~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2005, 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

from __future__ import absolute_import

# XXX: Some consideration of the problems that might occur if there are

# files whose id differs only in case.  That should probably be forbidden.

import os

from warnings import warn

from bzrlib import (

    errors,

    osutils,

    )

from bzrlib.store import TransportStore

from bzrlib.trace import mutter

import bzrlib.ui

class VersionedFileStore(TransportStore):

    """Collection of many versioned files in a transport."""

    # TODO: Rather than passing versionedfile_kwargs, perhaps pass in a

    # transport factory callable?

    def __init__(self, transport, prefixed=False, precious=False,

                 dir_mode=None, file_mode=None,

                 versionedfile_class=None,

                 versionedfile_kwargs={},

                 escaped=False):

        super(VersionedFileStore, self).__init__(transport,

                dir_mode=dir_mode, file_mode=file_mode,

                prefixed=prefixed, compressed=False, escaped=escaped)

        self._precious = precious

        self._versionedfile_class = versionedfile_class

        self._versionedfile_kwargs = versionedfile_kwargs

        # Used for passing get_scope to versioned file constructors;

        self.get_scope = None

    def filename(self, file_id):

        """Return the path relative to the transport root."""

        return self._relpath(file_id)

    def __iter__(self):

        suffixes = self._versionedfile_class.get_suffixes()

        ids = set()

        for relpath in self._iter_files_recursive():

            for suffix in suffixes:

                if relpath.endswith(suffix):

                    # TODO: use standard remove_suffix function

                    escaped_id = os.path.basename(relpath[:-len(suffix)])

                    file_id = self._mapper.unmap(escaped_id)[0]

                    if file_id not in ids:

                        ids.add(file_id)

                        yield file_id

                    break # only one suffix can match

    def has_id(self, file_id):

        suffixes = self._versionedfile_class.get_suffixes()

        filename = self.filename(file_id)

        for suffix in suffixes:

            if not self._transport.has(filename + suffix):

                return False

        return True

    def get_empty(self, file_id, transaction):

        """Get an empty weave, which implies deleting the existing one first."""

        if self.has_id(file_id):

            self.delete(file_id, transaction)

        return self.get_weave_or_empty(file_id, transaction)

    def delete(self, file_id, transaction):

        """Remove file_id from the store."""

        suffixes = self._versionedfile_class.get_suffixes()

        filename = self.filename(file_id)

        for suffix in suffixes:

            self._transport.delete(filename + suffix)

    def _get(self, file_id):

        return self._transport.get(self.filename(file_id))

    def _put(self, file_id, f):

        fn = self.filename(file_id)

        try:

            return self._transport.put_file(fn, f, mode=self._file_mode)

        except errors.NoSuchFile:

            if not self._prefixed:

                raise

            self._transport.mkdir(os.path.dirname(fn), mode=self._dir_mode)

            return self._transport.put_file(fn, f, mode=self._file_mode)

    def get_weave(self, file_id, transaction, _filename=None):

        """Return the VersionedFile for file_id.

        :param _filename: filename that would be returned from self.filename for

        file_id. This is used to reduce duplicate filename calculations when

        using 'get_weave_or_empty'. FOR INTERNAL USE ONLY.

        """

        if _filename is None:

            _filename = self.filename(file_id)

        if transaction.writeable():

            w = self._versionedfile_class(_filename, self._transport, self._file_mode,

                get_scope=self.get_scope, **self._versionedfile_kwargs)

        else:

            w = self._versionedfile_class(_filename,

                                          self._transport,

                                          self._file_mode,

                                          create=False,

                                          access_mode='r',

                                          get_scope=self.get_scope,

                                          **self._versionedfile_kwargs)

        return w

    def _make_new_versionedfile(self, file_id, transaction,

        known_missing=False, _filename=None):

        """Make a new versioned file.

        :param _filename: filename that would be returned from self.filename for

        file_id. This is used to reduce duplicate filename calculations when

        using 'get_weave_or_empty'. FOR INTERNAL USE ONLY.

        """

        if not known_missing and self.has_id(file_id):

            self.delete(file_id, transaction)

        if _filename is None:

            _filename = self.filename(file_id)

        try:

            # we try without making the directory first because thats optimising

            # for the common case.

            weave = self._versionedfile_class(_filename, self._transport, self._file_mode, create=True,

                get_scope=self.get_scope, **self._versionedfile_kwargs)

        except errors.NoSuchFile:

            if not self._prefixed:

                # unexpected error - NoSuchFile is expected to be raised on a

                # missing dir only and that only occurs when we are prefixed.

                raise

            dirname = osutils.dirname(_filename)

            self._transport.mkdir(dirname, mode=self._dir_mode)

            weave = self._versionedfile_class(_filename, self._transport,

                                              self._file_mode, create=True,

                                              get_scope=self.get_scope,

                                              **self._versionedfile_kwargs)

        return weave

    def get_weave_or_empty(self, file_id, transaction):

        """Return a weave, or an empty one if it doesn't exist."""

        # This is typically used from 'commit' and 'fetch/push/pull' where

        # we scan across many versioned files once. As such the small overhead

        # of calculating the filename before doing a cache lookup is more than

        # compensated for by not calculating the filename when making new

        # versioned files.

        _filename = self.filename(file_id)

        try:

            return self.get_weave(file_id, transaction, _filename=_filename)

        except errors.NoSuchFile:

            weave = self._make_new_versionedfile(file_id, transaction,

                known_missing=True, _filename=_filename)

            return weave

    def _put_weave(self, file_id, weave, transaction):

        """Preserved here for upgrades-to-weaves to use."""

        myweave = self._make_new_versionedfile(file_id, transaction)

        myweave.insert_record_stream(weave.get_record_stream(

            [(version,) for version in weave.versions()],

            'topological', False))

    def copy_all_ids(self, store_from, pb=None, from_transaction=None,

                     to_transaction=None):

        """Copy all the file ids from store_from into self."""

        if from_transaction is None:

            warn("Please pass from_transaction into "

                 "versioned_store.copy_all_ids.", stacklevel=2)

        if to_transaction is None:

            warn("Please pass to_transaction into "

                 "versioned_store.copy_all_ids.", stacklevel=2)

        if not store_from.listable():

            raise errors.UnlistableStore(store_from)

        ids = []

        for count, file_id in enumerate(store_from):

            if pb:

                pb.update('listing files', count, count)

            ids.append(file_id)

        if pb:

            pb.clear()

        mutter('copy_all ids: %r', ids)

        self.copy_multi(store_from, ids, pb=pb,

                        from_transaction=from_transaction,

                        to_transaction=to_transaction)

    def copy_multi(self, from_store, file_ids, pb=None, from_transaction=None,

                   to_transaction=None):

        """Copy all the versions for multiple file_ids from from_store.

        :param from_transaction: required current transaction in from_store.

        """

        from bzrlib.transactions import PassThroughTransaction

        if from_transaction is None:

            warn("VersionedFileStore.copy_multi without a from_transaction parameter "

                 "is deprecated. Please provide a from_transaction.",

                 DeprecationWarning,

                 stacklevel=2)

            # we are reading one object - caching is irrelevant.

            from_transaction = PassThroughTransaction()

        if to_transaction is None:

            warn("VersionedFileStore.copy_multi without a to_transaction parameter "

                 "is deprecated. Please provide a to_transaction.",

                 DeprecationWarning,

                 stacklevel=2)

            # we are copying single objects, and there may be open tranasactions

            # so again with the passthrough

            to_transaction = PassThroughTransaction()

        pb = bzrlib.ui.ui_factory.nested_progress_bar()

        try:

            for count, f in enumerate(file_ids):

                mutter("copy weave {%s} into %s", f, self)

                pb.update('copy', count, len(file_ids))

                # if we have it in cache, its faster.

                # joining is fast with knits, and bearable for weaves -

                # indeed the new case can be optimised if needed.

                target = self._make_new_versionedfile(f, to_transaction)

                source = from_store.get_weave(f, from_transaction)

                target.insert_record_stream(source.get_record_stream(

                    [(version,) for version in source.versions()],

                    'topological', False))

        finally:

            pb.finished()

    def total_size(self):

        count, bytes =  super(VersionedFileStore, self).total_size()

        return (count / len(self._versionedfile_class.get_suffixes())), bytes