/brz/remove-bazaar

# Copyright (C) 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

"""MemoryTree object.

See MemoryTree for more details.

"""

from __future__ import absolute_import

import os

import stat

from . import (

    errors,

    lock,

    revision as _mod_revision,

    )

from .bzr.inventory import Inventory

from .bzr.inventorytree import MutableInventoryTree

from .osutils import sha_file

from .transport.memory import MemoryTransport

class MemoryTree(MutableInventoryTree):

    """A MemoryTree is a specialisation of MutableTree.

    It maintains nearly no state outside of read_lock and write_lock

    transactions. (it keeps a reference to the branch, and its last-revision

    only).

    """

    def __init__(self, branch, revision_id):

        """Construct a MemoryTree for branch using revision_id."""

        self.branch = branch

        self.controldir = branch.controldir

        self._branch_revision_id = revision_id

        self._locks = 0

        self._lock_mode = None

    def supports_symlinks(self):

        return True

    def get_config_stack(self):

        return self.branch.get_config_stack()

    def is_control_filename(self, filename):

        # Memory tree doesn't have any control filenames

        return False

    def _add(self, files, ids, kinds):

        """See MutableTree._add."""

        with self.lock_tree_write():

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

                if kind is None:

                    st_mode = self._file_transport.stat(f).st_mode

                    if stat.S_ISREG(st_mode):

                        kind = 'file'

                    elif stat.S_ISLNK(st_mode):

                        kind = 'symlink'

                    elif stat.S_ISDIR(st_mode):

                        kind = 'directory'

                    else:

                        raise AssertionError('Unknown file kind')

                if file_id is None:

                    self._inventory.add_path(f, kind=kind)

                else:

                    self._inventory.add_path(f, kind=kind, file_id=file_id)

    def basis_tree(self):

        """See Tree.basis_tree()."""

        return self._basis_tree

    @staticmethod

    def create_on_branch(branch):

        """Create a MemoryTree for branch, using the last-revision of branch."""

        revision_id = _mod_revision.ensure_null(branch.last_revision())

        return MemoryTree(branch, revision_id)

    def _gather_kinds(self, files, kinds):

        """See MutableTree._gather_kinds.

        This implementation does not care about the file kind of

        missing files, so is a no-op.

        """

    def get_file(self, path):

        """See Tree.get_file."""

        return self._file_transport.get(path)

    def get_file_sha1(self, path, stat_value=None):

        """See Tree.get_file_sha1()."""

        stream = self._file_transport.get(path)

        return sha_file(stream)

    def _comparison_data(self, entry, path):

        """See Tree._comparison_data."""

        if entry is None:

            return None, False, None

        return entry.kind, entry.executable, None

    def rename_one(self, from_rel, to_rel):

        with self.lock_tree_write():

            file_id = self.path2id(from_rel)

            to_dir, to_tail = os.path.split(to_rel)

            to_parent_id = self.path2id(to_dir)

            self._file_transport.move(from_rel, to_rel)

            self._inventory.rename(file_id, to_parent_id, to_tail)

    def path_content_summary(self, path):

        """See Tree.path_content_summary."""

        id = self.path2id(path)

        if id is None:

            return 'missing', None, None, None

        kind = self.kind(path, id)

        if kind == 'file':

            bytes = self._file_transport.get_bytes(path)

            size = len(bytes)

            executable = self._inventory[id].executable

            sha1 = None  # no stat cache

            return (kind, size, executable, sha1)

        elif kind == 'directory':

            # memory tree does not support nested trees yet.

            return kind, None, None, None

        elif kind == 'symlink':

            return kind, None, None, self._inventory[id].symlink_target

        else:

            raise NotImplementedError('unknown kind')

    def get_parent_ids(self):

        """See Tree.get_parent_ids.

        This implementation returns the current cached value from

            self._parent_ids.

        """

        with self.lock_read():

            return list(self._parent_ids)

    def has_filename(self, filename):

        """See Tree.has_filename()."""

        return self._file_transport.has(filename)

    def is_executable(self, path):

        return self._inventory.get_entry_by_path(path).executable

    def kind(self, path):

        return self._inventory.get_entry_by_path(path).kind

    def mkdir(self, path, file_id=None):

        """See MutableTree.mkdir()."""

        self.add(path, file_id, 'directory')

        if file_id is None:

            file_id = self.path2id(path)

        self._file_transport.mkdir(path)

        return file_id

    def last_revision(self):

        """See MutableTree.last_revision."""

        with self.lock_read():

            return self._branch_revision_id

    def lock_read(self):

        """Lock the memory tree for reading.

        This triggers population of data from the branch for its revision.

        """

        self._locks += 1

        try:

            if self._locks == 1:

                self.branch.lock_read()

                self._lock_mode = "r"

                self._populate_from_branch()

            return lock.LogicalLockResult(self.unlock)

        except BaseException:

            self._locks -= 1

            raise

    def lock_tree_write(self):

        """See MutableTree.lock_tree_write()."""

        self._locks += 1

        try:

            if self._locks == 1:

                self.branch.lock_read()

                self._lock_mode = "w"

                self._populate_from_branch()

            elif self._lock_mode == "r":

                raise errors.ReadOnlyError(self)

        except BaseException:

            self._locks -= 1

            raise

        return lock.LogicalLockResult(self.unlock)

    def lock_write(self):

        """See MutableTree.lock_write()."""

        self._locks += 1

        try:

            if self._locks == 1:

                self.branch.lock_write()

                self._lock_mode = "w"

                self._populate_from_branch()

            elif self._lock_mode == "r":

                raise errors.ReadOnlyError(self)

            return lock.LogicalLockResult(self.unlock)

        except BaseException:

            self._locks -= 1

            raise

    def _populate_from_branch(self):

        """Populate the in-tree state from the branch."""

        self._set_basis()

        if self._branch_revision_id == _mod_revision.NULL_REVISION:

            self._parent_ids = []

        else:

            self._parent_ids = [self._branch_revision_id]

        self._inventory = Inventory(None, self._basis_tree.get_revision_id())

        self._file_transport = MemoryTransport()

        # TODO copy the revision trees content, or do it lazy, or something.

        inventory_entries = self._basis_tree.iter_entries_by_dir()

        for path, entry in inventory_entries:

            self._inventory.add(entry.copy())

            if path == '':

                continue

            if entry.kind == 'directory':

                self._file_transport.mkdir(path)

            elif entry.kind == 'symlink':

                self._file_transport.symlink(entry.symlink_target, path)

            elif entry.kind == 'file':

                self._file_transport.put_file(

                    path, self._basis_tree.get_file(path))

            else:

                raise NotImplementedError(self._populate_from_branch)

    def put_file_bytes_non_atomic(self, path, bytes):

        """See MutableTree.put_file_bytes_non_atomic."""

        self._file_transport.put_bytes(path, bytes)

    def unlock(self):

        """Release a lock.

        This frees all cached state when the last lock context for the tree is

        left.

        """

        if self._locks == 1:

            self._basis_tree = None

            self._parent_ids = []

            self._inventory = None

            try:

                self.branch.unlock()

            finally:

                self._locks = 0

                self._lock_mode = None

        else:

            self._locks -= 1

    def unversion(self, paths):

        """Remove the paths from the current versioned set.

        When a file_id is unversioned, all of its children are automatically

        unversioned.

        :param paths: The paths to stop versioning.

        :raises: NoSuchId if any fileid is not currently versioned.

        """

        with self.lock_tree_write():

            # XXX: This should be in mutabletree, but the inventory-save action

            # is not relevant to memory tree. Until that is done in unlock by

            # working tree, we cannot share the implementation.

            file_ids = set()

            for path in paths:

                file_id = self.path2id(path)

                if file_id is None:

                    raise errors.NoSuchFile(path)

                file_ids.add(file_id)

            for file_id in file_ids:

                if self._inventory.has_id(file_id):

                    self._inventory.remove_recursive_id(file_id)

    def set_parent_ids(self, revision_ids, allow_leftmost_as_ghost=False):

        """See MutableTree.set_parent_trees()."""

        for revision_id in revision_ids:

            _mod_revision.check_not_reserved_id(revision_id)

        if len(revision_ids) == 0:

            self._parent_ids = []

            self._branch_revision_id = _mod_revision.NULL_REVISION

        else:

            self._parent_ids = revision_ids

            self._branch_revision_id = revision_ids[0]

        self._allow_leftmost_as_ghost = allow_leftmost_as_ghost

        self._set_basis()

    def _set_basis(self):

        try:

            self._basis_tree = self.branch.repository.revision_tree(

                self._branch_revision_id)

        except errors.NoSuchRevision:

            if self._allow_leftmost_as_ghost:

                self._basis_tree = self.branch.repository.revision_tree(

                    _mod_revision.NULL_REVISION)

            else:

                raise

    def get_symlink_target(self, path):

        with self.lock_read():

            return self._file_transport.readlink(path)

    def set_parent_trees(self, parents_list, allow_leftmost_as_ghost=False):

        """See MutableTree.set_parent_trees()."""

        if len(parents_list) == 0:

            self._parent_ids = []

            self._basis_tree = self.branch.repository.revision_tree(

                _mod_revision.NULL_REVISION)

        else:

            if parents_list[0][1] is None and not allow_leftmost_as_ghost:

                # a ghost in the left most parent

                raise errors.GhostRevisionUnusableHere(parents_list[0][0])

            self._parent_ids = [parent_id for parent_id, tree in parents_list]

            if parents_list[0][1] is None or parents_list[0][1] == b'null:':

                self._basis_tree = self.branch.repository.revision_tree(

                    _mod_revision.NULL_REVISION)

            else:

                self._basis_tree = parents_list[0][1]

            self._branch_revision_id = parents_list[0][0]