Merge branch 'jc/show-merge'
[git/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"
10
11 static const char write_tree_usage[] =
12 "git-write-tree [--missing-ok] [--prefix=<prefix>/]";
13
14 int write_tree(unsigned char *sha1, int missing_ok, const char *prefix)
15 {
16 int entries, was_valid, newfd;
17
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));
20
21 newfd = hold_lock_file_for_update(lock_file, get_index_file());
22
23 entries = read_cache();
24 if (entries < 0)
25 die("git-write-tree: error reading cache");
26
27 if (!active_cache_tree)
28 active_cache_tree = cache_tree();
29
30 was_valid = cache_tree_fully_valid(active_cache_tree);
31
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 }
49
50 if (prefix) {
51 struct cache_tree *subtree =
52 cache_tree_find(active_cache_tree, prefix);
53 memcpy(sha1, subtree->sha1, 20);
54 }
55 else
56 memcpy(sha1, active_cache_tree->sha1, 20);
57
58 rollback_lock_file(lock_file);
59
60 return 0;
61 }
62
63 int cmd_write_tree(int argc, const char **argv, char **envp)
64 {
65 int missing_ok = 0, ret;
66 const char *prefix = NULL;
67 unsigned char sha1[20];
68
69 setup_git_directory();
70
71 while (1 < argc) {
72 const char *arg = argv[1];
73 if (!strcmp(arg, "--missing-ok"))
74 missing_ok = 1;
75 else if (!strncmp(arg, "--prefix=", 9))
76 prefix = arg + 9;
77 else
78 die(write_tree_usage);
79 argc--; argv++;
80 }
81
82 if (argc > 2)
83 die("too many options");
84
85 ret = write_tree(sha1, missing_ok, prefix);
86 printf("%s\n", sha1_to_hex(sha1));
87
88 return ret;
89 }