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 struct object_list *trees;
  17
  18 static int list_tree(unsigned char *sha1)
  19 {
  20         struct tree *tree = parse_tree_indirect(sha1);
  21         if (!tree)
  22                 return -1;
  23         object_list_append(&tree->object, &trees);
  24         return 0;
  25 }
  26
  27 static int read_cache_unmerged(void)
  28 {
  29         int i;
  30         struct cache_entry **dst;
  31         struct cache_entry *last = NULL;
  32
  33         read_cache();
  34         dst = active_cache;
  35         for (i = 0; i < active_nr; i++) {
  36                 struct cache_entry *ce = active_cache[i];
  37                 if (ce_stage(ce)) {
  38                         if (last && !strcmp(ce->name, last->name))
  39                                 continue;
  40                         cache_tree_invalidate_path(active_cache_tree, ce->name);
  41                         last = ce;
  42                         ce->ce_mode = 0;
  43                         ce->ce_flags &= ~htons(CE_STAGEMASK);
  44                 }
  45                 *dst++ = ce;
  46         }
  47         active_nr = dst - active_cache;
  48         return !!last;
  49 }
  50
  51 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
  52 {
  53         struct tree_desc desc;
  54         struct name_entry entry;
  55         int cnt;
  56
  57         hashcpy(it->sha1, tree->object.sha1);
  58         init_tree_desc(&desc, tree->buffer, tree->size);
  59         cnt = 0;
  60         while (tree_entry(&desc, &entry)) {
  61                 if (!S_ISDIR(entry.mode))
  62                         cnt++;
  63                 else {
  64                         struct cache_tree_sub *sub;
  65                         struct tree *subtree = lookup_tree(entry.sha1);
  66                         if (!subtree->object.parsed)
  67                                 parse_tree(subtree);
  68                         sub = cache_tree_sub(it, entry.path);
  69                         sub->cache_tree = cache_tree();
  70                         prime_cache_tree_rec(sub->cache_tree, subtree);
  71                         cnt += sub->cache_tree->entry_count;
  72                 }
  73         }
  74         it->entry_count = cnt;
  75 }
  76
  77 static void prime_cache_tree(void)
  78 {
  79         struct tree *tree = (struct tree *)trees->item;
  80         if (!tree)
  81                 return;
  82         active_cache_tree = cache_tree();
  83         prime_cache_tree_rec(active_cache_tree, tree);
  84
  85 }
  86
  87 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>]])";
  88
  89 static struct lock_file lock_file;
  90
  91 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  92 {
  93         int i, newfd, stage = 0;
  94         unsigned char sha1[20];
  95         struct unpack_trees_options opts;
  96
  97         memset(&opts, 0, sizeof(opts));
  98         opts.head_idx = -1;
  99
 100         git_config(git_default_config);
 101
 102         newfd = hold_locked_index(&lock_file, 1);
 103
 104         git_config(git_default_config);
 105
 106         for (i = 1; i < argc; i++) {
 107                 const char *arg = argv[i];
 108
 109                 /* "-u" means "update", meaning that a merge will update
 110                  * the working tree.
 111                  */
 112                 if (!strcmp(arg, "-u")) {
 113                         opts.update = 1;
 114                         continue;
 115                 }
 116
 117                 if (!strcmp(arg, "-v")) {
 118                         opts.verbose_update = 1;
 119                         continue;
 120                 }
 121
 122                 /* "-i" means "index only", meaning that a merge will
 123                  * not even look at the working tree.
 124                  */
 125                 if (!strcmp(arg, "-i")) {
 126                         opts.index_only = 1;
 127                         continue;
 128                 }
 129
 130                 if (!prefixcmp(arg, "--index-output=")) {
 131                         set_alternate_index_output(arg + 15);
 132                         continue;
 133                 }
 134
 135                 /* "--prefix=<subdirectory>/" means keep the current index
 136                  *  entries and put the entries from the tree under the
 137                  * given subdirectory.
 138                  */
 139                 if (!prefixcmp(arg, "--prefix=")) {
 140                         if (stage || opts.merge || opts.prefix)
 141                                 usage(read_tree_usage);
 142                         opts.prefix = arg + 9;
 143                         opts.merge = 1;
 144                         stage = 1;
 145                         if (read_cache_unmerged())
 146                                 die("you need to resolve your current index first");
 147                         continue;
 148                 }
 149
 150                 /* This differs from "-m" in that we'll silently ignore
 151                  * unmerged entries and overwrite working tree files that
 152                  * correspond to them.
 153                  */
 154                 if (!strcmp(arg, "--reset")) {
 155                         if (stage || opts.merge || opts.prefix)
 156                                 usage(read_tree_usage);
 157                         opts.reset = 1;
 158                         opts.merge = 1;
 159                         stage = 1;
 160                         read_cache_unmerged();
 161                         continue;
 162                 }
 163
 164                 if (!strcmp(arg, "--trivial")) {
 165                         opts.trivial_merges_only = 1;
 166                         continue;
 167                 }
 168
 169                 if (!strcmp(arg, "--aggressive")) {
 170                         opts.aggressive = 1;
 171                         continue;
 172                 }
 173
 174                 /* "-m" stands for "merge", meaning we start in stage 1 */
 175                 if (!strcmp(arg, "-m")) {
 176                         if (stage || opts.merge || opts.prefix)
 177                                 usage(read_tree_usage);
 178                         if (read_cache_unmerged())
 179                                 die("you need to resolve your current index first");
 180                         stage = 1;
 181                         opts.merge = 1;
 182                         continue;
 183                 }
 184
 185                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
 186                         struct dir_struct *dir;
 187
 188                         if (opts.dir)
 189                                 die("more than one --exclude-per-directory are given.");
 190
 191                         dir = xcalloc(1, sizeof(*opts.dir));
 192                         dir->show_ignored = 1;
 193                         dir->exclude_per_dir = arg + 24;
 194                         opts.dir = dir;
 195                         /* We do not need to nor want to do read-directory
 196                          * here; we are merely interested in reusing the
 197                          * per directory ignore stack mechanism.
 198                          */
 199                         continue;
 200                 }
 201
 202                 /* using -u and -i at the same time makes no sense */
 203                 if (1 < opts.index_only + opts.update)
 204                         usage(read_tree_usage);
 205
 206                 if (get_sha1(arg, sha1))
 207                         die("Not a valid object name %s", arg);
 208                 if (list_tree(sha1) < 0)
 209                         die("failed to unpack tree object %s", arg);
 210                 stage++;
 211         }
 212         if ((opts.update||opts.index_only) && !opts.merge)
 213                 usage(read_tree_usage);
 214         if ((opts.dir && !opts.update))
 215                 die("--exclude-per-directory is meaningless unless -u");
 216
 217         if (opts.prefix) {
 218                 int pfxlen = strlen(opts.prefix);
 219                 int pos;
 220                 if (opts.prefix[pfxlen-1] != '/')
 221                         die("prefix must end with /");
 222                 if (stage != 2)
 223                         die("binding merge takes only one tree");
 224                 pos = cache_name_pos(opts.prefix, pfxlen);
 225                 if (0 <= pos)
 226                         die("corrupt index file");
 227                 pos = -pos-1;
 228                 if (pos < active_nr &&
 229                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 230                         die("subdirectory '%s' already exists.", opts.prefix);
 231                 pos = cache_name_pos(opts.prefix, pfxlen-1);
 232                 if (0 <= pos)
 233                         die("file '%.*s' already exists.",
 234                                         pfxlen-1, opts.prefix);
 235                 opts.pos = -1 - pos;
 236         }
 237
 238         if (opts.merge) {
 239                 if (stage < 2)
 240                         die("just how do you expect me to merge %d trees?", stage-1);
 241                 switch (stage - 1) {
 242                 case 1:
 243                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 244                         break;
 245                 case 2:
 246                         opts.fn = twoway_merge;
 247                         break;
 248                 case 3:
 249                 default:
 250                         opts.fn = threeway_merge;
 251                         cache_tree_free(&active_cache_tree);
 252                         break;
 253                 }
 254
 255                 if (stage - 1 >= 3)
 256                         opts.head_idx = stage - 2;
 257                 else
 258                         opts.head_idx = 1;
 259         }
 260
 261         unpack_trees(trees, &opts);
 262
 263         /*
 264          * When reading only one tree (either the most basic form,
 265          * "-m ent" or "--reset ent" form), we can obtain a fully
 266          * valid cache-tree because the index must match exactly
 267          * what came from the tree.
 268          */
 269         if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
 270                 cache_tree_free(&active_cache_tree);
 271                 prime_cache_tree();
 272         }
 273
 274         if (write_cache(newfd, active_cache, active_nr) ||
 275             close(newfd) || commit_locked_index(&lock_file))
 276                 die("unable to write new index file");
 277         return 0;
 278 }