object name: introduce ':/<oneline prefix>' notation
[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 struct object_list *trees;
17
18 static int list_tree(unsigned char *sha1)
19 {
20         struct tree *tree = parse_tree_indirect(sha1);
21         if (!tree)
22                 return -1;
23         object_list_append(&tree->object, &trees);
24         return 0;
25 }
26
27 static int read_cache_unmerged(void)
28 {
29         int i;
30         struct cache_entry **dst;
31         struct cache_entry *last = NULL;
32
33         read_cache();
34         dst = active_cache;
35         for (i = 0; i < active_nr; i++) {
36                 struct cache_entry *ce = active_cache[i];
37                 if (ce_stage(ce)) {
38                         if (last && !strcmp(ce->name, last->name))
39                                 continue;
40                         cache_tree_invalidate_path(active_cache_tree, ce->name);
41                         last = ce;
42                         ce->ce_mode = 0;
43                         ce->ce_flags &= ~htons(CE_STAGEMASK);
44                 }
45                 *dst++ = ce;
46         }
47         active_nr = dst - active_cache;
48         return !!last;
49 }
50
51 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
52 {
53         struct tree_desc desc;
54         struct name_entry entry;
55         int cnt;
56
57         hashcpy(it->sha1, tree->object.sha1);
58         desc.buf = tree->buffer;
59         desc.size = tree->size;
60         cnt = 0;
61         while (tree_entry(&desc, &entry)) {
62                 if (!S_ISDIR(entry.mode))
63                         cnt++;
64                 else {
65                         struct cache_tree_sub *sub;
66                         struct tree *subtree = lookup_tree(entry.sha1);
67                         if (!subtree->object.parsed)
68                                 parse_tree(subtree);
69                         sub = cache_tree_sub(it, entry.path);
70                         sub->cache_tree = cache_tree();
71                         prime_cache_tree_rec(sub->cache_tree, subtree);
72                         cnt += sub->cache_tree->entry_count;
73                 }
74         }
75         it->entry_count = cnt;
76 }
77
78 static void prime_cache_tree(void)
79 {
80         struct tree *tree = (struct tree *)trees->item;
81         if (!tree)
82                 return;
83         active_cache_tree = cache_tree();
84         prime_cache_tree_rec(active_cache_tree, tree);
85
86 }
87
88 static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] <sha1> [<sha2> [<sha3>]])";
89
90 static struct lock_file lock_file;
91
92 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
93 {
94         int i, newfd, stage = 0;
95         unsigned char sha1[20];
96         struct unpack_trees_options opts;
97
98         memset(&opts, 0, sizeof(opts));
99         opts.head_idx = -1;
100
101         setup_git_directory();
102         git_config(git_default_config);
103
104         newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);
105
106         git_config(git_default_config);
107
108         for (i = 1; i < argc; i++) {
109                 const char *arg = argv[i];
110
111                 /* "-u" means "update", meaning that a merge will update
112                  * the working tree.
113                  */
114                 if (!strcmp(arg, "-u")) {
115                         opts.update = 1;
116                         continue;
117                 }
118
119                 if (!strcmp(arg, "-v")) {
120                         opts.verbose_update = 1;
121                         continue;
122                 }
123
124                 /* "-i" means "index only", meaning that a merge will
125                  * not even look at the working tree.
126                  */
127                 if (!strcmp(arg, "-i")) {
128                         opts.index_only = 1;
129                         continue;
130                 }
131
132                 /* "--prefix=<subdirectory>/" means keep the current index
133                  *  entries and put the entries from the tree under the
134                  * given subdirectory.
135                  */
136                 if (!prefixcmp(arg, "--prefix=")) {
137                         if (stage || opts.merge || opts.prefix)
138                                 usage(read_tree_usage);
139                         opts.prefix = arg + 9;
140                         opts.merge = 1;
141                         stage = 1;
142                         if (read_cache_unmerged())
143                                 die("you need to resolve your current index first");
144                         continue;
145                 }
146
147                 /* This differs from "-m" in that we'll silently ignore
148                  * unmerged entries and overwrite working tree files that
149                  * correspond to them.
150                  */
151                 if (!strcmp(arg, "--reset")) {
152                         if (stage || opts.merge || opts.prefix)
153                                 usage(read_tree_usage);
154                         opts.reset = 1;
155                         opts.merge = 1;
156                         stage = 1;
157                         read_cache_unmerged();
158                         continue;
159                 }
160
161                 if (!strcmp(arg, "--trivial")) {
162                         opts.trivial_merges_only = 1;
163                         continue;
164                 }
165
166                 if (!strcmp(arg, "--aggressive")) {
167                         opts.aggressive = 1;
168                         continue;
169                 }
170
171                 /* "-m" stands for "merge", meaning we start in stage 1 */
172                 if (!strcmp(arg, "-m")) {
173                         if (stage || opts.merge || opts.prefix)
174                                 usage(read_tree_usage);
175                         if (read_cache_unmerged())
176                                 die("you need to resolve your current index first");
177                         stage = 1;
178                         opts.merge = 1;
179                         continue;
180                 }
181
182                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
183                         struct dir_struct *dir;
184
185                         if (opts.dir)
186                                 die("more than one --exclude-per-directory are given.");
187
188                         dir = calloc(1, sizeof(*opts.dir));
189                         dir->show_ignored = 1;
190                         dir->exclude_per_dir = arg + 24;
191                         opts.dir = dir;
192                         /* We do not need to nor want to do read-directory
193                          * here; we are merely interested in reusing the
194                          * per directory ignore stack mechanism.
195                          */
196                         continue;
197                 }
198
199                 /* using -u and -i at the same time makes no sense */
200                 if (1 < opts.index_only + opts.update)
201                         usage(read_tree_usage);
202
203                 if (get_sha1(arg, sha1))
204                         die("Not a valid object name %s", arg);
205                 if (list_tree(sha1) < 0)
206                         die("failed to unpack tree object %s", arg);
207                 stage++;
208         }
209         if ((opts.update||opts.index_only) && !opts.merge)
210                 usage(read_tree_usage);
211         if ((opts.dir && !opts.update))
212                 die("--exclude-per-directory is meaningless unless -u");
213
214         if (opts.prefix) {
215                 int pfxlen = strlen(opts.prefix);
216                 int pos;
217                 if (opts.prefix[pfxlen-1] != '/')
218                         die("prefix must end with /");
219                 if (stage != 2)
220                         die("binding merge takes only one tree");
221                 pos = cache_name_pos(opts.prefix, pfxlen);
222                 if (0 <= pos)
223                         die("corrupt index file");
224                 pos = -pos-1;
225                 if (pos < active_nr &&
226                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
227                         die("subdirectory '%s' already exists.", opts.prefix);
228                 pos = cache_name_pos(opts.prefix, pfxlen-1);
229                 if (0 <= pos)
230                         die("file '%.*s' already exists.",
231                                         pfxlen-1, opts.prefix);
232         }
233
234         if (opts.merge) {
235                 if (stage < 2)
236                         die("just how do you expect me to merge %d trees?", stage-1);
237                 switch (stage - 1) {
238                 case 1:
239                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
240                         break;
241                 case 2:
242                         opts.fn = twoway_merge;
243                         break;
244                 case 3:
245                 default:
246                         opts.fn = threeway_merge;
247                         cache_tree_free(&active_cache_tree);
248                         break;
249                 }
250
251                 if (stage - 1 >= 3)
252                         opts.head_idx = stage - 2;
253                 else
254                         opts.head_idx = 1;
255         }
256
257         unpack_trees(trees, &opts);
258
259         /*
260          * When reading only one tree (either the most basic form,
261          * "-m ent" or "--reset ent" form), we can obtain a fully
262          * valid cache-tree because the index must match exactly
263          * what came from the tree.
264          */
265         if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
266                 cache_tree_free(&active_cache_tree);
267                 prime_cache_tree();
268         }
269
270         if (write_cache(newfd, active_cache, active_nr) ||
271             close(newfd) || commit_lock_file(&lock_file))
272                 die("unable to write new index file");
273         return 0;
274 }