Make 'unpack_trees()' have a separate source and destination index
[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
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 remove_index_entry(ce);
45 if (last && !strcmp(ce->name, last->name))
46 continue;
47 cache_tree_invalidate_path(active_cache_tree, ce->name);
48 last = ce;
49 continue;
50 }
51 *dst++ = ce;
52 }
53 active_nr = dst - active_cache;
54 return !!last;
55 }
56
57 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
58 {
59 struct tree_desc desc;
60 struct name_entry entry;
61 int cnt;
62
63 hashcpy(it->sha1, tree->object.sha1);
64 init_tree_desc(&desc, tree->buffer, tree->size);
65 cnt = 0;
66 while (tree_entry(&desc, &entry)) {
67 if (!S_ISDIR(entry.mode))
68 cnt++;
69 else {
70 struct cache_tree_sub *sub;
71 struct tree *subtree = lookup_tree(entry.sha1);
72 if (!subtree->object.parsed)
73 parse_tree(subtree);
74 sub = cache_tree_sub(it, entry.path);
75 sub->cache_tree = cache_tree();
76 prime_cache_tree_rec(sub->cache_tree, subtree);
77 cnt += sub->cache_tree->entry_count;
78 }
79 }
80 it->entry_count = cnt;
81 }
82
83 static void prime_cache_tree(void)
84 {
85 if (!nr_trees)
86 return;
87 active_cache_tree = cache_tree();
88 prime_cache_tree_rec(active_cache_tree, trees[0]);
89
90 }
91
92 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>]])";
93
94 static struct lock_file lock_file;
95
96 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
97 {
98 int i, newfd, stage = 0;
99 unsigned char sha1[20];
100 struct tree_desc t[MAX_TREES];
101 struct unpack_trees_options opts;
102
103 memset(&opts, 0, sizeof(opts));
104 opts.head_idx = -1;
105 opts.src_index = &the_index;
106 opts.dst_index = &the_index;
107
108 git_config(git_default_config);
109
110 newfd = hold_locked_index(&lock_file, 1);
111
112 git_config(git_default_config);
113
114 for (i = 1; i < argc; i++) {
115 const char *arg = argv[i];
116
117 /* "-u" means "update", meaning that a merge will update
118 * the working tree.
119 */
120 if (!strcmp(arg, "-u")) {
121 opts.update = 1;
122 continue;
123 }
124
125 if (!strcmp(arg, "-v")) {
126 opts.verbose_update = 1;
127 continue;
128 }
129
130 /* "-i" means "index only", meaning that a merge will
131 * not even look at the working tree.
132 */
133 if (!strcmp(arg, "-i")) {
134 opts.index_only = 1;
135 continue;
136 }
137
138 if (!prefixcmp(arg, "--index-output=")) {
139 set_alternate_index_output(arg + 15);
140 continue;
141 }
142
143 /* "--prefix=<subdirectory>/" means keep the current index
144 * entries and put the entries from the tree under the
145 * given subdirectory.
146 */
147 if (!prefixcmp(arg, "--prefix=")) {
148 if (stage || opts.merge || opts.prefix)
149 usage(read_tree_usage);
150 opts.prefix = arg + 9;
151 opts.merge = 1;
152 stage = 1;
153 if (read_cache_unmerged())
154 die("you need to resolve your current index first");
155 continue;
156 }
157
158 /* This differs from "-m" in that we'll silently ignore
159 * unmerged entries and overwrite working tree files that
160 * correspond to them.
161 */
162 if (!strcmp(arg, "--reset")) {
163 if (stage || opts.merge || opts.prefix)
164 usage(read_tree_usage);
165 opts.reset = 1;
166 opts.merge = 1;
167 stage = 1;
168 read_cache_unmerged();
169 continue;
170 }
171
172 if (!strcmp(arg, "--trivial")) {
173 opts.trivial_merges_only = 1;
174 continue;
175 }
176
177 if (!strcmp(arg, "--aggressive")) {
178 opts.aggressive = 1;
179 continue;
180 }
181
182 /* "-m" stands for "merge", meaning we start in stage 1 */
183 if (!strcmp(arg, "-m")) {
184 if (stage || opts.merge || opts.prefix)
185 usage(read_tree_usage);
186 if (read_cache_unmerged())
187 die("you need to resolve your current index first");
188 stage = 1;
189 opts.merge = 1;
190 continue;
191 }
192
193 if (!prefixcmp(arg, "--exclude-per-directory=")) {
194 struct dir_struct *dir;
195
196 if (opts.dir)
197 die("more than one --exclude-per-directory are given.");
198
199 dir = xcalloc(1, sizeof(*opts.dir));
200 dir->show_ignored = 1;
201 dir->exclude_per_dir = arg + 24;
202 opts.dir = dir;
203 /* We do not need to nor want to do read-directory
204 * here; we are merely interested in reusing the
205 * per directory ignore stack mechanism.
206 */
207 continue;
208 }
209
210 /* using -u and -i at the same time makes no sense */
211 if (1 < opts.index_only + opts.update)
212 usage(read_tree_usage);
213
214 if (get_sha1(arg, sha1))
215 die("Not a valid object name %s", arg);
216 if (list_tree(sha1) < 0)
217 die("failed to unpack tree object %s", arg);
218 stage++;
219 }
220 if ((opts.update||opts.index_only) && !opts.merge)
221 usage(read_tree_usage);
222 if ((opts.dir && !opts.update))
223 die("--exclude-per-directory is meaningless unless -u");
224
225 if (opts.merge) {
226 if (stage < 2)
227 die("just how do you expect me to merge %d trees?", stage-1);
228 switch (stage - 1) {
229 case 1:
230 opts.fn = opts.prefix ? bind_merge : oneway_merge;
231 break;
232 case 2:
233 opts.fn = twoway_merge;
234 break;
235 case 3:
236 default:
237 opts.fn = threeway_merge;
238 cache_tree_free(&active_cache_tree);
239 break;
240 }
241
242 if (stage - 1 >= 3)
243 opts.head_idx = stage - 2;
244 else
245 opts.head_idx = 1;
246 }
247
248 for (i = 0; i < nr_trees; i++) {
249 struct tree *tree = trees[i];
250 parse_tree(tree);
251 init_tree_desc(t+i, tree->buffer, tree->size);
252 }
253 if (unpack_trees(nr_trees, t, &opts))
254 return 128;
255
256 /*
257 * When reading only one tree (either the most basic form,
258 * "-m ent" or "--reset ent" form), we can obtain a fully
259 * valid cache-tree because the index must match exactly
260 * what came from the tree.
261 */
262 if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
263 cache_tree_free(&active_cache_tree);
264 prime_cache_tree();
265 }
266
267 if (write_cache(newfd, active_cache, active_nr) ||
268 commit_locked_index(&lock_file))
269 die("unable to write new index file");
270 return 0;
271 }