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                        remove_index_entry(ce);
  45                        if (last && !strcmp(ce->name, last->name))
  46                                continue;
  47                        cache_tree_invalidate_path(active_cache_tree, ce->name);
  48                        last = ce;
  49                        continue;
  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        opts.src_index = &the_index;
 106        opts.dst_index = &the_index;
 107
 108        git_config(git_default_config);
 109
 110        newfd = hold_locked_index(&lock_file, 1);
 111
 112        git_config(git_default_config);
 113
 114        for (i = 1; i < argc; i++) {
 115                const char *arg = argv[i];
 116
 117                /* "-u" means "update", meaning that a merge will update
 118                 * the working tree.
 119                 */
 120                if (!strcmp(arg, "-u")) {
 121                        opts.update = 1;
 122                        continue;
 123                }
 124
 125                if (!strcmp(arg, "-v")) {
 126                        opts.verbose_update = 1;
 127                        continue;
 128                }
 129
 130                /* "-i" means "index only", meaning that a merge will
 131                 * not even look at the working tree.
 132                 */
 133                if (!strcmp(arg, "-i")) {
 134                        opts.index_only = 1;
 135                        continue;
 136                }
 137
 138                if (!prefixcmp(arg, "--index-output=")) {
 139                        set_alternate_index_output(arg + 15);
 140                        continue;
 141                }
 142
 143                /* "--prefix=<subdirectory>/" means keep the current index
 144                 *  entries and put the entries from the tree under the
 145                 * given subdirectory.
 146                 */
 147                if (!prefixcmp(arg, "--prefix=")) {
 148                        if (stage || opts.merge || opts.prefix)
 149                                usage(read_tree_usage);
 150                        opts.prefix = arg + 9;
 151                        opts.merge = 1;
 152                        stage = 1;
 153                        if (read_cache_unmerged())
 154                                die("you need to resolve your current index first");
 155                        continue;
 156                }
 157
 158                /* This differs from "-m" in that we'll silently ignore
 159                 * unmerged entries and overwrite working tree files that
 160                 * correspond to them.
 161                 */
 162                if (!strcmp(arg, "--reset")) {
 163                        if (stage || opts.merge || opts.prefix)
 164                                usage(read_tree_usage);
 165                        opts.reset = 1;
 166                        opts.merge = 1;
 167                        stage = 1;
 168                        read_cache_unmerged();
 169                        continue;
 170                }
 171
 172                if (!strcmp(arg, "--trivial")) {
 173                        opts.trivial_merges_only = 1;
 174                        continue;
 175                }
 176
 177                if (!strcmp(arg, "--aggressive")) {
 178                        opts.aggressive = 1;
 179                        continue;
 180                }
 181
 182                /* "-m" stands for "merge", meaning we start in stage 1 */
 183                if (!strcmp(arg, "-m")) {
 184                        if (stage || opts.merge || opts.prefix)
 185                                usage(read_tree_usage);
 186                        if (read_cache_unmerged())
 187                                die("you need to resolve your current index first");
 188                        stage = 1;
 189                        opts.merge = 1;
 190                        continue;
 191                }
 192
 193                if (!prefixcmp(arg, "--exclude-per-directory=")) {
 194                        struct dir_struct *dir;
 195
 196                        if (opts.dir)
 197                                die("more than one --exclude-per-directory are given.");
 198
 199                        dir = xcalloc(1, sizeof(*opts.dir));
 200                        dir->show_ignored = 1;
 201                        dir->exclude_per_dir = arg + 24;
 202                        opts.dir = dir;
 203                        /* We do not need to nor want to do read-directory
 204                         * here; we are merely interested in reusing the
 205                         * per directory ignore stack mechanism.
 206                         */
 207                        continue;
 208                }
 209
 210                /* using -u and -i at the same time makes no sense */
 211                if (1 < opts.index_only + opts.update)
 212                        usage(read_tree_usage);
 213
 214                if (get_sha1(arg, sha1))
 215                        die("Not a valid object name %s", arg);
 216                if (list_tree(sha1) < 0)
 217                        die("failed to unpack tree object %s", arg);
 218                stage++;
 219        }
 220        if ((opts.update||opts.index_only) && !opts.merge)
 221                usage(read_tree_usage);
 222        if ((opts.dir && !opts.update))
 223                die("--exclude-per-directory is meaningless unless -u");
 224
 225        if (opts.merge) {
 226                if (stage < 2)
 227                        die("just how do you expect me to merge %d trees?", stage-1);
 228                switch (stage - 1) {
 229                case 1:
 230                        opts.fn = opts.prefix ? bind_merge : oneway_merge;
 231                        break;
 232                case 2:
 233                        opts.fn = twoway_merge;
 234                        break;
 235                case 3:
 236                default:
 237                        opts.fn = threeway_merge;
 238                        cache_tree_free(&active_cache_tree);
 239                        break;
 240                }
 241
 242                if (stage - 1 >= 3)
 243                        opts.head_idx = stage - 2;
 244                else
 245                        opts.head_idx = 1;
 246        }
 247
 248        for (i = 0; i < nr_trees; i++) {
 249                struct tree *tree = trees[i];
 250                parse_tree(tree);
 251                init_tree_desc(t+i, tree->buffer, tree->size);
 252        }
 253        if (unpack_trees(nr_trees, t, &opts))
 254                return 128;
 255
 256        /*
 257         * When reading only one tree (either the most basic form,
 258         * "-m ent" or "--reset ent" form), we can obtain a fully
 259         * valid cache-tree because the index must match exactly
 260         * what came from the tree.
 261         */
 262        if (nr_trees && !opts.prefix && (!opts.merge || (stage == 2))) {
 263                cache_tree_free(&active_cache_tree);
 264                prime_cache_tree();
 265        }
 266
 267        if (write_cache(newfd, active_cache, active_nr) ||
 268            commit_locked_index(&lock_file))
 269                die("unable to write new index file");
 270        return 0;
 271}