Merge git://git.kernel.org/pub/scm/gitk/gitk
[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 #define MAX_TREES 8
17 static int nr_trees;
18 static struct tree *trees[MAX_TREES];
19
20 static int list_tree(unsigned char *sha1)
21 {
22         struct tree *tree;
23
24         if (nr_trees >= MAX_TREES)
25                 die("I cannot read more than %d trees", MAX_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 int read_cache_unmerged(void)
34 {
35         int i;
36         struct cache_entry **dst;
37         struct cache_entry *last = NULL;
38
39         read_cache();
40         dst = active_cache;
41         for (i = 0; i < active_nr; i++) {
42                 struct cache_entry *ce = active_cache[i];
43                 if (ce_stage(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                         ce->ce_flags |= CE_REMOVE;
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_TREES];
100         struct unpack_trees_options opts;
101
102         memset(&opts, 0, sizeof(opts));
103         opts.head_idx = -1;
104
105         git_config(git_default_config);
106
107         newfd = hold_locked_index(&lock_file, 1);
108
109         git_config(git_default_config);
110
111         for (i = 1; i < argc; i++) {
112                 const char *arg = argv[i];
113
114                 /* "-u" means "update", meaning that a merge will update
115                  * the working tree.
116                  */
117                 if (!strcmp(arg, "-u")) {
118                         opts.update = 1;
119                         continue;
120                 }
121
122                 if (!strcmp(arg, "-v")) {
123                         opts.verbose_update = 1;
124                         continue;
125                 }
126
127                 /* "-i" means "index only", meaning that a merge will
128                  * not even look at the working tree.
129                  */
130                 if (!strcmp(arg, "-i")) {
131                         opts.index_only = 1;
132                         continue;
133                 }
134
135                 if (!prefixcmp(arg, "--index-output=")) {
136                         set_alternate_index_output(arg + 15);
137                         continue;
138                 }
139
140                 /* "--prefix=<subdirectory>/" means keep the current index
141                  *  entries and put the entries from the tree under the
142                  * given subdirectory.
143                  */
144                 if (!prefixcmp(arg, "--prefix=")) {
145                         if (stage || opts.merge || opts.prefix)
146                                 usage(read_tree_usage);
147                         opts.prefix = arg + 9;
148                         opts.merge = 1;
149                         stage = 1;
150                         if (read_cache_unmerged())
151                                 die("you need to resolve your current index first");
152                         continue;
153                 }
154
155                 /* This differs from "-m" in that we'll silently ignore
156                  * unmerged entries and overwrite working tree files that
157                  * correspond to them.
158                  */
159                 if (!strcmp(arg, "--reset")) {
160                         if (stage || opts.merge || opts.prefix)
161                                 usage(read_tree_usage);
162                         opts.reset = 1;
163                         opts.merge = 1;
164                         stage = 1;
165                         read_cache_unmerged();
166                         continue;
167                 }
168
169                 if (!strcmp(arg, "--trivial")) {
170                         opts.trivial_merges_only = 1;
171                         continue;
172                 }
173
174                 if (!strcmp(arg, "--aggressive")) {
175                         opts.aggressive = 1;
176                         continue;
177                 }
178
179                 /* "-m" stands for "merge", meaning we start in stage 1 */
180                 if (!strcmp(arg, "-m")) {
181                         if (stage || opts.merge || opts.prefix)
182                                 usage(read_tree_usage);
183                         if (read_cache_unmerged())
184                                 die("you need to resolve your current index first");
185                         stage = 1;
186                         opts.merge = 1;
187                         continue;
188                 }
189
190                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
191                         struct dir_struct *dir;
192
193                         if (opts.dir)
194                                 die("more than one --exclude-per-directory are given.");
195
196                         dir = xcalloc(1, sizeof(*opts.dir));
197                         dir->show_ignored = 1;
198                         dir->exclude_per_dir = arg + 24;
199                         opts.dir = dir;
200                         /* We do not need to nor want to do read-directory
201                          * here; we are merely interested in reusing the
202                          * per directory ignore stack mechanism.
203                          */
204                         continue;
205                 }
206
207                 /* using -u and -i at the same time makes no sense */
208                 if (1 < opts.index_only + opts.update)
209                         usage(read_tree_usage);
210
211                 if (get_sha1(arg, sha1))
212                         die("Not a valid object name %s", arg);
213                 if (list_tree(sha1) < 0)
214                         die("failed to unpack tree object %s", arg);
215                 stage++;
216         }
217         if ((opts.update||opts.index_only) && !opts.merge)
218                 usage(read_tree_usage);
219         if ((opts.dir && !opts.update))
220                 die("--exclude-per-directory is meaningless unless -u");
221
222         if (opts.prefix) {
223                 int pfxlen = strlen(opts.prefix);
224                 int pos;
225                 if (opts.prefix[pfxlen-1] != '/')
226                         die("prefix must end with /");
227                 if (stage != 2)
228                         die("binding merge takes only one tree");
229                 pos = cache_name_pos(opts.prefix, pfxlen);
230                 if (0 <= pos)
231                         die("corrupt index file");
232                 pos = -pos-1;
233                 if (pos < active_nr &&
234                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
235                         die("subdirectory '%s' already exists.", opts.prefix);
236                 pos = cache_name_pos(opts.prefix, pfxlen-1);
237                 if (0 <= pos)
238                         die("file '%.*s' already exists.",
239                                         pfxlen-1, opts.prefix);
240                 opts.pos = -1 - pos;
241         }
242
243         if (opts.merge) {
244                 if (stage < 2)
245                         die("just how do you expect me to merge %d trees?", stage-1);
246                 switch (stage - 1) {
247                 case 1:
248                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
249                         break;
250                 case 2:
251                         opts.fn = twoway_merge;
252                         break;
253                 case 3:
254                 default:
255                         opts.fn = threeway_merge;
256                         cache_tree_free(&active_cache_tree);
257                         break;
258                 }
259
260                 if (stage - 1 >= 3)
261                         opts.head_idx = stage - 2;
262                 else
263                         opts.head_idx = 1;
264         }
265
266         for (i = 0; i < nr_trees; i++) {
267                 struct tree *tree = trees[i];
268                 parse_tree(tree);
269                 init_tree_desc(t+i, tree->buffer, tree->size);
270         }
271         unpack_trees(nr_trees, t, &opts);
272
273         /*
274          * When reading only one tree (either the most basic form,
275          * "-m ent" or "--reset ent" form), we can obtain a fully
276          * valid cache-tree because the index must match exactly
277          * what came from the tree.
278          */
279         if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
280                 cache_tree_free(&active_cache_tree);
281                 prime_cache_tree();
282         }
283
284         if (write_cache(newfd, active_cache, active_nr) ||
285             commit_locked_index(&lock_file))
286                 die("unable to write new index file");
287         return 0;
288 }