Do a cross-project merge of Paul Mackerras' gitk visualizer
[git/git.git] / Documentation / git-fsck-cache.txt
1 git-fsck-cache(1)
2 =================
3 v0.1, May 2005
4
5 NAME
6 ----
7 git-fsck-cache - Verifies the connectivity and validity of the objects in the database
8
9
10 SYNOPSIS
11 --------
12 'git-fsck-cache' [--tags] [--root] [--delta-depth] [--unreachable] [--cache] [<object>*]
13
14 DESCRIPTION
15 -----------
16 Verifies the connectivity and validity of the objects in the database.
17
18 OPTIONS
19 -------
20 <object>::
21 An object to treat as the head of an unreachability trace.
22
23 If no objects are given, git-fsck-cache defaults to using the
24 index file and all SHA1 references in .git/refs/* as heads.
25
26 --unreachable::
27 Print out objects that exist but that aren't readable from any
28 of the reference nodes.
29
30 --root::
31 Report root nodes.
32
33 --tags::
34 Report tags.
35
36 --cache::
37 Consider any object recorded in the cache also as a head node for
38 an unreachability trace.
39
40 --delta-depth::
41 Report back the length of the longest delta chain found.
42
43 It tests SHA1 and general object sanity, and it does full tracking of
44 the resulting reachability and everything else. It prints out any
45 corruption it finds (missing or bad objects), and if you use the
46 '--unreachable' flag it will also print out objects that exist but
47 that aren't readable from any of the specified head nodes.
48
49 So for example
50
51 git-fsck-cache --unreachable $(cat .git/HEAD)
52
53 or, for Cogito users:
54
55 git-fsck-cache --unreachable $(cat .git/refs/heads/*)
56
57 will do quite a _lot_ of verification on the tree. There are a few
58 extra validity tests to be added (make sure that tree objects are
59 sorted properly etc), but on the whole if "git-fsck-cache" is happy, you
60 do have a valid tree.
61
62 Any corrupt objects you will have to find in backups or other archives
63 (ie you can just remove them and do an "rsync" with some other site in
64 the hopes that somebody else has the object you have corrupted).
65
66 Of course, "valid tree" doesn't mean that it wasn't generated by some
67 evil person, and the end result might be crap. Git is a revision
68 tracking system, not a quality assurance system ;)
69
70 Extracted Diagnostics
71 ---------------------
72
73 expect dangling commits - potential heads - due to lack of head information::
74 You haven't specified any nodes as heads so it won't be
75 possible to differentiate between un-parented commits and
76 root nodes.
77
78 missing sha1 directory '<dir>'::
79 The directory holding the sha1 objects is missing.
80
81 unreachable <type> <object>::
82 The <type> object <object>, isn't actually referred to directly
83 or indirectly in any of the trees or commits seen. This can
84 mean that there's another root node that you're not specifying
85 or that the tree is corrupt. If you haven't missed a root node
86 then you might as well delete unreachable nodes since they
87 can't be used.
88
89 missing <type> <object>::
90 The <type> object <object>, is referred to but isn't present in
91 the database.
92
93 dangling <type> <object>::
94 The <type> object <object>, is present in the database but never
95 'directly' used. A dangling commit could be a root node.
96
97 warning: git-fsck-cache: tree <tree> has full pathnames in it::
98 And it shouldn't...
99
100 sha1 mismatch <object>::
101 The database has an object who's sha1 doesn't match the
102 database value.
103 This indicates a serious data integrity problem.
104 (note: this error occured during early git development when
105 the database format changed.)
106
107 Environment Variables
108 ---------------------
109
110 GIT_OBJECT_DIRECTORY::
111 used to specify the object database root (usually .git/objects)
112
113 GIT_INDEX_FILE::
114 used to specify the cache
115
116
117 Author
118 ------
119 Written by Linus Torvalds <torvalds@osdl.org>
120
121 Documentation
122 --------------
123 Documentation by David Greaves, Junio C Hamano and the git-list <git@vger.kernel.org>.
124
125 GIT
126 ---
127 Part of the link:git.html[git] suite
128