~bzr-pqm/bzr/bzr.dev

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
from bzrlib.merge_core import merge_flex, ApplyMerge3, BackupBeforeChange
from bzrlib.changeset import generate_changeset, ExceptionConflictHandler
from bzrlib.changeset import Inventory, Diff3Merge
from bzrlib import find_branch
import bzrlib.osutils
from bzrlib.errors import BzrCommandError
from bzrlib.delta import compare_trees
from trace import mutter, warning
import os.path
import tempfile
import shutil
import errno


# 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 UnrelatedBranches(BzrCommandError):
    def __init__(self):
        msg = "Branches have no common ancestor, and no base revision"\
            " specified."
        BzrCommandError.__init__(self, msg)


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, dir, ignore_zero=False):
        ExceptionConflictHandler.__init__(self, dir)
        self.conflicts = 0
        self.ignore_zero = ignore_zero

    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:
            os.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")
        os.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."""
        self.copy(other_contents, filename + ".OTHER")
        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 finalize(self):
        if not self.ignore_zero:
            print "%d conflicts encountered.\n" % self.conflicts
            
def get_tree(treespec, temp_root, label):
    location, revno = treespec
    branch = find_branch(location)
    if revno is None:
        base_tree = branch.working_tree()
    elif revno == -1:
        base_tree = branch.basis_tree()
    else:
        base_tree = branch.revision_tree(branch.lookup_revision(revno))
    temp_path = os.path.join(temp_root, label)
    os.mkdir(temp_path)
    return branch, MergeTree(base_tree, temp_path)


def file_exists(tree, file_id):
    return tree.has_filename(tree.id2path(file_id))
    

class MergeTree(object):
    def __init__(self, tree, tempdir):
        object.__init__(self)
        if hasattr(tree, "basedir"):
            self.root = tree.basedir
        else:
            self.root = None
        self.tree = tree
        self.tempdir = tempdir
        os.mkdir(os.path.join(self.tempdir, "texts"))
        self.cached = {}

    def __iter__(self):
        return self.tree.__iter__()

    def __contains__(self, file_id):
        return file_id in self.tree

    def get_file(self, file_id):
        return self.tree.get_file(file_id)

    def get_file_sha1(self, id):
        return self.tree.get_file_sha1(id)

    def id2path(self, file_id):
        return self.tree.id2path(file_id)

    def has_id(self, file_id):
        return self.tree.has_id(file_id)

    def readonly_path(self, id):
        if id not in self.tree:
            return None
        if self.root is not None:
            return self.tree.abspath(self.tree.id2path(id))
        else:
            if self.tree.inventory[id].kind in ("directory", "root_directory"):
                return self.tempdir
            if not self.cached.has_key(id):
                path = os.path.join(self.tempdir, "texts", id)
                outfile = file(path, "wb")
                outfile.write(self.tree.get_file(id).read())
                assert(os.path.exists(path))
                self.cached[id] = path
            return self.cached[id]



def merge(other_revision, base_revision,
          check_clean=True, ignore_zero=False,
          this_dir=None, backup_files=False, merge_type=ApplyMerge3,
          file_list=None):
    """Merge changes into a tree.

    base_revision
        Base for three-way merge.
    other_revision
        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.
    """
    tempdir = tempfile.mkdtemp(prefix="bzr-")
    try:
        if this_dir is None:
            this_dir = '.'
        this_branch = find_branch(this_dir)
        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, tempdir, "other")
        if base_revision == [None, None]:
            if other_revision[1] == -1:
                o_revno = None
            else:
                o_revno = other_revision[1]
            base_revno = this_branch.common_ancestor(other_branch, 
                                                     other_revno=o_revno)[0]
            if base_revno is None:
                raise UnrelatedBranches()
            base_revision = ['.', base_revno]
        base_branch, base_tree = get_tree(base_revision, tempdir, "base")
        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_branch.relpath(fname)
                found_id = False
                for tree in (this_tree, base_tree.tree, other_tree.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)
        merge_inner(this_branch, other_tree, base_tree, tempdir, 
                    ignore_zero=ignore_zero, backup_files=backup_files, 
                    merge_type=merge_type, interesting_ids=interesting_ids)
    finally:
        shutil.rmtree(tempdir)


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 generate_cset_optimized(tree_a, tree_b, interesting_ids=None):
    """Generate a changeset.  If interesting_ids is supplied, only changes
    to those files will be shown.  Metadata changes are stripped.
    """ 
    cset =  generate_changeset(tree_a, tree_b, interesting_ids)
    for entry in cset.entries.itervalues():
        entry.metadata_change = None
    return cset


def merge_inner(this_branch, other_tree, base_tree, tempdir, 
                ignore_zero=False, merge_type=ApplyMerge3, backup_files=False,
                interesting_ids=None):

    def merge_factory(file_id, base, other):
        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), tempdir, "this")[1]

    def get_inventory(tree):
        return tree.tree.inventory

    inv_changes = merge_flex(this_tree, base_tree, other_tree,
                             generate_cset_optimized, get_inventory,
                             MergeConflictHandler(base_tree.root,
                                                  ignore_zero=ignore_zero),
                             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('./'), "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.root,
                                                  adjust_ids))


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")
              }