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
  16#define MAX_TREES 8
  17static int nr_trees;
  18static struct tree *trees[MAX_TREES];
  19
  20static int list_tree(unsigned char *sha1)
  21{
  22        struct tree *tree;
  23
  24        if (nr_trees >= MAX_TREES)
  25                die("I cannot read more than %d trees", MAX_TREES);
  26        tree = parse_tree_indirect(sha1);
  27        if (!tree)
  28                return -1;
  29        trees[nr_trees++] = tree;
  30        return 0;
  31}
  32
  33static int read_cache_unmerged(void)
  34{
  35        int i;
  36        struct cache_entry **dst;
  37        struct cache_entry *last = NULL;
  38
  39        read_cache();
  40        dst = active_cache;
  41        for (i = 0; i < active_nr; i++) {
  42                struct cache_entry *ce = active_cache[i];
  43                if (ce_stage(ce)) {
  44                        if (last && !strcmp(ce->name, last->name))
  45                                continue;
  46                        cache_tree_invalidate_path(active_cache_tree, ce->name);
  47                        last = ce;
  48                        ce->ce_mode = 0;
  49                        ce->ce_flags &= ~htons(CE_STAGEMASK);
  50                }
  51                *dst++ = ce;
  52        }
  53        active_nr = dst - active_cache;
  54        return !!last;
  55}
  56
  57static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)
  58{
  59        struct tree_desc desc;
  60        struct name_entry entry;
  61        int cnt;
  62
  63        hashcpy(it->sha1, tree->object.sha1);
  64        init_tree_desc(&desc, tree->buffer, tree->size);
  65        cnt = 0;
  66        while (tree_entry(&desc, &entry)) {
  67                if (!S_ISDIR(entry.mode))
  68                        cnt++;
  69                else {
  70                        struct cache_tree_sub *sub;
  71                        struct tree *subtree = lookup_tree(entry.sha1);
  72                        if (!subtree->object.parsed)
  73                                parse_tree(subtree);
  74                        sub = cache_tree_sub(it, entry.path);
  75                        sub->cache_tree = cache_tree();
  76                        prime_cache_tree_rec(sub->cache_tree, subtree);
  77                        cnt += sub->cache_tree->entry_count;
  78                }
  79        }
  80        it->entry_count = cnt;
  81}
  82
  83static void prime_cache_tree(void)
  84{
  85        if (!nr_trees)
  86                return;
  87        active_cache_tree = cache_tree();
  88        prime_cache_tree_rec(active_cache_tree, trees[0]);
  89
  90}
  91
  92static 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>]])";
  93
  94static struct lock_file lock_file;
  95
  96int cmd_read_tree(int argc, const char **argv, const char *unused_prefix)
  97{
  98        int i, newfd, stage = 0;
  99        unsigned char sha1[20];
 100        struct tree_desc t[MAX_TREES];
 101        struct unpack_trees_options opts;
 102
 103        memset(&opts, 0, sizeof(opts));
 104        opts.head_idx = -1;
 105
 106        git_config(git_default_config);
 107
 108        newfd = hold_locked_index(&lock_file, 1);
 109
 110        git_config(git_default_config);
 111
 112        for (i = 1; i < argc; i++) {
 113                const char *arg = argv[i];
 114
 115                /* "-u" means "update", meaning that a merge will update
 116                 * the working tree.
 117                 */
 118                if (!strcmp(arg, "-u")) {
 119                        opts.update = 1;
 120                        continue;
 121                }
 122
 123                if (!strcmp(arg, "-v")) {
 124                        opts.verbose_update = 1;
 125                        continue;
 126                }
 127
 128                /* "-i" means "index only", meaning that a merge will
 129                 * not even look at the working tree.
 130                 */
 131                if (!strcmp(arg, "-i")) {
 132                        opts.index_only = 1;
 133                        continue;
 134                }
 135
 136                if (!prefixcmp(arg, "--index-output=")) {
 137                        set_alternate_index_output(arg + 15);
 138                        continue;
 139                }
 140
 141                /* "--prefix=<subdirectory>/" means keep the current index
 142                 *  entries and put the entries from the tree under the
 143                 * given subdirectory.
 144                 */
 145                if (!prefixcmp(arg, "--prefix=")) {
 146                        if (stage || opts.merge || opts.prefix)
 147                                usage(read_tree_usage);
 148                        opts.prefix = arg + 9;
 149                        opts.merge = 1;
 150                        stage = 1;
 151                        if (read_cache_unmerged())
 152                                die("you need to resolve your current index first");
 153                        continue;
 154                }
 155
 156                /* This differs from "-m" in that we'll silently ignore
 157                 * unmerged entries and overwrite working tree files that
 158                 * correspond to them.
 159                 */
 160                if (!strcmp(arg, "--reset")) {
 161                        if (stage || opts.merge || opts.prefix)
 162                                usage(read_tree_usage);
 163                        opts.reset = 1;
 164                        opts.merge = 1;
 165                        stage = 1;
 166                        read_cache_unmerged();
 167                        continue;
 168                }
 169
 170                if (!strcmp(arg, "--trivial")) {
 171                        opts.trivial_merges_only = 1;
 172                        continue;
 173                }
 174
 175                if (!strcmp(arg, "--aggressive")) {
 176                        opts.aggressive = 1;
 177                        continue;
 178                }
 179
 180                /* "-m" stands for "merge", meaning we start in stage 1 */
 181                if (!strcmp(arg, "-m")) {
 182                        if (stage || opts.merge || opts.prefix)
 183                                usage(read_tree_usage);
 184                        if (read_cache_unmerged())
 185                                die("you need to resolve your current index first");
 186                        stage = 1;
 187                        opts.merge = 1;
 188                        continue;
 189                }
 190
 191                if (!prefixcmp(arg, "--exclude-per-directory=")) {
 192                        struct dir_struct *dir;
 193
 194                        if (opts.dir)
 195                                die("more than one --exclude-per-directory are given.");
 196
 197                        dir = xcalloc(1, sizeof(*opts.dir));
 198                        dir->show_ignored = 1;
 199                        dir->exclude_per_dir = arg + 24;
 200                        opts.dir = dir;
 201                        /* We do not need to nor want to do read-directory
 202                         * here; we are merely interested in reusing the
 203                         * per directory ignore stack mechanism.
 204                         */
 205                        continue;
 206                }
 207
 208                /* using -u and -i at the same time makes no sense */
 209                if (1 < opts.index_only + opts.update)
 210                        usage(read_tree_usage);
 211
 212                if (get_sha1(arg, sha1))
 213                        die("Not a valid object name %s", arg);
 214                if (list_tree(sha1) < 0)
 215                        die("failed to unpack tree object %s", arg);
 216                stage++;
 217        }
 218        if ((opts.update||opts.index_only) && !opts.merge)
 219                usage(read_tree_usage);
 220        if ((opts.dir && !opts.update))
 221                die("--exclude-per-directory is meaningless unless -u");
 222
 223        if (opts.prefix) {
 224                int pfxlen = strlen(opts.prefix);
 225                int pos;
 226                if (opts.prefix[pfxlen-1] != '/')
 227                        die("prefix must end with /");
 228                if (stage != 2)
 229                        die("binding merge takes only one tree");
 230                pos = cache_name_pos(opts.prefix, pfxlen);
 231                if (0 <= pos)
 232                        die("corrupt index file");
 233                pos = -pos-1;
 234                if (pos < active_nr &&
 235                    !strncmp(active_cache[pos]->name, opts.prefix, pfxlen))
 236                        die("subdirectory '%s' already exists.", opts.prefix);
 237                pos = cache_name_pos(opts.prefix, pfxlen-1);
 238                if (0 <= pos)
 239                        die("file '%.*s' already exists.",
 240                                        pfxlen-1, opts.prefix);
 241                opts.pos = -1 - pos;
 242        }
 243
 244        if (opts.merge) {
 245                if (stage < 2)
 246                        die("just how do you expect me to merge %d trees?", stage-1);
 247                switch (stage - 1) {
 248                case 1:
 249                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 250                        break;
 251                case 2:
 252                        opts.fn = twoway_merge;
 253                        break;
 254                case 3:
 255                default:
 256                        opts.fn = threeway_merge;
 257                        cache_tree_free(&active_cache_tree);
 258                        break;
 259                }
 260
 261                if (stage - 1 >= 3)
 262                        opts.head_idx = stage - 2;
 263                else
 264                        opts.head_idx = 1;
 265        }
 266
 267        for (i = 0; i < nr_trees; i++) {
 268                struct tree *tree = trees[i];
 269                parse_tree(tree);
 270                init_tree_desc(t+i, tree->buffer, tree->size);
 271        }
 272        unpack_trees(nr_trees, t, &opts);
 273
 274        /*
 275         * When reading only one tree (either the most basic form,
 276         * "-m ent" or "--reset ent" form), we can obtain a fully
 277         * valid cache-tree because the index must match exactly
 278         * what came from the tree.
 279         */
 280        if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
 281                cache_tree_free(&active_cache_tree);
 282                prime_cache_tree();
 283        }
 284
 285        if (write_cache(newfd, active_cache, active_nr) ||
 286            close(newfd) || commit_locked_index(&lock_file))
 287                die("unable to write new index file");
 288        return 0;
 289}