tag.c

   1 #include "tag.h"
   2 #include "cache.h"
   3
   4 const char *tag_type = "tag";
   5
   6 struct object *deref_tag(struct object *o)
   7 {
   8         while (o && o->type == tag_type)
   9                 o = parse_object(((struct tag *)o)->tagged->sha1);
  10         return o;
  11 }
  12
  13 struct tag *lookup_tag(const unsigned char *sha1)
  14 {
  15         struct object *obj = lookup_object(sha1);
  16         if (!obj) {
  17                 struct tag *ret = xmalloc(sizeof(struct tag));
  18                 memset(ret, 0, sizeof(struct tag));
  19                 created_object(sha1, &ret->object);
  20                 ret->object.type = tag_type;
  21                 return ret;
  22         }
  23         if (!obj->type)
  24                 obj->type = tag_type;
  25         if (obj->type != tag_type) {
  26                 error("Object %s is a %s, not a tree",
  27                       sha1_to_hex(sha1), obj->type);
  28                 return NULL;
  29         }
  30         return (struct tag *) obj;
  31 }
  32
  33 int parse_tag_buffer(struct tag *item, void *data, unsigned long size)
  34 {
  35         int typelen, taglen;
  36         unsigned char object[20];
  37         const char *type_line, *tag_line, *sig_line;
  38         char type[20];
  39
  40         if (item->object.parsed)
  41                 return 0;
  42         item->object.parsed = 1;
  43
  44         if (size < 64)
  45                 return -1;
  46         if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
  47                 return -1;
  48
  49         type_line = data + 48;
  50         if (memcmp("\ntype ", type_line-1, 6))
  51                 return -1;
  52
  53         tag_line = strchr(type_line, '\n');
  54         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  55                 return -1;
  56
  57         sig_line = strchr(tag_line, '\n');
  58         if (!sig_line)
  59                 return -1;
  60         sig_line++;
  61
  62         typelen = tag_line - type_line - strlen("type \n");
  63         if (typelen >= 20)
  64                 return -1;
  65         memcpy(type, type_line + 5, typelen);
  66         type[typelen] = '\0';
  67         taglen = sig_line - tag_line - strlen("tag \n");
  68         item->tag = xmalloc(taglen + 1);
  69         memcpy(item->tag, tag_line + 4, taglen);
  70         item->tag[taglen] = '\0';
  71
  72         item->tagged = lookup_object_type(object, type);
  73         if (item->tagged)
  74                 add_ref(&item->object, item->tagged);
  75
  76         return 0;
  77 }
  78
  79 int parse_tag(struct tag *item)
  80 {
  81         char type[20];
  82         void *data;
  83         unsigned long size;
  84         int ret;
  85
  86         if (item->object.parsed)
  87                 return 0;
  88         data = read_sha1_file(item->object.sha1, type, &size);
  89         if (!data)
  90                 return error("Could not read %s",
  91                              sha1_to_hex(item->object.sha1));
  92         if (strcmp(type, tag_type)) {
  93                 free(data);
  94                 return error("Object %s not a tag",
  95                              sha1_to_hex(item->object.sha1));
  96         }
  97         ret = parse_tag_buffer(item, data, size);
  98         free(data);
  99         return ret;
 100 }