Move name hashing functions into a file of its own
[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 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_name_hash(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 }