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        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
  78static 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
  88static const char read_tree_usage[] = "git-read-tree (<sha> | [[-m [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] <sha1> [<sha2> [<sha3>]])";
  89
  90static struct lock_file lock_file;
  91
  92int 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}