Andrew's git - gitweb.git/blob - 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
  16static struct object_list *trees;
  17
  18static 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
  27static 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
  51static 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
  77static 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
  87static 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
  89static struct lock_file lock_file;
  90
  91int 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}