Code

git-svn: documentation updates
[git.git] / builtin-write-tree.c
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
6 #include "builtin.h"
7 #include "cache.h"
8 #include "tree.h"
9 #include "cache-tree.h"
11 static const char write_tree_usage[] =
12 "git-write-tree [--missing-ok] [--prefix=<prefix>/]";
14 int write_tree(unsigned char *sha1, int missing_ok, const char *prefix)
15 {
16         int entries, was_valid, newfd;
18         /* We can't free this memory, it becomes part of a linked list parsed atexit() */
19         struct lock_file *lock_file = xcalloc(1, sizeof(struct lock_file));
21         newfd = hold_lock_file_for_update(lock_file, get_index_file(), 0);
23         entries = read_cache();
24         if (entries < 0)
25                 die("git-write-tree: error reading cache");
27         if (!active_cache_tree)
28                 active_cache_tree = cache_tree();
30         was_valid = cache_tree_fully_valid(active_cache_tree);
32         if (!was_valid) {
33                 if (cache_tree_update(active_cache_tree,
34                                       active_cache, active_nr,
35                                       missing_ok, 0) < 0)
36                         die("git-write-tree: error building trees");
37                 if (0 <= newfd) {
38                         if (!write_cache(newfd, active_cache, active_nr)
39                                         && !close(newfd))
40                                 commit_lock_file(lock_file);
41                 }
42                 /* Not being able to write is fine -- we are only interested
43                  * in updating the cache-tree part, and if the next caller
44                  * ends up using the old index with unupdated cache-tree part
45                  * it misses the work we did here, but that is just a
46                  * performance penalty and not a big deal.
47                  */
48         }
50         if (prefix) {
51                 struct cache_tree *subtree =
52                         cache_tree_find(active_cache_tree, prefix);
53                 hashcpy(sha1, subtree->sha1);
54         }
55         else
56                 hashcpy(sha1, active_cache_tree->sha1);
58         rollback_lock_file(lock_file);
60         return 0;
61 }
63 int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
64 {
65         int missing_ok = 0, ret;
66         const char *prefix = NULL;
67         unsigned char sha1[20];
69         while (1 < argc) {
70                 const char *arg = argv[1];
71                 if (!strcmp(arg, "--missing-ok"))
72                         missing_ok = 1;
73                 else if (!strncmp(arg, "--prefix=", 9))
74                         prefix = arg + 9;
75                 else
76                         usage(write_tree_usage);
77                 argc--; argv++;
78         }
80         if (argc > 2)
81                 die("too many options");
83         ret = write_tree(sha1, missing_ok, prefix);
84         printf("%s\n", sha1_to_hex(sha1));
86         return ret;
87 }