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 = xcalloc(1, sizeof(struct lock_file));
  20
  21         newfd = hold_locked_index(lock_file, 1);
  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                                         && !close(newfd)) {
  40                                 commit_lock_file(lock_file);
  41                                 newfd = -1;
  42                         }
  43                 }
  44                 /* Not being able to write is fine -- we are only interested
  45                  * in updating the cache-tree part, and if the next caller
  46                  * ends up using the old index with unupdated cache-tree part
  47                  * it misses the work we did here, but that is just a
  48                  * performance penalty and not a big deal.
  49                  */
  50         }
  51
  52         if (prefix) {
  53                 struct cache_tree *subtree =
  54                         cache_tree_find(active_cache_tree, prefix);
  55                 if (!subtree)
  56                         die("git-write-tree: prefix %s not found", prefix);
  57                 hashcpy(sha1, subtree->sha1);
  58         }
  59         else
  60                 hashcpy(sha1, active_cache_tree->sha1);
  61
  62         if (0 <= newfd)
  63                 close(newfd);
  64         rollback_lock_file(lock_file);
  65
  66         return 0;
  67 }
  68
  69 int cmd_write_tree(int argc, const char **argv, const char *unused_prefix)
  70 {
  71         int missing_ok = 0, ret;
  72         const char *prefix = NULL;
  73         unsigned char sha1[20];
  74
  75         while (1 < argc) {
  76                 const char *arg = argv[1];
  77                 if (!strcmp(arg, "--missing-ok"))
  78                         missing_ok = 1;
  79                 else if (!prefixcmp(arg, "--prefix="))
  80                         prefix = arg + 9;
  81                 else
  82                         usage(write_tree_usage);
  83                 argc--; argv++;
  84         }
  85
  86         if (argc > 2)
  87                 die("too many options");
  88
  89         ret = write_tree(sha1, missing_ok, prefix);
  90         printf("%s\n", sha1_to_hex(sha1));
  91
  92         return ret;
  93 }