builtin-write-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "builtin.h"
   7 #include "cache.h"
   8 #include "tree.h"
   9 #include "cache-tree.h"
  10
  11 static const char write_tree_usage[] =
  12 "git-write-tree [--missing-ok] [--prefix=<prefix>/]";
  13
  14 int write_tree(unsigned char *sha1, int missing_ok, const char *prefix)
  15 {
  16         int entries, was_valid, newfd;
  17
  18         /* We can't free this memory, it becomes part of a linked list parsed atexit() */
  19         struct lock_file *lock_file = xmalloc(sizeof(struct lock_file));
  20
  21         newfd = hold_lock_file_for_update(lock_file, get_index_file());
  22
  23         entries = read_cache();
  24         if (entries < 0)
  25                 die("git-write-tree: error reading cache");
  26
  27         if (!active_cache_tree)
  28                 active_cache_tree = cache_tree();
  29
  30         was_valid = cache_tree_fully_valid(active_cache_tree);
  31
  32         if (!was_valid) {
  33                 if (cache_tree_update(active_cache_tree,
  34                                       active_cache, active_nr,
  35                                       missing_ok, 0) < 0)
  36                         die("git-write-tree: error building trees");
  37                 if (0 <= newfd) {
  38                         if (!write_cache(newfd, active_cache, active_nr))
  39                                 commit_lock_file(lock_file);
  40                 }
  41                 /* Not being able to write is fine -- we are only interested
  42                  * in updating the cache-tree part, and if the next caller
  43                  * ends up using the old index with unupdated cache-tree part
  44                  * it misses the work we did here, but that is just a
  45                  * performance penalty and not a big deal.
  46                  */
  47         }
  48
  49         if (prefix) {
  50                 struct cache_tree *subtree =
  51                         cache_tree_find(active_cache_tree, prefix);
  52                 memcpy(sha1, subtree->sha1, 20);
  53         }
  54         else
  55                 memcpy(sha1, active_cache_tree->sha1, 20);
  56
  57         rollback_lock_file(lock_file);
  58
  59         return 0;
  60 }
  61
  62 int cmd_write_tree(int argc, const char **argv, char **envp)
  63 {
  64         int missing_ok = 0, ret;
  65         const char *prefix = NULL;
  66         unsigned char sha1[20];
  67
  68         setup_git_directory();
  69
  70         while (1 < argc) {
  71                 const char *arg = argv[1];
  72                 if (!strcmp(arg, "--missing-ok"))
  73                         missing_ok = 1;
  74                 else if (!strncmp(arg, "--prefix=", 9))
  75                         prefix = arg + 9;
  76                 else
  77                         die(write_tree_usage);
  78                 argc--; argv++;
  79         }
  80
  81         if (argc > 2)
  82                 die("too many options");
  83
  84         ret = write_tree(sha1, missing_ok, prefix);
  85         printf("%s\n", sha1_to_hex(sha1));
  86
  87         return ret;
  88 }