Thread-safe xmalloc and xrealloc needs a recursive mutex
[git/dscho.git] / builtin-read-tree.c
blob8bdcab11389e8b4facab355f27f0e1926134b86f
1 /*
2  * GIT - The information manager from hell
3  *
4  * Copyright (C) Linus Torvalds, 2005
5  */
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 #include "parse-options.h"
16 #include "resolve-undo.h"
18 static int nr_trees;
19 static struct tree *trees[MAX_UNPACK_TREES];
21 static int list_tree(unsigned char *sha1)
23         struct tree *tree;
25         if (nr_trees >= MAX_UNPACK_TREES)
26                 die("I cannot read more than %d trees", MAX_UNPACK_TREES);
27         tree = parse_tree_indirect(sha1);
28         if (!tree)
29                 return -1;
30         trees[nr_trees++] = tree;
31         return 0;
34 static const char * const read_tree_usage[] = {
35         "git read-tree [[-m [--trivial] [--aggressive] | --reset | --prefix=<prefix>] [-u [--exclude-per-directory=<gitignore>] | -i]] [--no-sparse-checkout] [--index-output=<file>] <tree-ish1> [<tree-ish2> [<tree-ish3>]]",
36         NULL
39 static int index_output_cb(const struct option *opt, const char *arg,
40                                  int unset)
42         set_alternate_index_output(arg);
43         return 0;
46 static int exclude_per_directory_cb(const struct option *opt, const char *arg,
47                                     int unset)
49         struct dir_struct *dir;
50         struct unpack_trees_options *opts;
52         opts = (struct unpack_trees_options *)opt->value;
54         if (opts->dir)
55                 die("more than one --exclude-per-directory given.");
57         dir = xcalloc(1, sizeof(*opts->dir));
58         dir->flags |= DIR_SHOW_IGNORED;
59         dir->exclude_per_dir = arg;
60         opts->dir = dir;
61         /* We do not need to nor want to do read-directory
62          * here; we are merely interested in reusing the
63          * per directory ignore stack mechanism.
64          */
65         return 0;
68 static void debug_stage(const char *label, struct cache_entry *ce,
69                         struct unpack_trees_options *o)
71         printf("%s ", label);
72         if (!ce)
73                 printf("(missing)\n");
74         else if (ce == o->df_conflict_entry)
75                 printf("(conflict)\n");
76         else
77                 printf("%06o #%d %s %.8s\n",
78                        ce->ce_mode, ce_stage(ce), ce->name,
79                        sha1_to_hex(ce->sha1));
82 static int debug_merge(struct cache_entry **stages, struct unpack_trees_options *o)
84         int i;
86         printf("* %d-way merge\n", o->merge_size);
87         debug_stage("index", stages[0], o);
88         for (i = 1; i <= o->merge_size; i++) {
89                 char buf[24];
90                 sprintf(buf, "ent#%d", i);
91                 debug_stage(buf, stages[i], o);
92         }
93         return 0;
96 static struct lock_file lock_file;
98 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
100         int i, newfd, stage = 0;
101         unsigned char sha1[20];
102         struct tree_desc t[MAX_UNPACK_TREES];
103         struct unpack_trees_options opts;
104         int prefix_set = 0;
105         const struct option read_tree_options[] = {
106                 { OPTION_CALLBACK, 0, "index-output", NULL, "FILE",
107                   "write resulting index to <FILE>",
108                   PARSE_OPT_NONEG, index_output_cb },
109                 OPT__VERBOSE(&opts.verbose_update),
110                 OPT_GROUP("Merging"),
111                 OPT_SET_INT('m', NULL, &opts.merge,
112                             "perform a merge in addition to a read", 1),
113                 OPT_SET_INT(0, "trivial", &opts.trivial_merges_only,
114                             "3-way merge if no file level merging required", 1),
115                 OPT_SET_INT(0, "aggressive", &opts.aggressive,
116                             "3-way merge in presence of adds and removes", 1),
117                 OPT_SET_INT(0, "reset", &opts.reset,
118                             "same as -m, but discard unmerged entries", 1),
119                 { OPTION_STRING, 0, "prefix", &opts.prefix, "<subdirectory>/",
120                   "read the tree into the index under <subdirectory>/",
121                   PARSE_OPT_NONEG | PARSE_OPT_LITERAL_ARGHELP },
122                 OPT_SET_INT('u', NULL, &opts.update,
123                             "update working tree with merge result", 1),
124                 { OPTION_CALLBACK, 0, "exclude-per-directory", &opts,
125                   "gitignore",
126                   "allow explicitly ignored files to be overwritten",
127                   PARSE_OPT_NONEG, exclude_per_directory_cb },
128                 OPT_SET_INT('i', NULL, &opts.index_only,
129                             "don't check the working tree after merging", 1),
130                 OPT_SET_INT(0, "no-sparse-checkout", &opts.skip_sparse_checkout,
131                             "skip applying sparse checkout filter", 1),
132                 OPT_SET_INT(0, "debug-unpack", &opts.debug_unpack,
133                             "debug unpack-trees", 1),
134                 OPT_END()
135         };
137         memset(&opts, 0, sizeof(opts));
138         opts.head_idx = -1;
139         opts.src_index = &the_index;
140         opts.dst_index = &the_index;
142         git_config(git_default_config, NULL);
144         argc = parse_options(argc, argv, unused_prefix, read_tree_options,
145                              read_tree_usage, 0);
147         newfd = hold_locked_index(&lock_file, 1);
149         prefix_set = opts.prefix ? 1 : 0;
150         if (1 < opts.merge + opts.reset + prefix_set)
151                 die("Which one? -m, --reset, or --prefix?");
153         if (opts.reset || opts.merge || opts.prefix) {
154                 if (read_cache_unmerged() && (opts.prefix || opts.merge))
155                         die("You need to resolve your current index first");
156                 stage = opts.merge = 1;
157         }
158         resolve_undo_clear();
160         for (i = 0; i < argc; i++) {
161                 const char *arg = argv[i];
163                 if (get_sha1(arg, sha1))
164                         die("Not a valid object name %s", arg);
165                 if (list_tree(sha1) < 0)
166                         die("failed to unpack tree object %s", arg);
167                 stage++;
168         }
169         if (1 < opts.index_only + opts.update)
170                 die("-u and -i at the same time makes no sense");
171         if ((opts.update||opts.index_only) && !opts.merge)
172                 die("%s is meaningless without -m, --reset, or --prefix",
173                     opts.update ? "-u" : "-i");
174         if ((opts.dir && !opts.update))
175                 die("--exclude-per-directory is meaningless unless -u");
176         if (opts.merge && !opts.index_only)
177                 setup_work_tree();
179         if (opts.merge) {
180                 if (stage < 2)
181                         die("just how do you expect me to merge %d trees?", stage-1);
182                 switch (stage - 1) {
183                 case 1:
184                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
185                         break;
186                 case 2:
187                         opts.fn = twoway_merge;
188                         opts.initial_checkout = is_cache_unborn();
189                         break;
190                 case 3:
191                 default:
192                         opts.fn = threeway_merge;
193                         break;
194                 }
196                 if (stage - 1 >= 3)
197                         opts.head_idx = stage - 2;
198                 else
199                         opts.head_idx = 1;
200         }
202         if (opts.debug_unpack)
203                 opts.fn = debug_merge;
205         cache_tree_free(&active_cache_tree);
206         for (i = 0; i < nr_trees; i++) {
207                 struct tree *tree = trees[i];
208                 parse_tree(tree);
209                 init_tree_desc(t+i, tree->buffer, tree->size);
210         }
211         if (unpack_trees(nr_trees, t, &opts))
212                 return 128;
214         if (opts.debug_unpack)
215                 return 0; /* do not write the index out */
217         /*
218          * When reading only one tree (either the most basic form,
219          * "-m ent" or "--reset ent" form), we can obtain a fully
220          * valid cache-tree because the index must match exactly
221          * what came from the tree.
222          *
223          * The same holds true if we are switching between two trees
224          * using read-tree -m A B.  The index must match B after that.
225          */
226         if (nr_trees == 1 && !opts.prefix)
227                 prime_cache_tree(&active_cache_tree, trees[0]);
228         else if (nr_trees == 2 && opts.merge)
229                 prime_cache_tree(&active_cache_tree, trees[1]);
231         if (write_cache(newfd, active_cache, active_nr) ||
232             commit_locked_index(&lock_file))
233                 die("unable to write new index file");
234         return 0;