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 void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
  33 {
  34         struct tree_desc desc;
  35         struct name_entry entry;
  36         int cnt;
  37
  38         hashcpy(it->sha1, tree->object.sha1);
  39         init_tree_desc(&desc, tree->buffer, tree->size);
  40         cnt = 0;
  41         while (tree_entry(&desc, &entry)) {
  42                 if (!S_ISDIR(entry.mode))
  43                         cnt++;
  44                 else {
  45                         struct cache_tree_sub *sub;
  46                         struct tree *subtree = lookup_tree(entry.sha1);
  47                         if (!subtree->object.parsed)
  48                                 parse_tree(subtree);
  49                         sub = cache_tree_sub(it, entry.path);
  50                         sub->cache_tree = cache_tree();
  51                         prime_cache_tree_rec(sub->cache_tree, subtree);
  52                         cnt += sub->cache_tree->entry_count;
  53                 }
  54         }
  55         it->entry_count = cnt;
  56 }
  57
  58 static void prime_cache_tree(void)
  59 {
  60         if (!nr_trees)
  61                 return;
  62         active_cache_tree = cache_tree();
  63         prime_cache_tree_rec(active_cache_tree, trees[0]);
  64
  65 }
  66
  67 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>]])";
  68
  69 static struct lock_file lock_file;
  70
  71 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  72 {
  73         int i, newfd, stage = 0;
  74         unsigned char sha1[20];
  75         struct tree_desc t[MAX_UNPACK_TREES];
  76         struct unpack_trees_options opts;
  77
  78         memset(&opts, 0, sizeof(opts));
  79         opts.head_idx = -1;
  80         opts.src_index = &the_index;
  81         opts.dst_index = &the_index;
  82
  83         git_config(git_default_config, NULL);
  84
  85         newfd = hold_locked_index(&lock_file, 1);
  86
  87         for (i = 1; i < argc; i++) {
  88                 const char *arg = argv[i];
  89
  90                 /* "-u" means "update", meaning that a merge will update
  91                  * the working tree.
  92                  */
  93                 if (!strcmp(arg, "-u")) {
  94                         opts.update = 1;
  95                         continue;
  96                 }
  97
  98                 if (!strcmp(arg, "-v")) {
  99                         opts.verbose_update = 1;
 100                         continue;
 101                 }
 102
 103                 /* "-i" means "index only", meaning that a merge will
 104                  * not even look at the working tree.
 105                  */
 106                 if (!strcmp(arg, "-i")) {
 107                         opts.index_only = 1;
 108                         continue;
 109                 }
 110
 111                 if (!prefixcmp(arg, "--index-output=")) {
 112                         set_alternate_index_output(arg + 15);
 113                         continue;
 114                 }
 115
 116                 /* "--prefix=<subdirectory>/" means keep the current index
 117                  *  entries and put the entries from the tree under the
 118                  * given subdirectory.
 119                  */
 120                 if (!prefixcmp(arg, "--prefix=")) {
 121                         if (stage || opts.merge || opts.prefix)
 122                                 usage(read_tree_usage);
 123                         opts.prefix = arg + 9;
 124                         opts.merge = 1;
 125                         stage = 1;
 126                         if (read_cache_unmerged())
 127                                 die("you need to resolve your current index first");
 128                         continue;
 129                 }
 130
 131                 /* This differs from "-m" in that we'll silently ignore
 132                  * unmerged entries and overwrite working tree files that
 133                  * correspond to them.
 134                  */
 135                 if (!strcmp(arg, "--reset")) {
 136                         if (stage || opts.merge || opts.prefix)
 137                                 usage(read_tree_usage);
 138                         opts.reset = 1;
 139                         opts.merge = 1;
 140                         stage = 1;
 141                         read_cache_unmerged();
 142                         continue;
 143                 }
 144
 145                 if (!strcmp(arg, "--trivial")) {
 146                         opts.trivial_merges_only = 1;
 147                         continue;
 148                 }
 149
 150                 if (!strcmp(arg, "--aggressive")) {
 151                         opts.aggressive = 1;
 152                         continue;
 153                 }
 154
 155                 /* "-m" stands for "merge", meaning we start in stage 1 */
 156                 if (!strcmp(arg, "-m")) {
 157                         if (stage || opts.merge || opts.prefix)
 158                                 usage(read_tree_usage);
 159                         if (read_cache_unmerged())
 160                                 die("you need to resolve your current index first");
 161                         stage = 1;
 162                         opts.merge = 1;
 163                         continue;
 164                 }
 165
 166                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
 167                         struct dir_struct *dir;
 168
 169                         if (opts.dir)
 170                                 die("more than one --exclude-per-directory are given.");
 171
 172                         dir = xcalloc(1, sizeof(*opts.dir));
 173                         dir->show_ignored = 1;
 174                         dir->exclude_per_dir = arg + 24;
 175                         opts.dir = dir;
 176                         /* We do not need to nor want to do read-directory
 177                          * here; we are merely interested in reusing the
 178                          * per directory ignore stack mechanism.
 179                          */
 180                         continue;
 181                 }
 182
 183                 /* using -u and -i at the same time makes no sense */
 184                 if (1 < opts.index_only + opts.update)
 185                         usage(read_tree_usage);
 186
 187                 if (get_sha1(arg, sha1))
 188                         die("Not a valid object name %s", arg);
 189                 if (list_tree(sha1) < 0)
 190                         die("failed to unpack tree object %s", arg);
 191                 stage++;
 192         }
 193         if ((opts.update||opts.index_only) && !opts.merge)
 194                 usage(read_tree_usage);
 195         if ((opts.dir && !opts.update))
 196                 die("--exclude-per-directory is meaningless unless -u");
 197
 198         if (opts.merge) {
 199                 if (stage < 2)
 200                         die("just how do you expect me to merge %d trees?", stage-1);
 201                 switch (stage - 1) {
 202                 case 1:
 203                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 204                         break;
 205                 case 2:
 206                         opts.fn = twoway_merge;
 207                         break;
 208                 case 3:
 209                 default:
 210                         opts.fn = threeway_merge;
 211                         cache_tree_free(&active_cache_tree);
 212                         break;
 213                 }
 214
 215                 if (stage - 1 >= 3)
 216                         opts.head_idx = stage - 2;
 217                 else
 218                         opts.head_idx = 1;
 219         }
 220
 221         for (i = 0; i < nr_trees; i++) {
 222                 struct tree *tree = trees[i];
 223                 parse_tree(tree);
 224                 init_tree_desc(t+i, tree->buffer, tree->size);
 225         }
 226         if (unpack_trees(nr_trees, t, &opts))
 227                 return 128;
 228
 229         /*
 230          * When reading only one tree (either the most basic form,
 231          * "-m ent" or "--reset ent" form), we can obtain a fully
 232          * valid cache-tree because the index must match exactly
 233          * what came from the tree.
 234          */
 235         if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
 236                 cache_tree_free(&active_cache_tree);
 237                 prime_cache_tree();
 238         }
 239
 240         if (write_cache(newfd, active_cache, active_nr) ||
 241             commit_locked_index(&lock_file))
 242                 die("unable to write new index file");
 243         return 0;
 244 }