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         char type[20];
  32
  33         if (item->object.parsed)
  34                 return 0;
  35         item->object.parsed = 1;
  36
  37         if (size < 64)
  38                 return -1;
  39         if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
  40                 return -1;
  41
  42         type_line = data + 48;
  43         if (memcmp("\ntype ", type_line-1, 6))
  44                 return -1;
  45
  46         tag_line = strchr(type_line, '\n');
  47         if (!tag_line || memcmp("tag ", ++tag_line, 4))
  48                 return -1;
  49
  50         sig_line = strchr(tag_line, '\n');
  51         if (!sig_line)
  52                 return -1;
  53         sig_line++;
  54
  55         typelen = tag_line - type_line - strlen("type \n");
  56         if (typelen >= 20)
  57                 return -1;
  58         memcpy(type, type_line + 5, typelen);
  59         type[typelen] = '\0';
  60         taglen = sig_line - tag_line - strlen("tag \n");
  61         item->tag = xmalloc(taglen + 1);
  62         memcpy(item->tag, tag_line + 4, taglen);
  63         item->tag[taglen] = '\0';
  64
  65         item->tagged = lookup_object_type(object, type);
  66         if (item->tagged)
  67                 add_ref(&item->object, item->tagged);
  68
  69         return 0;
  70 }
  71
  72 int parse_tag(struct tag *item)
  73 {
  74         char type[20];
  75         void *data;
  76         unsigned long size;
  77         int ret;
  78
  79         if (item->object.parsed)
  80                 return 0;
  81         data = read_sha1_file(item->object.sha1, type, &size);
  82         if (!data)
  83                 return error("Could not read %s",
  84                              sha1_to_hex(item->object.sha1));
  85         if (strcmp(type, tag_type)) {
  86                 free(data);
  87                 return error("Object %s not a tag",
  88                              sha1_to_hex(item->object.sha1));
  89         }
  90         ret = parse_tag_buffer(item, data, size);
  91         free(data);
  92         return ret;
  93 }