tag.c

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