summaryrefslogtreecommitdiff
path: root/cache.h
blob: 9cac7bb5185fff37e9906dd0dcad9187673c7e1f (plain)
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
#ifndef CACHE_H
#define CACHE_H

#include "git-compat-util.h"
#include "strbuf.h"
#include "hashmap.h"
#include "list.h"
#include "advice.h"
#include "gettext.h"
#include "convert.h"
#include "trace.h"
#include "string-list.h"
#include "pack-revindex.h"
#include "hash.h"
#include "path.h"
#include "sha1-array.h"
#include "repository.h"

#ifndef platform_SHA_CTX
/*
 * platform's underlying implementation of SHA-1; could be OpenSSL,
 * blk_SHA, Apple CommonCrypto, etc...  Note that including
 * SHA1_HEADER may have already defined platform_SHA_CTX for our
 * own implementations like block-sha1 and ppc-sha1, so we list
 * the default for OpenSSL compatible SHA-1 implementations here.
 */
#define platform_SHA_CTX	SHA_CTX
#define platform_SHA1_Init	SHA1_Init
#define platform_SHA1_Update	SHA1_Update
#define platform_SHA1_Final    	SHA1_Final
#endif

#define git_SHA_CTX		platform_SHA_CTX
#define git_SHA1_Init		platform_SHA1_Init
#define git_SHA1_Update		platform_SHA1_Update
#define git_SHA1_Final		platform_SHA1_Final

#ifdef SHA1_MAX_BLOCK_SIZE
#include "compat/sha1-chunked.h"
#undef git_SHA1_Update
#define git_SHA1_Update		git_SHA1_Update_Chunked
#endif

#include <zlib.h>
typedef struct git_zstream {
	z_stream z;
	unsigned long avail_in;
	unsigned long avail_out;
	unsigned long total_in;
	unsigned long total_out;
	unsigned char *next_in;
	unsigned char *next_out;
} git_zstream;

void git_inflate_init(git_zstream *);
void git_inflate_init_gzip_only(git_zstream *);
void git_inflate_end(git_zstream *);
int git_inflate(git_zstream *, int flush);

void git_deflate_init(git_zstream *, int level);
void git_deflate_init_gzip(git_zstream *, int level);
void git_deflate_init_raw(git_zstream *, int level);
void git_deflate_end(git_zstream *);
int git_deflate_abort(git_zstream *);
int git_deflate_end_gently(git_zstream *);
int git_deflate(git_zstream *, int flush);
unsigned long git_deflate_bound(git_zstream *, unsigned long);

/* The length in bytes and in hex digits of an object name (SHA-1 value). */
#define GIT_SHA1_RAWSZ 20
#define GIT_SHA1_HEXSZ (2 * GIT_SHA1_RAWSZ)

/* The length in byte and in hex digits of the largest possible hash value. */
#define GIT_MAX_RAWSZ GIT_SHA1_RAWSZ
#define GIT_MAX_HEXSZ GIT_SHA1_HEXSZ

struct object_id {
	unsigned char hash[GIT_MAX_RAWSZ];
};

#define the_hash_algo the_repository->hash_algo

#if defined(DT_UNKNOWN) && !defined(NO_D_TYPE_IN_DIRENT)
#define DTYPE(de)	((de)->d_type)
#else
#undef DT_UNKNOWN
#undef DT_DIR
#undef DT_REG
#undef DT_LNK
#define DT_UNKNOWN	0
#define DT_DIR		1
#define DT_REG		2
#define DT_LNK		3
#define DTYPE(de)	DT_UNKNOWN
#endif

/* unknown mode (impossible combination S_IFIFO|S_IFCHR) */
#define S_IFINVALID     0030000

/*
 * A "directory link" is a link to another git directory.
 *
 * The value 0160000 is not normally a valid mode, and
 * also just happens to be S_IFDIR + S_IFLNK
 */
#define S_IFGITLINK	0160000
#define S_ISGITLINK(m)	(((m) & S_IFMT) == S_IFGITLINK)

/*
 * Some mode bits are also used internally for computations.
 *
 * They *must* not overlap with any valid modes, and they *must* not be emitted
 * to outside world - i.e. appear on disk or network. In other words, it's just
 * temporary fields, which we internally use, but they have to stay in-house.
 *
 * ( such approach is valid, as standard S_IF* fits into 16 bits, and in Git
 *   codebase mode is `unsigned int` which is assumed to be at least 32 bits )
 */

/* used internally in tree-diff */
#define S_DIFFTREE_IFXMIN_NEQ	0x80000000


/*
 * Intensive research over the course of many years has shown that
 * port 9418 is totally unused by anything else. Or
 *
 *	Your search - "port 9418" - did not match any documents.
 *
 * as www.google.com puts it.
 *
 * This port has been properly assigned for git use by IANA:
 * git (Assigned-9418) [I06-050728-0001].
 *
 *	git  9418/tcp   git pack transfer service
 *	git  9418/udp   git pack transfer service
 *
 * with Linus Torvalds <torvalds@osdl.org> as the point of
 * contact. September 2005.
 *
 * See http://www.iana.org/assignments/port-numbers
 */
#define DEFAULT_GIT_PORT 9418

/*
 * Basic data structures for the directory cache
 */

#define CACHE_SIGNATURE 0x44495243	/* "DIRC" */
struct cache_header {
	uint32_t hdr_signature;
	uint32_t hdr_version;
	uint32_t hdr_entries;
};

#define INDEX_FORMAT_LB 2
#define INDEX_FORMAT_UB 4

/*
 * The "cache_time" is just the low 32 bits of the
 * time. It doesn't matter if it overflows - we only
 * check it for equality in the 32 bits we save.
 */
struct cache_time {
	uint32_t sec;
	uint32_t nsec;
};

struct stat_data {
	struct cache_time sd_ctime;
	struct cache_time sd_mtime;
	unsigned int sd_dev;
	unsigned int sd_ino;
	unsigned int sd_uid;
	unsigned int sd_gid;
	unsigned int sd_size;
};

struct cache_entry {
	struct hashmap_entry ent;
	struct stat_data ce_stat_data;
	unsigned int ce_mode;
	unsigned int ce_flags;
	unsigned int ce_namelen;
	unsigned int index;	/* for link extension */
	struct object_id oid;
	char name[FLEX_ARRAY]; /* more */
};

#define CE_STAGEMASK (0x3000)
#define CE_EXTENDED  (0x4000)
#define CE_VALID     (0x8000)
#define CE_STAGESHIFT 12

/*
 * Range 0xFFFF0FFF in ce_flags is divided into
 * two parts: in-memory flags and on-disk ones.
 * Flags in CE_EXTENDED_FLAGS will get saved on-disk
 * if you want to save a new flag, add it in
 * CE_EXTENDED_FLAGS
 *
 * In-memory only flags
 */
#define CE_UPDATE            (1 << 16)
#define CE_REMOVE            (1 << 17)
#define CE_UPTODATE          (1 << 18)
#define CE_ADDED             (1 << 19)

#define CE_HASHED            (1 << 20)
#define CE_FSMONITOR_VALID   (1 << 21)
#define CE_WT_REMOVE         (1 << 22) /* remove in work directory */
#define CE_CONFLICTED        (1 << 23)

#define CE_UNPACKED          (1 << 24)
#define CE_NEW_SKIP_WORKTREE (1 << 25)

/* used to temporarily mark paths matched by pathspecs */
#define CE_MATCHED           (1 << 26)

#define CE_UPDATE_IN_BASE    (1 << 27)
#define CE_STRIP_NAME        (1 << 28)

/*
 * Extended on-disk flags
 */
#define CE_INTENT_TO_ADD     (1 << 29)
#define CE_SKIP_WORKTREE     (1 << 30)
/* CE_EXTENDED2 is for future extension */
#define CE_EXTENDED2         (1U << 31)

#define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE)

/*
 * Safeguard to avoid saving wrong flags:
 *  - CE_EXTENDED2 won't get saved until its semantic is known
 *  - Bits in 0x0000FFFF have been saved in ce_flags already
 *  - Bits in 0x003F0000 are currently in-memory flags
 */
#if CE_EXTENDED_FLAGS & 0x803FFFFF
#error "CE_EXTENDED_FLAGS out of range"
#endif

/* Forward structure decls */
struct pathspec;
struct child_process;

/*
 * Copy the sha1 and stat state of a cache entry from one to
 * another. But we never change the name, or the hash state!
 */
static inline void copy_cache_entry(struct cache_entry *dst,
				    const struct cache_entry *src)
{
	unsigned int state = dst->ce_flags & CE_HASHED;

	/* Don't copy hash chain and name */
	memcpy(&dst->ce_stat_data, &src->ce_stat_data,
			offsetof(struct cache_entry, name) -
			offsetof(struct cache_entry, ce_stat_data));

	/* Restore the hash state */
	dst->ce_flags = (dst->ce_flags & ~CE_HASHED) | state;
}

static inline unsigned create_ce_flags(unsigned stage)
{
	return (stage << CE_STAGESHIFT);
}

#define ce_namelen(ce) ((ce)->ce_namelen)
#define ce_size(ce) cache_entry_size(ce_namelen(ce))
#define ce_stage(ce) ((CE_STAGEMASK & (ce)->ce_flags) >> CE_STAGESHIFT)
#define ce_uptodate(ce) ((ce)->ce_flags & CE_UPTODATE)
#define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE)
#define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE)
#define ce_intent_to_add(ce) ((ce)->ce_flags & CE_INTENT_TO_ADD)

#define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644)
static inline unsigned int create_ce_mode(unsigned int mode)
{
	if (S_ISLNK(mode))
		return S_IFLNK;
	if (S_ISDIR(mode) || S_ISGITLINK(mode))
		return S_IFGITLINK;
	return S_IFREG | ce_permissions(mode);
}
static inline unsigned int ce_mode_from_stat(const struct cache_entry *ce,
					     unsigned int mode)
{
	extern int trust_executable_bit, has_symlinks;
	if (!has_symlinks && S_ISREG(mode) &&
	    ce && S_ISLNK(ce->ce_mode))
		return ce->ce_mode;
	if (!trust_executable_bit && S_ISREG(mode)) {
		if (ce && S_ISREG(ce->ce_mode))
			return ce->ce_mode;
		return create_ce_mode(0666);
	}
	return create_ce_mode(mode);
}
static inline int ce_to_dtype(const struct cache_entry *ce)
{
	unsigned ce_mode = ntohl(ce->ce_mode);
	if (S_ISREG(ce_mode))
		return DT_REG;
	else if (S_ISDIR(ce_mode) || S_ISGITLINK(ce_mode))
		return DT_DIR;
	else if (S_ISLNK(ce_mode))
		return DT_LNK;
	else
		return DT_UNKNOWN;
}
static inline unsigned int canon_mode(unsigned int mode)
{
	if (S_ISREG(mode))
		return S_IFREG | ce_permissions(mode);
	if (S_ISLNK(mode))
		return S_IFLNK;
	if (S_ISDIR(mode))
		return S_IFDIR;
	return S_IFGITLINK;
}

#define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1)

#define SOMETHING_CHANGED	(1 << 0) /* unclassified changes go here */
#define CE_ENTRY_CHANGED	(1 << 1)
#define CE_ENTRY_REMOVED	(1 << 2)
#define CE_ENTRY_ADDED		(1 << 3)
#define RESOLVE_UNDO_CHANGED	(1 << 4)
#define CACHE_TREE_CHANGED	(1 << 5)
#define SPLIT_INDEX_ORDERED	(1 << 6)
#define UNTRACKED_CHANGED	(1 << 7)
#define FSMONITOR_CHANGED	(1 << 8)

struct split_index;
struct untracked_cache;

struct index_state {
	struct cache_entry **cache;
	unsigned int version;
	unsigned int cache_nr, cache_alloc, cache_changed;
	struct string_list *resolve_undo;
	struct cache_tree *cache_tree;
	struct split_index *split_index;
	struct cache_time timestamp;
	unsigned name_hash_initialized : 1,
		 initialized : 1,
		 drop_cache_tree : 1;
	struct hashmap name_hash;
	struct hashmap dir_hash;
	unsigned char sha1[20];
	struct untracked_cache *untracked;
	uint64_t fsmonitor_last_update;
	struct ewah_bitmap *fsmonitor_dirty;
};

extern struct index_state the_index;

/* Name hashing */
extern int test_lazy_init_name_hash(struct index_state *istate, int try_threaded);
extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
extern void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
extern void free_name_hash(struct index_state *istate);


#ifndef NO_THE_INDEX_COMPATIBILITY_MACROS
#define active_cache (the_index.cache)
#define active_nr (the_index.cache_nr)
#define active_alloc (the_index.cache_alloc)
#define active_cache_changed (the_index.cache_changed)
#define active_cache_tree (the_index.cache_tree)

#define read_cache() read_index(&the_index)
#define read_cache_from(path) read_index_from(&the_index, (path), (get_git_dir()))
#define read_cache_preload(pathspec) read_index_preload(&the_index, (pathspec))
#define is_cache_unborn() is_index_unborn(&the_index)
#define read_cache_unmerged() read_index_unmerged(&the_index)
#define discard_cache() discard_index(&the_index)
#define unmerged_cache() unmerged_index(&the_index)
#define cache_name_pos(name, namelen) index_name_pos(&the_index,(name),(namelen))
#define add_cache_entry(ce, option) add_index_entry(&the_index, (ce), (option))
#define rename_cache_entry_at(pos, new_name) rename_index_entry_at(&the_index, (pos), (new_name))
#define remove_cache_entry_at(pos) remove_index_entry_at(&the_index, (pos))
#define remove_file_from_cache(path) remove_file_from_index(&the_index, (path))
#define add_to_cache(path, st, flags) add_to_index(&the_index, (path), (st), (flags))
#define add_file_to_cache(path, flags) add_file_to_index(&the_index, (path), (flags))
#define chmod_cache_entry(ce, flip) chmod_index_entry(&the_index, (ce), (flip))
#define refresh_cache(flags) refresh_index(&the_index, (flags), NULL, NULL, NULL)
#define ce_match_stat(ce, st, options) ie_match_stat(&the_index, (ce), (st), (options))
#define ce_modified(ce, st, options) ie_modified(&the_index, (ce), (st), (options))
#define cache_dir_exists(name, namelen) index_dir_exists(&the_index, (name), (namelen))
#define cache_file_exists(name, namelen, igncase) index_file_exists(&the_index, (name), (namelen), (igncase))
#define cache_name_is_other(name, namelen) index_name_is_other(&the_index, (name), (namelen))
#define resolve_undo_clear() resolve_undo_clear_index(&the_index)
#define unmerge_cache_entry_at(at) unmerge_index_entry_at(&the_index, at)
#define unmerge_cache(pathspec) unmerge_index(&the_index, pathspec)
#define read_blob_data_from_cache(path, sz) read_blob_data_from_index(&the_index, (path), (sz))
#endif

enum object_type {
	OBJ_BAD = -1,
	OBJ_NONE = 0,
	OBJ_COMMIT = 1,
	OBJ_TREE = 2,
	OBJ_BLOB = 3,
	OBJ_TAG = 4,
	/* 5 for future expansion */
	OBJ_OFS_DELTA = 6,
	OBJ_REF_DELTA = 7,
	OBJ_ANY,
	OBJ_MAX
};

static inline enum object_type object_type(unsigned int mode)
{
	return S_ISDIR(mode) ? OBJ_TREE :
		S_ISGITLINK(mode) ? OBJ_COMMIT :
		OBJ_BLOB;
}

/* Double-check local_repo_env below if you add to this list. */
#define GIT_DIR_ENVIRONMENT "GIT_DIR"
#define GIT_COMMON_DIR_ENVIRONMENT "GIT_COMMON_DIR"
#define GIT_NAMESPACE_ENVIRONMENT "GIT_NAMESPACE"
#define GIT_WORK_TREE_ENVIRONMENT "GIT_WORK_TREE"
#define GIT_PREFIX_ENVIRONMENT "GIT_PREFIX"
#define GIT_SUPER_PREFIX_ENVIRONMENT "GIT_INTERNAL_SUPER_PREFIX"
#define DEFAULT_GIT_DIR_ENVIRONMENT ".git"
#define DB_ENVIRONMENT "GIT_OBJECT_DIRECTORY"
#define INDEX_ENVIRONMENT "GIT_INDEX_FILE"
#define GRAFT_ENVIRONMENT "GIT_GRAFT_FILE"
#define GIT_SHALLOW_FILE_ENVIRONMENT "GIT_SHALLOW_FILE"
#define TEMPLATE_DIR_ENVIRONMENT "GIT_TEMPLATE_DIR"
#define CONFIG_ENVIRONMENT "GIT_CONFIG"
#define CONFIG_DATA_ENVIRONMENT "GIT_CONFIG_PARAMETERS"
#define EXEC_PATH_ENVIRONMENT "GIT_EXEC_PATH"
#define CEILING_DIRECTORIES_ENVIRONMENT "GIT_CEILING_DIRECTORIES"
#define NO_REPLACE_OBJECTS_ENVIRONMENT "GIT_NO_REPLACE_OBJECTS"
#define GIT_REPLACE_REF_BASE_ENVIRONMENT "GIT_REPLACE_REF_BASE"
#define GITATTRIBUTES_FILE ".gitattributes"
#define INFOATTRIBUTES_FILE "info/attributes"
#define ATTRIBUTE_MACRO_PREFIX "[attr]"
#define GITMODULES_FILE ".gitmodules"
#define GIT_NOTES_REF_ENVIRONMENT "GIT_NOTES_REF"
#define GIT_NOTES_DEFAULT_REF "refs/notes/commits"
#define GIT_NOTES_DISPLAY_REF_ENVIRONMENT "GIT_NOTES_DISPLAY_REF"
#define GIT_NOTES_REWRITE_REF_ENVIRONMENT "GIT_NOTES_REWRITE_REF"
#define GIT_NOTES_REWRITE_MODE_ENVIRONMENT "GIT_NOTES_REWRITE_MODE"
#define GIT_LITERAL_PATHSPECS_ENVIRONMENT "GIT_LITERAL_PATHSPECS"
#define GIT_GLOB_PATHSPECS_ENVIRONMENT "GIT_GLOB_PATHSPECS"
#define GIT_NOGLOB_PATHSPECS_ENVIRONMENT "GIT_NOGLOB_PATHSPECS"
#define GIT_ICASE_PATHSPECS_ENVIRONMENT "GIT_ICASE_PATHSPECS"
#define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
#define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"

/*
 * Environment variable used in handshaking the wire protocol.
 * Contains a colon ':' separated list of keys with optional values
 * 'key[=value]'.  Presence of unknown keys and values must be
 * ignored.
 */
#define GIT_PROTOCOL_ENVIRONMENT "GIT_PROTOCOL"
/* HTTP header used to handshake the wire protocol */
#define GIT_PROTOCOL_HEADER "Git-Protocol"

/*
 * This environment variable is expected to contain a boolean indicating
 * whether we should or should not treat:
 *
 *   GIT_DIR=foo.git git ...
 *
 * as if GIT_WORK_TREE=. was given. It's not expected that users will make use
 * of this, but we use it internally to communicate to sub-processes that we
 * are in a bare repo. If not set, defaults to true.
 */
#define GIT_IMPLICIT_WORK_TREE_ENVIRONMENT "GIT_IMPLICIT_WORK_TREE"

/*
 * Repository-local GIT_* environment variables; these will be cleared
 * when git spawns a sub-process that runs inside another repository.
 * The array is NULL-terminated, which makes it easy to pass in the "env"
 * parameter of a run-command invocation, or to do a simple walk.
 */
extern const char * const local_repo_env[];

extern void setup_git_env(void);

/*
 * Returns true iff we have a configured git repository (either via
 * setup_git_directory, or in the environment via $GIT_DIR).
 */
int have_git_dir(void);

extern int is_bare_repository_cfg;
extern int is_bare_repository(void);
extern int is_inside_git_dir(void);
extern char *git_work_tree_cfg;
extern int is_inside_work_tree(void);
extern const char *get_git_dir(void);
extern const char *get_git_common_dir(void);
extern char *get_object_directory(void);
extern char *get_index_file(void);
extern char *get_graft_file(void);
extern int set_git_dir(const char *path);
extern int get_common_dir_noenv(struct strbuf *sb, const char *gitdir);
extern int get_common_dir(struct strbuf *sb, const char *gitdir);
extern const char *get_git_namespace(void);
extern const char *strip_namespace(const char *namespaced_ref);
extern const char *get_super_prefix(void);
extern const char *get_git_work_tree(void);

/*
 * Return true if the given path is a git directory; note that this _just_
 * looks at the directory itself. If you want to know whether "foo/.git"
 * is a repository, you must feed that path, not just "foo".
 */
extern int is_git_directory(const char *path);

/*
 * Return 1 if the given path is the root of a git repository or
 * submodule, else 0. Will not return 1 for bare repositories with the
 * exception of creating a bare repository in "foo/.git" and calling
 * is_git_repository("foo").
 *
 * If we run into read errors, we err on the side of saying "yes, it is",
 * as we usually consider sub-repos precious, and would prefer to err on the
 * side of not disrupting or deleting them.
 */
extern int is_nonbare_repository_dir(struct strbuf *path);

#define READ_GITFILE_ERR_STAT_FAILED 1
#define READ_GITFILE_ERR_NOT_A_FILE 2
#define READ_GITFILE_ERR_OPEN_FAILED 3
#define READ_GITFILE_ERR_READ_FAILED 4
#define READ_GITFILE_ERR_INVALID_FORMAT 5
#define READ_GITFILE_ERR_NO_PATH 6
#define READ_GITFILE_ERR_NOT_A_REPO 7
#define READ_GITFILE_ERR_TOO_LARGE 8
extern void read_gitfile_error_die(int error_code, const char *path, const char *dir);
extern const char *read_gitfile_gently(const char *path, int *return_error_code);
#define read_gitfile(path) read_gitfile_gently((path), NULL)
extern const char *resolve_gitdir_gently(const char *suspect, int *return_error_code);
#define resolve_gitdir(path) resolve_gitdir_gently((path), NULL)

extern void set_git_work_tree(const char *tree);

#define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"

extern void setup_work_tree(void);
/*
 * Find the commondir and gitdir of the repository that contains the current
 * working directory, without changing the working directory or other global
 * state. The result is appended to commondir and gitdir.  If the discovered
 * gitdir does not correspond to a worktree, then 'commondir' and 'gitdir' will
 * both have the same result appended to the buffer.  The return value is
 * either 0 upon success and non-zero if no repository was found.
 */
extern int discover_git_directory(struct strbuf *commondir,
				  struct strbuf *gitdir);
extern const char *setup_git_directory_gently(int *);
extern const char *setup_git_directory(void);
extern char *prefix_path(const char *prefix, int len, const char *path);
extern char *prefix_path_gently(const char *prefix, int len, int *remaining, const char *path);

/*
 * Concatenate "prefix" (if len is non-zero) and "path", with no
 * connecting characters (so "prefix" should end with a "/").
 * Unlike prefix_path, this should be used if the named file does
 * not have to interact with index entry; i.e. name of a random file
 * on the filesystem.
 *
 * The return value is always a newly allocated string (even if the
 * prefix was empty).
 */
extern char *prefix_filename(const char *prefix, const char *path);

extern int check_filename(const char *prefix, const char *name);
extern void verify_filename(const char *prefix,
			    const char *name,
			    int diagnose_misspelt_rev);
extern void verify_non_filename(const char *prefix, const char *name);
extern int path_inside_repo(const char *prefix, const char *path);

#define INIT_DB_QUIET 0x0001
#define INIT_DB_EXIST_OK 0x0002

extern int init_db(const char *git_dir, const char *real_git_dir,
		   const char *template_dir, unsigned int flags);

extern void sanitize_stdfds(void);
extern int daemonize(void);

#define alloc_nr(x) (((x)+16)*3/2)

/*
 * Realloc the buffer pointed at by variable 'x' so that it can hold
 * at least 'nr' entries; the number of entries currently allocated
 * is 'alloc', using the standard growing factor alloc_nr() macro.
 *
 * DO NOT USE any expression with side-effect for 'x', 'nr', or 'alloc'.
 */
#define ALLOC_GROW(x, nr, alloc) \
	do { \
		if ((nr) > alloc) { \
			if (alloc_nr(alloc) < (nr)) \
				alloc = (nr); \
			else \
				alloc = alloc_nr(alloc); \
			REALLOC_ARRAY(x, alloc); \
		} \
	} while (0)

/* Initialize and use the cache information */
struct lock_file;
extern int read_index(struct index_state *);
extern int read_index_preload(struct index_state *, const struct pathspec *pathspec);
extern int do_read_index(struct index_state *istate, const char *path,
			 int must_exist); /* for testting only! */
extern int read_index_from(struct index_state *, const char *path,
			   const char *gitdir);
extern int is_index_unborn(struct index_state *);
extern int read_index_unmerged(struct index_state *);

/* For use with `write_locked_index()`. */
#define COMMIT_LOCK		(1 << 0)

/*
 * Write the index while holding an already-taken lock. Close the lock,
 * and if `COMMIT_LOCK` is given, commit it.
 *
 * Unless a split index is in use, write the index into the lockfile.
 *
 * With a split index, write the shared index to a temporary file,
 * adjust its permissions and rename it into place, then write the
 * split index to the lockfile. If the temporary file for the shared
 * index cannot be created, fall back to the behavior described in
 * the previous paragraph.
 *
 * With `COMMIT_LOCK`, the lock is always committed or rolled back.
 * Without it, the lock is closed, but neither committed nor rolled
 * back.
 */
extern int write_locked_index(struct index_state *, struct lock_file *lock, unsigned flags);

extern int discard_index(struct index_state *);
extern void move_index_extensions(struct index_state *dst, struct index_state *src);
extern int unmerged_index(const struct index_state *);

/**
 * Returns 1 if the index differs from HEAD, 0 otherwise. When on an unborn
 * branch, returns 1 if there are entries in the index, 0 otherwise. If an
 * strbuf is provided, the space-separated list of files that differ will be
 * appended to it.
 */
extern int index_has_changes(struct strbuf *sb);

extern int verify_path(const char *path);
extern int strcmp_offset(const char *s1, const char *s2, size_t *first_change);
extern int index_dir_exists(struct index_state *istate, const char *name, int namelen);
extern void adjust_dirname_case(struct index_state *istate, char *name);
extern struct cache_entry *index_file_exists(struct index_state *istate, const char *name, int namelen, int igncase);

/*
 * Searches for an entry defined by name and namelen in the given index.
 * If the return value is positive (including 0) it is the position of an
 * exact match. If the return value is negative, the negated value minus 1
 * is the position where the entry would be inserted.
 * Example: The current index consists of these files and its stages:
 *
 *   b#0, d#0, f#1, f#3
 *
 * index_name_pos(&index, "a", 1) -> -1
 * index_name_pos(&index, "b", 1) ->  0
 * index_name_pos(&index, "c", 1) -> -2
 * index_name_pos(&index, "d", 1) ->  1
 * index_name_pos(&index, "e", 1) -> -3
 * index_name_pos(&index, "f", 1) -> -3
 * index_name_pos(&index, "g", 1) -> -5
 */
extern int index_name_pos(const struct index_state *, const char *name, int namelen);

#define ADD_CACHE_OK_TO_ADD 1		/* Ok to add */
#define ADD_CACHE_OK_TO_REPLACE 2	/* Ok to replace file/directory */
#define ADD_CACHE_SKIP_DFCHECK 4	/* Ok to skip DF conflict checks */
#define ADD_CACHE_JUST_APPEND 8		/* Append only; tree.c::read_tree() */
#define ADD_CACHE_NEW_ONLY 16		/* Do not replace existing ones */
#define ADD_CACHE_KEEP_CACHE_TREE 32	/* Do not invalidate cache-tree */
extern int add_index_entry(struct index_state *, struct cache_entry *ce, int option);
extern void rename_index_entry_at(struct index_state *, int pos, const char *new_name);

/* Remove entry, return true if there are more entries to go. */
extern int remove_index_entry_at(struct index_state *, int pos);

extern void remove_marked_cache_entries(struct index_state *istate);
extern int remove_file_from_index(struct index_state *, const char *path);
#define ADD_CACHE_VERBOSE 1
#define ADD_CACHE_PRETEND 2
#define ADD_CACHE_IGNORE_ERRORS	4
#define ADD_CACHE_IGNORE_REMOVAL 8
#define ADD_CACHE_INTENT 16
/*
 * These two are used to add the contents of the file at path
 * to the index, marking the working tree up-to-date by storing
 * the cached stat info in the resulting cache entry.  A caller
 * that has already run lstat(2) on the path can call
 * add_to_index(), and all others can call add_file_to_index();
 * the latter will do necessary lstat(2) internally before
 * calling the former.
 */
extern int add_to_index(struct index_state *, const char *path, struct stat *, int flags);
extern int add_file_to_index(struct index_state *, const char *path, int flags);

extern struct cache_entry *make_cache_entry(unsigned int mode, const unsigned char *sha1, const char *path, int stage, unsigned int refresh_options);
extern int chmod_index_entry(struct index_state *, struct cache_entry *ce, char flip);
extern int ce_same_name(const struct cache_entry *a, const struct cache_entry *b);
extern void set_object_name_for_intent_to_add_entry(struct cache_entry *ce);
extern int index_name_is_other(const struct index_state *, const char *, int);
extern void *read_blob_data_from_index(const struct index_state *, const char *, unsigned long *);

/* do stat comparison even if CE_VALID is true */
#define CE_MATCH_IGNORE_VALID		01
/* do not check the contents but report dirty on racily-clean entries */
#define CE_MATCH_RACY_IS_DIRTY		02
/* do stat comparison even if CE_SKIP_WORKTREE is true */
#define CE_MATCH_IGNORE_SKIP_WORKTREE	04
/* ignore non-existent files during stat update  */
#define CE_MATCH_IGNORE_MISSING		0x08
/* enable stat refresh */
#define CE_MATCH_REFRESH		0x10
/* don't refresh_fsmonitor state or do stat comparison even if CE_FSMONITOR_VALID is true */
#define CE_MATCH_IGNORE_FSMONITOR 0X20
extern int ie_match_stat(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);
extern int ie_modified(struct index_state *, const struct cache_entry *, struct stat *, unsigned int);

#define HASH_WRITE_OBJECT 1
#define HASH_FORMAT_CHECK 2
#define HASH_RENORMALIZE  4
extern int index_fd(struct object_id *oid, int fd, struct stat *st, enum object_type type, const char *path, unsigned flags);
extern int index_path(struct object_id *oid, const char *path, struct stat *st, unsigned flags);

/*
 * Record to sd the data from st that we use to check whether a file
 * might have changed.
 */
extern void fill_stat_data(struct stat_data *sd, struct stat *st);

/*
 * Return 0 if st is consistent with a file not having been changed
 * since sd was filled.  If there are differences, return a
 * combination of MTIME_CHANGED, CTIME_CHANGED, OWNER_CHANGED,
 * INODE_CHANGED, and DATA_CHANGED.
 */
extern int match_stat_data(const struct stat_data *sd, struct stat *st);
extern int match_stat_data_racy(const struct index_state *istate,
				const struct stat_data *sd, struct stat *st);

extern void fill_stat_cache_info(struct cache_entry *ce, struct stat *st);

#define REFRESH_REALLY		0x0001	/* ignore_valid */
#define REFRESH_UNMERGED	0x0002	/* allow unmerged */
#define REFRESH_QUIET		0x0004	/* be quiet about it */
#define REFRESH_IGNORE_MISSING	0x0008	/* ignore non-existent */
#define REFRESH_IGNORE_SUBMODULES	0x0010	/* ignore submodules */
#define REFRESH_IN_PORCELAIN	0x0020	/* user friendly output, not "needs update" */
extern int refresh_index(struct index_state *, unsigned int flags, const struct pathspec *pathspec, char *seen, const char *header_msg);
extern struct cache_entry *refresh_cache_entry(struct cache_entry *, unsigned int);

/*
 * Opportunistically update the index but do not complain if we can't.
 * The lockfile is always committed or rolled back.
 */
extern void update_index_if_able(struct index_state *, struct lock_file *);

extern int hold_locked_index(struct lock_file *, int);
extern void set_alternate_index_output(const char *);

extern int verify_index_checksum;
extern int verify_ce_order;

/* Environment bits from configuration mechanism */
extern int trust_executable_bit;
extern int trust_ctime;
extern int check_stat;
extern int quote_path_fully;
extern int has_symlinks;
extern int minimum_abbrev, default_abbrev;
extern int ignore_case;
extern int assume_unchanged;
extern int prefer_symlink_refs;
extern int warn_ambiguous_refs;
extern int warn_on_object_refname_ambiguity;
extern const char *apply_default_whitespace;
extern const char *apply_default_ignorewhitespace;
extern const char *git_attributes_file;
extern const char *git_hooks_path;
extern int zlib_compression_level;
extern int core_compression_level;
extern int pack_compression_level;
extern size_t packed_git_window_size;
extern size_t packed_git_limit;
extern size_t delta_base_cache_limit;
extern unsigned long big_file_threshold;
extern unsigned long pack_size_limit_cfg;

/*
 * Accessors for the core.sharedrepository config which lazy-load the value
 * from the config (if not already set). The "reset" function can be
 * used to unset "set" or cached value, meaning that the value will be loaded
 * fresh from the config file on the next call to get_shared_repository().
 */
void set_shared_repository(int value);
int get_shared_repository(void);
void reset_shared_repository(void);

/*
 * Do replace refs need to be checked this run?  This variable is
 * initialized to true unless --no-replace-object is used or
 * $GIT_NO_REPLACE_OBJECTS is set, but is set to false by some
 * commands that do not want replace references to be active.  As an
 * optimization it is also set to false if replace references have
 * been sought but there were none.
 */
extern int check_replace_refs;
extern char *git_replace_ref_base;

extern int fsync_object_files;
extern int core_preload_index;
extern int core_apply_sparse_checkout;
extern int precomposed_unicode;
extern int protect_hfs;
extern int protect_ntfs;
extern const char *core_fsmonitor;

/*
 * Include broken refs in all ref iterations, which will
 * generally choke dangerous operations rather than letting
 * them silently proceed without taking the broken ref into
 * account.
 */
extern int ref_paranoia;

/*
 * Returns the boolean value of $GIT_OPTIONAL_LOCKS (or the default value).
 */
int use_optional_locks(void);

/*
 * The character that begins a commented line in user-editable file
 * that is subject to stripspace.
 */
extern char comment_line_char;
extern int auto_comment_line_char;

/* Windows only */
enum hide_dotfiles_type {
	HIDE_DOTFILES_FALSE = 0,
	HIDE_DOTFILES_TRUE,
	HIDE_DOTFILES_DOTGITONLY
};
extern enum hide_dotfiles_type hide_dotfiles;

enum log_refs_config {
	LOG_REFS_UNSET = -1,
	LOG_REFS_NONE = 0,
	LOG_REFS_NORMAL,
	LOG_REFS_ALWAYS
};
extern enum log_refs_config log_all_ref_updates;

enum branch_track {
	BRANCH_TRACK_UNSPECIFIED = -1,
	BRANCH_TRACK_NEVER = 0,
	BRANCH_TRACK_REMOTE,
	BRANCH_TRACK_ALWAYS,
	BRANCH_TRACK_EXPLICIT,
	BRANCH_TRACK_OVERRIDE
};

enum rebase_setup_type {
	AUTOREBASE_NEVER = 0,
	AUTOREBASE_LOCAL,
	AUTOREBASE_REMOTE,
	AUTOREBASE_ALWAYS
};

enum push_default_type {
	PUSH_DEFAULT_NOTHING = 0,
	PUSH_DEFAULT_MATCHING,
	PUSH_DEFAULT_SIMPLE,
	PUSH_DEFAULT_UPSTREAM,
	PUSH_DEFAULT_CURRENT,
	PUSH_DEFAULT_UNSPECIFIED
};

extern enum branch_track git_branch_track;
extern enum rebase_setup_type autorebase;
extern enum push_default_type push_default;

enum object_creation_mode {
	OBJECT_CREATION_USES_HARDLINKS = 0,
	OBJECT_CREATION_USES_RENAMES = 1
};

extern enum object_creation_mode object_creation_mode;

extern char *notes_ref_name;

extern int grafts_replace_parents;

/*
 * GIT_REPO_VERSION is the version we write by default. The
 * _READ variant is the highest number we know how to
 * handle.
 */
#define GIT_REPO_VERSION 0
#define GIT_REPO_VERSION_READ 1
extern int repository_format_precious_objects;
extern char *repository_format_partial_clone;
extern const char *core_partial_clone_filter_default;

struct repository_format {
	int version;
	int precious_objects;
	char *partial_clone; /* value of extensions.partialclone */
	int is_bare;
	int hash_algo;
	char *work_tree;
	struct string_list unknown_extensions;
};

/*
 * Read the repository format characteristics from the config file "path" into
 * "format" struct. Returns the numeric version. On error, -1 is returned,
 * format->version is set to -1, and all other fields in the struct are
 * undefined.
 */
int read_repository_format(struct repository_format *format, const char *path);

/*
 * Verify that the repository described by repository_format is something we
 * can read. If it is, return 0. Otherwise, return -1, and "err" will describe
 * any errors encountered.
 */
int verify_repository_format(const struct repository_format *format,
			     struct strbuf *err);

/*
 * Check the repository format version in the path found in get_git_dir(),
 * and die if it is a version we don't understand. Generally one would
 * set_git_dir() before calling this, and use it only for "are we in a valid
 * repo?".
 */
extern void check_repository_format(void);

#define MTIME_CHANGED	0x0001
#define CTIME_CHANGED	0x0002
#define OWNER_CHANGED	0x0004
#define MODE_CHANGED    0x0008
#define INODE_CHANGED   0x0010
#define DATA_CHANGED    0x0020
#define TYPE_CHANGED    0x0040

/*
 * Put in `buf` the name of the file in the local object database that
 * would be used to store a loose object with the specified sha1.
 */
extern void sha1_file_name(struct strbuf *buf, const unsigned char *sha1);

/*
 * Return an abbreviated sha1 unique within this repository's object database.
 * The result will be at least `len` characters long, and will be NUL
 * terminated.
 *
 * The non-`_r` version returns a static buffer which remains valid until 4
 * more calls to find_unique_abbrev are made.
 *
 * The `_r` variant writes to a buffer supplied by the caller, which must be at
 * least `GIT_SHA1_HEXSZ + 1` bytes. The return value is the number of bytes
 * written (excluding the NUL terminator).
 *
 * Note that while this version avoids the static buffer, it is not fully
 * reentrant, as it calls into other non-reentrant git code.
 */
extern const char *find_unique_abbrev(const unsigned char *sha1, int len);
extern int find_unique_abbrev_r(char *hex, const unsigned char *sha1, int len);

extern const unsigned char null_sha1[GIT_MAX_RAWSZ];
extern const struct object_id null_oid;

static inline int hashcmp(const unsigned char *sha1, const unsigned char *sha2)
{
	return memcmp(sha1, sha2, GIT_SHA1_RAWSZ);
}

static inline int oidcmp(const struct object_id *oid1, const struct object_id *oid2)
{
	return hashcmp(oid1->hash, oid2->hash);
}

static inline int is_null_sha1(const unsigned char *sha1)
{
	return !hashcmp(sha1, null_sha1);
}

static inline int is_null_oid(const struct object_id *oid)
{
	return !hashcmp(oid->hash, null_sha1);
}

static inline void hashcpy(unsigned char *sha_dst, const unsigned char *sha_src)
{
	memcpy(sha_dst, sha_src, GIT_SHA1_RAWSZ);
}

static inline void oidcpy(struct object_id *dst, const struct object_id *src)
{
	hashcpy(dst->hash, src->hash);
}

static inline struct object_id *oiddup(const struct object_id *src)
{
	struct object_id *dst = xmalloc(sizeof(struct object_id));
	oidcpy(dst, src);
	return dst;
}

static inline void hashclr(unsigned char *hash)
{
	memset(hash, 0, GIT_SHA1_RAWSZ);
}

static inline void oidclr(struct object_id *oid)
{
	hashclr(oid->hash);
}


#define EMPTY_TREE_SHA1_HEX \
	"4b825dc642cb6eb9a060e54bf8d69288fbee4904"
#define EMPTY_TREE_SHA1_BIN_LITERAL \
	 "\x4b\x82\x5d\xc6\x42\xcb\x6e\xb9\xa0\x60" \
	 "\xe5\x4b\xf8\xd6\x92\x88\xfb\xee\x49\x04"
extern const struct object_id empty_tree_oid;
#define EMPTY_TREE_SHA1_BIN (empty_tree_oid.hash)

#define EMPTY_BLOB_SHA1_HEX \
	"e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"
#define EMPTY_BLOB_SHA1_BIN_LITERAL \
	"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
	"\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
extern const struct object_id empty_blob_oid;
#define EMPTY_BLOB_SHA1_BIN (empty_blob_oid.hash)


static inline int is_empty_blob_sha1(const unsigned char *sha1)
{
	return !hashcmp(sha1, the_hash_algo->empty_blob->hash);
}

static inline int is_empty_blob_oid(const struct object_id *oid)
{
	return !oidcmp(oid, the_hash_algo->empty_blob);
}

static inline int is_empty_tree_sha1(const unsigned char *sha1)
{
	return !hashcmp(sha1, the_hash_algo->empty_tree->hash);
}

static inline int is_empty_tree_oid(const struct object_id *oid)
{
	return !oidcmp(oid, the_hash_algo->empty_tree);
}

/* set default permissions by passing mode arguments to open(2) */
int git_mkstemps_mode(char *pattern, int suffix_len, int mode);
int git_mkstemp_mode(char *pattern, int mode);

/*
 * NOTE NOTE NOTE!!
 *
 * PERM_UMASK, OLD_PERM_GROUP and OLD_PERM_EVERYBODY enumerations must
 * not be changed. Old repositories have core.sharedrepository written in
 * numeric format, and therefore these values are preserved for compatibility
 * reasons.
 */
enum sharedrepo {
	PERM_UMASK          = 0,
	OLD_PERM_GROUP      = 1,
	OLD_PERM_EVERYBODY  = 2,
	PERM_GROUP          = 0660,
	PERM_EVERYBODY      = 0664
};
int git_config_perm(const char *var, const char *value);
int adjust_shared_perm(const char *path);

/*
 * Create the directory containing the named path, using care to be
 * somewhat safe against races. Return one of the scld_error values to
 * indicate success/failure. On error, set errno to describe the
 * problem.
 *
 * SCLD_VANISHED indicates that one of the ancestor directories of the
 * path existed at one point during the function call and then
 * suddenly vanished, probably because another process pruned the
 * directory while we were working.  To be robust against this kind of
 * race, callers might want to try invoking the function again when it
 * returns SCLD_VANISHED.
 *
 * safe_create_leading_directories() temporarily changes path while it
 * is working but restores it before returning.
 * safe_create_leading_directories_const() doesn't modify path, even
 * temporarily.
 */
enum scld_error {
	SCLD_OK = 0,
	SCLD_FAILED = -1,
	SCLD_PERMS = -2,
	SCLD_EXISTS = -3,
	SCLD_VANISHED = -4
};
enum scld_error safe_create_leading_directories(char *path);
enum scld_error safe_create_leading_directories_const(const char *path);

/*
 * Callback function for raceproof_create_file(). This function is
 * expected to do something that makes dirname(path) permanent despite
 * the fact that other processes might be cleaning up empty
 * directories at the same time. Usually it will create a file named
 * path, but alternatively it could create another file in that
 * directory, or even chdir() into that directory. The function should
 * return 0 if the action was completed successfully. On error, it
 * should return a nonzero result and set errno.
 * raceproof_create_file() treats two errno values specially:
 *
 * - ENOENT -- dirname(path) does not exist. In this case,
 *             raceproof_create_file() tries creating dirname(path)
 *             (and any parent directories, if necessary) and calls
 *             the function again.
 *
 * - EISDIR -- the file already exists and is a directory. In this
 *             case, raceproof_create_file() removes the directory if
 *             it is empty (and recursively any empty directories that
 *             it contains) and calls the function again.
 *
 * Any other errno causes raceproof_create_file() to fail with the
 * callback's return value and errno.
 *
 * Obviously, this function should be OK with being called again if it
 * fails with ENOENT or EISDIR. In other scenarios it will not be
 * called again.
 */
typedef int create_file_fn(const char *path, void *cb);

/*
 * Create a file in dirname(path) by calling fn, creating leading
 * directories if necessary. Retry a few times in case we are racing
 * with another process that is trying to clean up the directory that
 * contains path. See the documentation for create_file_fn for more
 * details.
 *
 * Return the value and set the errno that resulted from the most
 * recent call of fn. fn is always called at least once, and will be
 * called more than once if it returns ENOENT or EISDIR.
 */
int raceproof_create_file(const char *path, create_file_fn fn, void *cb);

int mkdir_in_gitdir(const char *path);
extern char *expand_user_path(const char *path, int real_home);
const char *enter_repo(const char *path, int strict);
static inline int is_absolute_path(const char *path)
{
	return is_dir_sep(path[0]) || has_dos_drive_prefix(path);
}
int is_directory(const char *);
char *strbuf_realpath(struct strbuf *resolved, const char *path,
		      int die_on_error);
const char *real_path(const char *path);
const char *real_path_if_valid(const char *path);
char *real_pathdup(const char *path, int die_on_error);
const char *absolute_path(const char *path);
char *absolute_pathdup(const char *path);
const char *remove_leading_path(const char *in, const char *prefix);
const char *relative_path(const char *in, const char *prefix, struct strbuf *sb);
int normalize_path_copy_len(char *dst, const char *src, int *prefix_len);
int normalize_path_copy(char *dst, const char *src);
int longest_ancestor_length(const char *path, struct string_list *prefixes);
char *strip_path_suffix(const char *path, const char *suffix);
int daemon_avoid_alias(const char *path);
extern int is_ntfs_dotgit(const char *name);

/*
 * Returns true iff "str" could be confused as a command-line option when
 * passed to a sub-program like "ssh". Note that this has nothing to do with
 * shell-quoting, which should be handled separately; we're assuming here that
 * the string makes it verbatim to the sub-program.
 */
int looks_like_command_line_option(const char *str);

/**
 * Return a newly allocated string with the evaluation of
 * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
 * "$HOME/.config/git/$filename". Return NULL upon error.
 */
extern char *xdg_config_home(const char *filename);

/**
 * Return a newly allocated string with the evaluation of
 * "$XDG_CACHE_HOME/git/$filename" if $XDG_CACHE_HOME is non-empty, otherwise
 * "$HOME/.cache/git/$filename". Return NULL upon error.
 */
extern char *xdg_cache_home(const char *filename);

extern void *read_sha1_file_extended(const unsigned char *sha1,
				     enum object_type *type,
				     unsigned long *size, int lookup_replace);
static inline void *read_sha1_file(const unsigned char *sha1, enum object_type *type, unsigned long *size)
{
	return read_sha1_file_extended(sha1, type, size, 1);
}

/*
 * This internal function is only declared here for the benefit of
 * lookup_replace_object().  Please do not call it directly.
 */
extern const unsigned char *do_lookup_replace_object(const unsigned char *sha1);

/*
 * If object sha1 should be replaced, return the replacement object's
 * name (replaced recursively, if necessary).  The return value is
 * either sha1 or a pointer to a permanently-allocated value.  When
 * object replacement is suppressed, always return sha1.
 */
static inline const unsigned char *lookup_replace_object(const unsigned char *sha1)
{
	if (!check_replace_refs)
		return sha1;
	return do_lookup_replace_object(sha1);
}

/* Read and unpack a sha1 file into memory, write memory to a sha1 file */
extern int sha1_object_info(const unsigned char *, unsigned long *);
extern int hash_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *sha1);
extern int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *return_sha1);
extern int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type, struct object_id *oid, unsigned flags);
extern int pretend_sha1_file(void *, unsigned long, enum object_type, unsigned char *);
extern int force_object_loose(const unsigned char *sha1, time_t mtime);
extern int git_open_cloexec(const char *name, int flags);
#define git_open(name) git_open_cloexec(name, O_RDONLY)
extern void *map_sha1_file(const unsigned char *sha1, unsigned long *size);
extern int unpack_sha1_header(git_zstream *stream, unsigned char *map, unsigned long mapsize, void *buffer, unsigned long bufsiz);
extern int parse_sha1_header(const char *hdr, unsigned long *sizep);

extern int check_sha1_signature(const unsigned char *sha1, void *buf, unsigned long size, const char *type);

extern int finalize_object_file(const char *tmpfile, const char *filename);

/*
 * Open the loose object at path, check its sha1, and return the contents,
 * type, and size. If the object is a blob, then "contents" may return NULL,
 * to allow streaming of large blobs.
 *
 * Returns 0 on success, negative on error (details may be written to stderr).
 */
int read_loose_object(const char *path,
		      const unsigned char *expected_sha1,
		      enum object_type *type,
		      unsigned long *size,
		      void **contents);

/*
 * Convenience for sha1_object_info_extended() with a NULL struct
 * object_info. OBJECT_INFO_SKIP_CACHED is automatically set; pass
 * nonzero flags to also set other flags.
 */
extern int has_sha1_file_with_flags(const unsigned char *sha1, int flags);
static inline int has_sha1_file(const unsigned char *sha1)
{
	return has_sha1_file_with_flags(sha1, 0);
}

/* Same as the above, except for struct object_id. */
extern int has_object_file(const struct object_id *oid);
extern int has_object_file_with_flags(const struct object_id *oid, int flags);

/*
 * Return true iff an alternate object database has a loose object
 * with the specified name.  This function does not respect replace
 * references.
 */
extern int has_loose_object_nonlocal(const unsigned char *sha1);

extern void assert_sha1_type(const unsigned char *sha1, enum object_type expect);

/* Helper to check and "touch" a file */
extern int check_and_freshen_file(const char *fn, int freshen);

extern const signed char hexval_table[256];
static inline unsigned int hexval(unsigned char c)
{
	return hexval_table[c];
}

/*
 * Convert two consecutive hexadecimal digits into a char.  Return a
 * negative value on error.  Don't run over the end of short strings.
 */
static inline int hex2chr(const char *s)
{
	unsigned int val = hexval(s[0]);
	return (val & ~0xf) ? val : (val << 4) | hexval(s[1]);
}

/* Convert to/from hex/sha1 representation */
#define MINIMUM_ABBREV minimum_abbrev
#define DEFAULT_ABBREV default_abbrev

/* used when the code does not know or care what the default abbrev is */
#define FALLBACK_DEFAULT_ABBREV 7

struct object_context {
	unsigned char tree[20];
	unsigned mode;
	/*
	 * symlink_path is only used by get_tree_entry_follow_symlinks,
	 * and only for symlinks that point outside the repository.
	 */
	struct strbuf symlink_path;
	/*
	 * If GET_OID_RECORD_PATH is set, this will record path (if any)
	 * found when resolving the name. The caller is responsible for
	 * releasing the memory.
	 */
	char *path;
};

#define GET_OID_QUIETLY           01
#define GET_OID_COMMIT            02
#define GET_OID_COMMITTISH        04
#define GET_OID_TREE             010
#define GET_OID_TREEISH          020
#define GET_OID_BLOB             040
#define GET_OID_FOLLOW_SYMLINKS 0100
#define GET_OID_RECORD_PATH     0200
#define GET_OID_ONLY_TO_DIE    04000

#define GET_OID_DISAMBIGUATORS \
	(GET_OID_COMMIT | GET_OID_COMMITTISH | \
	GET_OID_TREE | GET_OID_TREEISH | \
	GET_OID_BLOB)

extern int get_oid(const char *str, struct object_id *oid);
extern int get_oid_commit(const char *str, struct object_id *oid);
extern int get_oid_committish(const char *str, struct object_id *oid);
extern int get_oid_tree(const char *str, struct object_id *oid);
extern int get_oid_treeish(const char *str, struct object_id *oid);
extern int get_oid_blob(const char *str, struct object_id *oid);
extern void maybe_die_on_misspelt_object_name(const char *name, const char *prefix);
extern int get_oid_with_context(const char *str, unsigned flags, struct object_id *oid, struct object_context *oc);


typedef int each_abbrev_fn(const struct object_id *oid, void *);
extern int for_each_abbrev(const char *prefix, each_abbrev_fn, void *);

extern int set_disambiguate_hint_config(const char *var, const char *value);

/*
 * Try to read a SHA1 in hexadecimal format from the 40 characters
 * starting at hex.  Write the 20-byte result to sha1 in binary form.
 * Return 0 on success.  Reading stops if a NUL is encountered in the
 * input, so it is safe to pass this function an arbitrary
 * null-terminated string.
 */
extern int get_sha1_hex(const char *hex, unsigned char *sha1);
extern int get_oid_hex(const char *hex, struct object_id *sha1);

/*
 * Read `len` pairs of hexadecimal digits from `hex` and write the
 * values to `binary` as `len` bytes. Return 0 on success, or -1 if
 * the input does not consist of hex digits).
 */
extern int hex_to_bytes(unsigned char *binary, const char *hex, size_t len);

/*
 * Convert a binary sha1 to its hex equivalent. The `_r` variant is reentrant,
 * and writes the NUL-terminated output to the buffer `out`, which must be at
 * least `GIT_SHA1_HEXSZ + 1` bytes, and returns a pointer to out for
 * convenience.
 *
 * The non-`_r` variant returns a static buffer, but uses a ring of 4
 * buffers, making it safe to make multiple calls for a single statement, like:
 *
 *   printf("%s -> %s", sha1_to_hex(one), sha1_to_hex(two));
 */
extern char *sha1_to_hex_r(char *out, const unsigned char *sha1);
extern char *oid_to_hex_r(char *out, const struct object_id *oid);
extern char *sha1_to_hex(const unsigned char *sha1);	/* static buffer result! */
extern char *oid_to_hex(const struct object_id *oid);	/* same static buffer as sha1_to_hex */

/*
 * Parse a 40-character hexadecimal object ID starting from hex, updating the
 * pointer specified by end when parsing stops.  The resulting object ID is
 * stored in oid.  Returns 0 on success.  Parsing will stop on the first NUL or
 * other invalid character.  end is only updated on success; otherwise, it is
 * unmodified.
 */
extern int parse_oid_hex(const char *hex, struct object_id *oid, const char **end);

/*
 * This reads short-hand syntax that not only evaluates to a commit
 * object name, but also can act as if the end user spelled the name
 * of the branch from the command line.
 *
 * - "@{-N}" finds the name of the Nth previous branch we were on, and
 *   places the name of the branch in the given buf and returns the
 *   number of characters parsed if successful.
 *
 * - "<branch>@{upstream}" finds the name of the other ref that
 *   <branch> is configured to merge with (missing <branch> defaults
 *   to the current branch), and places the name of the branch in the
 *   given buf and returns the number of characters parsed if
 *   successful.
 *
 * If the input is not of the accepted format, it returns a negative
 * number to signal an error.
 *
 * If the input was ok but there are not N branch switches in the
 * reflog, it returns 0.
 *
 * If "allowed" is non-zero, it is a treated as a bitfield of allowable
 * expansions: local branches ("refs/heads/"), remote branches
 * ("refs/remotes/"), or "HEAD". If no "allowed" bits are set, any expansion is
 * allowed, even ones to refs outside of those namespaces.
 */
#define INTERPRET_BRANCH_LOCAL (1<<0)
#define INTERPRET_BRANCH_REMOTE (1<<1)
#define INTERPRET_BRANCH_HEAD (1<<2)
extern int interpret_branch_name(const char *str, int len, struct strbuf *,
				 unsigned allowed);
extern int get_oid_mb(const char *str, struct object_id *oid);

extern int validate_headref(const char *ref);

extern int base_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
extern int df_name_compare(const char *name1, int len1, int mode1, const char *name2, int len2, int mode2);
extern int name_compare(const char *name1, size_t len1, const char *name2, size_t len2);
extern int cache_name_stage_compare(const char *name1, int len1, int stage1, const char *name2, int len2, int stage2);

extern void *read_object_with_reference(const unsigned char *sha1,
					const char *required_type,
					unsigned long *size,
					unsigned char *sha1_ret);

extern struct object *peel_to_type(const char *name, int namelen,
				   struct object *o, enum object_type);

struct date_mode {
	enum date_mode_type {
		DATE_NORMAL = 0,
		DATE_RELATIVE,
		DATE_SHORT,
		DATE_ISO8601,
		DATE_ISO8601_STRICT,
		DATE_RFC2822,
		DATE_STRFTIME,
		DATE_RAW,
		DATE_UNIX
	} type;
	const char *strftime_fmt;
	int local;
};

/*
 * Convenience helper for passing a constant type, like:
 *
 *   show_date(t, tz, DATE_MODE(NORMAL));
 */
#define DATE_MODE(t) date_mode_from_type(DATE_##t)
struct date_mode *date_mode_from_type(enum date_mode_type type);

const char *show_date(timestamp_t time, int timezone, const struct date_mode *mode);
void show_date_relative(timestamp_t time, int tz, const struct timeval *now,
			struct strbuf *timebuf);
int parse_date(const char *date, struct strbuf *out);
int parse_date_basic(const char *date, timestamp_t *timestamp, int *offset);
int parse_expiry_date(const char *date, timestamp_t *timestamp);
void datestamp(struct strbuf *out);
#define approxidate(s) approxidate_careful((s), NULL)
timestamp_t approxidate_careful(const char *, int *);
timestamp_t approxidate_relative(const char *date, const struct timeval *now);
void parse_date_format(const char *format, struct date_mode *mode);
int date_overflows(timestamp_t date);

#define IDENT_STRICT	       1
#define IDENT_NO_DATE	       2
#define IDENT_NO_NAME	       4
extern const char *git_author_info(int);
extern const char *git_committer_info(int);
extern const char *fmt_ident(const char *name, const char *email, const char *date_str, int);
extern const char *fmt_name(const char *name, const char *email);
extern const char *ident_default_name(void);
extern const char *ident_default_email(void);
extern const char *git_editor(void);
extern const char *git_pager(int stdout_is_tty);
extern int is_terminal_dumb(void);
extern int git_ident_config(const char *, const char *, void *);
extern void reset_ident_date(void);

struct ident_split {
	const char *name_begin;
	const char *name_end;
	const char *mail_begin;
	const char *mail_end;
	const char *date_begin;
	const char *date_end;
	const char *tz_begin;
	const char *tz_end;
};
/*
 * Signals an success with 0, but time part of the result may be NULL
 * if the input lacks timestamp and zone
 */
extern int split_ident_line(struct ident_split *, const char *, int);

/*
 * Like show_date, but pull the timestamp and tz parameters from
 * the ident_split. It will also sanity-check the values and produce
 * a well-known sentinel date if they appear bogus.
 */
const char *show_ident_date(const struct ident_split *id,
			    const struct date_mode *mode);

/*
 * Compare split idents for equality or strict ordering. Note that we
 * compare only the ident part of the line, ignoring any timestamp.
 *
 * Because there are two fields, we must choose one as the primary key; we
 * currently arbitrarily pick the email.
 */
extern int ident_cmp(const struct ident_split *, const struct ident_split *);

struct checkout {
	struct index_state *istate;
	const char *base_dir;
	int base_dir_len;
	struct delayed_checkout *delayed_checkout;
	unsigned force:1,
		 quiet:1,
		 not_new:1,
		 refresh_cache:1;
};
#define CHECKOUT_INIT { NULL, "" }

#define TEMPORARY_FILENAME_LENGTH 25
extern int checkout_entry(struct cache_entry *ce, const struct checkout *state, char *topath);
extern void enable_delayed_checkout(struct checkout *state);
extern int finish_delayed_checkout(struct checkout *state);

struct cache_def {
	struct strbuf path;
	int flags;
	int track_flags;
	int prefix_len_stat_func;
};
#define CACHE_DEF_INIT { STRBUF_INIT, 0, 0, 0 }
static inline void cache_def_clear(struct cache_def *cache)
{
	strbuf_release(&cache->path);
}

extern int has_symlink_leading_path(const char *name, int len);
extern int threaded_has_symlink_leading_path(struct cache_def *, const char *, int);
extern int check_leading_path(const char *name, int len);
extern int has_dirs_only_path(const char *name, int len, int prefix_len);
extern void schedule_dir_for_removal(const char *name, int len);
extern void remove_scheduled_dirs(void);

extern struct alternate_object_database {
	struct alternate_object_database *next;

	/* see alt_scratch_buf() */
	struct strbuf scratch;
	size_t base_len;

	/*
	 * Used to store the results of readdir(3) calls when searching
	 * for unique abbreviated hashes.  This cache is never
	 * invalidated, thus it's racy and not necessarily accurate.
	 * That's fine for its purpose; don't use it for tasks requiring
	 * greater accuracy!
	 */
	char loose_objects_subdir_seen[256];
	struct oid_array loose_objects_cache;

	char path[FLEX_ARRAY];
} *alt_odb_list;
extern void prepare_alt_odb(void);
extern char *compute_alternate_path(const char *path, struct strbuf *err);
typedef int alt_odb_fn(struct alternate_object_database *, void *);
extern int foreach_alt_odb(alt_odb_fn, void*);

/*
 * Allocate a "struct alternate_object_database" but do _not_ actually
 * add it to the list of alternates.
 */
struct alternate_object_database *alloc_alt_odb(const char *dir);

/*
 * Add the directory to the on-disk alternates file; the new entry will also
 * take effect in the current process.
 */
extern void add_to_alternates_file(const char *dir);

/*
 * Add the directory to the in-memory list of alternates (along with any
 * recursive alternates it points to), but do not modify the on-disk alternates
 * file.
 */
extern void add_to_alternates_memory(const char *dir);

/*
 * Returns a scratch strbuf pre-filled with the alternate object directory,
 * including a trailing slash, which can be used to access paths in the
 * alternate. Always use this over direct access to alt->scratch, as it
 * cleans up any previous use of the scratch buffer.
 */
extern struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);

struct pack_window {
	struct pack_window *next;
	unsigned char *base;
	off_t offset;
	size_t len;
	unsigned int last_used;
	unsigned int inuse_cnt;
};

extern struct packed_git {
	struct packed_git *next;
	struct list_head mru;
	struct pack_window *windows;
	off_t pack_size;
	const void *index_data;
	size_t index_size;
	uint32_t num_objects;
	uint32_t num_bad_objects;
	unsigned char *bad_object_sha1;
	int index_version;
	time_t mtime;
	int pack_fd;
	unsigned pack_local:1,
		 pack_keep:1,
		 freshened:1,
		 do_not_close:1,
		 pack_promisor:1;
	unsigned char sha1[20];
	struct revindex_entry *revindex;
	/* something like ".git/objects/pack/xxxxx.pack" */
	char pack_name[FLEX_ARRAY]; /* more */
} *packed_git;

/*
 * A most-recently-used ordered version of the packed_git list.
 */
extern struct list_head packed_git_mru;

struct pack_entry {
	off_t offset;
	unsigned char sha1[20];
	struct packed_git *p;
};

/*
 * Create a temporary file rooted in the object database directory, or
 * die on failure. The filename is taken from "pattern", which should have the
 * usual "XXXXXX" trailer, and the resulting filename is written into the
 * "template" buffer. Returns the open descriptor.
 */
extern int odb_mkstemp(struct strbuf *template, const char *pattern);

/*
 * Create a pack .keep file named "name" (which should generally be the output
 * of odb_pack_name). Returns a file descriptor opened for writing, or -1 on
 * error.
 */
extern int odb_pack_keep(const char *name);

/*
 * Iterate over the files in the loose-object parts of the object
 * directory "path", triggering the following callbacks:
 *
 *  - loose_object is called for each loose object we find.
 *
 *  - loose_cruft is called for any files that do not appear to be
 *    loose objects. Note that we only look in the loose object
 *    directories "objects/[0-9a-f]{2}/", so we will not report
 *    "objects/foobar" as cruft.
 *
 *  - loose_subdir is called for each top-level hashed subdirectory
 *    of the object directory (e.g., "$OBJDIR/f0"). It is called
 *    after the objects in the directory are processed.
 *
 * Any callback that is NULL will be ignored. Callbacks returning non-zero
 * will end the iteration.
 *
 * In the "buf" variant, "path" is a strbuf which will also be used as a
 * scratch buffer, but restored to its original contents before
 * the function returns.
 */
typedef int each_loose_object_fn(const struct object_id *oid,
				 const char *path,
				 void *data);
typedef int each_loose_cruft_fn(const char *basename,
				const char *path,
				void *data);
typedef int each_loose_subdir_fn(unsigned int nr,
				 const char *path,
				 void *data);
int for_each_file_in_obj_subdir(unsigned int subdir_nr,
				struct strbuf *path,
				each_loose_object_fn obj_cb,
				each_loose_cruft_fn cruft_cb,
				each_loose_subdir_fn subdir_cb,
				void *data);
int for_each_loose_file_in_objdir(const char *path,
				  each_loose_object_fn obj_cb,
				  each_loose_cruft_fn cruft_cb,
				  each_loose_subdir_fn subdir_cb,
				  void *data);
int for_each_loose_file_in_objdir_buf(struct strbuf *path,
				      each_loose_object_fn obj_cb,
				      each_loose_cruft_fn cruft_cb,
				      each_loose_subdir_fn subdir_cb,
				      void *data);

/*
 * Iterate over loose objects in both the local
 * repository and any alternates repositories (unless the
 * LOCAL_ONLY flag is set).
 */
#define FOR_EACH_OBJECT_LOCAL_ONLY 0x1
extern int for_each_loose_object(each_loose_object_fn, void *, unsigned flags);

struct object_info {
	/* Request */
	enum object_type *typep;
	unsigned long *sizep;
	off_t *disk_sizep;
	unsigned char *delta_base_sha1;
	struct strbuf *typename;
	void **contentp;

	/* Response */
	enum {
		OI_CACHED,
		OI_LOOSE,
		OI_PACKED,
		OI_DBCACHED
	} whence;
	union {
		/*
		 * struct {
		 * 	... Nothing to expose in this case
		 * } cached;
		 * struct {
		 * 	... Nothing to expose in this case
		 * } loose;
		 */
		struct {
			struct packed_git *pack;
			off_t offset;
			unsigned int is_delta;
		} packed;
	} u;
};

/*
 * Initializer for a "struct object_info" that wants no items. You may
 * also memset() the memory to all-zeroes.
 */
#define OBJECT_INFO_INIT {NULL}

/* Invoke lookup_replace_object() on the given hash */
#define OBJECT_INFO_LOOKUP_REPLACE 1
/* Allow reading from a loose object file of unknown/bogus type */
#define OBJECT_INFO_ALLOW_UNKNOWN_TYPE 2
/* Do not check cached storage */
#define OBJECT_INFO_SKIP_CACHED 4
/* Do not retry packed storage after checking packed and loose storage */
#define OBJECT_INFO_QUICK 8
extern int sha1_object_info_extended(const unsigned char *, struct object_info *, unsigned flags);

/*
 * Set this to 0 to prevent sha1_object_info_extended() from fetching missing
 * blobs. This has a difference only if extensions.partialClone is set.
 *
 * Its default value is 1.
 */
extern int fetch_if_missing;

/* Dumb servers support */
extern int update_server_info(int);

extern const char *get_log_output_encoding(void);
extern const char *get_commit_output_encoding(void);

/*
 * This is a hack for test programs like test-dump-untracked-cache to
 * ensure that they do not modify the untracked cache when reading it.
 * Do not use it otherwise!
 */
extern int ignore_untracked_cache_config;

extern int committer_ident_sufficiently_given(void);
extern int author_ident_sufficiently_given(void);

extern const char *git_commit_encoding;
extern const char *git_log_output_encoding;
extern const char *git_mailmap_file;
extern const char *git_mailmap_blob;

/* IO helper functions */
extern void maybe_flush_or_die(FILE *, const char *);
__attribute__((format (printf, 2, 3)))
extern void fprintf_or_die(FILE *, const char *fmt, ...);

#define COPY_READ_ERROR (-2)
#define COPY_WRITE_ERROR (-3)
extern int copy_fd(int ifd, int ofd);
extern int copy_file(const char *dst, const char *src, int mode);
extern int copy_file_with_time(const char *dst, const char *src, int mode);

extern void write_or_die(int fd, const void *buf, size_t count);
extern void fsync_or_die(int fd, const char *);

extern ssize_t read_in_full(int fd, void *buf, size_t count);
extern ssize_t write_in_full(int fd, const void *buf, size_t count);
extern ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset);

static inline ssize_t write_str_in_full(int fd, const char *str)
{
	return write_in_full(fd, str, strlen(str));
}

/**
 * Open (and truncate) the file at path, write the contents of buf to it,
 * and close it. Dies if any errors are encountered.
 */
extern void write_file_buf(const char *path, const char *buf, size_t len);

/**
 * Like write_file_buf(), but format the contents into a buffer first.
 * Additionally, write_file() will append a newline if one is not already
 * present, making it convenient to write text files:
 *
 *   write_file(path, "counter: %d", ctr);
 */
__attribute__((format (printf, 2, 3)))
extern void write_file(const char *path, const char *fmt, ...);

/* pager.c */
extern void setup_pager(void);
extern int pager_in_use(void);
extern int pager_use_color;
extern int term_columns(void);
extern int decimal_width(uintmax_t);
extern int check_pager_config(const char *cmd);
extern void prepare_pager_args(struct child_process *, const char *pager);

extern const char *editor_program;
extern const char *askpass_program;
extern const char *excludes_file;

/* base85 */
int decode_85(char *dst, const char *line, int linelen);
void encode_85(char *buf, const unsigned char *data, int bytes);

/* alloc.c */
extern void *alloc_blob_node(void);
extern void *alloc_tree_node(void);
extern void *alloc_commit_node(void);
extern void *alloc_tag_node(void);
extern void *alloc_object_node(void);
extern void alloc_report(void);
extern unsigned int alloc_commit_index(void);

/* pkt-line.c */
void packet_trace_identity(const char *prog);

/* add */
/*
 * return 0 if success, 1 - if addition of a file failed and
 * ADD_FILES_IGNORE_ERRORS was specified in flags
 */
int add_files_to_cache(const char *prefix, const struct pathspec *pathspec, int flags);

/* diff.c */
extern int diff_auto_refresh_index;

/* match-trees.c */
void shift_tree(const struct object_id *, const struct object_id *, struct object_id *, int);
void shift_tree_by(const struct object_id *, const struct object_id *, struct object_id *, const char *);

/*
 * whitespace rules.
 * used by both diff and apply
 * last two digits are tab width
 */
#define WS_BLANK_AT_EOL         0100
#define WS_SPACE_BEFORE_TAB     0200
#define WS_INDENT_WITH_NON_TAB  0400
#define WS_CR_AT_EOL           01000
#define WS_BLANK_AT_EOF        02000
#define WS_TAB_IN_INDENT       04000
#define WS_TRAILING_SPACE      (WS_BLANK_AT_EOL|WS_BLANK_AT_EOF)
#define WS_DEFAULT_RULE (WS_TRAILING_SPACE|WS_SPACE_BEFORE_TAB|8)
#define WS_TAB_WIDTH_MASK        077
/* All WS_* -- when extended, adapt diff.c emit_symbol */
#define WS_RULE_MASK           07777
extern unsigned whitespace_rule_cfg;
extern unsigned whitespace_rule(const char *);
extern unsigned parse_whitespace_rule(const char *);
extern unsigned ws_check(const char *line, int len, unsigned ws_rule);
extern void ws_check_emit(const char *line, int len, unsigned ws_rule, FILE *stream, const char *set, const char *reset, const char *ws);
extern char *whitespace_error_string(unsigned ws);
extern void ws_fix_copy(struct strbuf *, const char *, int, unsigned, int *);
extern int ws_blank_line(const char *line, int len, unsigned ws_rule);
#define ws_tab_width(rule)     ((rule) & WS_TAB_WIDTH_MASK)

/* ls-files */
void overlay_tree_on_index(struct index_state *istate,
			   const char *tree_name, const char *prefix);

char *alias_lookup(const char *alias);
int split_cmdline(char *cmdline, const char ***argv);
/* Takes a negative value returned by split_cmdline */
const char *split_cmdline_strerror(int cmdline_errno);

/* setup.c */
struct startup_info {
	int have_repository;
	const char *prefix;
};
extern struct startup_info *startup_info;

/* merge.c */
struct commit_list;
int try_merge_command(const char *strategy, size_t xopts_nr,
		const char **xopts, struct commit_list *common,
		const char *head_arg, struct commit_list *remotes);
int checkout_fast_forward(const struct object_id *from,
			  const struct object_id *to,
			  int overwrite_ignore);


int sane_execvp(const char *file, char *const argv[]);

/*
 * A struct to encapsulate the concept of whether a file has changed
 * since we last checked it. This uses criteria similar to those used
 * for the index.
 */
struct stat_validity {
	struct stat_data *sd;
};

void stat_validity_clear(struct stat_validity *sv);

/*
 * Returns 1 if the path is a regular file (or a symlink to a regular
 * file) and matches the saved stat_validity, 0 otherwise.  A missing
 * or inaccessible file is considered a match if the struct was just
 * initialized, or if the previous update found an inaccessible file.
 */
int stat_validity_check(struct stat_validity *sv, const char *path);

/*
 * Update the stat_validity from a file opened at descriptor fd. If
 * the file is missing, inaccessible, or not a regular file, then
 * future calls to stat_validity_check will match iff one of those
 * conditions continues to be true.
 */
void stat_validity_update(struct stat_validity *sv, int fd);

int versioncmp(const char *s1, const char *s2);
void sleep_millisec(int millisec);

/*
 * Create a directory and (if share is nonzero) adjust its permissions
 * according to the shared_repository setting. Only use this for
 * directories under $GIT_DIR.  Don't use it for working tree
 * directories.
 */
void safe_create_dir(const char *dir, int share);

/*
 * Should we print an ellipsis after an abbreviated SHA-1 value
 * when doing diff-raw output or indicating a detached HEAD?
 */
extern int print_sha1_ellipsis(void);

#endif /* CACHE_H */