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                         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_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 }