git-tar-tree: no more void pointer arithmetic
[git.git] / write-tree.c
index cef0c5b..bd07da6 100644 (file)
@@ -7,39 +7,66 @@
 #include "tree.h"
 #include "cache-tree.h"
 
-static unsigned char active_cache_sha1[20];
-static struct cache_tree *active_cache_tree;
-
 static int missing_ok = 0;
+static char *prefix = NULL;
+
+static const char write_tree_usage[] =
+"git-write-tree [--missing-ok] [--prefix=<prefix>/]";
 
-static const char write_tree_usage[] = "git-write-tree [--missing-ok]";
+static struct lock_file lock_file;
 
 int main(int argc, char **argv)
 {
-       int entries;
+       int entries, was_valid, newfd;
 
        setup_git_directory();
 
-       entries = read_cache_1(active_cache_sha1);
-       active_cache_tree = read_cache_tree(active_cache_sha1);
-       if (argc == 2) {
-               if (!strcmp(argv[1], "--missing-ok"))
+       newfd = hold_lock_file_for_update(&lock_file, get_index_file());
+       entries = read_cache();
+
+       while (1 < argc) {
+               char *arg = argv[1];
+               if (!strcmp(arg, "--missing-ok"))
                        missing_ok = 1;
+               else if (!strncmp(arg, "--prefix=", 9))
+                       prefix = arg + 9;
                else
                        die(write_tree_usage);
+               argc--; argv++;
        }
-       
+
        if (argc > 2)
                die("too many options");
 
        if (entries < 0)
                die("git-write-tree: error reading cache");
 
-       if (cache_tree_update(active_cache_tree, active_cache, active_nr,
-                             missing_ok))
-               die("git-write-tree: error building trees");
-       write_cache_tree(active_cache_sha1, active_cache_tree);
+       if (!active_cache_tree)
+               active_cache_tree = cache_tree();
 
-       printf("%s\n", sha1_to_hex(active_cache_tree->sha1));
+       was_valid = cache_tree_fully_valid(active_cache_tree);
+       if (!was_valid) {
+               if (cache_tree_update(active_cache_tree,
+                                     active_cache, active_nr,
+                                     missing_ok, 0) < 0)
+                       die("git-write-tree: error building trees");
+               if (0 <= newfd) {
+                       if (!write_cache(newfd, active_cache, active_nr))
+                               commit_lock_file(&lock_file);
+               }
+               /* Not being able to write is fine -- we are only interested
+                * in updating the cache-tree part, and if the next caller
+                * ends up using the old index with unupdated cache-tree part
+                * it misses the work we did here, but that is just a
+                * performance penalty and not a big deal.
+                */
+       }
+       if (prefix) {
+               struct cache_tree *subtree =
+                       cache_tree_find(active_cache_tree, prefix);
+               printf("%s\n", sha1_to_hex(subtree->sha1));
+       }
+       else
+               printf("%s\n", sha1_to_hex(active_cache_tree->sha1));
        return 0;
 }