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 "builtin.h"
  14
  15 static struct object_list *trees;
  16
  17 static int list_tree(unsigned char *sha1)
  18 {
  19         struct tree *tree = parse_tree_indirect(sha1);
  20         if (!tree)
  21                 return -1;
  22         object_list_append(&tree->object, &trees);
  23         return 0;
  24 }
  25
  26 static int read_cache_unmerged(void)
  27 {
  28         int i;
  29         struct cache_entry **dst;
  30         struct cache_entry *last = NULL;
  31
  32         read_cache();
  33         dst = active_cache;
  34         for (i = 0; i < active_nr; i++) {
  35                 struct cache_entry *ce = active_cache[i];
  36                 if (ce_stage(ce)) {
  37                         if (last && !strcmp(ce->name, last->name))
  38                                 continue;
  39                         cache_tree_invalidate_path(active_cache_tree, ce->name);
  40                         last = ce;
  41                         ce->ce_mode = 0;
  42                         ce->ce_flags &= ~htons(CE_STAGEMASK);
  43                 }
  44                 *dst++ = ce;
  45         }
  46         active_nr = dst - active_cache;
  47         return !!last;
  48 }
  49
  50 static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
  51 {
  52         struct tree_desc desc;
  53         struct name_entry entry;
  54         int cnt;
  55
  56         memcpy(it->sha1, tree->object.sha1, 20);
  57         desc.buf = tree->buffer;
  58         desc.size = 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 [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] <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         setup_git_directory();
 101         git_config(git_default_config);
 102
 103         newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);
 104
 105         git_config(git_default_config);
 106
 107         for (i = 1; i < argc; i++) {
 108                 const char *arg = argv[i];
 109
 110                 /* "-u" means "update", meaning that a merge will update
 111                  * the working tree.
 112                  */
 113                 if (!strcmp(arg, "-u")) {
 114                         opts.update = 1;
 115                         continue;
 116                 }
 117
 118                 if (!strcmp(arg, "-v")) {
 119                         opts.verbose_update = 1;
 120                         continue;
 121                 }
 122
 123                 /* "-i" means "index only", meaning that a merge will
 124                  * not even look at the working tree.
 125                  */
 126                 if (!strcmp(arg, "-i")) {
 127                         opts.index_only = 1;
 128                         continue;
 129                 }
 130
 131                 /* "--prefix=<subdirectory>/" means keep the current index
 132                  *  entries and put the entries from the tree under the
 133                  * given subdirectory.
 134                  */
 135                 if (!strncmp(arg, "--prefix=", 9)) {
 136                         if (stage || opts.merge || opts.prefix)
 137                                 usage(read_tree_usage);
 138                         opts.prefix = arg + 9;
 139                         opts.merge = 1;
 140                         stage = 1;
 141                         if (read_cache_unmerged())
 142                                 die("you need to resolve your current index first");
 143                         continue;
 144                 }
 145
 146                 /* This differs from "-m" in that we'll silently ignore
 147                  * unmerged entries and overwrite working tree files that
 148                  * correspond to them.
 149                  */
 150                 if (!strcmp(arg, "--reset")) {
 151                         if (stage || opts.merge || opts.prefix)
 152                                 usage(read_tree_usage);
 153                         opts.reset = 1;
 154                         opts.merge = 1;
 155                         stage = 1;
 156                         read_cache_unmerged();
 157                         continue;
 158                 }
 159
 160                 if (!strcmp(arg, "--trivial")) {
 161                         opts.trivial_merges_only = 1;
 162                         continue;
 163                 }
 164
 165                 if (!strcmp(arg, "--aggressive")) {
 166                         opts.aggressive = 1;
 167                         continue;
 168                 }
 169
 170                 /* "-m" stands for "merge", meaning we start in stage 1 */
 171                 if (!strcmp(arg, "-m")) {
 172                         if (stage || opts.merge || opts.prefix)
 173                                 usage(read_tree_usage);
 174                         if (read_cache_unmerged())
 175                                 die("you need to resolve your current index first");
 176                         stage = 1;
 177                         opts.merge = 1;
 178                         continue;
 179                 }
 180
 181                 /* using -u and -i at the same time makes no sense */
 182                 if (1 < opts.index_only + opts.update)
 183                         usage(read_tree_usage);
 184
 185                 if (get_sha1(arg, sha1))
 186                         die("Not a valid object name %s", arg);
 187                 if (list_tree(sha1) < 0)
 188                         die("failed to unpack tree object %s", arg);
 189                 stage++;
 190         }
 191         if ((opts.update||opts.index_only) && !opts.merge)
 192                 usage(read_tree_usage);
 193
 194         if (opts.prefix) {
 195                 int pfxlen = strlen(opts.prefix);
 196                 int pos;
 197                 if (opts.prefix[pfxlen-1] != '/')
 198                         die("prefix must end with /");
 199                 if (stage != 2)
 200                         die("binding merge takes only one tree");
 201                 pos = cache_name_pos(opts.prefix, pfxlen);
 202                 if (0 <= pos)
 203                         die("corrupt index file");
 204                 pos = -pos-1;
 205                 if (pos < active_nr &&
 206                     !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 207                         die("subdirectory '%s' already exists.", opts.prefix);
 208                 pos = cache_name_pos(opts.prefix, pfxlen-1);
 209                 if (0 <= pos)
 210                         die("file '%.*s' already exists.",
 211                                         pfxlen-1, opts.prefix);
 212         }
 213
 214         if (opts.merge) {
 215                 if (stage < 2)
 216                         die("just how do you expect me to merge %d trees?", stage-1);
 217                 switch (stage - 1) {
 218                 case 1:
 219                         opts.fn = opts.prefix ? bind_merge : oneway_merge;
 220                         break;
 221                 case 2:
 222                         opts.fn = twoway_merge;
 223                         break;
 224                 case 3:
 225                 default:
 226                         opts.fn = threeway_merge;
 227                         cache_tree_free(&active_cache_tree);
 228                         break;
 229                 }
 230
 231                 if (stage - 1 >= 3)
 232                         opts.head_idx = stage - 2;
 233                 else
 234                         opts.head_idx = 1;
 235         }
 236
 237         unpack_trees(trees, &opts);
 238
 239         /*
 240          * When reading only one tree (either the most basic form,
 241          * "-m ent" or "--reset ent" form), we can obtain a fully
 242          * valid cache-tree because the index must match exactly
 243          * what came from the tree.
 244          */
 245         if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
 246                 cache_tree_free(&active_cache_tree);
 247                 prime_cache_tree();
 248         }
 249
 250         if (write_cache(newfd, active_cache, active_nr) ||
 251             close(newfd) || commit_lock_file(&lock_file))
 252                 die("unable to write new index file");
 253         return 0;
 254 }