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                         ce->ce_mode = 0;
  49                         ce->ce_flags &= ~htons(CE_STAGEMASK);
  50                 }
  51                 *dst++ = ce;
  52         }
  53         active_nr = dst - active_cache;
  54         return !!last;
  55 }
  56
  57 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
  58 {
  59         struct tree_desc desc;
  60         struct name_entry entry;
  61         int cnt;
  62
  63         hashcpy(it->sha1, tree->object.sha1);
  64         init_tree_desc(&desc, tree->buffer, tree->size);
  65         cnt = 0;
  66         while (tree_entry(&desc, &entry)) {
  67                 if (!S_ISDIR(entry.mode))
  68                         cnt++;
  69                 else {
  70                         struct cache_tree_sub *sub;
  71                         struct tree *subtree = lookup_tree(entry.sha1);
  72                         if (!subtree->object.parsed)
  73                                 parse_tree(subtree);
  74                         sub = cache_tree_sub(it, entry.path);
  75                         sub->cache_tree = cache_tree();
  76                         prime_cache_tree_rec(sub->cache_tree, subtree);
  77                         cnt += sub->cache_tree->entry_count;
  78                 }
  79         }
  80         it->entry_count = cnt;
  81 }
  82
  83 static void prime_cache_tree(void)
  84 {
  85         if (!nr_trees)
  86                 return;
  87         active_cache_tree = cache_tree();
  88         prime_cache_tree_rec(active_cache_tree, trees[0]);
  89
  90 }
  91
  92 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>]])";
  93
  94 static struct lock_file lock_file;
  95
  96 int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  97 {
  98         int i, newfd, stage = 0;
  99         unsigned char sha1[20];
 100         struct tree_desc t[MAX_TREES];
 101         struct unpack_trees_options opts;
 102
 103         memset(&opts, 0, sizeof(opts));
 104         opts.head_idx = -1;
 105
 106         git_config(git_default_config);
 107
 108         newfd = hold_locked_index(&lock_file, 1);
 109
 110         git_config(git_default_config);
 111
 112         for (i = 1; i < argc; i++) {
 113                 const char *arg = argv[i];
 114
 115                 /* "-u" means "update", meaning that a merge will update
 116                  * the working tree.
 117                  */
 118                 if (!strcmp(arg, "-u")) {
 119                         opts.update = 1;
 120                         continue;
 121                 }
 122
 123                 if (!strcmp(arg, "-v")) {
 124                         opts.verbose_update = 1;
 125                         continue;
 126                 }
 127
 128                 /* "-i" means "index only", meaning that a merge will
 129                  * not even look at the working tree.
 130                  */
 131                 if (!strcmp(arg, "-i")) {
 132                         opts.index_only = 1;
 133                         continue;
 134                 }
 135
 136                 if (!prefixcmp(arg, "--index-output=")) {
 137                         set_alternate_index_output(arg + 15);
 138                         continue;
 139                 }
 140
 141                 /* "--prefix=<subdirectory>/" means keep the current index
 142                  *  entries and put the entries from the tree under the
 143                  * given subdirectory.
 144                  */
 145                 if (!prefixcmp(arg, "--prefix=")) {
 146                         if (stage || opts.merge || opts.prefix)
 147                                 usage(read_tree_usage);
 148                         opts.prefix = arg + 9;
 149                         opts.merge = 1;
 150                         stage = 1;
 151                         if (read_cache_unmerged())
 152                                 die("you need to resolve your current index first");
 153                         continue;
 154                 }
 155
 156                 /* This differs from "-m" in that we'll silently ignore
 157                  * unmerged entries and overwrite working tree files that
 158                  * correspond to them.
 159                  */
 160                 if (!strcmp(arg, "--reset")) {
 161                         if (stage || opts.merge || opts.prefix)
 162                                 usage(read_tree_usage);
 163                         opts.reset = 1;
 164                         opts.merge = 1;
 165                         stage = 1;
 166                         read_cache_unmerged();
 167                         continue;
 168                 }
 169
 170                 if (!strcmp(arg, "--trivial")) {
 171                         opts.trivial_merges_only = 1;
 172                         continue;
 173                 }
 174
 175                 if (!strcmp(arg, "--aggressive")) {
 176                         opts.aggressive = 1;
 177                         continue;
 178                 }
 179
 180                 /* "-m" stands for "merge", meaning we start in stage 1 */
 181                 if (!strcmp(arg, "-m")) {
 182                         if (stage || opts.merge || opts.prefix)
 183                                 usage(read_tree_usage);
 184                         if (read_cache_unmerged())
 185                                 die("you need to resolve your current index first");
 186                         stage = 1;
 187                         opts.merge = 1;
 188                         continue;
 189                 }
 190
 191                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
 192                         struct dir_struct *dir;
 193
 194                         if (opts.dir)
 195                                 die("more than one --exclude-per-directory are given.");
 196
 197                         dir = xcalloc(1, sizeof(*opts.dir));
 198                         dir->show_ignored = 1;
 199                         dir->exclude_per_dir = arg + 24;
 200                         opts.dir = dir;
 201                         /* We do not need to nor want to do read-directory
 202                          * here; we are merely interested in reusing the
 203                          * per directory ignore stack mechanism.
 204                          */
 205                         continue;
 206                 }
 207
 208                 /* using -u and -i at the same time makes no sense */
 209                 if (1 < opts.index_only + opts.update)
 210                         usage(read_tree_usage);
 211
 212                 if (get_sha1(arg, sha1))
 213                         die("Not a valid object name %s", arg);
 214                 if (list_tree(sha1) < 0)
 215                         die("failed to unpack tree object %s", arg);
 216                 stage++;
 217         }
 218         if ((opts.update||opts.index_only) && !opts.merge)
 219                 usage(read_tree_usage);
 220         if ((opts.dir && !opts.update))
 221                 die("--exclude-per-directory is meaningless unless -u");
 222
 223         if (opts.prefix) {
 224                 int pfxlen = strlen(opts.prefix);
 225                 int pos;
 226                 if (opts.prefix[pfxlen-1] != '/')
 227                         die("prefix must end with /");
 228                 if (stage != 2)
 229                         die("binding merge takes only one tree");
 230                 pos = cache_name_pos(opts.prefix, pfxlen);
 231                 if (0 <= pos)
 232                         die("corrupt index file");
 233                 pos = -pos-1;
 234                 if (pos < active_nr &&
 235                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 236                         die("subdirectory '%s' already exists.", opts.prefix);
 237                 pos = cache_name_pos(opts.prefix, pfxlen-1);
 238                 if (0 <= pos)
 239                         die("file '%.*s' already exists.",
 240                                         pfxlen-1, opts.prefix);
 241                 opts.pos = -1 - pos;
 242         }
 243
 244         if (opts.merge) {
 245                 if (stage < 2)
 246                         die("just how do you expect me to merge %d trees?", stage-1);
 247                 switch (stage - 1) {
 248                 case 1:
 249                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 250                         break;
 251                 case 2:
 252                         opts.fn = twoway_merge;
 253                         break;
 254                 case 3:
 255                 default:
 256                         opts.fn = threeway_merge;
 257                         cache_tree_free(&active_cache_tree);
 258                         break;
 259                 }
 260
 261                 if (stage - 1 >= 3)
 262                         opts.head_idx = stage - 2;
 263                 else
 264                         opts.head_idx = 1;
 265         }
 266
 267         for (i = 0; i < nr_trees; i++) {
 268                 struct tree *tree = trees[i];
 269                 parse_tree(tree);
 270                 init_tree_desc(t+i, tree->buffer, tree->size);
 271         }
 272         unpack_trees(nr_trees, t, &opts);
 273
 274         /*
 275          * When reading only one tree (either the most basic form,
 276          * "-m ent" or "--reset ent" form), we can obtain a fully
 277          * valid cache-tree because the index must match exactly
 278          * what came from the tree.
 279          */
 280         if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
 281                 cache_tree_free(&active_cache_tree);
 282                 prime_cache_tree();
 283         }
 284
 285         if (write_cache(newfd, active_cache, active_nr) ||
 286             close(newfd) || commit_locked_index(&lock_file))
 287                 die("unable to write new index file");
 288         return 0;
 289 }