~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
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
# Copyright (C) 2007-2010 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

"""WorkingTree4 format and implementation.

WorkingTree4 provides the dirstate based working tree logic.

To get a WorkingTree, call bzrdir.open_workingtree() or
WorkingTree.open(dir).
"""

from cStringIO import StringIO
import os
import sys

from bzrlib.lazy_import import lazy_import
lazy_import(globals(), """
import errno
import stat

import bzrlib
from bzrlib import (
    bzrdir,
    cache_utf8,
    debug,
    dirstate,
    errors,
    generate_ids,
    osutils,
    revision as _mod_revision,
    revisiontree,
    trace,
    transform,
    views,
    )
import bzrlib.branch
import bzrlib.ui
""")

from bzrlib.decorators import needs_read_lock, needs_write_lock
from bzrlib.filters import filtered_input_file, internal_size_sha_file_byname
from bzrlib.inventory import Inventory, ROOT_ID, entry_factory
from bzrlib.lock import LogicalLockResult
from bzrlib.mutabletree import needs_tree_write_lock
from bzrlib.osutils import (
    file_kind,
    isdir,
    pathjoin,
    realpath,
    safe_unicode,
    )
from bzrlib.trace import mutter
from bzrlib.transport.local import LocalTransport
from bzrlib.tree import InterTree
from bzrlib.tree import Tree
from bzrlib.workingtree import WorkingTree, WorkingTree3, WorkingTreeFormat3


class DirStateWorkingTree(WorkingTree3):
    def __init__(self, basedir,
                 branch,
                 _control_files=None,
                 _format=None,
                 _bzrdir=None):
        """Construct a WorkingTree for basedir.

        If the branch is not supplied, it is opened automatically.
        If the branch is supplied, it must be the branch for this basedir.
        (branch.base is not cross checked, because for remote branches that
        would be meaningless).
        """
        self._format = _format
        self.bzrdir = _bzrdir
        basedir = safe_unicode(basedir)
        mutter("opening working tree %r", basedir)
        self._branch = branch
        self.basedir = realpath(basedir)
        # if branch is at our basedir and is a format 6 or less
        # assume all other formats have their own control files.
        self._control_files = _control_files
        self._transport = self._control_files._transport
        self._dirty = None
        #-------------
        # during a read or write lock these objects are set, and are
        # None the rest of the time.
        self._dirstate = None
        self._inventory = None
        #-------------
        self._setup_directory_is_tree_reference()
        self._detect_case_handling()
        self._rules_searcher = None
        self.views = self._make_views()
        #--- allow tests to select the dirstate iter_changes implementation
        self._iter_changes = dirstate._process_entry

    @needs_tree_write_lock
    def _add(self, files, ids, kinds):
        """See MutableTree._add."""
        state = self.current_dirstate()
        for f, file_id, kind in zip(files, ids, kinds):
            f = f.strip('/')
            if self.path2id(f):
                # special case tree root handling.
                if f == '' and self.path2id(f) == ROOT_ID:
                    state.set_path_id('', generate_ids.gen_file_id(f))
                continue
            if file_id is None:
                file_id = generate_ids.gen_file_id(f)
            # deliberately add the file with no cached stat or sha1
            # - on the first access it will be gathered, and we can
            # always change this once tests are all passing.
            state.add(f, file_id, kind, None, '')
        self._make_dirty(reset_inventory=True)

    def _make_dirty(self, reset_inventory):
        """Make the tree state dirty.

        :param reset_inventory: True if the cached inventory should be removed
            (presuming there is one).
        """
        self._dirty = True
        if reset_inventory and self._inventory is not None:
            self._inventory = None

    @needs_tree_write_lock
    def add_reference(self, sub_tree):
        # use standard implementation, which calls back to self._add
        #
        # So we don't store the reference_revision in the working dirstate,
        # it's just recorded at the moment of commit.
        self._add_reference(sub_tree)

    def break_lock(self):
        """Break a lock if one is present from another instance.

        Uses the ui factory to ask for confirmation if the lock may be from
        an active process.

        This will probe the repository for its lock as well.
        """
        # if the dirstate is locked by an active process, reject the break lock
        # call.
        try:
            if self._dirstate is None:
                clear = True
            else:
                clear = False
            state = self._current_dirstate()
            if state._lock_token is not None:
                # we already have it locked. sheese, cant break our own lock.
                raise errors.LockActive(self.basedir)
            else:
                try:
                    # try for a write lock - need permission to get one anyhow
                    # to break locks.
                    state.lock_write()
                except errors.LockContention:
                    # oslocks fail when a process is still live: fail.
                    # TODO: get the locked lockdir info and give to the user to
                    # assist in debugging.
                    raise errors.LockActive(self.basedir)
                else:
                    state.unlock()
        finally:
            if clear:
                self._dirstate = None
        self._control_files.break_lock()
        self.branch.break_lock()

    def _comparison_data(self, entry, path):
        kind, executable, stat_value = \
            WorkingTree3._comparison_data(self, entry, path)
        # it looks like a plain directory, but it's really a reference -- see
        # also kind()
        if (self._repo_supports_tree_reference and kind == 'directory'
            and entry is not None and entry.kind == 'tree-reference'):
            kind = 'tree-reference'
        return kind, executable, stat_value

    @needs_write_lock
    def commit(self, message=None, revprops=None, *args, **kwargs):
        # mark the tree as dirty post commit - commit
        # can change the current versioned list by doing deletes.
        result = WorkingTree3.commit(self, message, revprops, *args, **kwargs)
        self._make_dirty(reset_inventory=True)
        return result

    def current_dirstate(self):
        """Return the current dirstate object.

        This is not part of the tree interface and only exposed for ease of
        testing.

        :raises errors.NotWriteLocked: when not in a lock.
        """
        self._must_be_locked()
        return self._current_dirstate()

    def _current_dirstate(self):
        """Internal function that does not check lock status.

        This is needed for break_lock which also needs the dirstate.
        """
        if self._dirstate is not None:
            return self._dirstate
        local_path = self.bzrdir.get_workingtree_transport(None
            ).local_abspath('dirstate')
        self._dirstate = dirstate.DirState.on_file(local_path,
            self._sha1_provider())
        return self._dirstate

    def _sha1_provider(self):
        """A function that returns a SHA1Provider suitable for this tree.

        :return: None if content filtering is not supported by this tree.
          Otherwise, a SHA1Provider is returned that sha's the canonical
          form of files, i.e. after read filters are applied.
        """
        if self.supports_content_filtering():
            return ContentFilterAwareSHA1Provider(self)
        else:
            return None

    def filter_unversioned_files(self, paths):
        """Filter out paths that are versioned.

        :return: set of paths.
        """
        # TODO: make a generic multi-bisect routine roughly that should list
        # the paths, then process one half at a time recursively, and feed the
        # results of each bisect in further still
        paths = sorted(paths)
        result = set()
        state = self.current_dirstate()
        # TODO we want a paths_to_dirblocks helper I think
        for path in paths:
            dirname, basename = os.path.split(path.encode('utf8'))
            _, _, _, path_is_versioned = state._get_block_entry_index(
                dirname, basename, 0)
            if not path_is_versioned:
                result.add(path)
        return result

    def flush(self):
        """Write all cached data to disk."""
        if self._control_files._lock_mode != 'w':
            raise errors.NotWriteLocked(self)
        self.current_dirstate().save()
        self._inventory = None
        self._dirty = False

    @needs_tree_write_lock
    def _gather_kinds(self, files, kinds):
        """See MutableTree._gather_kinds."""
        for pos, f in enumerate(files):
            if kinds[pos] is None:
                kinds[pos] = self._kind(f)

    def _generate_inventory(self):
        """Create and set self.inventory from the dirstate object.

        This is relatively expensive: we have to walk the entire dirstate.
        Ideally we would not, and can deprecate this function.
        """
        #: uncomment to trap on inventory requests.
        # import pdb;pdb.set_trace()
        state = self.current_dirstate()
        state._read_dirblocks_if_needed()
        root_key, current_entry = self._get_entry(path='')
        current_id = root_key[2]
        if not (current_entry[0][0] == 'd'): # directory
            raise AssertionError(current_entry)
        inv = Inventory(root_id=current_id)
        # Turn some things into local variables
        minikind_to_kind = dirstate.DirState._minikind_to_kind
        factory = entry_factory
        utf8_decode = cache_utf8._utf8_decode
        inv_byid = inv._byid
        # we could do this straight out of the dirstate; it might be fast
        # and should be profiled - RBC 20070216
        parent_ies = {'' : inv.root}
        for block in state._dirblocks[1:]: # skip the root
            dirname = block[0]
            try:
                parent_ie = parent_ies[dirname]
            except KeyError:
                # all the paths in this block are not versioned in this tree
                continue
            for key, entry in block[1]:
                minikind, link_or_sha1, size, executable, stat = entry[0]
                if minikind in ('a', 'r'): # absent, relocated
                    # a parent tree only entry
                    continue
                name = key[1]
                name_unicode = utf8_decode(name)[0]
                file_id = key[2]
                kind = minikind_to_kind[minikind]
                inv_entry = factory[kind](file_id, name_unicode,
                                          parent_ie.file_id)
                if kind == 'file':
                    # This is only needed on win32, where this is the only way
                    # we know the executable bit.
                    inv_entry.executable = executable
                    # not strictly needed: working tree
                    #inv_entry.text_size = size
                    #inv_entry.text_sha1 = sha1
                elif kind == 'directory':
                    # add this entry to the parent map.
                    parent_ies[(dirname + '/' + name).strip('/')] = inv_entry
                elif kind == 'tree-reference':
                    if not self._repo_supports_tree_reference:
                        raise errors.UnsupportedOperation(
                            self._generate_inventory,
                            self.branch.repository)
                    inv_entry.reference_revision = link_or_sha1 or None
                elif kind != 'symlink':
                    raise AssertionError("unknown kind %r" % kind)
                # These checks cost us around 40ms on a 55k entry tree
                if file_id in inv_byid:
                    raise AssertionError('file_id %s already in'
                        ' inventory as %s' % (file_id, inv_byid[file_id]))
                if name_unicode in parent_ie.children:
                    raise AssertionError('name %r already in parent'
                        % (name_unicode,))
                inv_byid[file_id] = inv_entry
                parent_ie.children[name_unicode] = inv_entry
        self._inventory = inv

    def _get_entry(self, file_id=None, path=None):
        """Get the dirstate row for file_id or path.

        If either file_id or path is supplied, it is used as the key to lookup.
        If both are supplied, the fastest lookup is used, and an error is
        raised if they do not both point at the same row.

        :param file_id: An optional unicode file_id to be looked up.
        :param path: An optional unicode path to be looked up.
        :return: The dirstate row tuple for path/file_id, or (None, None)
        """
        if file_id is None and path is None:
            raise errors.BzrError('must supply file_id or path')
        state = self.current_dirstate()
        if path is not None:
            path = path.encode('utf8')
        return state._get_entry(0, fileid_utf8=file_id, path_utf8=path)

    def get_file_sha1(self, file_id, path=None, stat_value=None):
        # check file id is valid unconditionally.
        entry = self._get_entry(file_id=file_id, path=path)
        if entry[0] is None:
            raise errors.NoSuchId(self, file_id)
        if path is None:
            path = pathjoin(entry[0][0], entry[0][1]).decode('utf8')

        file_abspath = self.abspath(path)
        state = self.current_dirstate()
        if stat_value is None:
            try:
                stat_value = os.lstat(file_abspath)
            except OSError, e:
                if e.errno == errno.ENOENT:
                    return None
                else:
                    raise
        link_or_sha1 = dirstate.update_entry(state, entry, file_abspath,
            stat_value=stat_value)
        if entry[1][0][0] == 'f':
            if link_or_sha1 is None:
                file_obj, statvalue = self.get_file_with_stat(file_id, path)
                try:
                    sha1 = osutils.sha_file(file_obj)
                finally:
                    file_obj.close()
                self._observed_sha1(file_id, path, (sha1, statvalue))
                return sha1
            else:
                return link_or_sha1
        return None

    def _get_inventory(self):
        """Get the inventory for the tree. This is only valid within a lock."""
        if 'evil' in debug.debug_flags:
            trace.mutter_callsite(2,
                "accessing .inventory forces a size of tree translation.")
        if self._inventory is not None:
            return self._inventory
        self._must_be_locked()
        self._generate_inventory()
        return self._inventory

    inventory = property(_get_inventory,
                         doc="Inventory of this Tree")

    @needs_read_lock
    def get_parent_ids(self):
        """See Tree.get_parent_ids.

        This implementation requests the ids list from the dirstate file.
        """
        return self.current_dirstate().get_parent_ids()

    def get_reference_revision(self, file_id, path=None):
        # referenced tree's revision is whatever's currently there
        return self.get_nested_tree(file_id, path).last_revision()

    def get_nested_tree(self, file_id, path=None):
        if path is None:
            path = self.id2path(file_id)
        # else: check file_id is at path?
        return WorkingTree.open(self.abspath(path))

    @needs_read_lock
    def get_root_id(self):
        """Return the id of this trees root"""
        return self._get_entry(path='')[0][2]

    def has_id(self, file_id):
        state = self.current_dirstate()
        row, parents = self._get_entry(file_id=file_id)
        if row is None:
            return False
        return osutils.lexists(pathjoin(
                    self.basedir, row[0].decode('utf8'), row[1].decode('utf8')))

    def has_or_had_id(self, file_id):
        state = self.current_dirstate()
        row, parents = self._get_entry(file_id=file_id)
        return row is not None

    @needs_read_lock
    def id2path(self, file_id):
        "Convert a file-id to a path."
        state = self.current_dirstate()
        entry = self._get_entry(file_id=file_id)
        if entry == (None, None):
            raise errors.NoSuchId(tree=self, file_id=file_id)
        path_utf8 = osutils.pathjoin(entry[0][0], entry[0][1])
        return path_utf8.decode('utf8')

    def _is_executable_from_path_and_stat_from_basis(self, path, stat_result):
        entry = self._get_entry(path=path)
        if entry == (None, None):
            return False # Missing entries are not executable
        return entry[1][0][3] # Executable?

    if not osutils.supports_executable():
        def is_executable(self, file_id, path=None):
            """Test if a file is executable or not.

            Note: The caller is expected to take a read-lock before calling this.
            """
            entry = self._get_entry(file_id=file_id, path=path)
            if entry == (None, None):
                return False
            return entry[1][0][3]

        _is_executable_from_path_and_stat = \
            _is_executable_from_path_and_stat_from_basis
    else:
        def is_executable(self, file_id, path=None):
            """Test if a file is executable or not.

            Note: The caller is expected to take a read-lock before calling this.
            """
            self._must_be_locked()
            if not path:
                path = self.id2path(file_id)
            mode = os.lstat(self.abspath(path)).st_mode
            return bool(stat.S_ISREG(mode) and stat.S_IEXEC & mode)

    def all_file_ids(self):
        """See Tree.iter_all_file_ids"""
        self._must_be_locked()
        result = set()
        for key, tree_details in self.current_dirstate()._iter_entries():
            if tree_details[0][0] in ('a', 'r'): # relocated
                continue
            result.add(key[2])
        return result

    @needs_read_lock
    def __iter__(self):
        """Iterate through file_ids for this tree.

        file_ids are in a WorkingTree if they are in the working inventory
        and the working file exists.
        """
        result = []
        for key, tree_details in self.current_dirstate()._iter_entries():
            if tree_details[0][0] in ('a', 'r'): # absent, relocated
                # not relevant to the working tree
                continue
            path = pathjoin(self.basedir, key[0].decode('utf8'), key[1].decode('utf8'))
            if osutils.lexists(path):
                result.append(key[2])
        return iter(result)

    def iter_references(self):
        if not self._repo_supports_tree_reference:
            # When the repo doesn't support references, we will have nothing to
            # return
            return
        for key, tree_details in self.current_dirstate()._iter_entries():
            if tree_details[0][0] in ('a', 'r'): # absent, relocated
                # not relevant to the working tree
                continue
            if not key[1]:
                # the root is not a reference.
                continue
            relpath = pathjoin(key[0].decode('utf8'), key[1].decode('utf8'))
            try:
                if self._kind(relpath) == 'tree-reference':
                    yield relpath, key[2]
            except errors.NoSuchFile:
                # path is missing on disk.
                continue

    def _observed_sha1(self, file_id, path, (sha1, statvalue)):
        """See MutableTree._observed_sha1."""
        state = self.current_dirstate()
        entry = self._get_entry(file_id=file_id, path=path)
        state._observed_sha1(entry, sha1, statvalue)

    def kind(self, file_id):
        """Return the kind of a file.

        This is always the actual kind that's on disk, regardless of what it
        was added as.

        Note: The caller is expected to take a read-lock before calling this.
        """
        relpath = self.id2path(file_id)
        if relpath is None:
            raise AssertionError(
                "path for id {%s} is None!" % file_id)
        return self._kind(relpath)

    def _kind(self, relpath):
        abspath = self.abspath(relpath)
        kind = file_kind(abspath)
        if (self._repo_supports_tree_reference and kind == 'directory'):
            entry = self._get_entry(path=relpath)
            if entry[1] is not None:
                if entry[1][0][0] == 't':
                    kind = 'tree-reference'
        return kind

    @needs_read_lock
    def _last_revision(self):
        """See Mutable.last_revision."""
        parent_ids = self.current_dirstate().get_parent_ids()
        if parent_ids:
            return parent_ids[0]
        else:
            return _mod_revision.NULL_REVISION

    def lock_read(self):
        """See Branch.lock_read, and WorkingTree.unlock.

        :return: A bzrlib.lock.LogicalLockResult.
        """
        self.branch.lock_read()
        try:
            self._control_files.lock_read()
            try:
                state = self.current_dirstate()
                if not state._lock_token:
                    state.lock_read()
                # set our support for tree references from the repository in
                # use.
                self._repo_supports_tree_reference = getattr(
                    self.branch.repository._format, "supports_tree_reference",
                    False)
            except:
                self._control_files.unlock()
                raise
        except:
            self.branch.unlock()
            raise
        return LogicalLockResult(self.unlock)

    def _lock_self_write(self):
        """This should be called after the branch is locked."""
        try:
            self._control_files.lock_write()
            try:
                state = self.current_dirstate()
                if not state._lock_token:
                    state.lock_write()
                # set our support for tree references from the repository in
                # use.
                self._repo_supports_tree_reference = getattr(
                    self.branch.repository._format, "supports_tree_reference",
                    False)
            except:
                self._control_files.unlock()
                raise
        except:
            self.branch.unlock()
            raise
        return LogicalLockResult(self.unlock)

    def lock_tree_write(self):
        """See MutableTree.lock_tree_write, and WorkingTree.unlock.

        :return: A bzrlib.lock.LogicalLockResult.
        """
        self.branch.lock_read()
        return self._lock_self_write()

    def lock_write(self):
        """See MutableTree.lock_write, and WorkingTree.unlock.

        :return: A bzrlib.lock.LogicalLockResult.
        """
        self.branch.lock_write()
        return self._lock_self_write()

    @needs_tree_write_lock
    def move(self, from_paths, to_dir, after=False):
        """See WorkingTree.move()."""
        result = []
        if not from_paths:
            return result
        state = self.current_dirstate()
        if isinstance(from_paths, basestring):
            raise ValueError()
        to_dir_utf8 = to_dir.encode('utf8')
        to_entry_dirname, to_basename = os.path.split(to_dir_utf8)
        id_index = state._get_id_index()
        # check destination directory
        # get the details for it
        to_entry_block_index, to_entry_entry_index, dir_present, entry_present = \
            state._get_block_entry_index(to_entry_dirname, to_basename, 0)
        if not entry_present:
            raise errors.BzrMoveFailedError('', to_dir,
                errors.NotVersionedError(to_dir))
        to_entry = state._dirblocks[to_entry_block_index][1][to_entry_entry_index]
        # get a handle on the block itself.
        to_block_index = state._ensure_block(
            to_entry_block_index, to_entry_entry_index, to_dir_utf8)
        to_block = state._dirblocks[to_block_index]
        to_abs = self.abspath(to_dir)
        if not isdir(to_abs):
            raise errors.BzrMoveFailedError('',to_dir,
                errors.NotADirectory(to_abs))

        if to_entry[1][0][0] != 'd':
            raise errors.BzrMoveFailedError('',to_dir,
                errors.NotADirectory(to_abs))

        if self._inventory is not None:
            update_inventory = True
            inv = self.inventory
            to_dir_id = to_entry[0][2]
            to_dir_ie = inv[to_dir_id]
        else:
            update_inventory = False

        rollbacks = []
        def move_one(old_entry, from_path_utf8, minikind, executable,
                     fingerprint, packed_stat, size,
                     to_block, to_key, to_path_utf8):
            state._make_absent(old_entry)
            from_key = old_entry[0]
            rollbacks.append(
                lambda:state.update_minimal(from_key,
                    minikind,
                    executable=executable,
                    fingerprint=fingerprint,
                    packed_stat=packed_stat,
                    size=size,
                    path_utf8=from_path_utf8))
            state.update_minimal(to_key,
                    minikind,
                    executable=executable,
                    fingerprint=fingerprint,
                    packed_stat=packed_stat,
                    size=size,
                    path_utf8=to_path_utf8)
            added_entry_index, _ = state._find_entry_index(to_key, to_block[1])
            new_entry = to_block[1][added_entry_index]
            rollbacks.append(lambda:state._make_absent(new_entry))

        for from_rel in from_paths:
            # from_rel is 'pathinroot/foo/bar'
            from_rel_utf8 = from_rel.encode('utf8')
            from_dirname, from_tail = osutils.split(from_rel)
            from_dirname, from_tail_utf8 = osutils.split(from_rel_utf8)
            from_entry = self._get_entry(path=from_rel)
            if from_entry == (None, None):
                raise errors.BzrMoveFailedError(from_rel,to_dir,
                    errors.NotVersionedError(path=from_rel))

            from_id = from_entry[0][2]
            to_rel = pathjoin(to_dir, from_tail)
            to_rel_utf8 = pathjoin(to_dir_utf8, from_tail_utf8)
            item_to_entry = self._get_entry(path=to_rel)
            if item_to_entry != (None, None):
                raise errors.BzrMoveFailedError(from_rel, to_rel,
                    "Target is already versioned.")

            if from_rel == to_rel:
                raise errors.BzrMoveFailedError(from_rel, to_rel,
                    "Source and target are identical.")

            from_missing = not self.has_filename(from_rel)
            to_missing = not self.has_filename(to_rel)
            if after:
                move_file = False
            else:
                move_file = True
            if to_missing:
                if not move_file:
                    raise errors.BzrMoveFailedError(from_rel, to_rel,
                        errors.NoSuchFile(path=to_rel,
                        extra="New file has not been created yet"))
                elif from_missing:
                    # neither path exists
                    raise errors.BzrRenameFailedError(from_rel, to_rel,
                        errors.PathsDoNotExist(paths=(from_rel, to_rel)))
            else:
                if from_missing: # implicitly just update our path mapping
                    move_file = False
                elif not after:
                    raise errors.RenameFailedFilesExist(from_rel, to_rel)

            rollbacks = []
            def rollback_rename():
                """A single rename has failed, roll it back."""
                # roll back everything, even if we encounter trouble doing one
                # of them.
                #
                # TODO: at least log the other exceptions rather than just
                # losing them mbp 20070307
                exc_info = None
                for rollback in reversed(rollbacks):
                    try:
                        rollback()
                    except Exception, e:
                        exc_info = sys.exc_info()
                if exc_info:
                    raise exc_info[0], exc_info[1], exc_info[2]

            # perform the disk move first - its the most likely failure point.
            if move_file:
                from_rel_abs = self.abspath(from_rel)
                to_rel_abs = self.abspath(to_rel)
                try:
                    osutils.rename(from_rel_abs, to_rel_abs)
                except OSError, e:
                    raise errors.BzrMoveFailedError(from_rel, to_rel, e[1])
                rollbacks.append(lambda: osutils.rename(to_rel_abs, from_rel_abs))
            try:
                # perform the rename in the inventory next if needed: its easy
                # to rollback
                if update_inventory:
                    # rename the entry
                    from_entry = inv[from_id]
                    current_parent = from_entry.parent_id
                    inv.rename(from_id, to_dir_id, from_tail)
                    rollbacks.append(
                        lambda: inv.rename(from_id, current_parent, from_tail))
                # finally do the rename in the dirstate, which is a little
                # tricky to rollback, but least likely to need it.
                old_block_index, old_entry_index, dir_present, file_present = \
                    state._get_block_entry_index(from_dirname, from_tail_utf8, 0)
                old_block = state._dirblocks[old_block_index][1]
                old_entry = old_block[old_entry_index]
                from_key, old_entry_details = old_entry
                cur_details = old_entry_details[0]
                # remove the old row
                to_key = ((to_block[0],) + from_key[1:3])
                minikind = cur_details[0]
                move_one(old_entry, from_path_utf8=from_rel_utf8,
                         minikind=minikind,
                         executable=cur_details[3],
                         fingerprint=cur_details[1],
                         packed_stat=cur_details[4],
                         size=cur_details[2],
                         to_block=to_block,
                         to_key=to_key,
                         to_path_utf8=to_rel_utf8)

                if minikind == 'd':
                    def update_dirblock(from_dir, to_key, to_dir_utf8):
                        """Recursively update all entries in this dirblock."""
                        if from_dir == '':
                            raise AssertionError("renaming root not supported")
                        from_key = (from_dir, '')
                        from_block_idx, present = \
                            state._find_block_index_from_key(from_key)
                        if not present:
                            # This is the old record, if it isn't present, then
                            # there is theoretically nothing to update.
                            # (Unless it isn't present because of lazy loading,
                            # but we don't do that yet)
                            return
                        from_block = state._dirblocks[from_block_idx]
                        to_block_index, to_entry_index, _, _ = \
                            state._get_block_entry_index(to_key[0], to_key[1], 0)
                        to_block_index = state._ensure_block(
                            to_block_index, to_entry_index, to_dir_utf8)
                        to_block = state._dirblocks[to_block_index]

                        # Grab a copy since move_one may update the list.
                        for entry in from_block[1][:]:
                            if not (entry[0][0] == from_dir):
                                raise AssertionError()
                            cur_details = entry[1][0]
                            to_key = (to_dir_utf8, entry[0][1], entry[0][2])
                            from_path_utf8 = osutils.pathjoin(entry[0][0], entry[0][1])
                            to_path_utf8 = osutils.pathjoin(to_dir_utf8, entry[0][1])
                            minikind = cur_details[0]
                            if minikind in 'ar':
                                # Deleted children of a renamed directory
                                # Do not need to be updated.
                                # Children that have been renamed out of this
                                # directory should also not be updated
                                continue
                            move_one(entry, from_path_utf8=from_path_utf8,
                                     minikind=minikind,
                                     executable=cur_details[3],
                                     fingerprint=cur_details[1],
                                     packed_stat=cur_details[4],
                                     size=cur_details[2],
                                     to_block=to_block,
                                     to_key=to_key,
                                     to_path_utf8=to_path_utf8)
                            if minikind == 'd':
                                # We need to move all the children of this
                                # entry
                                update_dirblock(from_path_utf8, to_key,
                                                to_path_utf8)
                    update_dirblock(from_rel_utf8, to_key, to_rel_utf8)
            except:
                rollback_rename()
                raise
            result.append((from_rel, to_rel))
            state._dirblock_state = dirstate.DirState.IN_MEMORY_MODIFIED
            self._make_dirty(reset_inventory=False)

        return result

    def _must_be_locked(self):
        if not self._control_files._lock_count:
            raise errors.ObjectNotLocked(self)

    def _new_tree(self):
        """Initialize the state in this tree to be a new tree."""
        self._dirty = True

    @needs_read_lock
    def path2id(self, path):
        """Return the id for path in this tree."""
        path = path.strip('/')
        entry = self._get_entry(path=path)
        if entry == (None, None):
            return None
        return entry[0][2]

    def paths2ids(self, paths, trees=[], require_versioned=True):
        """See Tree.paths2ids().

        This specialisation fast-paths the case where all the trees are in the
        dirstate.
        """
        if paths is None:
            return None
        parents = self.get_parent_ids()
        for tree in trees:
            if not (isinstance(tree, DirStateRevisionTree) and tree._revision_id in
                parents):
                return super(DirStateWorkingTree, self).paths2ids(paths,
                    trees, require_versioned)
        search_indexes = [0] + [1 + parents.index(tree._revision_id) for tree in trees]
        # -- make all paths utf8 --
        paths_utf8 = set()
        for path in paths:
            paths_utf8.add(path.encode('utf8'))
        paths = paths_utf8
        # -- paths is now a utf8 path set --
        # -- get the state object and prepare it.
        state = self.current_dirstate()
        if False and (state._dirblock_state == dirstate.DirState.NOT_IN_MEMORY
            and '' not in paths):
            paths2ids = self._paths2ids_using_bisect
        else:
            paths2ids = self._paths2ids_in_memory
        return paths2ids(paths, search_indexes,
                         require_versioned=require_versioned)

    def _paths2ids_in_memory(self, paths, search_indexes,
                             require_versioned=True):
        state = self.current_dirstate()
        state._read_dirblocks_if_needed()
        def _entries_for_path(path):
            """Return a list with all the entries that match path for all ids.
            """
            dirname, basename = os.path.split(path)
            key = (dirname, basename, '')
            block_index, present = state._find_block_index_from_key(key)
            if not present:
                # the block which should contain path is absent.
                return []
            result = []
            block = state._dirblocks[block_index][1]
            entry_index, _ = state._find_entry_index(key, block)
            # we may need to look at multiple entries at this path: walk while the paths match.
            while (entry_index < len(block) and
                block[entry_index][0][0:2] == key[0:2]):
                result.append(block[entry_index])
                entry_index += 1
            return result
        if require_versioned:
            # -- check all supplied paths are versioned in a search tree. --
            all_versioned = True
            for path in paths:
                path_entries = _entries_for_path(path)
                if not path_entries:
                    # this specified path is not present at all: error
                    all_versioned = False
                    break
                found_versioned = False
                # for each id at this path
                for entry in path_entries:
                    # for each tree.
                    for index in search_indexes:
                        if entry[1][index][0] != 'a': # absent
                            found_versioned = True
                            # all good: found a versioned cell
                            break
                if not found_versioned:
                    # none of the indexes was not 'absent' at all ids for this
                    # path.
                    all_versioned = False
                    break
            if not all_versioned:
                raise errors.PathsNotVersionedError(paths)
        # -- remove redundancy in supplied paths to prevent over-scanning --
        search_paths = osutils.minimum_path_selection(paths)
        # sketch:
        # for all search_indexs in each path at or under each element of
        # search_paths, if the detail is relocated: add the id, and add the
        # relocated path as one to search if its not searched already. If the
        # detail is not relocated, add the id.
        searched_paths = set()
        found_ids = set()
        def _process_entry(entry):
            """Look at search_indexes within entry.

            If a specific tree's details are relocated, add the relocation
            target to search_paths if not searched already. If it is absent, do
            nothing. Otherwise add the id to found_ids.
            """
            for index in search_indexes:
                if entry[1][index][0] == 'r': # relocated
                    if not osutils.is_inside_any(searched_paths, entry[1][index][1]):
                        search_paths.add(entry[1][index][1])
                elif entry[1][index][0] != 'a': # absent
                    found_ids.add(entry[0][2])
        while search_paths:
            current_root = search_paths.pop()
            searched_paths.add(current_root)
            # process the entries for this containing directory: the rest will be
            # found by their parents recursively.
            root_entries = _entries_for_path(current_root)
            if not root_entries:
                # this specified path is not present at all, skip it.
                continue
            for entry in root_entries:
                _process_entry(entry)
            initial_key = (current_root, '', '')
            block_index, _ = state._find_block_index_from_key(initial_key)
            while (block_index < len(state._dirblocks) and
                osutils.is_inside(current_root, state._dirblocks[block_index][0])):
                for entry in state._dirblocks[block_index][1]:
                    _process_entry(entry)
                block_index += 1
        return found_ids

    def _paths2ids_using_bisect(self, paths, search_indexes,
                                require_versioned=True):
        state = self.current_dirstate()
        found_ids = set()

        split_paths = sorted(osutils.split(p) for p in paths)
        found = state._bisect_recursive(split_paths)

        if require_versioned:
            found_dir_names = set(dir_name_id[:2] for dir_name_id in found)
            for dir_name in split_paths:
                if dir_name not in found_dir_names:
                    raise errors.PathsNotVersionedError(paths)

        for dir_name_id, trees_info in found.iteritems():
            for index in search_indexes:
                if trees_info[index][0] not in ('r', 'a'):
                    found_ids.add(dir_name_id[2])
        return found_ids

    def read_working_inventory(self):
        """Read the working inventory.

        This is a meaningless operation for dirstate, but we obey it anyhow.
        """
        return self.inventory

    @needs_read_lock
    def revision_tree(self, revision_id):
        """See Tree.revision_tree.

        WorkingTree4 supplies revision_trees for any basis tree.
        """
        dirstate = self.current_dirstate()
        parent_ids = dirstate.get_parent_ids()
        if revision_id not in parent_ids:
            raise errors.NoSuchRevisionInTree(self, revision_id)
        if revision_id in dirstate.get_ghosts():
            raise errors.NoSuchRevisionInTree(self, revision_id)
        return DirStateRevisionTree(dirstate, revision_id,
            self.branch.repository)

    @needs_tree_write_lock
    def set_last_revision(self, new_revision):
        """Change the last revision in the working tree."""
        parents = self.get_parent_ids()
        if new_revision in (_mod_revision.NULL_REVISION, None):
            if len(parents) >= 2:
                raise AssertionError(
                    "setting the last parent to none with a pending merge is "
                    "unsupported.")
            self.set_parent_ids([])
        else:
            self.set_parent_ids([new_revision] + parents[1:],
                allow_leftmost_as_ghost=True)

    @needs_tree_write_lock
    def set_parent_ids(self, revision_ids, allow_leftmost_as_ghost=False):
        """Set the parent ids to revision_ids.

        See also set_parent_trees. This api will try to retrieve the tree data
        for each element of revision_ids from the trees repository. If you have
        tree data already available, it is more efficient to use
        set_parent_trees rather than set_parent_ids. set_parent_ids is however
        an easier API to use.

        :param revision_ids: The revision_ids to set as the parent ids of this
            working tree. Any of these may be ghosts.
        """
        trees = []
        for revision_id in revision_ids:
            try:
                revtree = self.branch.repository.revision_tree(revision_id)
                # TODO: jam 20070213 KnitVersionedFile raises
                #       RevisionNotPresent rather than NoSuchRevision if a
                #       given revision_id is not present. Should Repository be
                #       catching it and re-raising NoSuchRevision?
            except (errors.NoSuchRevision, errors.RevisionNotPresent):
                revtree = None
            trees.append((revision_id, revtree))
        self.set_parent_trees(trees,
            allow_leftmost_as_ghost=allow_leftmost_as_ghost)

    @needs_tree_write_lock
    def set_parent_trees(self, parents_list, allow_leftmost_as_ghost=False):
        """Set the parents of the working tree.

        :param parents_list: A list of (revision_id, tree) tuples.
            If tree is None, then that element is treated as an unreachable
            parent tree - i.e. a ghost.
        """
        dirstate = self.current_dirstate()
        if len(parents_list) > 0:
            if not allow_leftmost_as_ghost and parents_list[0][1] is None:
                raise errors.GhostRevisionUnusableHere(parents_list[0][0])
        real_trees = []
        ghosts = []

        parent_ids = [rev_id for rev_id, tree in parents_list]
        graph = self.branch.repository.get_graph()
        heads = graph.heads(parent_ids)
        accepted_revisions = set()

        # convert absent trees to the null tree, which we convert back to
        # missing on access.
        for rev_id, tree in parents_list:
            if len(accepted_revisions) > 0:
                # we always accept the first tree
                if rev_id in accepted_revisions or rev_id not in heads:
                    # We have already included either this tree, or its
                    # descendent, so we skip it.
                    continue
            _mod_revision.check_not_reserved_id(rev_id)
            if tree is not None:
                real_trees.append((rev_id, tree))
            else:
                real_trees.append((rev_id,
                    self.branch.repository.revision_tree(
                        _mod_revision.NULL_REVISION)))
                ghosts.append(rev_id)
            accepted_revisions.add(rev_id)
        dirstate.set_parent_trees(real_trees, ghosts=ghosts)
        self._make_dirty(reset_inventory=False)

    def _set_root_id(self, file_id):
        """See WorkingTree.set_root_id."""
        state = self.current_dirstate()
        state.set_path_id('', file_id)
        if state._dirblock_state == dirstate.DirState.IN_MEMORY_MODIFIED:
            self._make_dirty(reset_inventory=True)

    def _sha_from_stat(self, path, stat_result):
        """Get a sha digest from the tree's stat cache.

        The default implementation assumes no stat cache is present.

        :param path: The path.
        :param stat_result: The stat result being looked up.
        """
        return self.current_dirstate().sha1_from_stat(path, stat_result)

    @needs_read_lock
    def supports_tree_reference(self):
        return self._repo_supports_tree_reference

    def unlock(self):
        """Unlock in format 4 trees needs to write the entire dirstate."""
        # do non-implementation specific cleanup
        self._cleanup()

        if self._control_files._lock_count == 1:
            # eventually we should do signature checking during read locks for
            # dirstate updates.
            if self._control_files._lock_mode == 'w':
                if self._dirty:
                    self.flush()
            if self._dirstate is not None:
                # This is a no-op if there are no modifications.
                self._dirstate.save()
                self._dirstate.unlock()
            # TODO: jam 20070301 We shouldn't have to wipe the dirstate at this
            #       point. Instead, it could check if the header has been
            #       modified when it is locked, and if not, it can hang on to
            #       the data it has in memory.
            self._dirstate = None
            self._inventory = None
        # reverse order of locking.
        try:
            return self._control_files.unlock()
        finally:
            self.branch.unlock()

    @needs_tree_write_lock
    def unversion(self, file_ids):
        """Remove the file ids in file_ids from the current versioned set.

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

        :param file_ids: The file ids to stop versioning.
        :raises: NoSuchId if any fileid is not currently versioned.
        """
        if not file_ids:
            return
        state = self.current_dirstate()
        state._read_dirblocks_if_needed()
        ids_to_unversion = set(file_ids)
        paths_to_unversion = set()
        # sketch:
        # check if the root is to be unversioned, if so, assert for now.
        # walk the state marking unversioned things as absent.
        # if there are any un-unversioned ids at the end, raise
        for key, details in state._dirblocks[0][1]:
            if (details[0][0] not in ('a', 'r') and # absent or relocated
                key[2] in ids_to_unversion):
                # I haven't written the code to unversion / yet - it should be
                # supported.
                raise errors.BzrError('Unversioning the / is not currently supported')
        block_index = 0
        while block_index < len(state._dirblocks):
            # process one directory at a time.
            block = state._dirblocks[block_index]
            # first check: is the path one to remove - it or its children
            delete_block = False
            for path in paths_to_unversion:
                if (block[0].startswith(path) and
                    (len(block[0]) == len(path) or
                     block[0][len(path)] == '/')):
                    # this entire block should be deleted - its the block for a
                    # path to unversion; or the child of one
                    delete_block = True
                    break
            # TODO: trim paths_to_unversion as we pass by paths
            if delete_block:
                # this block is to be deleted: process it.
                # TODO: we can special case the no-parents case and
                # just forget the whole block.
                entry_index = 0
                while entry_index < len(block[1]):
                    entry = block[1][entry_index]
                    if entry[1][0][0] in 'ar':
                        # don't remove absent or renamed entries
                        entry_index += 1
                    else:
                        # Mark this file id as having been removed
                        ids_to_unversion.discard(entry[0][2])
                        if not state._make_absent(entry):
                            # The block has not shrunk.
                            entry_index += 1
                # go to the next block. (At the moment we dont delete empty
                # dirblocks)
                block_index += 1
                continue
            entry_index = 0
            while entry_index < len(block[1]):
                entry = block[1][entry_index]
                if (entry[1][0][0] in ('a', 'r') or # absent, relocated
                    # ^ some parent row.
                    entry[0][2] not in ids_to_unversion):
                    # ^ not an id to unversion
                    entry_index += 1
                    continue
                if entry[1][0][0] == 'd':
                    paths_to_unversion.add(pathjoin(entry[0][0], entry[0][1]))
                if not state._make_absent(entry):
                    entry_index += 1
                # we have unversioned this id
                ids_to_unversion.remove(entry[0][2])
            block_index += 1
        if ids_to_unversion:
            raise errors.NoSuchId(self, iter(ids_to_unversion).next())
        self._make_dirty(reset_inventory=False)
        # have to change the legacy inventory too.
        if self._inventory is not None:
            for file_id in file_ids:
                if self._inventory.has_id(file_id):
                    self._inventory.remove_recursive_id(file_id)

    @needs_tree_write_lock
    def rename_one(self, from_rel, to_rel, after=False):
        """See WorkingTree.rename_one"""
        self.flush()
        WorkingTree.rename_one(self, from_rel, to_rel, after)

    @needs_tree_write_lock
    def apply_inventory_delta(self, changes):
        """See MutableTree.apply_inventory_delta"""
        state = self.current_dirstate()
        state.update_by_delta(changes)
        self._make_dirty(reset_inventory=True)

    def update_basis_by_delta(self, new_revid, delta):
        """See MutableTree.update_basis_by_delta."""
        if self.last_revision() == new_revid:
            raise AssertionError()
        self.current_dirstate().update_basis_by_delta(delta, new_revid)

    @needs_read_lock
    def _validate(self):
        self._dirstate._validate()

    @needs_tree_write_lock
    def _write_inventory(self, inv):
        """Write inventory as the current inventory."""
        if self._dirty:
            raise AssertionError("attempting to write an inventory when the "
                "dirstate is dirty will lose pending changes")
        had_inventory = self._inventory is not None
        # Setting self._inventory = None forces the dirstate to regenerate the
        # working inventory. We do this because self.inventory may be inv, or
        # may have been modified, and either case would prevent a clean delta
        # being created.
        self._inventory = None
        # generate a delta,
        delta = inv._make_delta(self.inventory)
        # and apply it.
        self.apply_inventory_delta(delta)
        if had_inventory:
            self._inventory = inv
        self.flush()


class ContentFilterAwareSHA1Provider(dirstate.SHA1Provider):

    def __init__(self, tree):
        self.tree = tree

    def sha1(self, abspath):
        """See dirstate.SHA1Provider.sha1()."""
        filters = self.tree._content_filter_stack(
            self.tree.relpath(osutils.safe_unicode(abspath)))
        return internal_size_sha_file_byname(abspath, filters)[1]

    def stat_and_sha1(self, abspath):
        """See dirstate.SHA1Provider.stat_and_sha1()."""
        filters = self.tree._content_filter_stack(
            self.tree.relpath(osutils.safe_unicode(abspath)))
        file_obj = file(abspath, 'rb', 65000)
        try:
            statvalue = os.fstat(file_obj.fileno())
            if filters:
                file_obj = filtered_input_file(file_obj, filters)
            sha1 = osutils.size_sha_file(file_obj)[1]
        finally:
            file_obj.close()
        return statvalue, sha1


class ContentFilteringDirStateWorkingTree(DirStateWorkingTree):
    """Dirstate working tree that supports content filtering.

    The dirstate holds the hash and size of the canonical form of the file, 
    and most methods must return that.
    """

    def _file_content_summary(self, path, stat_result):
        # This is to support the somewhat obsolete path_content_summary method
        # with content filtering: see
        # <https://bugs.launchpad.net/bzr/+bug/415508>.
        #
        # If the dirstate cache is up to date and knows the hash and size,
        # return that.
        # Otherwise if there are no content filters, return the on-disk size
        # and leave the hash blank.
        # Otherwise, read and filter the on-disk file and use its size and
        # hash.
        #
        # The dirstate doesn't store the size of the canonical form so we
        # can't trust it for content-filtered trees.  We just return None.
        dirstate_sha1 = self._dirstate.sha1_from_stat(path, stat_result)
        executable = self._is_executable_from_path_and_stat(path, stat_result)
        return ('file', None, executable, dirstate_sha1)


class WorkingTree4(DirStateWorkingTree):
    """This is the Format 4 working tree.

    This differs from WorkingTree3 by:
     - Having a consolidated internal dirstate, stored in a
       randomly-accessible sorted file on disk.
     - Not having a regular inventory attribute.  One can be synthesized
       on demand but this is expensive and should be avoided.

    This is new in bzr 0.15.
    """


class WorkingTree5(ContentFilteringDirStateWorkingTree):
    """This is the Format 5 working tree.

    This differs from WorkingTree4 by:
     - Supporting content filtering.

    This is new in bzr 1.11.
    """


class WorkingTree6(ContentFilteringDirStateWorkingTree):
    """This is the Format 6 working tree.

    This differs from WorkingTree5 by:
     - Supporting a current view that may mask the set of files in a tree
       impacted by most user operations.

    This is new in bzr 1.14.
    """

    def _make_views(self):
        return views.PathBasedViews(self)


class DirStateWorkingTreeFormat(WorkingTreeFormat3):

    def initialize(self, a_bzrdir, revision_id=None, from_branch=None,
                   accelerator_tree=None, hardlink=False):
        """See WorkingTreeFormat.initialize().

        :param revision_id: allows creating a working tree at a different
        revision than the branch is at.
        :param accelerator_tree: A tree which can be used for retrieving file
            contents more quickly than the revision tree, i.e. a workingtree.
            The revision tree will be used for cases where accelerator_tree's
            content is different.
        :param hardlink: If true, hard-link files from accelerator_tree,
            where possible.

        These trees get an initial random root id, if their repository supports
        rich root data, TREE_ROOT otherwise.
        """
        if not isinstance(a_bzrdir.transport, LocalTransport):
            raise errors.NotLocalUrl(a_bzrdir.transport.base)
        transport = a_bzrdir.get_workingtree_transport(self)
        control_files = self._open_control_files(a_bzrdir)
        control_files.create_lock()
        control_files.lock_write()
        transport.put_bytes('format', self.get_format_string(),
            mode=a_bzrdir._get_file_mode())
        if from_branch is not None:
            branch = from_branch
        else:
            branch = a_bzrdir.open_branch()
        if revision_id is None:
            revision_id = branch.last_revision()
        local_path = transport.local_abspath('dirstate')
        # write out new dirstate (must exist when we create the tree)
        state = dirstate.DirState.initialize(local_path)
        state.unlock()
        del state
        wt = self._tree_class(a_bzrdir.root_transport.local_abspath('.'),
                         branch,
                         _format=self,
                         _bzrdir=a_bzrdir,
                         _control_files=control_files)
        wt._new_tree()
        wt.lock_tree_write()
        try:
            self._init_custom_control_files(wt)
            if revision_id in (None, _mod_revision.NULL_REVISION):
                if branch.repository.supports_rich_root():
                    wt._set_root_id(generate_ids.gen_root_id())
                else:
                    wt._set_root_id(ROOT_ID)
                wt.flush()
            basis = None
            # frequently, we will get here due to branching.  The accelerator
            # tree will be the tree from the branch, so the desired basis
            # tree will often be a parent of the accelerator tree.
            if accelerator_tree is not None:
                try:
                    basis = accelerator_tree.revision_tree(revision_id)
                except errors.NoSuchRevision:
                    pass
            if basis is None:
                basis = branch.repository.revision_tree(revision_id)
            if revision_id == _mod_revision.NULL_REVISION:
                parents_list = []
            else:
                parents_list = [(revision_id, basis)]
            basis.lock_read()
            try:
                wt.set_parent_trees(parents_list, allow_leftmost_as_ghost=True)
                wt.flush()
                # if the basis has a root id we have to use that; otherwise we
                # use a new random one
                basis_root_id = basis.get_root_id()
                if basis_root_id is not None:
                    wt._set_root_id(basis_root_id)
                    wt.flush()
                if wt.supports_content_filtering():
                    # The original tree may not have the same content filters
                    # applied so we can't safely build the inventory delta from
                    # the source tree.
                    delta_from_tree = False
                else:
                    delta_from_tree = True
                # delta_from_tree is safe even for DirStateRevisionTrees,
                # because wt4.apply_inventory_delta does not mutate the input
                # inventory entries.
                transform.build_tree(basis, wt, accelerator_tree,
                                     hardlink=hardlink,
                                     delta_from_tree=delta_from_tree)
            finally:
                basis.unlock()
        finally:
            control_files.unlock()
            wt.unlock()
        return wt

    def _init_custom_control_files(self, wt):
        """Subclasses with custom control files should override this method.

        The working tree and control files are locked for writing when this
        method is called.

        :param wt: the WorkingTree object
        """

    def _open(self, a_bzrdir, control_files):
        """Open the tree itself.

        :param a_bzrdir: the dir for the tree.
        :param control_files: the control files for the tree.
        """
        return self._tree_class(a_bzrdir.root_transport.local_abspath('.'),
                           branch=a_bzrdir.open_branch(),
                           _format=self,
                           _bzrdir=a_bzrdir,
                           _control_files=control_files)

    def __get_matchingbzrdir(self):
        return self._get_matchingbzrdir()

    def _get_matchingbzrdir(self):
        """Overrideable method to get a bzrdir for testing."""
        # please test against something that will let us do tree references
        return bzrdir.format_registry.make_bzrdir(
            'dirstate-with-subtree')

    _matchingbzrdir = property(__get_matchingbzrdir)


class WorkingTreeFormat4(DirStateWorkingTreeFormat):
    """The first consolidated dirstate working tree format.

    This format:
        - exists within a metadir controlling .bzr
        - includes an explicit version marker for the workingtree control
          files, separate from the BzrDir format
        - modifies the hash cache format
        - is new in bzr 0.15
        - uses a LockDir to guard access to it.
    """

    upgrade_recommended = False

    _tree_class = WorkingTree4

    def get_format_string(self):
        """See WorkingTreeFormat.get_format_string()."""
        return "Bazaar Working Tree Format 4 (bzr 0.15)\n"

    def get_format_description(self):
        """See WorkingTreeFormat.get_format_description()."""
        return "Working tree format 4"


class WorkingTreeFormat5(DirStateWorkingTreeFormat):
    """WorkingTree format supporting content filtering.
    """

    upgrade_recommended = False

    _tree_class = WorkingTree5

    def get_format_string(self):
        """See WorkingTreeFormat.get_format_string()."""
        return "Bazaar Working Tree Format 5 (bzr 1.11)\n"

    def get_format_description(self):
        """See WorkingTreeFormat.get_format_description()."""
        return "Working tree format 5"

    def supports_content_filtering(self):
        return True


class WorkingTreeFormat6(DirStateWorkingTreeFormat):
    """WorkingTree format supporting views.
    """

    upgrade_recommended = False

    _tree_class = WorkingTree6

    def get_format_string(self):
        """See WorkingTreeFormat.get_format_string()."""
        return "Bazaar Working Tree Format 6 (bzr 1.14)\n"

    def get_format_description(self):
        """See WorkingTreeFormat.get_format_description()."""
        return "Working tree format 6"

    def _init_custom_control_files(self, wt):
        """Subclasses with custom control files should override this method."""
        wt._transport.put_bytes('views', '', mode=wt.bzrdir._get_file_mode())

    def supports_content_filtering(self):
        return True

    def supports_views(self):
        return True


class DirStateRevisionTree(Tree):
    """A revision tree pulling the inventory from a dirstate.
    
    Note that this is one of the historical (ie revision) trees cached in the
    dirstate for easy access, not the workingtree.
    """

    def __init__(self, dirstate, revision_id, repository):
        self._dirstate = dirstate
        self._revision_id = revision_id
        self._repository = repository
        self._inventory = None
        self._locked = 0
        self._dirstate_locked = False
        self._repo_supports_tree_reference = getattr(
            repository._format, "supports_tree_reference",
            False)

    def __repr__(self):
        return "<%s of %s in %s>" % \
            (self.__class__.__name__, self._revision_id, self._dirstate)

    def annotate_iter(self, file_id,
                      default_revision=_mod_revision.CURRENT_REVISION):
        """See Tree.annotate_iter"""
        text_key = (file_id, self.inventory[file_id].revision)
        annotations = self._repository.texts.annotate(text_key)
        return [(key[-1], line) for (key, line) in annotations]

    def _get_ancestors(self, default_revision):
        return set(self._repository.get_ancestry(self._revision_id,
                                                 topo_sorted=False))
    def _comparison_data(self, entry, path):
        """See Tree._comparison_data."""
        if entry is None:
            return None, False, None
        # trust the entry as RevisionTree does, but this may not be
        # sensible: the entry might not have come from us?
        return entry.kind, entry.executable, None

    def _file_size(self, entry, stat_value):
        return entry.text_size

    def filter_unversioned_files(self, paths):
        """Filter out paths that are not versioned.

        :return: set of paths.
        """
        pred = self.has_filename
        return set((p for p in paths if not pred(p)))

    def get_root_id(self):
        return self.path2id('')

    def id2path(self, file_id):
        "Convert a file-id to a path."
        entry = self._get_entry(file_id=file_id)
        if entry == (None, None):
            raise errors.NoSuchId(tree=self, file_id=file_id)
        path_utf8 = osutils.pathjoin(entry[0][0], entry[0][1])
        return path_utf8.decode('utf8')

    def iter_references(self):
        if not self._repo_supports_tree_reference:
            # When the repo doesn't support references, we will have nothing to
            # return
            return iter([])
        # Otherwise, fall back to the default implementation
        return super(DirStateRevisionTree, self).iter_references()

    def _get_parent_index(self):
        """Return the index in the dirstate referenced by this tree."""
        return self._dirstate.get_parent_ids().index(self._revision_id) + 1

    def _get_entry(self, file_id=None, path=None):
        """Get the dirstate row for file_id or path.

        If either file_id or path is supplied, it is used as the key to lookup.
        If both are supplied, the fastest lookup is used, and an error is
        raised if they do not both point at the same row.

        :param file_id: An optional unicode file_id to be looked up.
        :param path: An optional unicode path to be looked up.
        :return: The dirstate row tuple for path/file_id, or (None, None)
        """
        if file_id is None and path is None:
            raise errors.BzrError('must supply file_id or path')
        if path is not None:
            path = path.encode('utf8')
        parent_index = self._get_parent_index()
        return self._dirstate._get_entry(parent_index, fileid_utf8=file_id, path_utf8=path)

    def _generate_inventory(self):
        """Create and set self.inventory from the dirstate object.

        (So this is only called the first time the inventory is requested for
        this tree; it then remains in memory until it's out of date.)

        This is relatively expensive: we have to walk the entire dirstate.
        """
        if not self._locked:
            raise AssertionError(
                'cannot generate inventory of an unlocked '
                'dirstate revision tree')
        # separate call for profiling - makes it clear where the costs are.
        self._dirstate._read_dirblocks_if_needed()
        if self._revision_id not in self._dirstate.get_parent_ids():
            raise AssertionError(
                'parent %s has disappeared from %s' % (
                self._revision_id, self._dirstate.get_parent_ids()))
        parent_index = self._dirstate.get_parent_ids().index(self._revision_id) + 1
        # This is identical now to the WorkingTree _generate_inventory except
        # for the tree index use.
        root_key, current_entry = self._dirstate._get_entry(parent_index, path_utf8='')
        current_id = root_key[2]
        if current_entry[parent_index][0] != 'd':
            raise AssertionError()
        inv = Inventory(root_id=current_id, revision_id=self._revision_id)
        inv.root.revision = current_entry[parent_index][4]
        # Turn some things into local variables
        minikind_to_kind = dirstate.DirState._minikind_to_kind
        factory = entry_factory
        utf8_decode = cache_utf8._utf8_decode
        inv_byid = inv._byid
        # we could do this straight out of the dirstate; it might be fast
        # and should be profiled - RBC 20070216
        parent_ies = {'' : inv.root}
        for block in self._dirstate._dirblocks[1:]: #skip root
            dirname = block[0]
            try:
                parent_ie = parent_ies[dirname]
            except KeyError:
                # all the paths in this block are not versioned in this tree
                continue
            for key, entry in block[1]:
                minikind, fingerprint, size, executable, revid = entry[parent_index]
                if minikind in ('a', 'r'): # absent, relocated
                    # not this tree
                    continue
                name = key[1]
                name_unicode = utf8_decode(name)[0]
                file_id = key[2]
                kind = minikind_to_kind[minikind]
                inv_entry = factory[kind](file_id, name_unicode,
                                          parent_ie.file_id)
                inv_entry.revision = revid
                if kind == 'file':
                    inv_entry.executable = executable
                    inv_entry.text_size = size
                    inv_entry.text_sha1 = fingerprint
                elif kind == 'directory':
                    parent_ies[(dirname + '/' + name).strip('/')] = inv_entry
                elif kind == 'symlink':
                    inv_entry.symlink_target = utf8_decode(fingerprint)[0]
                elif kind == 'tree-reference':
                    inv_entry.reference_revision = fingerprint or None
                else:
                    raise AssertionError("cannot convert entry %r into an InventoryEntry"
                            % entry)
                # These checks cost us around 40ms on a 55k entry tree
                if file_id in inv_byid:
                    raise AssertionError('file_id %s already in'
                        ' inventory as %s' % (file_id, inv_byid[file_id]))
                if name_unicode in parent_ie.children:
                    raise AssertionError('name %r already in parent'
                        % (name_unicode,))
                inv_byid[file_id] = inv_entry
                parent_ie.children[name_unicode] = inv_entry
        self._inventory = inv

    def get_file_mtime(self, file_id, path=None):
        """Return the modification time for this record.

        We return the timestamp of the last-changed revision.
        """
        # Make sure the file exists
        entry = self._get_entry(file_id, path=path)
        if entry == (None, None): # do we raise?
            return None
        parent_index = self._get_parent_index()
        last_changed_revision = entry[1][parent_index][4]
        try:
            rev = self._repository.get_revision(last_changed_revision)
        except errors.NoSuchRevision:
            raise errors.FileTimestampUnavailable(self.id2path(file_id))
        return rev.timestamp

    def get_file_sha1(self, file_id, path=None, stat_value=None):
        entry = self._get_entry(file_id=file_id, path=path)
        parent_index = self._get_parent_index()
        parent_details = entry[1][parent_index]
        if parent_details[0] == 'f':
            return parent_details[1]
        return None

    def get_file(self, file_id, path=None):
        return StringIO(self.get_file_text(file_id))

    def get_file_size(self, file_id):
        """See Tree.get_file_size"""
        return self.inventory[file_id].text_size

    def get_file_text(self, file_id, path=None):
        _, content = list(self.iter_files_bytes([(file_id, None)]))[0]
        return ''.join(content)

    def get_reference_revision(self, file_id, path=None):
        return self.inventory[file_id].reference_revision

    def iter_files_bytes(self, desired_files):
        """See Tree.iter_files_bytes.

        This version is implemented on top of Repository.iter_files_bytes"""
        parent_index = self._get_parent_index()
        repo_desired_files = []
        for file_id, identifier in desired_files:
            entry = self._get_entry(file_id)
            if entry == (None, None):
                raise errors.NoSuchId(self, file_id)
            repo_desired_files.append((file_id, entry[1][parent_index][4],
                                       identifier))
        return self._repository.iter_files_bytes(repo_desired_files)

    def get_symlink_target(self, file_id):
        entry = self._get_entry(file_id=file_id)
        parent_index = self._get_parent_index()
        if entry[1][parent_index][0] != 'l':
            return None
        else:
            target = entry[1][parent_index][1]
            target = target.decode('utf8')
            return target

    def get_revision_id(self):
        """Return the revision id for this tree."""
        return self._revision_id

    def _get_inventory(self):
        if self._inventory is not None:
            return self._inventory
        self._must_be_locked()
        self._generate_inventory()
        return self._inventory

    inventory = property(_get_inventory,
                         doc="Inventory of this Tree")

    def get_parent_ids(self):
        """The parents of a tree in the dirstate are not cached."""
        return self._repository.get_revision(self._revision_id).parent_ids

    def has_filename(self, filename):
        return bool(self.path2id(filename))

    def kind(self, file_id):
        entry = self._get_entry(file_id=file_id)[1]
        if entry is None:
            raise errors.NoSuchId(tree=self, file_id=file_id)
        parent_index = self._get_parent_index()
        return dirstate.DirState._minikind_to_kind[entry[parent_index][0]]

    def stored_kind(self, file_id):
        """See Tree.stored_kind"""
        return self.kind(file_id)

    def path_content_summary(self, path):
        """See Tree.path_content_summary."""
        id = self.inventory.path2id(path)
        if id is None:
            return ('missing', None, None, None)
        entry = self._inventory[id]
        kind = entry.kind
        if kind == 'file':
            return (kind, entry.text_size, entry.executable, entry.text_sha1)
        elif kind == 'symlink':
            return (kind, None, None, entry.symlink_target)
        else:
            return (kind, None, None, None)

    def is_executable(self, file_id, path=None):
        ie = self.inventory[file_id]
        if ie.kind != "file":
            return None
        return ie.executable

    def is_locked(self):
        return self._locked

    def list_files(self, include_root=False, from_dir=None, recursive=True):
        # We use a standard implementation, because DirStateRevisionTree is
        # dealing with one of the parents of the current state
        inv = self._get_inventory()
        if from_dir is None:
            from_dir_id = None
        else:
            from_dir_id = inv.path2id(from_dir)
            if from_dir_id is None:
                # Directory not versioned
                return
        entries = inv.iter_entries(from_dir=from_dir_id, recursive=recursive)
        if inv.root is not None and not include_root and from_dir is None:
            entries.next()
        for path, entry in entries:
            yield path, 'V', entry.kind, entry.file_id, entry

    def lock_read(self):
        """Lock the tree for a set of operations.

        :return: A bzrlib.lock.LogicalLockResult.
        """
        if not self._locked:
            self._repository.lock_read()
            if self._dirstate._lock_token is None:
                self._dirstate.lock_read()
                self._dirstate_locked = True
        self._locked += 1
        return LogicalLockResult(self.unlock)

    def _must_be_locked(self):
        if not self._locked:
            raise errors.ObjectNotLocked(self)

    @needs_read_lock
    def path2id(self, path):
        """Return the id for path in this tree."""
        # lookup by path: faster than splitting and walking the ivnentory.
        entry = self._get_entry(path=path)
        if entry == (None, None):
            return None
        return entry[0][2]

    def unlock(self):
        """Unlock, freeing any cache memory used during the lock."""
        # outside of a lock, the inventory is suspect: release it.
        self._locked -=1
        if not self._locked:
            self._inventory = None
            self._locked = 0
            if self._dirstate_locked:
                self._dirstate.unlock()
                self._dirstate_locked = False
            self._repository.unlock()

    @needs_read_lock
    def supports_tree_reference(self):
        return self._repo_supports_tree_reference

    def walkdirs(self, prefix=""):
        # TODO: jam 20070215 This is the lazy way by using the RevisionTree
        # implementation based on an inventory.
        # This should be cleaned up to use the much faster Dirstate code
        # So for now, we just build up the parent inventory, and extract
        # it the same way RevisionTree does.
        _directory = 'directory'
        inv = self._get_inventory()
        top_id = inv.path2id(prefix)
        if top_id is None:
            pending = []
        else:
            pending = [(prefix, top_id)]
        while pending:
            dirblock = []
            relpath, file_id = pending.pop()
            # 0 - relpath, 1- file-id
            if relpath:
                relroot = relpath + '/'
            else:
                relroot = ""
            # FIXME: stash the node in pending
            entry = inv[file_id]
            for name, child in entry.sorted_children():
                toppath = relroot + name
                dirblock.append((toppath, name, child.kind, None,
                    child.file_id, child.kind
                    ))
            yield (relpath, entry.file_id), dirblock
            # push the user specified dirs from dirblock
            for dir in reversed(dirblock):
                if dir[2] == _directory:
                    pending.append((dir[0], dir[4]))


class InterDirStateTree(InterTree):
    """Fast path optimiser for changes_from with dirstate trees.

    This is used only when both trees are in the dirstate working file, and
    the source is any parent within the dirstate, and the destination is
    the current working tree of the same dirstate.
    """
    # this could be generalized to allow comparisons between any trees in the
    # dirstate, and possibly between trees stored in different dirstates.

    def __init__(self, source, target):
        super(InterDirStateTree, self).__init__(source, target)
        if not InterDirStateTree.is_compatible(source, target):
            raise Exception, "invalid source %r and target %r" % (source, target)

    @staticmethod
    def make_source_parent_tree(source, target):
        """Change the source tree into a parent of the target."""
        revid = source.commit('record tree')
        target.branch.repository.fetch(source.branch.repository, revid)
        target.set_parent_ids([revid])
        return target.basis_tree(), target

    @classmethod
    def make_source_parent_tree_python_dirstate(klass, test_case, source, target):
        result = klass.make_source_parent_tree(source, target)
        result[1]._iter_changes = dirstate.ProcessEntryPython
        return result

    @classmethod
    def make_source_parent_tree_compiled_dirstate(klass, test_case, source,
                                                  target):
        from bzrlib.tests.test__dirstate_helpers import \
            compiled_dirstate_helpers_feature
        test_case.requireFeature(compiled_dirstate_helpers_feature)
        from bzrlib._dirstate_helpers_pyx import ProcessEntryC
        result = klass.make_source_parent_tree(source, target)
        result[1]._iter_changes = ProcessEntryC
        return result

    _matching_from_tree_format = WorkingTreeFormat4()
    _matching_to_tree_format = WorkingTreeFormat4()

    @classmethod
    def _test_mutable_trees_to_test_trees(klass, test_case, source, target):
        # This method shouldn't be called, because we have python and C
        # specific flavours.
        raise NotImplementedError

    def iter_changes(self, include_unchanged=False,
                      specific_files=None, pb=None, extra_trees=[],
                      require_versioned=True, want_unversioned=False):
        """Return the changes from source to target.

        :return: An iterator that yields tuples. See InterTree.iter_changes
            for details.
        :param specific_files: An optional list of file paths to restrict the
            comparison to. When mapping filenames to ids, all matches in all
            trees (including optional extra_trees) are used, and all children of
            matched directories are included.
        :param include_unchanged: An optional boolean requesting the inclusion of
            unchanged entries in the result.
        :param extra_trees: An optional list of additional trees to use when
            mapping the contents of specific_files (paths) to file_ids.
        :param require_versioned: If True, all files in specific_files must be
            versioned in one of source, target, extra_trees or
            PathsNotVersionedError is raised.
        :param want_unversioned: Should unversioned files be returned in the
            output. An unversioned file is defined as one with (False, False)
            for the versioned pair.
        """
        # TODO: handle extra trees in the dirstate.
        if (extra_trees or specific_files == []):
            # we can't fast-path these cases (yet)
            return super(InterDirStateTree, self).iter_changes(
                include_unchanged, specific_files, pb, extra_trees,
                require_versioned, want_unversioned=want_unversioned)
        parent_ids = self.target.get_parent_ids()
        if not (self.source._revision_id in parent_ids
                or self.source._revision_id == _mod_revision.NULL_REVISION):
            raise AssertionError(
                "revision {%s} is not stored in {%s}, but %s "
                "can only be used for trees stored in the dirstate"
                % (self.source._revision_id, self.target, self.iter_changes))
        target_index = 0
        if self.source._revision_id == _mod_revision.NULL_REVISION:
            source_index = None
            indices = (target_index,)
        else:
            if not (self.source._revision_id in parent_ids):
                raise AssertionError(
                    "Failure: source._revision_id: %s not in target.parent_ids(%s)" % (
                    self.source._revision_id, parent_ids))
            source_index = 1 + parent_ids.index(self.source._revision_id)
            indices = (source_index, target_index)
        # -- make all specific_files utf8 --
        if specific_files:
            specific_files_utf8 = set()
            for path in specific_files:
                # Note, if there are many specific files, using cache_utf8
                # would be good here.
                specific_files_utf8.add(path.encode('utf8'))
            specific_files = specific_files_utf8
        else:
            specific_files = set([''])
        # -- specific_files is now a utf8 path set --

        # -- get the state object and prepare it.
        state = self.target.current_dirstate()
        state._read_dirblocks_if_needed()
        if require_versioned:
            # -- check all supplied paths are versioned in a search tree. --
            not_versioned = []
            for path in specific_files:
                path_entries = state._entries_for_path(path)
                if not path_entries:
                    # this specified path is not present at all: error
                    not_versioned.append(path)
                    continue
                found_versioned = False
                # for each id at this path
                for entry in path_entries:
                    # for each tree.
                    for index in indices:
                        if entry[1][index][0] != 'a': # absent
                            found_versioned = True
                            # all good: found a versioned cell
                            break
                if not found_versioned:
                    # none of the indexes was not 'absent' at all ids for this
                    # path.
                    not_versioned.append(path)
            if len(not_versioned) > 0:
                raise errors.PathsNotVersionedError(not_versioned)
        # -- remove redundancy in supplied specific_files to prevent over-scanning --
        search_specific_files = osutils.minimum_path_selection(specific_files)

        use_filesystem_for_exec = (sys.platform != 'win32')
        iter_changes = self.target._iter_changes(include_unchanged,
            use_filesystem_for_exec, search_specific_files, state,
            source_index, target_index, want_unversioned, self.target)
        return iter_changes.iter_changes()

    @staticmethod
    def is_compatible(source, target):
        # the target must be a dirstate working tree
        if not isinstance(target, DirStateWorkingTree):
            return False
        # the source must be a revtree or dirstate rev tree.
        if not isinstance(source,
            (revisiontree.RevisionTree, DirStateRevisionTree)):
            return False
        # the source revid must be in the target dirstate
        if not (source._revision_id == _mod_revision.NULL_REVISION or
            source._revision_id in target.get_parent_ids()):
            # TODO: what about ghosts? it may well need to
            # check for them explicitly.
            return False
        return True

InterTree.register_optimiser(InterDirStateTree)


class Converter3to4(object):
    """Perform an in-place upgrade of format 3 to format 4 trees."""

    def __init__(self):
        self.target_format = WorkingTreeFormat4()

    def convert(self, tree):
        # lock the control files not the tree, so that we dont get tree
        # on-unlock behaviours, and so that noone else diddles with the
        # tree during upgrade.
        tree._control_files.lock_write()
        try:
            tree.read_working_inventory()
            self.create_dirstate_data(tree)
            self.update_format(tree)
            self.remove_xml_files(tree)
        finally:
            tree._control_files.unlock()

    def create_dirstate_data(self, tree):
        """Create the dirstate based data for tree."""
        local_path = tree.bzrdir.get_workingtree_transport(None
            ).local_abspath('dirstate')
        state = dirstate.DirState.from_tree(tree, local_path)
        state.save()
        state.unlock()

    def remove_xml_files(self, tree):
        """Remove the oldformat 3 data."""
        transport = tree.bzrdir.get_workingtree_transport(None)
        for path in ['basis-inventory-cache', 'inventory', 'last-revision',
            'pending-merges', 'stat-cache']:
            try:
                transport.delete(path)
            except errors.NoSuchFile:
                # some files are optional - just deal.
                pass

    def update_format(self, tree):
        """Change the format marker."""
        tree._transport.put_bytes('format',
            self.target_format.get_format_string(),
            mode=tree.bzrdir._get_file_mode())


class Converter4to5(object):
    """Perform an in-place upgrade of format 4 to format 5 trees."""

    def __init__(self):
        self.target_format = WorkingTreeFormat5()

    def convert(self, tree):
        # lock the control files not the tree, so that we don't get tree
        # on-unlock behaviours, and so that no-one else diddles with the
        # tree during upgrade.
        tree._control_files.lock_write()
        try:
            self.update_format(tree)
        finally:
            tree._control_files.unlock()

    def update_format(self, tree):
        """Change the format marker."""
        tree._transport.put_bytes('format',
            self.target_format.get_format_string(),
            mode=tree.bzrdir._get_file_mode())


class Converter4or5to6(object):
    """Perform an in-place upgrade of format 4 or 5 to format 6 trees."""

    def __init__(self):
        self.target_format = WorkingTreeFormat6()

    def convert(self, tree):
        # lock the control files not the tree, so that we don't get tree
        # on-unlock behaviours, and so that no-one else diddles with the
        # tree during upgrade.
        tree._control_files.lock_write()
        try:
            self.init_custom_control_files(tree)
            self.update_format(tree)
        finally:
            tree._control_files.unlock()

    def init_custom_control_files(self, tree):
        """Initialize custom control files."""
        tree._transport.put_bytes('views', '',
            mode=tree.bzrdir._get_file_mode())

    def update_format(self, tree):
        """Change the format marker."""
        tree._transport.put_bytes('format',
            self.target_format.get_format_string(),
            mode=tree.bzrdir._get_file_mode())