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 "builtin.h"
  14
  15static struct object_list *trees = NULL;
  16
  17static 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
  26static 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
  50static 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
  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]] <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 (!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}