Merge branch 'mv/defer-gc'
[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
16 static int nr_trees;
17 static struct tree *trees[MAX_UNPACK_TREES];
18
19 static int list_tree(unsigned char *sha1)
20 {
21         struct tree *tree;
22
23         if (nr_trees >= MAX_UNPACK_TREES)
24                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
25         tree = parse_tree_indirect(sha1);
26         if (!tree)
27                 return -1;
28         trees[nr_trees++] = tree;
29         return 0;
30 }
31
32 static int read_cache_unmerged(void)
33 {
34         int i;
35         struct cache_entry **dst;
36         struct cache_entry *last = NULL;
37
38         read_cache();
39         dst = active_cache;
40         for (i = 0; i < active_nr; i++) {
41                 struct cache_entry *ce = active_cache[i];
42                 if (ce_stage(ce)) {
43                         remove_index_entry(ce);
44                         if (last && !strcmp(ce->name, last->name))
45                                 continue;
46                         cache_tree_invalidate_path(active_cache_tree, ce->name);
47                         last = ce;
48                         continue;
49                 }
50                 *dst++ = ce;
51         }
52         active_nr = dst - active_cache;
53         return !!last;
54 }
55
56 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
57 {
58         struct tree_desc desc;
59         struct name_entry entry;
60         int cnt;
61
62         hashcpy(it->sha1, tree->object.sha1);
63         init_tree_desc(&desc, tree->buffer, tree->size);
64         cnt = 0;
65         while (tree_entry(&desc, &entry)) {
66                 if (!S_ISDIR(entry.mode))
67                         cnt++;
68                 else {
69                         struct cache_tree_sub *sub;
70                         struct tree *subtree = lookup_tree(entry.sha1);
71                         if (!subtree->object.parsed)
72                                 parse_tree(subtree);
73                         sub = cache_tree_sub(it, entry.path);
74                         sub->cache_tree = cache_tree();
75                         prime_cache_tree_rec(sub->cache_tree, subtree);
76                         cnt += sub->cache_tree->entry_count;
77                 }
78         }
79         it->entry_count = cnt;
80 }
81
82 static void prime_cache_tree(void)
83 {
84         if (!nr_trees)
85                 return;
86         active_cache_tree = cache_tree();
87         prime_cache_tree_rec(active_cache_tree, trees[0]);
88
89 }
90
91 static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] [--index-output=<file>] <sha1> [<sha2> [<sha3>]])";
92
93 static struct lock_file lock_file;
94
95 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
96 {
97         int i, newfd, stage = 0;
98         unsigned char sha1[20];
99         struct tree_desc t[MAX_UNPACK_TREES];
100         struct unpack_trees_options opts;
101
102         memset(&opts, 0, sizeof(opts));
103         opts.head_idx = -1;
104         opts.src_index = &the_index;
105         opts.dst_index = &the_index;
106
107         git_config(git_default_config);
108
109         newfd = hold_locked_index(&lock_file, 1);
110
111         git_config(git_default_config);
112
113         for (i = 1; i < argc; i++) {
114                 const char *arg = argv[i];
115
116                 /* "-u" means "update", meaning that a merge will update
117                  * the working tree.
118                  */
119                 if (!strcmp(arg, "-u")) {
120                         opts.update = 1;
121                         continue;
122                 }
123
124                 if (!strcmp(arg, "-v")) {
125                         opts.verbose_update = 1;
126                         continue;
127                 }
128
129                 /* "-i" means "index only", meaning that a merge will
130                  * not even look at the working tree.
131                  */
132                 if (!strcmp(arg, "-i")) {
133                         opts.index_only = 1;
134                         continue;
135                 }
136
137                 if (!prefixcmp(arg, "--index-output=")) {
138                         set_alternate_index_output(arg + 15);
139                         continue;
140                 }
141
142                 /* "--prefix=<subdirectory>/" means keep the current index
143                  *  entries and put the entries from the tree under the
144                  * given subdirectory.
145                  */
146                 if (!prefixcmp(arg, "--prefix=")) {
147                         if (stage || opts.merge || opts.prefix)
148                                 usage(read_tree_usage);
149                         opts.prefix = arg + 9;
150                         opts.merge = 1;
151                         stage = 1;
152                         if (read_cache_unmerged())
153                                 die("you need to resolve your current index first");
154                         continue;
155                 }
156
157                 /* This differs from "-m" in that we'll silently ignore
158                  * unmerged entries and overwrite working tree files that
159                  * correspond to them.
160                  */
161                 if (!strcmp(arg, "--reset")) {
162                         if (stage || opts.merge || opts.prefix)
163                                 usage(read_tree_usage);
164                         opts.reset = 1;
165                         opts.merge = 1;
166                         stage = 1;
167                         read_cache_unmerged();
168                         continue;
169                 }
170
171                 if (!strcmp(arg, "--trivial")) {
172                         opts.trivial_merges_only = 1;
173                         continue;
174                 }
175
176                 if (!strcmp(arg, "--aggressive")) {
177                         opts.aggressive = 1;
178                         continue;
179                 }
180
181                 /* "-m" stands for "merge", meaning we start in stage 1 */
182                 if (!strcmp(arg, "-m")) {
183                         if (stage || opts.merge || opts.prefix)
184                                 usage(read_tree_usage);
185                         if (read_cache_unmerged())
186                                 die("you need to resolve your current index first");
187                         stage = 1;
188                         opts.merge = 1;
189                         continue;
190                 }
191
192                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
193                         struct dir_struct *dir;
194
195                         if (opts.dir)
196                                 die("more than one --exclude-per-directory are given.");
197
198                         dir = xcalloc(1, sizeof(*opts.dir));
199                         dir->show_ignored = 1;
200                         dir->exclude_per_dir = arg + 24;
201                         opts.dir = dir;
202                         /* We do not need to nor want to do read-directory
203                          * here; we are merely interested in reusing the
204                          * per directory ignore stack mechanism.
205                          */
206                         continue;
207                 }
208
209                 /* using -u and -i at the same time makes no sense */
210                 if (1 < opts.index_only + opts.update)
211                         usage(read_tree_usage);
212
213                 if (get_sha1(arg, sha1))
214                         die("Not a valid object name %s", arg);
215                 if (list_tree(sha1) < 0)
216                         die("failed to unpack tree object %s", arg);
217                 stage++;
218         }
219         if ((opts.update||opts.index_only) && !opts.merge)
220                 usage(read_tree_usage);
221         if ((opts.dir && !opts.update))
222                 die("--exclude-per-directory is meaningless unless -u");
223
224         if (opts.merge) {
225                 if (stage < 2)
226                         die("just how do you expect me to merge %d trees?", stage-1);
227                 switch (stage - 1) {
228                 case 1:
229                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
230                         break;
231                 case 2:
232                         opts.fn = twoway_merge;
233                         break;
234                 case 3:
235                 default:
236                         opts.fn = threeway_merge;
237                         cache_tree_free(&active_cache_tree);
238                         break;
239                 }
240
241                 if (stage - 1 >= 3)
242                         opts.head_idx = stage - 2;
243                 else
244                         opts.head_idx = 1;
245         }
246
247         for (i = 0; i < nr_trees; i++) {
248                 struct tree *tree = trees[i];
249                 parse_tree(tree);
250                 init_tree_desc(t+i, tree->buffer, tree->size);
251         }
252         if (unpack_trees(nr_trees, t, &opts))
253                 return 128;
254
255         /*
256          * When reading only one tree (either the most basic form,
257          * "-m ent" or "--reset ent" form), we can obtain a fully
258          * valid cache-tree because the index must match exactly
259          * what came from the tree.
260          */
261         if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
262                 cache_tree_free(&active_cache_tree);
263                 prime_cache_tree();
264         }
265
266         if (write_cache(newfd, active_cache, active_nr) ||
267             commit_locked_index(&lock_file))
268                 die("unable to write new index file");
269         return 0;
270 }