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 [--aggressive] | --reset | --prefix=<prefix>] [-u | -i]] [--exclude-per-directory=<gitignore>] <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        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 (!prefixcmp(arg, "--prefix=")) {
 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                if (!prefixcmp(arg, "--exclude-per-directory=")) {
 182                        struct dir_struct *dir;
 183
 184                        if (opts.dir)
 185                                die("more than one --exclude-per-directory are given.");
 186
 187                        dir = xcalloc(1, sizeof(*opts.dir));
 188                        dir->show_ignored = 1;
 189                        dir->exclude_per_dir = arg + 24;
 190                        opts.dir = dir;
 191                        /* We do not need to nor want to do read-directory
 192                         * here; we are merely interested in reusing the
 193                         * per directory ignore stack mechanism.
 194                         */
 195                        continue;
 196                }
 197
 198                /* using -u and -i at the same time makes no sense */
 199                if (1 < opts.index_only + opts.update)
 200                        usage(read_tree_usage);
 201
 202                if (get_sha1(arg, sha1))
 203                        die("Not a valid object name %s", arg);
 204                if (list_tree(sha1) < 0)
 205                        die("failed to unpack tree object %s", arg);
 206                stage++;
 207        }
 208        if ((opts.update||opts.index_only) && !opts.merge)
 209                usage(read_tree_usage);
 210        if ((opts.dir && !opts.update))
 211                die("--exclude-per-directory is meaningless unless -u");
 212
 213        if (opts.prefix) {
 214                int pfxlen = strlen(opts.prefix);
 215                int pos;
 216                if (opts.prefix[pfxlen-1] != '/')
 217                        die("prefix must end with /");
 218                if (stage != 2)
 219                        die("binding merge takes only one tree");
 220                pos = cache_name_pos(opts.prefix, pfxlen);
 221                if (0 <= pos)
 222                        die("corrupt index file");
 223                pos = -pos-1;
 224                if (pos < active_nr &&
 225                    !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 226                        die("subdirectory '%s' already exists.", opts.prefix);
 227                pos = cache_name_pos(opts.prefix, pfxlen-1);
 228                if (0 <= pos)
 229                        die("file '%.*s' already exists.",
 230                                        pfxlen-1, opts.prefix);
 231        }
 232
 233        if (opts.merge) {
 234                if (stage < 2)
 235                        die("just how do you expect me to merge %d trees?", stage-1);
 236                switch (stage - 1) {
 237                case 1:
 238                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 239                        break;
 240                case 2:
 241                        opts.fn = twoway_merge;
 242                        break;
 243                case 3:
 244                default:
 245                        opts.fn = threeway_merge;
 246                        cache_tree_free(&active_cache_tree);
 247                        break;
 248                }
 249
 250                if (stage - 1 >= 3)
 251                        opts.head_idx = stage - 2;
 252                else
 253                        opts.head_idx = 1;
 254        }
 255
 256        unpack_trees(trees, &opts);
 257
 258        /*
 259         * When reading only one tree (either the most basic form,
 260         * "-m ent" or "--reset ent" form), we can obtain a fully
 261         * valid cache-tree because the index must match exactly
 262         * what came from the tree.
 263         */
 264        if (trees && trees->item && !opts.prefix && (!opts.merge || (stage == 2))) {
 265                cache_tree_free(&active_cache_tree);
 266                prime_cache_tree();
 267        }
 268
 269        if (write_cache(newfd, active_cache, active_nr) ||
 270            close(newfd) || commit_lock_file(&lock_file))
 271                die("unable to write new index file");
 272        return 0;
 273}