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