write-tree.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  */
   6 #include "cache.h"
   7
   8 static int check_valid_sha1(unsigned char *sha1)
   9 {
  10         int ret;
  11
  12         /* If we were anal, we'd check that the sha1 of the contents actually matches */
  13         ret = has_sha1_file(sha1);
  14         if (ret == 0)
  15                 perror(sha1_file_name(sha1));
  16         return ret ? 0 : -1;
  17 }
  18
  19 static int write_tree(struct cache_entry **cachep, int maxentries, const char *base, int baselen, unsigned char *returnsha1)
  20 {
  21         unsigned char subdir_sha1[20];
  22         unsigned long size, offset;
  23         char *buffer;
  24         int nr;
  25
  26         /* Guess at some random initial size */
  27         size = 8192;
  28         buffer = xmalloc(size);
  29         offset = 0;
  30
  31         nr = 0;
  32         while (nr < maxentries) {
  33                 struct cache_entry *ce = cachep[nr];
  34                 const char *pathname = ce->name, *filename, *dirname;
  35                 int pathlen = ce_namelen(ce), entrylen;
  36                 unsigned char *sha1;
  37                 unsigned int mode;
  38
  39                 /* Did we hit the end of the directory? Return how many we wrote */
  40                 if (baselen >= pathlen || memcmp(base, pathname, baselen))
  41                         break;
  42
  43                 sha1 = ce->sha1;
  44                 mode = ntohl(ce->ce_mode);
  45
  46                 /* Do we have _further_ subdirectories? */
  47                 filename = pathname + baselen;
  48                 dirname = strchr(filename, '/');
  49                 if (dirname) {
  50                         int subdir_written;
  51
  52                         subdir_written = write_tree(cachep + nr, maxentries - nr, pathname, dirname-pathname+1, subdir_sha1);
  53                         nr += subdir_written;
  54
  55                         /* Now we need to write out the directory entry into this tree.. */
  56                         mode = S_IFDIR;
  57                         pathlen = dirname - pathname;
  58
  59                         /* ..but the directory entry doesn't count towards the total count */
  60                         nr--;
  61                         sha1 = subdir_sha1;
  62                 }
  63
  64                 if (check_valid_sha1(sha1) < 0)
  65                         exit(1);
  66
  67                 entrylen = pathlen - baselen;
  68                 if (offset + entrylen + 100 > size) {
  69                         size = alloc_nr(offset + entrylen + 100);
  70                         buffer = xrealloc(buffer, size);
  71                 }
  72                 offset += sprintf(buffer + offset, "%o %.*s", mode, entrylen, filename);
  73                 buffer[offset++] = 0;
  74                 memcpy(buffer + offset, sha1, 20);
  75                 offset += 20;
  76                 nr++;
  77         }
  78
  79         write_sha1_file(buffer, offset, "tree", returnsha1);
  80         free(buffer);
  81         return nr;
  82 }
  83
  84 int main(int argc, char **argv)
  85 {
  86         int i, funny;
  87         int entries = read_cache();
  88         unsigned char sha1[20];
  89
  90         if (entries < 0)
  91                 die("git-write-tree: error reading cache");
  92
  93         /* Verify that the tree is merged */
  94         funny = 0;
  95         for (i = 0; i < entries; i++) {
  96                 struct cache_entry *ce = active_cache[i];
  97                 if (ntohs(ce->ce_flags) & ~CE_NAMEMASK) {
  98                         if (10 < ++funny) {
  99                                 fprintf(stderr, "...\n");
 100                                 break;
 101                         }
 102                         fprintf(stderr, "%s: unmerged (%s)\n", ce->name, sha1_to_hex(ce->sha1));
 103                 }
 104         }
 105         if (funny)
 106                 die("git-write-tree: not able to write tree");
 107
 108         /* Also verify that the cache does not have path and path/file
 109          * at the same time.  At this point we know the cache has only
 110          * stage 0 entries.
 111          */
 112         funny = 0;
 113         for (i = 0; i < entries - 1; i++) {
 114                 /* path/file always comes after path because of the way
 115                  * the cache is sorted.  Also path can appear only once,
 116                  * which means conflicting one would immediately follow.
 117                  */
 118                 const char *this_name = active_cache[i]->name;
 119                 const char *next_name = active_cache[i+1]->name;
 120                 int this_len = strlen(this_name);
 121                 if (this_len < strlen(next_name) &&
 122                     strncmp(this_name, next_name, this_len) == 0 &&
 123                     next_name[this_len] == '/') {
 124                         if (10 < ++funny) {
 125                                 fprintf(stderr, "...\n");
 126                                 break;
 127                         }
 128                         fprintf(stderr, "You have both %s and %s\n",
 129                                 this_name, next_name);
 130                 }
 131         }
 132         if (funny)
 133                 die("git-write-tree: not able to write tree");
 134
 135         /* Ok, write it out */
 136         if (write_tree(active_cache, entries, "", 0, sha1) != entries)
 137                 die("git-write-tree: internal error");
 138         printf("%s\n", sha1_to_hex(sha1));
 139         return 0;
 140 }