~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

# TODO: build_working_dir can be built on something simpler than merge()

import os

import errno

import bzrlib

from bzrlib._changeset import generate_changeset, ExceptionConflictHandler

from bzrlib._changeset import Inventory, Diff3Merge, ReplaceContents

from bzrlib._merge_core import WeaveMerge

from bzrlib._merge_core import merge_flex, ApplyMerge3, BackupBeforeChange

from bzrlib.branch import Branch

from bzrlib.delta import compare_trees

from bzrlib.errors import (BzrCommandError,

                           BzrError,

                           NoCommonAncestor,

                           NoCommits,

                           NoSuchRevision,

                           NotBranchError,

                           NotVersionedError,

                           UnrelatedBranches,

                           WorkingTreeNotRevision,

                           )

from bzrlib.fetch import greedy_fetch, fetch

import bzrlib.osutils

from bzrlib.osutils import rename, pathjoin

from bzrlib.revision import common_ancestor, is_ancestor, NULL_REVISION

from bzrlib.trace import mutter, warning, note

from bzrlib.workingtree import WorkingTree

# TODO: Report back as changes are merged in

# comments from abentley on irc: merge happens in two stages, each

# of which generates a changeset object

# stage 1: generate OLD->OTHER,

# stage 2: use MINE and OLD->OTHER to generate MINE -> RESULT

class _MergeConflictHandler(ExceptionConflictHandler):

    """Handle conflicts encountered while merging.

    This subclasses ExceptionConflictHandler, so that any types of

    conflict that are not explicitly handled cause an exception and

    terminate the merge.

    """

    def __init__(self, this_tree, base_tree, other_tree, ignore_zero=False):

        ExceptionConflictHandler.__init__(self)

        self.conflicts = 0

        self.ignore_zero = ignore_zero

        self.this_tree = this_tree

        self.base_tree = base_tree

        self.other_tree = other_tree

    def copy(self, source, dest):

        """Copy the text and mode of a file

        :param source: The path of the file to copy

        :param dest: The distination file to create

        """

        s_file = file(source, "rb")

        d_file = file(dest, "wb")

        for line in s_file:

            d_file.write(line)

        os.chmod(dest, 0777 & os.stat(source).st_mode)

    def dump(self, lines, dest):

        """Copy the text and mode of a file

        :param source: The path of the file to copy

        :param dest: The distination file to create

        """

        d_file = file(dest, "wb")

        for line in lines:

            d_file.write(line)

    def add_suffix(self, name, suffix, last_new_name=None, fix_inventory=True):

        """Rename a file to append a suffix.  If the new name exists, the

        suffix is added repeatedly until a non-existant name is found

        :param name: The path of the file

        :param suffix: The suffix to append

        :param last_new_name: (used for recursive calls) the last name tried

        """

        if last_new_name is None:

            last_new_name = name

        new_name = last_new_name+suffix

        try:

            rename(name, new_name)

            if fix_inventory is True:

                try:

                    relpath = self.this_tree.relpath(name)

                except NotBranchError:

                    relpath = None

                if relpath is not None:

                    file_id = self.this_tree.path2id(relpath)

                    if file_id is not None:

                        new_path = self.this_tree.relpath(new_name)

                        rename(new_name, name)

                        self.this_tree.rename_one(relpath, new_path)

                        assert self.this_tree.id2path(file_id) == new_path

        except OSError, e:

            if e.errno != errno.EEXIST and e.errno != errno.ENOTEMPTY:

                raise

            return self.add_suffix(name, suffix, last_new_name=new_name, 

                                   fix_inventory=fix_inventory)

        return new_name

    def conflict(self, text):

        warning(text)

        self.conflicts += 1

    def merge_conflict(self, new_file, this_path, base_lines, other_lines):

        """

        Handle diff3 conflicts by producing a .THIS, .BASE and .OTHER.  The

        main file will be a version with diff3 conflicts.

        :param new_file: Path to the output file with diff3 markers

        :param this_path: Path to the file text for the THIS tree

        :param base_path: Path to the file text for the BASE tree

        :param other_path: Path to the file text for the OTHER tree

        """

        self.add_suffix(this_path, ".THIS", fix_inventory=False)

        self.dump(base_lines, this_path+".BASE")

        self.dump(other_lines, this_path+".OTHER")

        rename(new_file, this_path)

        self.conflict("Diff3 conflict encountered in %s" % this_path)

    def weave_merge_conflict(self, filename, weave, other_i, out_file):

        """

        Handle weave conflicts by producing a .THIS, and .OTHER.  The

        main file will be a version with diff3-style conflicts.

        """

        self.add_suffix(filename, ".THIS", fix_inventory=False)

        out_file.commit()

        self.dump(weave.get_iter(other_i), filename+".OTHER")

        self.conflict("Text conflict encountered in %s" % filename)

    def new_contents_conflict(self, filename, other_contents):

        """Conflicting contents for newly added file."""

        other_contents(filename + ".OTHER", self, False)

        self.conflict("Conflict in newly added file %s" % filename)

    def target_exists(self, entry, target, old_path):

        """Handle the case when the target file or dir exists"""

        moved_path = self.add_suffix(target, ".moved")

        self.conflict("Moved existing %s to %s" % (target, moved_path))

    def rmdir_non_empty(self, filename):

        """Handle the case where the dir to be removed still has contents"""

        self.conflict("Directory %s not removed because it is not empty"\

            % filename)

        return "skip"

    def rem_contents_conflict(self, filename, this_contents, base_contents):

        base_contents(filename+".BASE", self)

        this_contents(filename+".THIS", self)

        self.conflict("Other branch deleted locally modified file %s" %

                      filename)

        return ReplaceContents(this_contents, None)

    def abs_this_path(self, file_id):

        """Return the absolute path for a file_id in the this tree."""

        return self.this_tree.id2abspath(file_id)

    def add_missing_parents(self, file_id, tree):

        """If some of the parents for file_id are missing, add them."""

        entry = tree.inventory[file_id]

        if entry.parent_id not in self.this_tree:

            return self.create_all_missing(entry.parent_id, tree)

        else:

            return self.abs_this_path(entry.parent_id)

    def create_all_missing(self, file_id, tree):

        """Add contents for a file_id and all its parents to a tree."""

        entry = tree.inventory[file_id]

        if entry.parent_id is not None and entry.parent_id not in self.this_tree:

            abspath = self.create_all_missing(entry.parent_id, tree)

        else:

            abspath = self.abs_this_path(entry.parent_id)

        entry_path = pathjoin(abspath, entry.name)

        if not os.path.isdir(entry_path):

            self.create(file_id, entry_path, tree)

        return entry_path

    def create(self, file_id, path, tree):

        """Uses tree data to create a filesystem object for the file_id"""

        from bzrlib._changeset import get_contents

        get_contents(tree, file_id)(path, self)

    def missing_for_merge(self, file_id, other_path):

        """The file_id doesn't exist in THIS, but does in OTHER and BASE"""

        self.conflict("Other branch modified locally deleted file %s" %

                      other_path)

        parent_dir = self.add_missing_parents(file_id, self.other_tree)

        stem = pathjoin(parent_dir, os.path.basename(other_path))

        self.create(file_id, stem+".OTHER", self.other_tree)

        self.create(file_id, stem+".BASE", self.base_tree)

    def threeway_contents_conflict(filename, this_contents, base_contents,

                                   other_contents):

        self.conflict("Three-way conflict merging %s" % filename)

    def finalize(self):

        if self.conflicts == 0:

            if not self.ignore_zero:

                note("All changes applied successfully.")

        else:

            note("%d conflicts encountered." % self.conflicts)

def _get_tree(treespec, local_branch=None):

    location, revno = treespec

    branch = Branch.open_containing(location)[0]

    if revno is None:

        revision = None

    elif revno == -1:

        revision = branch.last_revision()

    else:

        revision = branch.get_rev_id(revno)

        if revision is None:

            revision = NULL_REVISION

    return branch, _get_revid_tree(branch, revision, local_branch)

def _get_revid_tree(branch, revision, local_branch):

    if revision is None:

        base_tree = branch.working_tree()

    else:

        if local_branch is not None:

            if local_branch.base != branch.base:

                greedy_fetch(local_branch, branch, revision)

            base_tree = local_branch.repository.revision_tree(revision)

        else:

            base_tree = branch.repository.revision_tree(revision)

    return base_tree

def build_working_dir(to_dir):

    """Build a working directory in an empty directory.

    to_dir is a directory containing branch metadata but no working files,

    typically constructed by cloning an existing branch. 

    This is split out as a special idiomatic case of merge.  It could

    eventually be done by just building the tree directly calling into 

    lower-level code (e.g. constructing a changeset).

    """

    # RBC 20051019 is this not just 'export' ?

    # AB Well, export doesn't take care of inventory...

    this_branch = Branch.open_containing(to_dir)[0]

    transform_tree(this_branch.working_tree(), this_branch.basis_tree())

def transform_tree(from_tree, to_tree, interesting_ids=None):

    merge_inner(from_tree.branch, to_tree, from_tree, ignore_zero=True,

                interesting_ids=interesting_ids)

def merge_inner(this_branch, other_tree, base_tree, ignore_zero=False,

                backup_files=False, 

                merge_type=ApplyMerge3, 

                interesting_ids=None, 

                show_base=False, 

                reprocess=False, 

                other_rev_id=None,

                interesting_files=None,

                this_tree=None):

    """Primary interface for merging. 

        typical use is probably 

        'merge_inner(branch, branch.get_revision_tree(other_revision),

                     branch.get_revision_tree(base_revision))'

        """

    if this_tree is None:

        this_tree = this_branch.working_tree()

    merger = Merger(this_branch, other_tree, base_tree, this_tree=this_tree)

    merger.backup_files = backup_files

    merger.merge_type = merge_type

    merger.interesting_ids = interesting_ids

    if interesting_files:

        assert not interesting_ids, ('Only supply interesting_ids'

                                     ' or interesting_files')

        merger._set_interesting_files(interesting_files)

    merger.show_base = show_base 

    merger.reprocess = reprocess

    merger.conflict_handler = _MergeConflictHandler(merger.this_tree, 

                                                    base_tree, other_tree,

                                                    ignore_zero=ignore_zero)

    merger.other_rev_id = other_rev_id

    merger.other_basis = other_rev_id

    return merger.do_merge()

class Merger(object):

    def __init__(self, this_branch, other_tree=None, base_tree=None, this_tree=None):

        object.__init__(self)

        assert this_tree is not None, "this_tree is required"

        self.this_branch = this_branch

        self.this_basis = this_branch.last_revision()

        self.this_rev_id = None

        self.this_tree = this_tree

        self.this_revision_tree = None

        self.this_basis_tree = None

        self.other_tree = other_tree

        self.base_tree = base_tree

        self.ignore_zero = False

        self.backup_files = False

        self.interesting_ids = None

        self.show_base = False

        self.reprocess = False

        self.conflict_handler = _MergeConflictHandler(self.this_tree, 

                                                      base_tree, other_tree)

    def revision_tree(self, revision_id):

        return self.this_branch.repository.revision_tree(revision_id)

    def ensure_revision_trees(self):

        if self.this_revision_tree is None:

            self.this_basis_tree = self.this_branch.repository.revision_tree(

                self.this_basis)

            if self.this_basis == self.this_rev_id:

                self.this_revision_tree = self.this_basis_tree

        if self.other_rev_id is None:

            other_basis_tree = self.revision_tree(self.other_basis)

            changes = compare_trees(self.other_tree, other_basis_tree)

            if changes.has_changed():

                raise WorkingTreeNotRevision(self.this_tree)

            other_rev_id = other_basis

            self.other_tree = other_basis_tree

    def file_revisions(self, file_id):

        self.ensure_revision_trees()

        def get_id(tree, file_id):

            revision_id = tree.inventory[file_id].revision

            assert revision_id is not None

            return revision_id

        if self.this_rev_id is None:

            if self.this_basis_tree.get_file_sha1(file_id) != \

                self.this_tree.get_file_sha1(file_id):

                raise WorkingTreeNotRevision(self.this_tree)

        trees = (self.this_basis_tree, self.other_tree)

        return [get_id(tree, file_id) for tree in trees]

    def merge_factory(self, file_id, base, other):

        if self.merge_type.history_based:

            if self.show_base is True:

                raise BzrError("Cannot show base for hisory-based merges")

            if self.reprocess is True:

                raise BzrError("Cannot reprocess history-based merges")

            t_revid, o_revid = self.file_revisions(file_id)

            weave = self.this_basis_tree.get_weave(file_id)

            contents_change = self.merge_type(weave, t_revid, o_revid)

        else:

            if self.show_base is True or self.reprocess is True:

                contents_change = self.merge_type(file_id, base, other, 

                                                  show_base=self.show_base, 

                                                  reprocess=self.reprocess)

            else:

                contents_change = self.merge_type(file_id, base, other)

        if self.backup_files:

            contents_change = BackupBeforeChange(contents_change)

        return contents_change

    def check_basis(self, check_clean):

        if self.this_basis is None:

            raise BzrCommandError("This branch has no commits")

        if check_clean:

            self.compare_basis()

            if self.this_basis != self.this_rev_id:

                raise BzrCommandError("Working tree has uncommitted changes.")

    def compare_basis(self):

        changes = compare_trees(self.this_tree, 

                                self.this_branch.basis_tree(), False)

        if not changes.has_changed():

            self.this_rev_id = self.this_basis

    def set_interesting_files(self, file_list):

        try:

            self._set_interesting_files(file_list)

        except NotVersionedError, e:

            raise BzrCommandError("%s is not a source file in any"

                                      " tree." % e.path)

    def _set_interesting_files(self, file_list):

        """Set the list of interesting ids from a list of files."""

        if file_list is None:

            self.interesting_ids = None

            return

        interesting_ids = set()

        for path in file_list:

            found_id = False

            for tree in (self.this_tree, self.base_tree, self.other_tree):

                file_id = tree.inventory.path2id(path)

                if file_id is not None:

                    interesting_ids.add(file_id)

                    found_id = True

            if not found_id:

                raise NotVersionedError(path=path)

        self.interesting_ids = interesting_ids

    def set_pending(self):

        if not self.base_is_ancestor:

            return

        if self.other_rev_id is None:

            return

        ancestry = self.this_branch.repository.get_ancestry(self.this_basis)

        if self.other_rev_id in ancestry:

            return

        self.this_tree.add_pending_merge(self.other_rev_id)

    def set_other(self, other_revision):

        other_branch, self.other_tree = _get_tree(other_revision, 

                                                  self.this_branch)

        if other_revision[1] == -1:

            self.other_rev_id = other_branch.last_revision()

            if self.other_rev_id is None:

                raise NoCommits(other_branch)

            self.other_basis = self.other_rev_id

        elif other_revision[1] is not None:

            self.other_rev_id = other_branch.get_rev_id(other_revision[1])

            self.other_basis = self.other_rev_id

        else:

            self.other_rev_id = None

            self.other_basis = other_branch.last_revision()

            if self.other_basis is None:

                raise NoCommits(other_branch)

        if other_branch.base != self.this_branch.base:

            fetch(from_branch=other_branch, to_branch=self.this_branch, 

                  last_revision=self.other_basis)

    def set_base(self, base_revision):

        mutter("doing merge() with no base_revision specified")

        if base_revision == [None, None]:

            try:

                self.base_rev_id = common_ancestor(self.this_basis, 

                                                   self.other_basis, 

                                                   self.this_branch.repository)

            except NoCommonAncestor:

                raise UnrelatedBranches()

            self.base_tree = _get_revid_tree(self.this_branch, self.base_rev_id,

                                            None)

            self.base_is_ancestor = True

        else:

            base_branch, self.base_tree = _get_tree(base_revision)

            if base_revision[1] == -1:

                self.base_rev_id = base_branch.last_revision()

            elif base_revision[1] is None:

                self.base_rev_id = None

            else:

                self.base_rev_id = base_branch.get_rev_id(base_revision[1])

            fetch(from_branch=base_branch, to_branch=self.this_branch)

            self.base_is_ancestor = is_ancestor(self.this_basis, 

                                                self.base_rev_id,

                                                self.this_branch)

    def do_merge(self):

        def get_inventory(tree):

            return tree.inventory

        inv_changes = merge_flex(self.this_tree, self.base_tree, 

                                 self.other_tree,

                                 generate_changeset, get_inventory,

                                 self.conflict_handler,

                                 merge_factory=self.merge_factory, 

                                 interesting_ids=self.interesting_ids)

        adjust_ids = []

        for id, path in inv_changes.iteritems():

            if path is not None:

                if path == u'.':

                    path = u''

                else:

                    assert path.startswith('.' + '/') or path.startswith('.' + '\\'), "path is %s" % path

                path = path[2:]

            adjust_ids.append((path, id))

        if len(adjust_ids) > 0:

            self.this_tree.set_inventory(self.regen_inventory(adjust_ids))

        conflicts = self.conflict_handler.conflicts

        self.conflict_handler.finalize()

        return conflicts

    def regen_inventory(self, new_entries):

        old_entries = self.this_tree.read_working_inventory()

        new_inventory = {}

        by_path = {}

        new_entries_map = {} 

        for path, file_id in new_entries:

            if path is None:

                continue

            new_entries_map[file_id] = path

        def id2path(file_id):

            path = new_entries_map.get(file_id)

            if path is not None:

                return path

            entry = old_entries[file_id]

            if entry.parent_id is None:

                return entry.name

            return pathjoin(id2path(entry.parent_id), entry.name)

        for file_id in old_entries:

            entry = old_entries[file_id]

            path = id2path(file_id)

            new_inventory[file_id] = (path, file_id, entry.parent_id, 

                                      entry.kind)

            by_path[path] = file_id

        deletions = 0

        insertions = 0

        new_path_list = []

        for path, file_id in new_entries:

            if path is None:

                del new_inventory[file_id]

                deletions += 1

            else:

                new_path_list.append((path, file_id))

                if file_id not in old_entries:

                    insertions += 1

        # Ensure no file is added before its parent

        new_path_list.sort()

        for path, file_id in new_path_list:

            if path == '':

                parent = None

            else:

                parent = by_path[os.path.dirname(path)]

            abspath = pathjoin(self.this_tree.basedir, path)

            kind = bzrlib.osutils.file_kind(abspath)

            new_inventory[file_id] = (path, file_id, parent, kind)

            by_path[path] = file_id 

        # Get a list in insertion order

        new_inventory_list = new_inventory.values()

        mutter ("""Inventory regeneration:

    old length: %i insertions: %i deletions: %i new_length: %i"""\

            % (len(old_entries), insertions, deletions, 

               len(new_inventory_list)))

        assert len(new_inventory_list) == len(old_entries) + insertions\

            - deletions

        new_inventory_list.sort()

        return new_inventory_list

merge_types = {     "merge3": (ApplyMerge3, "Native diff3-style merge"), 

                     "diff3": (Diff3Merge,  "Merge using external diff3"),

                     'weave': (WeaveMerge, "Weave-based merge")

              }