# 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 os import tempfile import shutil import errno import bzrlib.osutils import bzrlib.revision from bzrlib.merge_core import merge_flex, ApplyMerge3, BackupBeforeChange from bzrlib.changeset import generate_changeset, ExceptionConflictHandler from bzrlib.changeset import Inventory, Diff3Merge, ReplaceContents from bzrlib.branch import Branch from bzrlib.errors import BzrCommandError, UnrelatedBranches, NoCommonAncestor from bzrlib.errors import NoCommits from bzrlib.delta import compare_trees from bzrlib.trace import mutter, warning, note from bzrlib.fetch import greedy_fetch, fetch from bzrlib.revision import is_ancestor from bzrlib.osutils import rename from bzrlib.revision import common_ancestor, MultipleRevisionSources from bzrlib.errors import NoSuchRevision # TODO: Report back as changes are merged in # TODO: build_working_dir can be built on something simpler than merge() # FIXME: merge() parameters seem oriented towards the command line # NOTABUG: merge is a helper for commandline functions. merge_inner is the # the core functionality. # 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): """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) return new_name 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) 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") 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 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, False) this_contents(filename+".THIS", self, False) return ReplaceContents(this_contents, None) def rem_contents_conflict(self, filename, this_contents, base_contents): base_contents(filename+".BASE", self, False) this_contents(filename+".THIS", self, False) 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 = os.path.join(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, reverse=False): """Uses tree data to create a filesystem object for the file_id""" from changeset import get_contents get_contents(tree, file_id)(path, self, reverse) 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 = os.path.join(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 not self.ignore_zero: note("%d conflicts encountered.\n" % 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) 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: greedy_fetch(local_branch, branch, revision) base_tree = local_branch.revision_tree(revision) else: base_tree = branch.revision_tree(revision) return base_tree def file_exists(tree, file_id): return tree.has_filename(tree.id2path(file_id)) 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' ? merge((to_dir, -1), (to_dir, 0), this_dir=to_dir, check_clean=False, ignore_zero=True) def merge(other_revision, base_revision, check_clean=True, ignore_zero=False, this_dir=None, backup_files=False, merge_type=ApplyMerge3, file_list=None, show_base=False): """Merge changes into a tree. base_revision tuple(path, revno) Base for three-way merge. If (None, None) then a base will be automatically determined. other_revision tuple(path, revno) Other revision for three-way merge. this_dir Directory to merge changes into; '.' by default. check_clean If true, this_dir must have no uncommitted changes before the merge begins. ignore_zero - If true, suppress the "zero conflicts" message when there are no conflicts; should be set when doing something we expect to complete perfectly. file_list - If true, merge only changes to selected files. All available ancestors of other_revision and base_revision are automatically pulled into the branch. The revno may be -1 to indicate the last revision on the branch, which is the typical case. This function is intended for use from the command line; programmatic clients might prefer to call merge_inner(), which has less magic behavior. """ # TODO: please check this docstring is true and accurate - mbp 20051024 if this_dir is None: this_dir = '.' this_branch = Branch.open_containing(this_dir)[0] this_rev_id = this_branch.last_revision() if this_rev_id is None: raise BzrCommandError("This branch has no commits") if check_clean: changes = compare_trees(this_branch.working_tree(), this_branch.basis_tree(), False) if changes.has_changed(): raise BzrCommandError("Working tree has uncommitted changes.") other_branch, other_tree = get_tree(other_revision, this_branch) if other_revision[1] == -1: other_rev_id = other_branch.last_revision() if other_rev_id is None: raise NoCommits(other_branch) other_basis = other_rev_id elif other_revision[1] is not None: other_rev_id = other_branch.get_rev_id(other_revision[1]) other_basis = other_rev_id else: other_rev_id = None other_basis = other_branch.last_revision() if other_basis is None: raise NoCommits(other_branch) fetch(from_branch=other_branch, to_branch=this_branch) if base_revision == [None, None]: mutter("doing merge() with no base_revision specified") try: base_rev_id = common_ancestor(this_rev_id, other_basis, this_branch) except NoCommonAncestor: raise UnrelatedBranches() # fetch() is probably unnecessary in this case, because # get_revid_tree() does it anyway if base_rev_id is not None and the # local_branch is None -- but we do it above just to be sure -- mbp 20051024 base_tree = get_revid_tree(this_branch, base_rev_id, None) base_is_ancestor = True else: mutter('doing merge() with base %r' % (base_revision,)) base_branch, base_tree = get_tree(base_revision) if base_revision[1] == -1: base_rev_id = base_branch.last_revision() elif base_revision[1] is None: base_rev_id = None else: base_rev_id = base_branch.get_rev_id(base_revision[1]) fetch(from_branch=base_branch, to_branch=this_branch) base_is_ancestor = is_ancestor(this_rev_id, base_rev_id, this_branch) if file_list is None: interesting_ids = None else: interesting_ids = set() this_tree = this_branch.working_tree() for fname in file_list: path = this_tree.relpath(fname) found_id = False for tree in (this_tree, base_tree, 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 BzrCommandError("%s is not a source file in any" " tree." % fname) conflicts = merge_inner(this_branch, other_tree, base_tree, tempdir=None, ignore_zero=ignore_zero, backup_files=backup_files, merge_type=merge_type, interesting_ids=interesting_ids, show_base=show_base) if base_is_ancestor and other_rev_id is not None\ and other_rev_id not in this_branch.revision_history(): this_branch.add_pending_merge(other_rev_id) return conflicts def set_interesting(inventory_a, inventory_b, interesting_ids): """Mark files whose ids are in interesting_ids as interesting """ for inventory in (inventory_a, inventory_b): for path, source_file in inventory.iteritems(): source_file.interesting = source_file.id in interesting_ids def merge_inner(this_branch, other_tree, base_tree, tempdir=None, ignore_zero=False, merge_type=ApplyMerge3, backup_files=False, interesting_ids=None, show_base=False): """Primary interface for merging. typical use is probably 'merge_inner(branch, branch.get_revision_tree(other_revision), branch.get_revision_tree(base_revision))' """ if tempdir is None: _tempdir = tempfile.mkdtemp(prefix="bzr-") else: _tempdir = tempdir try: return _merge_inner(this_branch, other_tree, base_tree, _tempdir, ignore_zero, merge_type, backup_files, interesting_ids, show_base=show_base) finally: if tempdir is None: shutil.rmtree(_tempdir) def _merge_inner(this_branch, other_tree, base_tree, user_tempdir, ignore_zero=False, merge_type=ApplyMerge3, backup_files=False, interesting_ids=None, show_base=False): def merge_factory(file_id, base, other): if show_base is True: contents_change = merge_type(file_id, base, other, show_base=True) else: contents_change = merge_type(file_id, base, other) if backup_files: contents_change = BackupBeforeChange(contents_change) return contents_change this_tree = get_tree((this_branch.base, None))[1] def get_inventory(tree): return tree.inventory conflict_handler = MergeConflictHandler(this_tree, base_tree, other_tree, ignore_zero=ignore_zero) inv_changes = merge_flex(this_tree, base_tree, other_tree, generate_changeset, get_inventory, conflict_handler, merge_factory=merge_factory, interesting_ids=interesting_ids) adjust_ids = [] for id, path in inv_changes.iteritems(): if path is not None: if path == '.': path = '' else: assert path.startswith('.' + os.sep), "path is %s" % path path = path[2:] adjust_ids.append((path, id)) if len(adjust_ids) > 0: this_branch.set_inventory(regen_inventory(this_branch, this_tree.basedir, adjust_ids)) conflicts = conflict_handler.conflicts conflict_handler.finalize() return conflicts def regen_inventory(this_branch, root, new_entries): old_entries = this_branch.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 os.path.join(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)] kind = bzrlib.osutils.file_kind(os.path.join(root, path)) 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") }