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         char *filename = sha1_file_name(sha1);
  11         int ret;
  12
  13         /* If we were anal, we'd check that the sha1 of the contents actually matches */
  14         ret = access(filename, R_OK);
  15         if (ret)
  16                 perror(filename);
  17         return ret;
  18 }
  19
  20 static int write_tree(struct cache_entry **cachep, int maxentries, const char *base, int baselen, unsigned char *returnsha1)
  21 {
  22         unsigned char subdir_sha1[20];
  23         unsigned long size, offset;
  24         char *buffer;
  25         int nr;
  26
  27         /* Guess at some random initial size */
  28         size = 8192;
  29         buffer = xmalloc(size);
  30         offset = 0;
  31
  32         nr = 0;
  33         while (nr < maxentries) {
  34                 struct cache_entry *ce = cachep[nr];
  35                 const char *pathname = ce->name, *filename, *dirname;
  36                 int pathlen = ce_namelen(ce), entrylen;
  37                 unsigned char *sha1;
  38                 unsigned int mode;
  39
  40                 /* Did we hit the end of the directory? Return how many we wrote */
  41                 if (baselen >= pathlen || memcmp(base, pathname, baselen))
  42                         break;
  43
  44                 sha1 = ce->sha1;
  45                 mode = ntohl(ce->ce_mode);
  46
  47                 /* Do we have _further_ subdirectories? */
  48                 filename = pathname + baselen;
  49                 dirname = strchr(filename, '/');
  50                 if (dirname) {
  51                         int subdir_written;
  52
  53                         subdir_written = write_tree(cachep + nr, maxentries - nr, pathname, dirname-pathname+1, subdir_sha1);
  54                         nr += subdir_written;
  55
  56                         /* Now we need to write out the directory entry into this tree.. */
  57                         mode = S_IFDIR;
  58                         pathlen = dirname - pathname;
  59
  60                         /* ..but the directory entry doesn't count towards the total count */
  61                         nr--;
  62                         sha1 = subdir_sha1;
  63                 }
  64
  65                 if (check_valid_sha1(sha1) < 0)
  66                         exit(1);
  67
  68                 entrylen = pathlen - baselen;
  69                 if (offset + entrylen + 100 > size) {
  70                         size = alloc_nr(offset + entrylen + 100);
  71                         buffer = xrealloc(buffer, size);
  72                 }
  73                 offset += sprintf(buffer + offset, "%o %.*s", mode, entrylen, filename);
  74                 buffer[offset++] = 0;
  75                 memcpy(buffer + offset, sha1, 20);
  76                 offset += 20;
  77                 nr++;
  78         }
  79
  80         write_sha1_file(buffer, offset, "tree", returnsha1);
  81         free(buffer);
  82         return nr;
  83 }
  84
  85 int main(int argc, char **argv)
  86 {
  87         int i, funny;
  88         int entries = read_cache();
  89         unsigned char sha1[20];
  90
  91         if (entries < 0)
  92                 die("git-write-tree: error reading cache");
  93
  94         /* Verify that the tree is merged */
  95         funny = 0;
  96         for (i = 0; i < entries; i++) {
  97                 struct cache_entry *ce = active_cache[i];
  98                 if (ntohs(ce->ce_flags) & ~CE_NAMEMASK) {
  99                         if (10 < ++funny) {
 100                                 fprintf(stderr, "...\n");
 101                                 break;
 102                         }
 103                         fprintf(stderr, "%s: unmerged (%s)\n", ce->name, sha1_to_hex(ce->sha1));
 104                 }
 105         }
 106         if (funny)
 107                 die("git-write-tree: not able to write tree");
 108
 109         /* Also verify that the cache does not have path and path/file
 110          * at the same time.  At this point we know the cache has only
 111          * stage 0 entries.
 112          */
 113         funny = 0;
 114         for (i = 0; i < entries - 1; i++) {
 115                 /* path/file always comes after path because of the way
 116                  * the cache is sorted.  Also path can appear only once,
 117                  * which means conflicting one would immediately follow.
 118                  */
 119                 const char *this_name = active_cache[i]->name;
 120                 const char *next_name = active_cache[i+1]->name;
 121                 int this_len = strlen(this_name);
 122                 if (this_len < strlen(next_name) &&
 123                     strncmp(this_name, next_name, this_len) == 0 &&
 124                     next_name[this_len] == '/') {
 125                         if (10 < ++funny) {
 126                                 fprintf(stderr, "...\n");
 127                                 break;
 128                         }
 129                         fprintf(stderr, "You have both %s and %s\n",
 130                                 this_name, next_name);
 131                 }
 132         }
 133         if (funny)
 134                 die("git-write-tree: not able to write tree");
 135
 136         /* Ok, write it out */
 137         if (write_tree(active_cache, entries, "", 0, sha1) != entries)
 138                 die("git-write-tree: internal error");
 139         printf("%s\n", sha1_to_hex(sha1));
 140         return 0;
 141 }