~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
import changeset
from changeset import Inventory, apply_changeset, invert_dict
import os.path
from osutils import backup_file, rename
from merge3 import Merge3

class ApplyMerge3:
    """Contents-change wrapper around merge3.Merge3"""
    def __init__(self, file_id, base, other):
        self.file_id = file_id
        self.base = base
        self.other = other
 
    def __eq__(self, other):
        if not isinstance(other, ApplyMerge3):
            return False
        return (self.base == other.base and 
                self.other == other.other and self.file_id == other.file_id)

    def __ne__(self, other):
        return not (self == other)


    def apply(self, filename, conflict_handler, reverse=False):
        new_file = filename+".new" 
        if not reverse:
            base = self.base
            other = self.other
        else:
            base = self.other
            other = self.base
        def get_lines(tree):
            if self.file_id not in tree:
                raise Exception("%s not in tree" % self.file_id)
                return ()
            return tree.get_file(self.file_id).readlines()
        base_lines = get_lines(base)
        other_lines = get_lines(other)
        m3 = Merge3(base_lines, file(filename, "rb").readlines(), other_lines)

        new_conflicts = False
        output_file = file(new_file, "wb")
        start_marker = "!START OF MERGE CONFLICT!" + "I HOPE THIS IS UNIQUE"
        for line in m3.merge_lines(name_a = "TREE", name_b = "MERGE-SOURCE", 
                       start_marker=start_marker):
            if line.startswith(start_marker):
                new_conflicts = True
                output_file.write(line.replace(start_marker, '<' * 7))
            else:
                output_file.write(line)
        output_file.close()
        if not new_conflicts:
            os.chmod(new_file, os.stat(filename).st_mode)
            rename(new_file, filename)
            return
        else:
            conflict_handler.merge_conflict(new_file, filename, base_lines,
                                            other_lines)


class BackupBeforeChange:
    """Contents-change wrapper to back up file first"""
    def __init__(self, contents_change):
        self.contents_change = contents_change
 
    def __eq__(self, other):
        if not isinstance(other, BackupBeforeChange):
            return False
        return (self.contents_change == other.contents_change)

    def __ne__(self, other):
        return not (self == other)

    def apply(self, filename, conflict_handler, reverse=False):
        backup_file(filename)
        self.contents_change.apply(filename, conflict_handler, reverse)


def invert_invent(inventory):
    invert_invent = {}
    for file_id in inventory:
        path = inventory.id2path(file_id)
        if path == '':
            path = './.'
        else:
            path = './' + path
        invert_invent[file_id] = path
    return invert_invent


def merge_flex(this, base, other, changeset_function, inventory_function,
               conflict_handler, merge_factory, interesting_ids):
    cset = changeset_function(base, other, interesting_ids)
    new_cset = make_merge_changeset(cset, this, base, other, 
                                    conflict_handler, merge_factory)
    result = apply_changeset(new_cset, invert_invent(this.tree.inventory),
                             this.root, conflict_handler, False)
    conflict_handler.finalize()
    return result

    

def make_merge_changeset(cset, this, base, other, 
                         conflict_handler, merge_factory):
    new_cset = changeset.Changeset()
    def get_this_contents(id):
        path = this.readonly_path(id)
        if os.path.isdir(path):
            return changeset.dir_create
        else:
            return changeset.FileCreate(file(path, "rb").read())

    for entry in cset.entries.itervalues():
        if entry.is_boring():
            new_cset.add_entry(entry)
        else:
            new_entry = make_merged_entry(entry, this, base, other, 
                                          conflict_handler)
            new_contents = make_merged_contents(entry, this, base, other, 
                                                conflict_handler,
                                                merge_factory)
            new_entry.contents_change = new_contents
            new_entry.metadata_change = make_merged_metadata(entry, base, other)
            new_cset.add_entry(new_entry)

    return new_cset

class ThreeWayConflict(Exception):
    def __init__(self, this, base, other):
        self.this = this
        self.base = base
        self.other = other
        msg = "Conflict merging %s %s and %s" % (this, base, other)
        Exception.__init__(self, msg)

def threeway_select(this, base, other):
    """Returns a value selected by the three-way algorithm.
    Raises ThreewayConflict if the algorithm yields a conflict"""
    if base == other:
        return this
    elif base == this:
        return other
    elif other == this:
        return this
    else:
        raise ThreeWayConflict(this, base, other)


def make_merged_entry(entry, this, base, other, conflict_handler):
    from bzrlib.trace import mutter
    def entry_data(file_id, tree):
        assert hasattr(tree, "__contains__"), "%s" % tree
        if not tree.has_or_had_id(file_id):
            return (None, None, "")
        entry = tree.tree.inventory[file_id]
        my_dir = tree.id2path(entry.parent_id)
        if my_dir is None:
            my_dir = ""
        return entry.name, entry.parent_id, my_dir 
    this_name, this_parent, this_dir = entry_data(entry.id, this)
    base_name, base_parent, base_dir = entry_data(entry.id, base)
    other_name, other_parent, other_dir = entry_data(entry.id, other)
    mutter("Dirs: this, base, other %r %r %r" % (this_dir, base_dir, other_dir))
    mutter("Names: this, base, other %r %r %r" % (this_name, base_name, other_name))
    old_name = this_name
    try:
        new_name = threeway_select(this_name, base_name, other_name)
    except ThreeWayConflict:
        new_name = conflict_handler.rename_conflict(entry.id, this_name, 
                                                    base_name, other_name)

    old_parent = this_parent
    try:
        new_parent = threeway_select(this_parent, base_parent, other_parent)
    except ThreeWayConflict:
        new_parent = conflict_handler.move_conflict(entry.id, this_dir,
                                                    base_dir, other_dir)
    def get_path(name, parent):
        if name is not None:
            if name == "":
                assert parent is None
                return './.'
            parent_dir = {this_parent: this_dir, other_parent: other_dir, 
                          base_parent: base_dir}
            directory = parent_dir[parent]
            return os.path.join(directory, name)
        else:
            assert parent is None
            return None

    old_path = get_path(old_name, old_parent)
        
    new_entry = changeset.ChangesetEntry(entry.id, old_parent, old_path)
    new_entry.new_path = get_path(new_name, new_parent)
    new_entry.new_parent = new_parent
    mutter(repr(new_entry))
    return new_entry


def get_contents(entry, tree):
    """Get a contents change element suitable for use with ReplaceContents
    """
    tree_entry = tree.tree.inventory[entry.id]
    if tree_entry.kind == "file":
        return changeset.FileCreate(tree.get_file(entry.id).read())
    else:
        assert tree_entry.kind in ("root_directory", "directory")
        return changeset.dir_create


def make_merged_contents(entry, this, base, other, conflict_handler,
                         merge_factory):
    contents = entry.contents_change
    if contents is None:
        return None
    this_path = this.readonly_path(entry.id)
    def make_merge():
        if this_path is None:
            return conflict_handler.missing_for_merge(entry.id, 
                                                      other.id2path(entry.id))
        return merge_factory(entry.id, base, other)

    if isinstance(contents, changeset.ReplaceContents):
        if contents.old_contents is None and contents.new_contents is None:
            return None
        if contents.new_contents is None:
            if this_path is not None and os.path.exists(this_path):
                return contents
            else:
                return None
        elif contents.old_contents is None:
            if this_path is None or not os.path.exists(this_path):
                return contents
            else:
                this_contents = get_contents(entry, this)
                if this_contents == contents.new_contents:
                    return None
                else:
                    other_path = other.readonly_path(entry.id)    
                    conflict_handler.new_contents_conflict(this_path, 
                                                           other_path)
        elif isinstance(contents.old_contents, changeset.FileCreate) and \
            isinstance(contents.new_contents, changeset.FileCreate):
            return make_merge()
        else:
            raise Exception("Unhandled merge scenario")

def make_merged_metadata(entry, base, other):
    if entry.metadata_change is not None:
        base_path = base.readonly_path(entry.id)
        other_path = other.readonly_path(entry.id)    
        return PermissionsMerge(base_path, other_path)
    

class PermissionsMerge(object):
    def __init__(self, base_path, other_path):
        self.base_path = base_path
        self.other_path = other_path

    def apply(self, filename, conflict_handler, reverse=False):
        if not reverse:
            base = self.base_path
            other = self.other_path
        else:
            base = self.other_path
            other = self.base_path
        base_stat = os.stat(base).st_mode
        other_stat = os.stat(other).st_mode
        this_stat = os.stat(filename).st_mode
        if base_stat &0777 == other_stat &0777:
            return
        elif this_stat &0777 == other_stat &0777:
            return
        elif this_stat &0777 == base_stat &0777:
            os.chmod(filename, other_stat)
        else:
            conflict_handler.permission_conflict(filename, base, other)