Merge branch 'nd/sparse'
[git/git.git] / builtin-read-tree.c
1 /*
2 * GIT - The information manager from hell
3 *
4 * Copyright (C) Linus Torvalds, 2005
5 */
6
7 #include "cache.h"
8 #include "object.h"
9 #include "tree.h"
10 #include "tree-walk.h"
11 #include "cache-tree.h"
12 #include "unpack-trees.h"
13 #include "dir.h"
14 #include "builtin.h"
15 #include "parse-options.h"
16
17 static int nr_trees;
18 static struct tree *trees[MAX_UNPACK_TREES];
19
20 static int list_tree(unsigned char *sha1)
21 {
22 struct tree *tree;
23
24 if (nr_trees >= MAX_UNPACK_TREES)
25 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
26 tree = parse_tree_indirect(sha1);
27 if (!tree)
28 return -1;
29 trees[nr_trees++] = tree;
30 return 0;
31 }
32
33 static const char * const read_tree_usage[] = {
34 "git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] <tree-ish1> [<tree-ish2> [<tree-ish3>]]",
35 NULL
36 };
37
38 static int index_output_cb(const struct option *opt, const char *arg,
39 int unset)
40 {
41 set_alternate_index_output(arg);
42 return 0;
43 }
44
45 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
46 int unset)
47 {
48 struct dir_struct *dir;
49 struct unpack_trees_options *opts;
50
51 opts = (struct unpack_trees_options *)opt->value;
52
53 if (opts->dir)
54 die("more than one --exclude-per-directory given.");
55
56 dir = xcalloc(1, sizeof(*opts->dir));
57 dir->flags |= DIR_SHOW_IGNORED;
58 dir->exclude_per_dir = arg;
59 opts->dir = dir;
60 /* We do not need to nor want to do read-directory
61 * here; we are merely interested in reusing the
62 * per directory ignore stack mechanism.
63 */
64 return 0;
65 }
66
67 static struct lock_file lock_file;
68
69 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
70 {
71 int i, newfd, stage = 0;
72 unsigned char sha1[20];
73 struct tree_desc t[MAX_UNPACK_TREES];
74 struct unpack_trees_options opts;
75 int prefix_set = 0;
76 const struct option read_tree_options[] = {
77 { OPTION_CALLBACK, 0, "index-output", NULL, "FILE",
78 "write resulting index to <FILE>",
79 PARSE_OPT_NONEG, index_output_cb },
80 OPT__VERBOSE(&opts.verbose_update),
81 OPT_GROUP("Merging"),
82 OPT_SET_INT('m', NULL, &opts.merge,
83 "perform a merge in addition to a read", 1),
84 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
85 "3-way merge if no file level merging required", 1),
86 OPT_SET_INT(0, "aggressive", &opts.aggressive,
87 "3-way merge in presence of adds and removes", 1),
88 OPT_SET_INT(0, "reset", &opts.reset,
89 "same as -m, but discard unmerged entries", 1),
90 { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
91 "read the tree into the index under <subdirectory>/",
92 PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
93 OPT_SET_INT('u', NULL, &opts.update,
94 "update working tree with merge result", 1),
95 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
96 "gitignore",
97 "allow explicitly ignored files to be overwritten",
98 PARSE_OPT_NONEG, exclude_per_directory_cb },
99 OPT_SET_INT('i', NULL, &opts.index_only,
100 "don't check the working tree after merging", 1),
101 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
102 "skip applying sparse checkout filter", 1),
103 OPT_END()
104 };
105
106 memset(&opts, 0, sizeof(opts));
107 opts.head_idx = -1;
108 opts.src_index = &the_index;
109 opts.dst_index = &the_index;
110
111 git_config(git_default_config, NULL);
112
113 argc = parse_options(argc, argv, unused_prefix, read_tree_options,
114 read_tree_usage, 0);
115
116 newfd = hold_locked_index(&lock_file, 1);
117
118 prefix_set = opts.prefix ? 1 : 0;
119 if (1 < opts.merge + opts.reset + prefix_set)
120 die("Which one? -m, --reset, or --prefix?");
121
122 if (opts.reset || opts.merge || opts.prefix) {
123 if (read_cache_unmerged() && (opts.prefix || opts.merge))
124 die("You need to resolve your current index first");
125 stage = opts.merge = 1;
126 }
127
128 for (i = 0; i < argc; i++) {
129 const char *arg = argv[i];
130
131 if (get_sha1(arg, sha1))
132 die("Not a valid object name %s", arg);
133 if (list_tree(sha1) < 0)
134 die("failed to unpack tree object %s", arg);
135 stage++;
136 }
137 if (1 < opts.index_only + opts.update)
138 die("-u and -i at the same time makes no sense");
139 if ((opts.update||opts.index_only) && !opts.merge)
140 die("%s is meaningless without -m, --reset, or --prefix",
141 opts.update ? "-u" : "-i");
142 if ((opts.dir && !opts.update))
143 die("--exclude-per-directory is meaningless unless -u");
144 if (opts.merge && !opts.index_only)
145 setup_work_tree();
146
147 if (opts.merge) {
148 if (stage < 2)
149 die("just how do you expect me to merge %d trees?", stage-1);
150 switch (stage - 1) {
151 case 1:
152 opts.fn = opts.prefix ? bind_merge : oneway_merge;
153 break;
154 case 2:
155 opts.fn = twoway_merge;
156 opts.initial_checkout = is_cache_unborn();
157 break;
158 case 3:
159 default:
160 opts.fn = threeway_merge;
161 break;
162 }
163
164 if (stage - 1 >= 3)
165 opts.head_idx = stage - 2;
166 else
167 opts.head_idx = 1;
168 }
169
170 cache_tree_free(&active_cache_tree);
171 for (i = 0; i < nr_trees; i++) {
172 struct tree *tree = trees[i];
173 parse_tree(tree);
174 init_tree_desc(t+i, tree->buffer, tree->size);
175 }
176 if (unpack_trees(nr_trees, t, &opts))
177 return 128;
178
179 /*
180 * When reading only one tree (either the most basic form,
181 * "-m ent" or "--reset ent" form), we can obtain a fully
182 * valid cache-tree because the index must match exactly
183 * what came from the tree.
184 *
185 * The same holds true if we are switching between two trees
186 * using read-tree -m A B. The index must match B after that.
187 */
188 if (nr_trees == 1 && !opts.prefix)
189 prime_cache_tree(&active_cache_tree, trees[0]);
190 else if (nr_trees == 2 && opts.merge)
191 prime_cache_tree(&active_cache_tree, trees[1]);
192
193 if (write_cache(newfd, active_cache, active_nr) ||
194 commit_locked_index(&lock_file))
195 die("unable to write new index file");
196 return 0;
197 }