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                         remove_index_entry(ce);
  45                         if (last && !strcmp(ce->name, last->name))
  46                                 continue;
  47                         cache_tree_invalidate_path(active_cache_tree, ce->name);
  48                         last = ce;
  49                         continue;
  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         opts.index = &the_index;
 106
 107         git_config(git_default_config);
 108
 109         newfd = hold_locked_index(&lock_file, 1);
 110
 111         git_config(git_default_config);
 112
 113         for (i = 1; i < argc; i++) {
 114                 const char *arg = argv[i];
 115
 116                 /* "-u" means "update", meaning that a merge will update
 117                  * the working tree.
 118                  */
 119                 if (!strcmp(arg, "-u")) {
 120                         opts.update = 1;
 121                         continue;
 122                 }
 123
 124                 if (!strcmp(arg, "-v")) {
 125                         opts.verbose_update = 1;
 126                         continue;
 127                 }
 128
 129                 /* "-i" means "index only", meaning that a merge will
 130                  * not even look at the working tree.
 131                  */
 132                 if (!strcmp(arg, "-i")) {
 133                         opts.index_only = 1;
 134                         continue;
 135                 }
 136
 137                 if (!prefixcmp(arg, "--index-output=")) {
 138                         set_alternate_index_output(arg + 15);
 139                         continue;
 140                 }
 141
 142                 /* "--prefix=<subdirectory>/" means keep the current index
 143                  *  entries and put the entries from the tree under the
 144                  * given subdirectory.
 145                  */
 146                 if (!prefixcmp(arg, "--prefix=")) {
 147                         if (stage || opts.merge || opts.prefix)
 148                                 usage(read_tree_usage);
 149                         opts.prefix = arg + 9;
 150                         opts.merge = 1;
 151                         stage = 1;
 152                         if (read_cache_unmerged())
 153                                 die("you need to resolve your current index first");
 154                         continue;
 155                 }
 156
 157                 /* This differs from "-m" in that we'll silently ignore
 158                  * unmerged entries and overwrite working tree files that
 159                  * correspond to them.
 160                  */
 161                 if (!strcmp(arg, "--reset")) {
 162                         if (stage || opts.merge || opts.prefix)
 163                                 usage(read_tree_usage);
 164                         opts.reset = 1;
 165                         opts.merge = 1;
 166                         stage = 1;
 167                         read_cache_unmerged();
 168                         continue;
 169                 }
 170
 171                 if (!strcmp(arg, "--trivial")) {
 172                         opts.trivial_merges_only = 1;
 173                         continue;
 174                 }
 175
 176                 if (!strcmp(arg, "--aggressive")) {
 177                         opts.aggressive = 1;
 178                         continue;
 179                 }
 180
 181                 /* "-m" stands for "merge", meaning we start in stage 1 */
 182                 if (!strcmp(arg, "-m")) {
 183                         if (stage || opts.merge || opts.prefix)
 184                                 usage(read_tree_usage);
 185                         if (read_cache_unmerged())
 186                                 die("you need to resolve your current index first");
 187                         stage = 1;
 188                         opts.merge = 1;
 189                         continue;
 190                 }
 191
 192                 if (!prefixcmp(arg, "--exclude-per-directory=")) {
 193                         struct dir_struct *dir;
 194
 195                         if (opts.dir)
 196                                 die("more than one --exclude-per-directory are given.");
 197
 198                         dir = xcalloc(1, sizeof(*opts.dir));
 199                         dir->show_ignored = 1;
 200                         dir->exclude_per_dir = arg + 24;
 201                         opts.dir = dir;
 202                         /* We do not need to nor want to do read-directory
 203                          * here; we are merely interested in reusing the
 204                          * per directory ignore stack mechanism.
 205                          */
 206                         continue;
 207                 }
 208
 209                 /* using -u and -i at the same time makes no sense */
 210                 if (1 < opts.index_only + opts.update)
 211                         usage(read_tree_usage);
 212
 213                 if (get_sha1(arg, sha1))
 214                         die("Not a valid object name %s", arg);
 215                 if (list_tree(sha1) < 0)
 216                         die("failed to unpack tree object %s", arg);
 217                 stage++;
 218         }
 219         if ((opts.update||opts.index_only) && !opts.merge)
 220                 usage(read_tree_usage);
 221         if ((opts.dir && !opts.update))
 222                 die("--exclude-per-directory is meaningless unless -u");
 223
 224         if (opts.prefix) {
 225                 int pfxlen = strlen(opts.prefix);
 226                 int pos;
 227                 if (opts.prefix[pfxlen-1] != '/')
 228                         die("prefix must end with /");
 229                 if (stage != 2)
 230                         die("binding merge takes only one tree");
 231                 pos = cache_name_pos(opts.prefix, pfxlen);
 232                 if (0 <= pos)
 233                         die("corrupt index file");
 234                 pos = -pos-1;
 235                 if (pos < active_nr &&
 236                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 237                         die("subdirectory '%s' already exists.", opts.prefix);
 238                 pos = cache_name_pos(opts.prefix, pfxlen-1);
 239                 if (0 <= pos)
 240                         die("file '%.*s' already exists.",
 241                                         pfxlen-1, opts.prefix);
 242                 opts.pos = -1 - pos;
 243         }
 244
 245         if (opts.merge) {
 246                 if (stage < 2)
 247                         die("just how do you expect me to merge %d trees?", stage-1);
 248                 switch (stage - 1) {
 249                 case 1:
 250                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 251                         break;
 252                 case 2:
 253                         opts.fn = twoway_merge;
 254                         break;
 255                 case 3:
 256                 default:
 257                         opts.fn = threeway_merge;
 258                         cache_tree_free(&active_cache_tree);
 259                         break;
 260                 }
 261
 262                 if (stage - 1 >= 3)
 263                         opts.head_idx = stage - 2;
 264                 else
 265                         opts.head_idx = 1;
 266         }
 267
 268         for (i = 0; i < nr_trees; i++) {
 269                 struct tree *tree = trees[i];
 270                 parse_tree(tree);
 271                 init_tree_desc(t+i, tree->buffer, tree->size);
 272         }
 273         if (unpack_trees(nr_trees, t, &opts))
 274                 return 128;
 275
 276         /*
 277          * When reading only one tree (either the most basic form,
 278          * "-m ent" or "--reset ent" form), we can obtain a fully
 279          * valid cache-tree because the index must match exactly
 280          * what came from the tree.
 281          */
 282         if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
 283                 cache_tree_free(&active_cache_tree);
 284                 prime_cache_tree();
 285         }
 286
 287         if (write_cache(newfd, active_cache, active_nr) ||
 288             commit_locked_index(&lock_file))
 289                 die("unable to write new index file");
 290         return 0;
 291 }