tag.c

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