~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005 Canonical Ltd

# 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

import sys

import os

import errno

from warnings import warn

from cStringIO import StringIO

import bzrlib

from bzrlib.inventory import InventoryEntry

import bzrlib.inventory as inventory

from bzrlib.trace import mutter, note

from bzrlib.osutils import (isdir, quotefn, compact_date, rand_bytes, 

                            rename, splitpath, sha_file, appendpath, 

                            file_kind)

import bzrlib.errors as errors

from bzrlib.errors import (BzrError, InvalidRevisionNumber, InvalidRevisionId,

                           NoSuchRevision, HistoryMissing, NotBranchError,

                           DivergedBranches, LockError, UnlistableStore,

                           UnlistableBranch, NoSuchFile)

from bzrlib.textui import show_status

from bzrlib.revision import Revision

from bzrlib.delta import compare_trees

from bzrlib.tree import EmptyTree, RevisionTree

from bzrlib.inventory import Inventory

from bzrlib.store import copy_all

from bzrlib.store.compressed_text import CompressedTextStore

from bzrlib.store.text import TextStore

from bzrlib.store.weave import WeaveStore

import bzrlib.transactions as transactions

from bzrlib.transport import Transport, get_transport

import bzrlib.xml5

import bzrlib.ui

BZR_BRANCH_FORMAT_4 = "Bazaar-NG branch, format 0.0.4\n"

BZR_BRANCH_FORMAT_5 = "Bazaar-NG branch, format 5\n"

BZR_BRANCH_FORMAT_6 = "Bazaar-NG branch, format 6\n"

## TODO: Maybe include checks for common corruption of newlines, etc?

# TODO: Some operations like log might retrieve the same revisions

# repeatedly to calculate deltas.  We could perhaps have a weakref

# cache in memory to make this faster.  In general anything can be

# cached in memory between lock and unlock operations.

def find_branch(*ignored, **ignored_too):

    # XXX: leave this here for about one release, then remove it

    raise NotImplementedError('find_branch() is not supported anymore, '

                              'please use one of the new branch constructors')

def _relpath(base, path):

    """Return path relative to base, or raise exception.

    The path may be either an absolute path or a path relative to the

    current working directory.

    Lifted out of Branch.relpath for ease of testing.

    os.path.commonprefix (python2.4) has a bad bug that it works just

    on string prefixes, assuming that '/u' is a prefix of '/u2'.  This

    avoids that problem."""

    rp = os.path.abspath(path)

    s = []

    head = rp

    while len(head) >= len(base):

        if head == base:

            break

        head, tail = os.path.split(head)

        if tail:

            s.insert(0, tail)

    else:

        raise NotBranchError("path %r is not within branch %r" % (rp, base))

    return os.sep.join(s)

def find_branch_root(t):

    """Find the branch root enclosing the transport's base.

    t is a Transport object.

    It is not necessary that the base of t exists.

    Basically we keep looking up until we find the control directory or

    run into the root.  If there isn't one, raises NotBranchError.

    """

    orig_base = t.base

    while True:

        if t.has(bzrlib.BZRDIR):

            return t

        new_t = t.clone('..')

        if new_t.base == t.base:

            # reached the root, whatever that may be

            raise NotBranchError('%s is not in a branch' % orig_base)

        t = new_t

######################################################################

# branch objects

class Branch(object):

    """Branch holding a history of revisions.

    base

        Base directory/url of the branch.

    """

    base = None

    def __init__(self, *ignored, **ignored_too):

        raise NotImplementedError('The Branch class is abstract')

    @staticmethod

    def open_downlevel(base):

        """Open a branch which may be of an old format.

        Only local branches are supported."""

        return _Branch(get_transport(base), relax_version_check=True)

    @staticmethod

    def open(base):

        """Open an existing branch, rooted at 'base' (url)"""

        t = get_transport(base)

        mutter("trying to open %r with transport %r", base, t)

        return _Branch(t)

    @staticmethod

    def open_containing(url):

        """Open an existing branch which contains url.

        This probes for a branch at url, and searches upwards from there.

        """

        t = get_transport(url)

        t = find_branch_root(t)

        return _Branch(t)

    @staticmethod

    def initialize(base):

        """Create a new branch, rooted at 'base' (url)"""

        t = get_transport(base)

        return _Branch(t, init=True)

    def setup_caching(self, cache_root):

        """Subclasses that care about caching should override this, and set

        up cached stores located under cache_root.

        """

        self.cache_root = cache_root

class _Branch(Branch):

    """A branch stored in the actual filesystem.

    Note that it's "local" in the context of the filesystem; it doesn't

    really matter if it's on an nfs/smb/afs/coda/... share, as long as

    it's writable, and can be accessed via the normal filesystem API.

    _lock_mode

        None, or 'r' or 'w'

    _lock_count

        If _lock_mode is true, a positive count of the number of times the

        lock has been taken.

    _lock

        Lock object from bzrlib.lock.

    """

    # We actually expect this class to be somewhat short-lived; part of its

    # purpose is to try to isolate what bits of the branch logic are tied to

    # filesystem access, so that in a later step, we can extricate them to

    # a separarte ("storage") class.

    _lock_mode = None

    _lock_count = None

    _lock = None

    _inventory_weave = None

    # Map some sort of prefix into a namespace

    # stuff like "revno:10", "revid:", etc.

    # This should match a prefix with a function which accepts

    REVISION_NAMESPACES = {}

    def push_stores(self, branch_to):

        """Copy the content of this branches store to branch_to."""

        if (self._branch_format != branch_to._branch_format

            or self._branch_format != 4):

            from bzrlib.fetch import greedy_fetch

            mutter("falling back to fetch logic to push between %s(%s) and %s(%s)",

                   self, self._branch_format, branch_to, branch_to._branch_format)

            greedy_fetch(to_branch=branch_to, from_branch=self,

                         revision=self.last_revision())

            return

        store_pairs = ((self.text_store,      branch_to.text_store),

                       (self.inventory_store, branch_to.inventory_store),

                       (self.revision_store,  branch_to.revision_store))

        try:

            for from_store, to_store in store_pairs: 

                copy_all(from_store, to_store)

        except UnlistableStore:

            raise UnlistableBranch(from_store)

    def __init__(self, transport, init=False,

                 relax_version_check=False):

        """Create new branch object at a particular location.

        transport -- A Transport object, defining how to access files.

                (If a string, transport.transport() will be used to

                create a Transport object)

        init -- If True, create new control files in a previously

             unversioned directory.  If False, the branch must already

             be versioned.

        relax_version_check -- If true, the usual check for the branch

            version is not applied.  This is intended only for

            upgrade/recovery type use; it's not guaranteed that

            all operations will work on old format branches.

        In the test suite, creation of new trees is tested using the

        `ScratchBranch` class.

        """

        assert isinstance(transport, Transport), \

            "%r is not a Transport" % transport

        self._transport = transport

        if init:

            self._make_control()

        self._check_format(relax_version_check)

        def get_store(name, compressed=True, prefixed=False):

            # FIXME: This approach of assuming stores are all entirely compressed

            # or entirely uncompressed is tidy, but breaks upgrade from 

            # some existing branches where there's a mixture; we probably 

            # still want the option to look for both.

            relpath = self._rel_controlfilename(name)

            if compressed:

                store = CompressedTextStore(self._transport.clone(relpath),

                                            prefixed=prefixed)

            else:

                store = TextStore(self._transport.clone(relpath),

                                  prefixed=prefixed)

            #if self._transport.should_cache():

            #    cache_path = os.path.join(self.cache_root, name)

            #    os.mkdir(cache_path)

            #    store = bzrlib.store.CachedStore(store, cache_path)

            return store

        def get_weave(name, prefixed=False):

            relpath = self._rel_controlfilename(name)

            ws = WeaveStore(self._transport.clone(relpath), prefixed=prefixed)

            if self._transport.should_cache():

                ws.enable_cache = True

            return ws

        if self._branch_format == 4:

            self.inventory_store = get_store('inventory-store')

            self.text_store = get_store('text-store')

            self.revision_store = get_store('revision-store')

        elif self._branch_format == 5:

            self.control_weaves = get_weave([])

            self.weave_store = get_weave('weaves')

            self.revision_store = get_store('revision-store', compressed=False)

        elif self._branch_format == 6:

            self.control_weaves = get_weave([])

            self.weave_store = get_weave('weaves', prefixed=True)

            self.revision_store = get_store('revision-store', compressed=False,

                                            prefixed=True)

        self._transaction = None

    def __str__(self):

        return '%s(%r)' % (self.__class__.__name__, self._transport.base)

    __repr__ = __str__

    def __del__(self):

        if self._lock_mode or self._lock:

            # XXX: This should show something every time, and be suitable for

            # headless operation and embedding

            warn("branch %r was not explicitly unlocked" % self)

            self._lock.unlock()

        # TODO: It might be best to do this somewhere else,

        # but it is nice for a Branch object to automatically

        # cache it's information.

        # Alternatively, we could have the Transport objects cache requests

        # See the earlier discussion about how major objects (like Branch)

        # should never expect their __del__ function to run.

        if hasattr(self, 'cache_root') and self.cache_root is not None:

            try:

                import shutil

                shutil.rmtree(self.cache_root)

            except:

                pass

            self.cache_root = None

    def _get_base(self):

        if self._transport:

            return self._transport.base

        return None

    base = property(_get_base)

    def _finish_transaction(self):

        """Exit the current transaction."""

        if self._transaction is None:

            raise errors.LockError('Branch %s is not in a transaction' %

                                   self)

        transaction = self._transaction

        self._transaction = None

        transaction.finish()

    def get_transaction(self):

        """Return the current active transaction.

        If no transaction is active, this returns a passthrough object

        for which all data is immedaitely flushed and no caching happens.

        """

        if self._transaction is None:

            return transactions.PassThroughTransaction()

        else:

            return self._transaction

    def _set_transaction(self, new_transaction):

        """Set a new active transaction."""

        if self._transaction is not None:

            raise errors.LockError('Branch %s is in a transaction already.' %

                                   self)

        self._transaction = new_transaction

    def lock_write(self):

        mutter("lock write: %s (%s)", self, self._lock_count)

        # TODO: Upgrade locking to support using a Transport,

        # and potentially a remote locking protocol

        if self._lock_mode:

            if self._lock_mode != 'w':

                raise LockError("can't upgrade to a write lock from %r" %

                                self._lock_mode)

            self._lock_count += 1

        else:

            self._lock = self._transport.lock_write(

                    self._rel_controlfilename('branch-lock'))

            self._lock_mode = 'w'

            self._lock_count = 1

            self._set_transaction(transactions.PassThroughTransaction())

    def lock_read(self):

        mutter("lock read: %s (%s)", self, self._lock_count)

        if self._lock_mode:

            assert self._lock_mode in ('r', 'w'), \

                   "invalid lock mode %r" % self._lock_mode

            self._lock_count += 1

        else:

            self._lock = self._transport.lock_read(

                    self._rel_controlfilename('branch-lock'))

            self._lock_mode = 'r'

            self._lock_count = 1

            self._set_transaction(transactions.ReadOnlyTransaction())

            # 5K may be excessive, but hey, its a knob.

            self.get_transaction().set_cache_size(5000)

    def unlock(self):

        mutter("unlock: %s (%s)", self, self._lock_count)

        if not self._lock_mode:

            raise LockError('branch %r is not locked' % (self))

        if self._lock_count > 1:

            self._lock_count -= 1

        else:

            self._finish_transaction()

            self._lock.unlock()

            self._lock = None

            self._lock_mode = self._lock_count = None

    def abspath(self, name):

        """Return absolute filename for something in the branch"""

        return self._transport.abspath(name)

    def relpath(self, path):

        """Return path relative to this branch of something inside it.

        Raises an error if path is not in this branch."""

        return self._transport.relpath(path)

    def _rel_controlfilename(self, file_or_path):

        if isinstance(file_or_path, basestring):

            file_or_path = [file_or_path]

        return [bzrlib.BZRDIR] + file_or_path

    def controlfilename(self, file_or_path):

        """Return location relative to branch."""

        return self._transport.abspath(self._rel_controlfilename(file_or_path))

    def controlfile(self, file_or_path, mode='r'):

        """Open a control file for this branch.

        There are two classes of file in the control directory: text

        and binary.  binary files are untranslated byte streams.  Text

        control files are stored with Unix newlines and in UTF-8, even

        if the platform or locale defaults are different.

        Controlfiles should almost never be opened in write mode but

        rather should be atomically copied and replaced using atomicfile.

        """

        import codecs

        relpath = self._rel_controlfilename(file_or_path)

        #TODO: codecs.open() buffers linewise, so it was overloaded with

        # a much larger buffer, do we need to do the same for getreader/getwriter?

        if mode == 'rb': 

            return self._transport.get(relpath)

        elif mode == 'wb':

            raise BzrError("Branch.controlfile(mode='wb') is not supported, use put_controlfiles")

        elif mode == 'r':

            return codecs.getreader('utf-8')(self._transport.get(relpath), errors='replace')

        elif mode == 'w':

            raise BzrError("Branch.controlfile(mode='w') is not supported, use put_controlfiles")

        else:

            raise BzrError("invalid controlfile mode %r" % mode)

    def put_controlfile(self, path, f, encode=True):

        """Write an entry as a controlfile.

        :param path: The path to put the file, relative to the .bzr control

                     directory

        :param f: A file-like or string object whose contents should be copied.

        :param encode:  If true, encode the contents as utf-8

        """

        self.put_controlfiles([(path, f)], encode=encode)

    def put_controlfiles(self, files, encode=True):

        """Write several entries as controlfiles.

        :param files: A list of [(path, file)] pairs, where the path is the directory

                      underneath the bzr control directory

        :param encode:  If true, encode the contents as utf-8

        """

        import codecs

        ctrl_files = []

        for path, f in files:

            if encode:

                if isinstance(f, basestring):

                    f = f.encode('utf-8', 'replace')

                else:

                    f = codecs.getwriter('utf-8')(f, errors='replace')

            path = self._rel_controlfilename(path)

            ctrl_files.append((path, f))

        self._transport.put_multi(ctrl_files)

    def _make_control(self):

        from bzrlib.inventory import Inventory

        from bzrlib.weavefile import write_weave_v5

        from bzrlib.weave import Weave

        # Create an empty inventory

        sio = StringIO()

        # if we want per-tree root ids then this is the place to set

        # them; they're not needed for now and so ommitted for

        # simplicity.

        bzrlib.xml5.serializer_v5.write_inventory(Inventory(), sio)

        empty_inv = sio.getvalue()

        sio = StringIO()

        bzrlib.weavefile.write_weave_v5(Weave(), sio)

        empty_weave = sio.getvalue()

        dirs = [[], 'revision-store', 'weaves']

        files = [('README', 

            "This is a Bazaar-NG control directory.\n"

            "Do not change any files in this directory.\n"),

            ('branch-format', BZR_BRANCH_FORMAT_6),

            ('revision-history', ''),

            ('branch-name', ''),

            ('branch-lock', ''),

            ('pending-merges', ''),

            ('inventory', empty_inv),

            ('inventory.weave', empty_weave),

            ('ancestry.weave', empty_weave)

        ]

        cfn = self._rel_controlfilename

        self._transport.mkdir_multi([cfn(d) for d in dirs])

        self.put_controlfiles(files)

        mutter('created control directory in ' + self._transport.base)

    def _check_format(self, relax_version_check):

        """Check this branch format is supported.

        The format level is stored, as an integer, in

        self._branch_format for code that needs to check it later.

        In the future, we might need different in-memory Branch

        classes to support downlevel branches.  But not yet.

        """

        try:

            fmt = self.controlfile('branch-format', 'r').read()

        except NoSuchFile:

            raise NotBranchError(self.base)

        mutter("got branch format %r", fmt)

        if fmt == BZR_BRANCH_FORMAT_6:

            self._branch_format = 6

        elif fmt == BZR_BRANCH_FORMAT_5:

            self._branch_format = 5

        elif fmt == BZR_BRANCH_FORMAT_4:

            self._branch_format = 4

        if (not relax_version_check

            and self._branch_format not in (5, 6)):

            raise errors.UnsupportedFormatError(

                           'sorry, branch format %r not supported' % fmt,

                           ['use a different bzr version',

                            'or remove the .bzr directory'

                            ' and "bzr init" again'])

    def get_root_id(self):

        """Return the id of this branches root"""

        inv = self.read_working_inventory()

        return inv.root.file_id

    def set_root_id(self, file_id):

        inv = self.read_working_inventory()

        orig_root_id = inv.root.file_id

        del inv._byid[inv.root.file_id]

        inv.root.file_id = file_id

        inv._byid[inv.root.file_id] = inv.root

        for fid in inv:

            entry = inv[fid]

            if entry.parent_id in (None, orig_root_id):

                entry.parent_id = inv.root.file_id

        self._write_inventory(inv)

    def read_working_inventory(self):

        """Read the working inventory."""

        self.lock_read()

        try:

            # ElementTree does its own conversion from UTF-8, so open in

            # binary.

            f = self.controlfile('inventory', 'rb')

            return bzrlib.xml5.serializer_v5.read_inventory(f)

        finally:

            self.unlock()

    def _write_inventory(self, inv):

        """Update the working inventory.

        That is to say, the inventory describing changes underway, that

        will be committed to the next revision.

        """

        from cStringIO import StringIO

        self.lock_write()

        try:

            sio = StringIO()

            bzrlib.xml5.serializer_v5.write_inventory(inv, sio)

            sio.seek(0)

            # Transport handles atomicity

            self.put_controlfile('inventory', sio)

        finally:

            self.unlock()

        mutter('wrote working inventory')

    inventory = property(read_working_inventory, _write_inventory, None,

                         """Inventory for the working copy.""")

    def add(self, files, ids=None):

        """Make files versioned.

        Note that the command line normally calls smart_add instead,

        which can automatically recurse.

        This puts the files in the Added state, so that they will be

        recorded by the next commit.

        files

            List of paths to add, relative to the base of the tree.

        ids

            If set, use these instead of automatically generated ids.

            Must be the same length as the list of files, but may

            contain None for ids that are to be autogenerated.

        TODO: Perhaps have an option to add the ids even if the files do

              not (yet) exist.

        TODO: Perhaps yield the ids and paths as they're added.

        """

        # TODO: Re-adding a file that is removed in the working copy

        # should probably put it back with the previous ID.

        if isinstance(files, basestring):

            assert(ids is None or isinstance(ids, basestring))

            files = [files]

            if ids is not None:

                ids = [ids]

        if ids is None:

            ids = [None] * len(files)

        else:

            assert(len(ids) == len(files))

        self.lock_write()

        try:

            inv = self.read_working_inventory()

            for f,file_id in zip(files, ids):

                if is_control_file(f):

                    raise BzrError("cannot add control file %s" % quotefn(f))

                fp = splitpath(f)

                if len(fp) == 0:

                    raise BzrError("cannot add top-level %r" % f)

                fullpath = os.path.normpath(self.abspath(f))

                try:

                    kind = file_kind(fullpath)

                except OSError:

                    # maybe something better?

                    raise BzrError('cannot add: not a regular file, symlink or directory: %s' % quotefn(f))

                if not InventoryEntry.versionable_kind(kind):

                    raise BzrError('cannot add: not a versionable file ('

                                   'i.e. regular file, symlink or directory): %s' % quotefn(f))

                if file_id is None:

                    file_id = gen_file_id(f)

                inv.add_path(f, kind=kind, file_id=file_id)

                mutter("add file %s file_id:{%s} kind=%r" % (f, file_id, kind))

            self._write_inventory(inv)

        finally:

            self.unlock()

    def print_file(self, file, revno):

        """Print `file` to stdout."""

        self.lock_read()

        try:

            tree = self.revision_tree(self.get_rev_id(revno))

            # use inventory as it was in that revision

            file_id = tree.inventory.path2id(file)

            if not file_id:

                raise BzrError("%r is not present in revision %s" % (file, revno))

            tree.print_file(file_id)

        finally:

            self.unlock()

    def remove(self, files, verbose=False):

        """Mark nominated files for removal from the inventory.

        This does not remove their text.  This does not run on 

        TODO: Refuse to remove modified files unless --force is given?