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         desc.buf = tree->buffer;
  59         desc.size = tree->size;
  60         cnt = 0;
  61         while (tree_entry(&desc, &entry)) {
  62                 if (!S_ISDIR(entry.mode))
  63                         cnt++;
  64                 else {
  65                         struct cache_tree_sub *sub;
  66                         struct tree *subtree = lookup_tree(entry.sha1);
  67                         if (!subtree->object.parsed)
  68                                 parse_tree(subtree);
  69                         sub = cache_tree_sub(it, entry.path);
  70                         sub->cache_tree = cache_tree();
  71                         prime_cache_tree_rec(sub->cache_tree, subtree);
  72                         cnt += sub->cache_tree->entry_count;
  73                 }
  74         }
  75         it->entry_count = cnt;
  76 }
  77
  78 static void prime_cache_tree(void)
  79 {
  80         struct tree *tree = (struct tree *)trees->item;
  81         if (!tree)
  82                 return;
  83         active_cache_tree = cache_tree();
  84         prime_cache_tree_rec(active_cache_tree, tree);
  85
  86 }
  87
  88 static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] <sha1> [<sha2> [<sha3>]])";
  89
  90 static struct lock_file lock_file;
  91
  92 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  93 {
  94         int i, newfd, stage = 0;
  95         unsigned char sha1[20];
  96         struct unpack_trees_options opts;
  97
  98         memset(&opts, 0, sizeof(opts));
  99         opts.head_idx = -1;
 100
 101         setup_git_directory();
 102         git_config(git_default_config);
 103
 104         newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);
 105
 106         git_config(git_default_config);
 107
 108         for (i = 1; i < argc; i++) {
 109                 const char *arg = argv[i];
 110
 111                 /* "-u" means "update", meaning that a merge will update
 112                  * the working tree.
 113                  */
 114                 if (!strcmp(arg, "-u")) {
 115                         opts.update = 1;
 116                         continue;
 117                 }
 118
 119                 if (!strcmp(arg, "-v")) {
 120                         opts.verbose_update = 1;
 121                         continue;
 122                 }
 123
 124                 /* "-i" means "index only", meaning that a merge will
 125                  * not even look at the working tree.
 126                  */
 127                 if (!strcmp(arg, "-i")) {
 128                         opts.index_only = 1;
 129                         continue;
 130                 }
 131
 132                 /* "--prefix=<subdirectory>/" means keep the current index
 133                  *  entries and put the entries from the tree under the
 134                  * given subdirectory.
 135                  */
 136                 if (!prefixcmp(arg, "--prefix=")) {
 137                         if (stage || opts.merge || opts.prefix)
 138                                 usage(read_tree_usage);
 139                         opts.prefix = arg + 9;
 140                         opts.merge = 1;
 141                         stage = 1;
 142                         if (read_cache_unmerged())
 143                                 die("you need to resolve your current index first");
 144                         continue;
 145                 }
 146
 147                 /* This differs from "-m" in that we'll silently ignore
 148                  * unmerged entries and overwrite working tree files that
 149                  * correspond to them.
 150                  */
 151                 if (!strcmp(arg, "--reset")) {
 152                         if (stage || opts.merge || opts.prefix)
 153                                 usage(read_tree_usage);
 154                         opts.reset = 1;
 155                         opts.merge = 1;
 156                         stage = 1;
 157                         read_cache_unmerged();
 158                         continue;
 159                 }
 160
 161                 if (!strcmp(arg, "--trivial")) {
 162                         opts.trivial_merges_only = 1;
 163                         continue;
 164                 }
 165
 166                 if (!strcmp(arg, "--aggressive")) {
 167                         opts.aggressive = 1;
 168                         continue;
 169                 }
 170
 171                 /* "-m" stands for "merge", meaning we start in stage 1 */
 172                 if (!strcmp(arg, "-m")) {
 173                         if (stage || opts.merge || opts.prefix)
 174                                 usage(read_tree_usage);
 175                         if (read_cache_unmerged())
 176                                 die("you need to resolve your current index first");
 177                         stage = 1;
 178                         opts.merge = 1;
 179                         continue;
 180                 }
 181
 182                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
 183                         struct dir_struct *dir;
 184
 185                         if (opts.dir)
 186                                 die("more than one --exclude-per-directory are given.");
 187
 188                         dir = calloc(1, sizeof(*opts.dir));
 189                         dir->show_ignored = 1;
 190                         dir->exclude_per_dir = arg + 24;
 191                         opts.dir = dir;
 192                         /* We do not need to nor want to do read-directory
 193                          * here; we are merely interested in reusing the
 194                          * per directory ignore stack mechanism.
 195                          */
 196                         continue;
 197                 }
 198
 199                 /* using -u and -i at the same time makes no sense */
 200                 if (1 < opts.index_only + opts.update)
 201                         usage(read_tree_usage);
 202
 203                 if (get_sha1(arg, sha1))
 204                         die("Not a valid object name %s", arg);
 205                 if (list_tree(sha1) < 0)
 206                         die("failed to unpack tree object %s", arg);
 207                 stage++;
 208         }
 209         if ((opts.update||opts.index_only) && !opts.merge)
 210                 usage(read_tree_usage);
 211         if ((opts.dir && !opts.update))
 212                 die("--exclude-per-directory is meaningless unless -u");
 213
 214         if (opts.prefix) {
 215                 int pfxlen = strlen(opts.prefix);
 216                 int pos;
 217                 if (opts.prefix[pfxlen-1] != '/')
 218                         die("prefix must end with /");
 219                 if (stage != 2)
 220                         die("binding merge takes only one tree");
 221                 pos = cache_name_pos(opts.prefix, pfxlen);
 222                 if (0 <= pos)
 223                         die("corrupt index file");
 224                 pos = -pos-1;
 225                 if (pos < active_nr &&
 226                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 227                         die("subdirectory '%s' already exists.", opts.prefix);
 228                 pos = cache_name_pos(opts.prefix, pfxlen-1);
 229                 if (0 <= pos)
 230                         die("file '%.*s' already exists.",
 231                                         pfxlen-1, opts.prefix);
 232         }
 233
 234         if (opts.merge) {
 235                 if (stage < 2)
 236                         die("just how do you expect me to merge %d trees?", stage-1);
 237                 switch (stage - 1) {
 238                 case 1:
 239                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 240                         break;
 241                 case 2:
 242                         opts.fn = twoway_merge;
 243                         break;
 244                 case 3:
 245                 default:
 246                         opts.fn = threeway_merge;
 247                         cache_tree_free(&active_cache_tree);
 248                         break;
 249                 }
 250
 251                 if (stage - 1 >= 3)
 252                         opts.head_idx = stage - 2;
 253                 else
 254                         opts.head_idx = 1;
 255         }
 256
 257         unpack_trees(trees, &opts);
 258
 259         /*
 260          * When reading only one tree (either the most basic form,
 261          * "-m ent" or "--reset ent" form), we can obtain a fully
 262          * valid cache-tree because the index must match exactly
 263          * what came from the tree.
 264          */
 265         if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
 266                 cache_tree_free(&active_cache_tree);
 267                 prime_cache_tree();
 268         }
 269
 270         if (write_cache(newfd, active_cache, active_nr) ||
 271             close(newfd) || commit_lock_file(&lock_file))
 272                 die("unable to write new index file");
 273         return 0;
 274 }