Make on-disk index representation separate from in-core one
[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 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 }