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         while (size) {
  24                 int len = 1+strlen(data);
  25                 unsigned char *file_sha1 = data + len;
  26                 char *path = strchr(data, ' ');
  27                 if (size < len + 20 || !path)
  28                         return -1;
  29                 data += len + 20;
  30                 size -= len + 20;
  31                 mark_needs_sha1(sha1, "blob", file_sha1);
  32         }
  33         return 0;
  34 }
  35
  36 static int fsck_commit(unsigned char *sha1, void *data, unsigned long size)
  37 {
  38         unsigned char tree_sha1[20];
  39         unsigned char parent_sha1[20];
  40
  41         if (memcmp(data, "tree ", 5))
  42                 return -1;
  43         if (get_sha1_hex(data + 5, tree_sha1) < 0)
  44                 return -1;
  45         mark_needs_sha1(sha1, "tree", tree_sha1);
  46         data += 5 + 40 + 1;     /* "tree " + <hex sha1> + '\n' */
  47         while (!memcmp(data, "parent ", 7)) {
  48                 if (get_sha1_hex(data + 7, parent_sha1) < 0)
  49                         return -1;
  50                 mark_needs_sha1(sha1, "commit", parent_sha1);
  51                 data += 7 + 40 + 1;     /* "parent " + <hex sha1> + '\n' */
  52         }
  53         return 0;
  54 }
  55
  56 static int fsck_entry(unsigned char *sha1, char *tag, void *data, unsigned long size)
  57 {
  58         if (!strcmp(tag, "blob")) {
  59                 /* Nothing to check */;
  60         } else if (!strcmp(tag, "tree")) {
  61                 if (fsck_tree(sha1, data, size) < 0)
  62                         return -1;
  63         } else if (!strcmp(tag, "commit")) {
  64                 if (fsck_commit(sha1, data, size) < 0)
  65                         return -1;
  66         } else
  67                 return -1;
  68         return mark_sha1_seen(sha1, tag);
  69 }
  70
  71 static int fsck_name(char *hex)
  72 {
  73         unsigned char sha1[20];
  74         if (!get_sha1_hex(hex, sha1)) {
  75                 unsigned long mapsize;
  76                 void *map = map_sha1_file(sha1, &mapsize);
  77                 if (map) {
  78                         char type[100];
  79                         unsigned long size;
  80                         void *buffer = NULL;
  81                         if (!check_sha1_signature(sha1, map, mapsize))
  82                                 buffer = unpack_sha1_file(map, mapsize, type, &size);
  83                         munmap(map, mapsize);
  84                         if (buffer && !fsck_entry(sha1, type, buffer, size))
  85                                 return 0;
  86                 }
  87         }
  88         return -1;
  89 }
  90
  91 static int fsck_dir(int i, char *path)
  92 {
  93         DIR *dir = opendir(path);
  94         struct dirent *de;
  95
  96         if (!dir) {
  97                 fprintf(stderr, "missing sha1 directory '%s'", path);
  98                 return -1;
  99         }
 100
 101         while ((de = readdir(dir)) != NULL) {
 102                 char name[100];
 103                 int len = strlen(de->d_name);
 104
 105                 switch (len) {
 106                 case 2:
 107                         if (de->d_name[1] != '.')
 108                                 break;
 109                 case 1:
 110                         if (de->d_name[0] != '.')
 111                                 break;
 112                         continue;
 113                 case 38:
 114                         sprintf(name, "%02x", i);
 115                         memcpy(name+2, de->d_name, len+1);
 116                         if (!fsck_name(name))
 117                                 continue;
 118                 }
 119                 fprintf(stderr, "bad sha1 file: %s/%s\n", path, de->d_name);
 120         }
 121         closedir(dir);
 122         return 0;
 123 }
 124
 125 int main(int argc, char **argv)
 126 {
 127         int i;
 128         char *sha1_dir;
 129
 130         if (argc != 1)
 131                 usage("fsck-cache");
 132         sha1_dir = getenv(DB_ENVIRONMENT) ? : DEFAULT_DB_ENVIRONMENT;
 133         for (i = 0; i < 256; i++) {
 134                 static char dir[4096];
 135                 sprintf(dir, "%s/%02x", sha1_dir, i);
 136                 fsck_dir(i, dir);
 137         }
 138         return 0;
 139 }