fsck-cache.c

   1 #include "cache.h"
   2
   3 #include <sys/types.h>
   4 #include <dirent.h>
   5
   6 /*
   7  * These two functions should build up a graph in memory about
   8  * what objects we've referenced, and found, and types..
   9  *
  10  * Right now we don't do that kind of reachability checking. Yet.
  11  */
  12 static void mark_needs_sha1(unsigned char *parent, const char * type, unsigned char *child)
  13 {
  14 }
  15
  16 static int mark_sha1_seen(unsigned char *sha1, char *tag)
  17 {
  18         return 0;
  19 }
  20
  21 static int fsck_tree(unsigned char *sha1, void *data, unsigned long size)
  22 {
  23         int warn_old_tree = 1;
  24
  25         while (size) {
  26                 int len = 1+strlen(data);
  27                 unsigned char *file_sha1 = data + len;
  28                 char *path = strchr(data, ' ');
  29                 unsigned int mode;
  30                 if (size < len + 20 || !path || sscanf(data, "%o", &mode) != 1)
  31                         return -1;
  32
  33                 /* Warn about trees that don't do the recursive thing.. */
  34                 if (warn_old_tree && strchr(path, '/')) {
  35                         fprintf(stderr, "warning: fsck-cache: tree %s has full pathnames in it\n", sha1_to_hex(sha1));
  36                         warn_old_tree = 0;
  37                 }
  38
  39                 data += len + 20;
  40                 size -= len + 20;
  41                 mark_needs_sha1(sha1, S_ISDIR(mode) ? "tree" : "blob", file_sha1);
  42         }
  43         return 0;
  44 }
  45
  46 static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
  47 {
  48         int parents;
  49         unsigned char tree_sha1[20];
  50         unsigned char parent_sha1[20];
  51
  52         if (memcmp(data, "tree ", 5))
  53                 return -1;
  54         if (get_sha1_hex(data + 5, tree_sha1) < 0)
  55                 return -1;
  56         mark_needs_sha1(sha1, "tree", tree_sha1);
  57         data += 5 + 40 + 1;     /* "tree " + <hex sha1> + '\n' */
  58         parents = 0;
  59         while (!memcmp(data, "parent ", 7)) {
  60                 if (get_sha1_hex(data + 7, parent_sha1) < 0)
  61                         return -1;
  62                 mark_needs_sha1(sha1, "commit", parent_sha1);
  63                 data += 7 + 40 + 1;     /* "parent " + <hex sha1> + '\n' */
  64                 parents++;
  65         }
  66         if (!parents)
  67                 printf("root: %s\n", sha1_to_hex(sha1));
  68         return 0;
  69 }
  70
  71 static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
  72 {
  73         if (!strcmp(tag, "blob")) {
  74                 /* Nothing to check */;
  75         } else if (!strcmp(tag, "tree")) {
  76                 if (fsck_tree(sha1, data, size) < 0)
  77                         return -1;
  78         } else if (!strcmp(tag, "commit")) {
  79                 if (fsck_commit(sha1, data, size) < 0)
  80                         return -1;
  81         } else
  82                 return -1;
  83         return mark_sha1_seen(sha1, tag);
  84 }
  85
  86 static int fsck_name(char *hex)
  87 {
  88         unsigned char sha1[20];
  89         if (!get_sha1_hex(hex, sha1)) {
  90                 unsigned long mapsize;
  91                 void *map = map_sha1_file(sha1, &mapsize);
  92                 if (map) {
  93                         char type[100];
  94                         unsigned long size;
  95                         void *buffer = NULL;
  96                         if (!check_sha1_signature(sha1, map, mapsize))
  97                                 buffer = unpack_sha1_file(map, mapsize, type, &size);
  98                         munmap(map, mapsize);
  99                         if (buffer && !fsck_entry(sha1, type, buffer, size))
 100                                 return 0;
 101                 }
 102         }
 103         return -1;
 104 }
 105
 106 static int fsck_dir(int i, char *path)
 107 {
 108         DIR *dir = opendir(path);
 109         struct dirent *de;
 110
 111         if (!dir) {
 112                 fprintf(stderr, "missing sha1 directory '%s'", path);
 113                 return -1;
 114         }
 115
 116         while ((de = readdir(dir)) != NULL) {
 117                 char name[100];
 118                 int len = strlen(de->d_name);
 119
 120                 switch (len) {
 121                 case 2:
 122                         if (de->d_name[1] != '.')
 123                                 break;
 124                 case 1:
 125                         if (de->d_name[0] != '.')
 126                                 break;
 127                         continue;
 128                 case 38:
 129                         sprintf(name, "%02x", i);
 130                         memcpy(name+2, de->d_name, len+1);
 131                         if (!fsck_name(name))
 132                                 continue;
 133                 }
 134                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 135         }
 136         closedir(dir);
 137         return 0;
 138 }
 139
 140 int main(int argc, char **argv)
 141 {
 142         int i;
 143         char *sha1_dir;
 144
 145         if (argc != 1)
 146                 usage("fsck-cache");
 147         sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
 148         for (i = 0; i < 256; i++) {
 149                 static char dir[4096];
 150                 sprintf(dir, "%s/%02x", sha1_dir, i);
 151                 fsck_dir(i, dir);
 152         }
 153         return 0;
 154 }