lockfile.h: extract new header file for the functions in lockfile.c
[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 "lockfile.h"
9 #include "object.h"
10 #include "tree.h"
11 #include "tree-walk.h"
12 #include "cache-tree.h"
13 #include "unpack-trees.h"
14 #include "dir.h"
15 #include "builtin.h"
16 #include "parse-options.h"
17 #include "resolve-undo.h"
18
19 static int nr_trees;
20 static int read_empty;
21 static struct tree *trees[MAX_UNPACK_TREES];
22
23 static int list_tree(unsigned char *sha1)
24 {
25 struct tree *tree;
26
27 if (nr_trees >= MAX_UNPACK_TREES)
28 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
29 tree = parse_tree_indirect(sha1);
30 if (!tree)
31 return -1;
32 trees[nr_trees++] = tree;
33 return 0;
34 }
35
36 static const char * const read_tree_usage[] = {
37 N_("git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] (--empty | <tree-ish1> [<tree-ish2> [<tree-ish3>]])"),
38 NULL
39 };
40
41 static int index_output_cb(const struct option *opt, const char *arg,
42 int unset)
43 {
44 set_alternate_index_output(arg);
45 return 0;
46 }
47
48 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
49 int unset)
50 {
51 struct dir_struct *dir;
52 struct unpack_trees_options *opts;
53
54 opts = (struct unpack_trees_options *)opt->value;
55
56 if (opts->dir)
57 die("more than one --exclude-per-directory given.");
58
59 dir = xcalloc(1, sizeof(*opts->dir));
60 dir->flags |= DIR_SHOW_IGNORED;
61 dir->exclude_per_dir = arg;
62 opts->dir = dir;
63 /* We do not need to nor want to do read-directory
64 * here; we are merely interested in reusing the
65 * per directory ignore stack mechanism.
66 */
67 return 0;
68 }
69
70 static void debug_stage(const char *label, const struct cache_entry *ce,
71 struct unpack_trees_options *o)
72 {
73 printf("%s ", label);
74 if (!ce)
75 printf("(missing)\n");
76 else if (ce == o->df_conflict_entry)
77 printf("(conflict)\n");
78 else
79 printf("%06o #%d %s %.8s\n",
80 ce->ce_mode, ce_stage(ce), ce->name,
81 sha1_to_hex(ce->sha1));
82 }
83
84 static int debug_merge(const struct cache_entry * const *stages,
85 struct unpack_trees_options *o)
86 {
87 int i;
88
89 printf("* %d-way merge\n", o->merge_size);
90 debug_stage("index", stages[0], o);
91 for (i = 1; i <= o->merge_size; i++) {
92 char buf[24];
93 sprintf(buf, "ent#%d", i);
94 debug_stage(buf, stages[i], o);
95 }
96 return 0;
97 }
98
99 static struct lock_file lock_file;
100
101 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
102 {
103 int i, stage = 0;
104 unsigned char sha1[20];
105 struct tree_desc t[MAX_UNPACK_TREES];
106 struct unpack_trees_options opts;
107 int prefix_set = 0;
108 const struct option read_tree_options[] = {
109 { OPTION_CALLBACK, 0, "index-output", NULL, N_("file"),
110 N_("write resulting index to <file>"),
111 PARSE_OPT_NONEG, index_output_cb },
112 OPT_SET_INT(0, "empty", &read_empty,
113 N_("only empty the index"), 1),
114 OPT__VERBOSE(&opts.verbose_update, N_("be verbose")),
115 OPT_GROUP(N_("Merging")),
116 OPT_SET_INT('m', NULL, &opts.merge,
117 N_("perform a merge in addition to a read"), 1),
118 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
119 N_("3-way merge if no file level merging required"), 1),
120 OPT_SET_INT(0, "aggressive", &opts.aggressive,
121 N_("3-way merge in presence of adds and removes"), 1),
122 OPT_SET_INT(0, "reset", &opts.reset,
123 N_("same as -m, but discard unmerged entries"), 1),
124 { OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
125 N_("read the tree into the index under <subdirectory>/"),
126 PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
127 OPT_SET_INT('u', NULL, &opts.update,
128 N_("update working tree with merge result"), 1),
129 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
130 N_("gitignore"),
131 N_("allow explicitly ignored files to be overwritten"),
132 PARSE_OPT_NONEG, exclude_per_directory_cb },
133 OPT_SET_INT('i', NULL, &opts.index_only,
134 N_("don't check the working tree after merging"), 1),
135 OPT__DRY_RUN(&opts.dry_run, N_("don't update the index or the work tree")),
136 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
137 N_("skip applying sparse checkout filter"), 1),
138 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
139 N_("debug unpack-trees"), 1),
140 OPT_END()
141 };
142
143 memset(&opts, 0, sizeof(opts));
144 opts.head_idx = -1;
145 opts.src_index = &the_index;
146 opts.dst_index = &the_index;
147
148 git_config(git_default_config, NULL);
149
150 argc = parse_options(argc, argv, unused_prefix, read_tree_options,
151 read_tree_usage, 0);
152
153 hold_locked_index(&lock_file, 1);
154
155 prefix_set = opts.prefix ? 1 : 0;
156 if (1 < opts.merge + opts.reset + prefix_set)
157 die("Which one? -m, --reset, or --prefix?");
158
159 /*
160 * NEEDSWORK
161 *
162 * The old index should be read anyway even if we're going to
163 * destroy all index entries because we still need to preserve
164 * certain information such as index version or split-index
165 * mode.
166 */
167
168 if (opts.reset || opts.merge || opts.prefix) {
169 if (read_cache_unmerged() && (opts.prefix || opts.merge))
170 die("You need to resolve your current index first");
171 stage = opts.merge = 1;
172 }
173 resolve_undo_clear();
174
175 for (i = 0; i < argc; i++) {
176 const char *arg = argv[i];
177
178 if (get_sha1(arg, sha1))
179 die("Not a valid object name %s", arg);
180 if (list_tree(sha1) < 0)
181 die("failed to unpack tree object %s", arg);
182 stage++;
183 }
184 if (nr_trees == 0 && !read_empty)
185 warning("read-tree: emptying the index with no arguments is deprecated; use --empty");
186 else if (nr_trees > 0 && read_empty)
187 die("passing trees as arguments contradicts --empty");
188
189 if (1 < opts.index_only + opts.update)
190 die("-u and -i at the same time makes no sense");
191 if ((opts.update || opts.index_only) && !opts.merge)
192 die("%s is meaningless without -m, --reset, or --prefix",
193 opts.update ? "-u" : "-i");
194 if ((opts.dir && !opts.update))
195 die("--exclude-per-directory is meaningless unless -u");
196 if (opts.merge && !opts.index_only)
197 setup_work_tree();
198
199 if (opts.merge) {
200 if (stage < 2)
201 die("just how do you expect me to merge %d trees?", stage-1);
202 switch (stage - 1) {
203 case 1:
204 opts.fn = opts.prefix ? bind_merge : oneway_merge;
205 break;
206 case 2:
207 opts.fn = twoway_merge;
208 opts.initial_checkout = is_cache_unborn();
209 break;
210 case 3:
211 default:
212 opts.fn = threeway_merge;
213 break;
214 }
215
216 if (stage - 1 >= 3)
217 opts.head_idx = stage - 2;
218 else
219 opts.head_idx = 1;
220 }
221
222 if (opts.debug_unpack)
223 opts.fn = debug_merge;
224
225 cache_tree_free(&active_cache_tree);
226 for (i = 0; i < nr_trees; i++) {
227 struct tree *tree = trees[i];
228 parse_tree(tree);
229 init_tree_desc(t+i, tree->buffer, tree->size);
230 }
231 if (unpack_trees(nr_trees, t, &opts))
232 return 128;
233
234 if (opts.debug_unpack || opts.dry_run)
235 return 0; /* do not write the index out */
236
237 /*
238 * When reading only one tree (either the most basic form,
239 * "-m ent" or "--reset ent" form), we can obtain a fully
240 * valid cache-tree because the index must match exactly
241 * what came from the tree.
242 */
243 if (nr_trees == 1 && !opts.prefix)
244 prime_cache_tree(&the_index, trees[0]);
245
246 if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
247 die("unable to write new index file");
248 return 0;
249 }