[PATCH] Add tag header/parser to library
This adds preliminary support for tags in the library. It doesn't even
store the signature, however, let alone provide any way of checking it.
Signed-Off-By: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/tag.c b/tag.c
new file mode 100644
index 0000000..f079d83
--- /dev/null
+++ b/tag.c
@@ -0,0 +1,73 @@
+#include "tag.h"
+#include "cache.h"
+
+const char *tag_type = "tag";
+
+struct tag *lookup_tag(unsigned char *sha1)
+{
+ struct object *obj = lookup_object(sha1);
+ if (!obj) {
+ struct tag *ret = xmalloc(sizeof(struct tag));
+ memset(ret, 0, sizeof(struct tag));
+ created_object(sha1, &ret->object);
+ ret->object.type = tag_type;
+ return ret;
+ }
+ if (obj->type != tag_type) {
+ error("Object %s is a %s, not a tree",
+ sha1_to_hex(sha1), obj->type);
+ return NULL;
+ }
+ return (struct tag *) obj;
+}
+
+int parse_tag(struct tag *item)
+{
+ char type[20];
+ void *data, *bufptr;
+ unsigned long size;
+ if (item->object.parsed)
+ return 0;
+ item->object.parsed = 1;
+ data = bufptr = read_sha1_file(item->object.sha1, type, &size);
+ if (!data)
+ return error("Could not read %s",
+ sha1_to_hex(item->object.sha1));
+ if (strcmp(type, tag_type))
+ return error("Object %s not a tag",
+ sha1_to_hex(item->object.sha1));
+
+ int typelen, taglen;
+ unsigned char object[20];
+ const char *type_line, *tag_line, *sig_line;
+
+ if (size < 64)
+ return -1;
+ if (memcmp("object ", data, 7) || get_sha1_hex(data + 7, object))
+ return -1;
+
+ item->tagged = parse_object(object);
+
+ type_line = data + 48;
+ if (memcmp("\ntype ", type_line-1, 6))
+ return -1;
+
+ tag_line = strchr(type_line, '\n');
+ if (!tag_line || memcmp("tag ", ++tag_line, 4))
+ return -1;
+
+ sig_line = strchr(tag_line, '\n');
+ if (!sig_line)
+ return -1;
+ sig_line++;
+
+ typelen = tag_line - type_line - strlen("type \n");
+ if (typelen >= 20)
+ return -1;
+ taglen = sig_line - tag_line - strlen("tag \n");
+ item->tag = xmalloc(taglen + 1);
+ memcpy(item->tag, tag_line + 4, taglen);
+ item->tag[taglen] = '\0';
+
+ return 0;
+}
