in kwds.items():

            setattr(self, key, value)

    def __str__(self):

        try:

            # __str__() should always return a 'str' object

            # never a 'unicode' object.

            s = self.__doc__ % self.__dict__

            if isinstance(s, unicode):

                return s.encode('utf8')

            return s

        except (TypeError, NameError, ValueError, KeyError), e:

            return 'Unprintable exception %s(%r): %s' \

                % (self.__class__.__name__,

                   self.__dict__, str(e))

class AlreadyBuilding(BzrNewError):

    """The tree builder is already building a tree."""

class BzrCheckError(BzrNewError):

    """Internal check failed: %(message)s"""

    is_user_error = False

    def __init__(self, message):

        BzrNewError.__init__(self)

        self.message = message

class InvalidEntryName(BzrNewError):

    """Invalid entry name: %(name)s"""

    is_user_error = False

    def __init__(self, name):

        BzrNewError.__init__(self)

        self.name = name

class InvalidRevisionNumber(BzrNewError):

    """Invalid revision number %(revno)d"""

    def __init__(self, revno):

        BzrNewError.__init__(self)

        self.revno = revno

class InvalidRevisionId(BzrNewError):

    """Invalid revision-id {%(revision_id)s} in %(branch)s"""

    def __init__(self, revision_id, branch):

        # branch can be any string or object with __str__ defined

        BzrNewError.__init__(self)

        self.revision_id = revision_id

        self.branch = branch

class NoSuchId(BzrNewError):

    """The file id %(file_id)s is not present in the tree %(tree)s."""

    def __init__(self, tree, file_id):

        BzrNewError.__init__(self)

        self.file_id = file_id

        self.tree = tree

class NoWorkingTree(BzrNewError):

    """No WorkingTree exists for %(base)s."""

    def __init__(self, base):

        BzrNewError.__init__(self)

        self.base = base

class NotBuilding(BzrNewError):

    """Not currently building a tree."""

class NotLocalUrl(BzrNewError):

    """%(url)s is not a local path."""

    def __init__(self, url):

        BzrNewError.__init__(self)

        self.url = url

class BzrCommandError(BzrNewError):

    """Error from user command"""

    is_user_error = True

    # Error from malformed user command; please avoid raising this as a

    # generic exception not caused by user input.

    #

    # I think it's a waste of effort to differentiate between errors that

    # are not intended to be caught anyway.  UI code need not subclass

    # BzrCommandError, and non-UI code should not throw a subclass of

    # BzrCommandError.  ADHB 20051211

    def __init__(self, msg):

        # Object.__str__() must return a real string

        # returning a Unicode string is a python error.

        if isinstance(msg, unicode):

            self.msg = msg.encode('utf8')

        else:

            self.msg = msg

    def __str__(self):

        return self.msg

class BzrOptionError(BzrCommandError):

    """Error in command line options"""

class StrictCommitFailed(BzrNewError):

    """Commit refused because there are unknown files in the tree"""

# XXX: Should be unified with TransportError; they seem to represent the

# same thing

class PathError(BzrNewError):

    """Generic path error: %(path)r%(extra)s)"""

    def __init__(self, path, extra=None):

        BzrNewError.__init__(self)

        self.path = path

        if extra:

            self.extra = ': ' + str(extra)

        else:

            self.extra = ''

class NoSuchFile(PathError):

    """No such file: %(path)r%(extra)s"""

class FileExists(PathError):

    """File exists: %(path)r%(extra)s"""

class DirectoryNotEmpty(PathError):

    """Directory not empty: %(path)r%(extra)s"""

class ResourceBusy(PathError):

    """Device or resource busy: %(path)r%(extra)s"""

class PermissionDenied(PathError):

    """Permission denied: %(path)r%(extra)s"""

class InvalidURL(PathError):

    """Invalid url supplied to transport: %(path)r%(extra)s"""

class InvalidURLJoin(PathError):

    """Invalid URL join request: %(args)s%(extra)s"""

    def __init__(self, msg, base, args):

        PathError.__init__(self, base, msg)

        self.args = [base] + list(args)

class UnsupportedProtocol(PathError):

    """Unsupported protocol for url "%(path)s"%(extra)s"""

    def __init__(self, url, extra):

        PathError.__init__(self, url, extra=extra)

class ShortReadvError(PathError):

    """readv() read %(actual)s bytes rather than %(length)s bytes at %(offset)s for %(path)s%(extra)s"""

    is_user_error = False

    def __init__(self, path, offset, length, actual, extra=None):

        PathError.__init__(self, path, extra=extra)

        self.offset = offset

        self.length = length

        self.actual = actual

class PathNotChild(BzrNewError):

    """Path %(path)r is not a child of path %(base)r%(extra)s"""

    is_user_error = False

    def __init__(self, path, base, extra=None):

        BzrNewError.__init__(self)

        self.path = path

        self.base = base

        if extra:

            self.extra = ': ' + str(extra)

        else:

            self.extra = ''

class InvalidNormalization(PathError):

    """Path %(path)r is not unicode normalized"""

# TODO: This is given a URL; we try to unescape it but doing that from inside

# the exception object is a bit undesirable.

# TODO: Probably this behavior of should be a common superclass 

class NotBranchError(PathError):

    """Not a branch: %(path)s"""

    def __init__(self, path):

       import bzrlib.urlutils as urlutils

       self.path = urlutils.unescape_for_display(path, 'ascii')

class AlreadyBranchError(PathError):

    """Already a branch: %(path)s."""

class BranchExistsWithoutWorkingTree(PathError):

    """Directory contains a branch, but no working tree \

(use bzr checkout if you wish to build a working tree): %(path)s"""

class AtomicFileAlreadyClosed(PathError):

    """'%(function)s' called on an AtomicFile after it was closed: %(path)s"""

    def __init__(self, path, function):

        PathError.__init__(self, path=path, extra=None)

        self.function = function

class InaccessibleParent(PathError):

    """Parent not accessible given base %(base)s and relative path %(path)s"""

    def __init__(self, path, base):

        PathError.__init__(self, path)

        self.base = base

class NoRepositoryPresent(BzrNewError):

    """No repository present: %(path)r"""

    def __init__(self, bzrdir):

        BzrNewError.__init__(self)

        self.path = bzrdir.transport.clone('..').base

class FileInWrongBranch(BzrNewError):

    """File %(path)s in not in branch %(branch_base)s."""

    def __init__(self, branch, path):

        BzrNewError.__init__(self)

        self.branch = branch

        self.branch_base = branch.base

        self.path = path

class UnsupportedFormatError(BzrNewError):

    """Unsupported branch format: %(format)s"""

class UnknownFormatError(BzrNewError):

    """Unknown branch format: %(format)r"""

class IncompatibleFormat(BzrNewError):

    """Format %(format)s is not compatible with .bzr version %(bzrdir)s."""

    def __init__(self, format, bzrdir_format):

        BzrNewError.__init__(self)

        self.format = format

        self.bzrdir = bzrdir_format

class NotVersionedError(BzrNewError):

    """%(path)s is not versioned"""

    def __init__(self, path):

        BzrNewError.__init__(self)

        self.path = path

class PathsNotVersionedError(BzrNewError):

    # used when reporting several paths are not versioned

    """Path(s) are not versioned: %(paths_as_string)s"""

    def __init__(self, paths):

        from bzrlib.osutils import quotefn

        BzrNewError.__init__(self)

        self.paths = paths

        self.paths_as_string = ' '.join([quotefn(p) for p in paths])

class PathsDoNotExist(BzrNewError):

    """Path(s) do not exist: %(paths_as_string)s"""

    # used when reporting that paths are neither versioned nor in the working

    # tree

    def __init__(self, paths):

        # circular import

        from bzrlib.osutils import quotefn

        BzrNewError.__init__(self)

        self.paths = paths

        self.paths_as_string = ' '.join([quotefn(p) for p in paths])

class BadFileKindError(BzrNewError):

    """Cannot operate on %(filename)s of unsupported kind %(kind)s"""

class ForbiddenControlFileError(BzrNewError):

    """Cannot operate on %(filename)s because it is a control file"""

class LockError(BzrNewError):

    """Lock error: %(message)s"""

    # All exceptions from the lock/unlock functions should be from

    # this exception class.  They will be translated as necessary. The

    # original exception is available as e.original_error

    #

    # New code should prefer to raise specific subclasses

    def __init__(self, message):

        self.message = message

class CommitNotPossible(LockError):

    """A commit was attempted but we do not have a write lock open."""

    def __init__(self):

        pass

class AlreadyCommitted(LockError):

    """A rollback was requested, but is not able to be accomplished."""

    def __init__(self):

        pass

class ReadOnlyError(LockError):

    """A write attempt was made in a read only transaction on %(obj)s"""

    def __init__(self, obj):

        self.obj = obj

class OutSideTransaction(BzrNewError):

    """A transaction related operation was attempted after the transaction finished."""

class ObjectNotLocked(LockError):

    """%(obj)r is not locked"""

    is_user_error = False

    # this can indicate that any particular object is not locked; see also

    # LockNotHeld which means that a particular *lock* object is not held by

    # the caller -- perhaps they should be unified.

    def __init__(self, obj):

        self.obj = obj

class ReadOnlyObjectDirtiedError(ReadOnlyError):

    """Cannot change object %(obj)r in read only transaction"""

    def __init__(self, obj):

        self.obj = obj

class UnlockableTransport(LockError):

    """Cannot lock: transport is read only: %(transport)s"""

    def __init__(self, transport):

        self.transport = transport

class LockContention(LockError):

    """Could not acquire lock %(lock)s"""

    # TODO: show full url for lock, combining the transport and relative bits?

    def __init__(self, lock):

        self.lock = lock

class LockBroken(LockError):

    """Lock was broken while still open: %(lock)s - check storage consistency!"""

    def __init__(self, lock):

        self.lock = lock

class LockBreakMismatch(LockError):

    """Lock was released and re-acquired before being broken: %(lock)s: held by %(holder)r, wanted to break %(target)r"""

    def __init__(self, lock, holder, target):

        self.lock = lock

        self.holder = holder

        self.target = target

class LockNotHeld(LockError):

    """Lock not held: %(lock)s"""

    def __init__(self, lock):

        self.lock = lock

class PointlessCommit(BzrNewError):

    """No changes to commit"""

class UpgradeReadonly(BzrNewError):

    """Upgrade URL cannot work with readonly URL's."""

class UpToDateFormat(BzrNewError):

    """The branch format %(format)s is already at the most recent format."""

    def __init__(self, format):

        BzrNewError.__init__(self)

        self.format = format

class StrictCommitFailed(Exception):

    """Commit refused because there are unknowns in the tree."""

class NoSuchRevision(BzrNewError):

    """Branch %(branch)s has no revision %(revision)s"""

    is_user_error = False

    def __init__(self, branch, revision):

        BzrNewError.__init__(self, branch=branch, revision=revision)

class NoSuchRevisionSpec(BzrNewError):

    """No namespace registered for string: %(spec)r"""

    def __init__(self, spec):

        BzrNewError.__init__(self, spec=spec)

class InvalidRevisionSpec(BzrNewError):

    """Requested revision: '%(spec)s' does not exist in branch:

%(branch)s%(extra)s"""

    def __init__(self, spec, branch, extra=None):

        BzrNewError.__init__(self, branch=branch, spec=spec)

        if extra:

            self.extra = '\n' + str(extra)

        else:

            self.extra = ''

class HistoryMissing(BzrError):

    def __init__(self, branch, object_type, object_id):

        self.branch = branch

        BzrError.__init__(self,

                          '%s is missing %s {%s}'

                          % (branch, object_type, object_id))

class DivergedBranches(BzrNewError):

    "These branches have diverged.  Use the merge command to reconcile them."""

    is_user_error = True

    def __init__(self, branch1, branch2):

        self.branch1 = branch1

        self.branch2 = branch2

class UnrelatedBranches(BzrNewError):

    "Branches have no common ancestor, and no merge base revision was specified."

    is_user_error = True

class NoCommonAncestor(BzrNewError):

    "Revisions have no common ancestor: %(revision_a)s %(revision_b)s"

    def __init__(self, revision_a, revision_b):

        self.revision_a = revision_a

        self.revision_b = revision_b

class NoCommonRoot(BzrError):

    def __init__(self, revision_a, revision_b):

        msg = "Revisions are not derived from the same root: %s %s." \

            % (revision_a, revision_b) 

        BzrError.__init__(self, msg)

class NotAncestor(BzrError):

    def __init__(self, rev_id, not_ancestor_id):

        msg = "Revision %s is not an ancestor of %s" % (not_ancestor_id, 

                                                        rev_id)

        BzrError.__init__(self, msg)

        self.rev_id = rev_id

        self.not_ancestor_id = not_ancestor_id

class InstallFailed(BzrError):

    def __init__(self, revisions):

        msg = "Could not install revisions:\n%s" % " ,".join(revisions)

        BzrError.__init__(self, msg)

        self.revisions = revisions

class AmbiguousBase(BzrError):

    def __init__(self, bases):

        warn("BzrError AmbiguousBase has been deprecated as of bzrlib 0.8.",

                DeprecationWarning)

        msg = "The correct base is unclear, because %s are all equally close" %\

            ", ".join(bases)

        BzrError.__init__(self, msg)

        self.bases = bases

class NoCommits(BzrNewError):

    """Branch %(branch)s has no commits."""

    def __init__(self, branch):

        BzrNewError.__init__(self, branch=branch)

class UnlistableStore(BzrError):

    def __init__(self, store):

        BzrError.__init__(self, "Store %s is not listable" % store)

class UnlistableBranch(BzrError):

    def __init__(self, br):

        BzrError.__init__(self, "Stores for branch %s are not listable" % br)

class BoundBranchOutOfDate(BzrNewError):

    """Bound branch %(branch)s is out of date with master branch %(master)s."""

    def __init__(self, branch, master):

        BzrNewError.__init__(self)

        self.branch = branch

        self.master = master

class CommitToDoubleBoundBranch(BzrNewError):

    """Cannot commit to branch %(branch)s. It is bound to %(master)s, which is bound to %(remote)s."""

    def __init__(self, branch, master, remote):

        BzrNewError.__init__(self)

        self.branch = branch

        self.master = master

        self.remote = remote

class OverwriteBoundBranch(BzrNewError):

    """Cannot pull --overwrite to a branch which is bound %(branch)s"""

    def __init__(self, branch):

        BzrNewError.__init__(self)

        self.branch = branch

class BoundBranchConnectionFailure(BzrNewError):

    """Unable to connect to target of bound branch %(branch)s => %(target)s: %(error)s"""

    def __init__(self, branch, target, error):

        BzrNewError.__init__(self)

        self.branch = branch

        self.target = target

        self.error = error

class WeaveError(BzrNewError):

    """Error in processing weave: %(message)s"""

    def __init__(self, message=None):

        BzrNewError.__init__(self)

        self.message = message

class WeaveRevisionAlreadyPresent(WeaveError):

    """Revision {%(revision_id)s} already present in %(weave)s"""

    def __init__(self, revision_id, weave):

        WeaveError.__init__(self)

        self.revision_id = revision_id

        self.weave = weave

class WeaveRevisionNotPresent(WeaveError):

    """Revision {%(revision_id)s} not present in %(weave)s"""

    def __init__(self, revision_id, weave):

        WeaveError.__init__(self)

        self.revision_id = revision_id

        self.weave = weave

class WeaveFormatError(WeaveError):

    """Weave invariant violated: %(what)s"""

    def __init__(self, what):

        WeaveError.__init__(self)

        self.what = what

class WeaveParentMismatch(WeaveError):

    """Parents are mismatched between two revisions."""

class WeaveInvalidChecksum(WeaveError):

    """Text did not match it's checksum: %(message)s"""

class WeaveTextDiffers(WeaveError):

    """Weaves differ on text content. Revision: {%(revision_id)s}, %(weave_a)s, %(weave_b)s"""

    def __init__(self, revision_id, weave_a, weave_b):

        WeaveError.__init__(self)

        self.revision_id = revision_id

        self.weave_a = weave_a

        self.weave_b = weave_b