Move refspec parser from connect.c and cache.h to remote.{c,h}

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 246 insertions, 0 deletions

diff --git a/remote.c b/remote.c
index b032e81ac..bc27a8e3d 100644
--- a/remote.c
+++ b/remote.c
@@ -201,6 +201,44 @@ static void read_config(void)
 	git_config(handle_config);
 }
 
+static struct refspec *parse_ref_spec(int nr_refspec, const char **refspec)
+{
+	int i;
+	struct refspec *rs = xcalloc(sizeof(*rs), nr_refspec);
+	for (i = 0; i < nr_refspec; i++) {
+		const char *sp, *ep, *gp;
+		sp = refspec[i];
+		if (*sp == '+') {
+			rs[i].force = 1;
+			sp++;
+		}
+		gp = strchr(sp, '*');
+		ep = strchr(sp, ':');
+		if (gp && ep && gp > ep)
+			gp = NULL;
+		if (ep) {
+			if (ep[1]) {
+				const char *glob = strchr(ep + 1, '*');
+				if (!glob)
+					gp = NULL;
+				if (gp)
+					rs[i].dst = xstrndup(ep + 1,
+							     glob - ep - 1);
+				else
+					rs[i].dst = xstrdup(ep + 1);
+			}
+		} else {
+			ep = sp + strlen(sp);
+		}
+		if (gp) {
+			rs[i].pattern = 1;
+			ep = gp;
+		}
+		rs[i].src = xstrndup(sp, ep - sp);
+	}
+	return rs;
+}
+
 struct remote *remote_get(const char *name)
 {
 	struct remote *ret;
@@ -219,5 +257,213 @@ struct remote *remote_get(const char *name)
 		add_uri(ret, name);
 	if (!ret->uri)
 		return NULL;
+	ret->push = parse_ref_spec(ret->push_refspec_nr, ret->push_refspec);
 	return ret;
 }
+
+static int count_refspec_match(const char *pattern,
+			       struct ref *refs,
+			       struct ref **matched_ref)
+{
+	int patlen = strlen(pattern);
+	struct ref *matched_weak = NULL;
+	struct ref *matched = NULL;
+	int weak_match = 0;
+	int match = 0;
+
+	for (weak_match = match = 0; refs; refs = refs->next) {
+		char *name = refs->name;
+		int namelen = strlen(name);
+		int weak_match;
+
+		if (namelen < patlen ||
+		    memcmp(name + namelen - patlen, pattern, patlen))
+			continue;
+		if (namelen != patlen && name[namelen - patlen - 1] != '/')
+			continue;
+
+		/* A match is "weak" if it is with refs outside
+		 * heads or tags, and did not specify the pattern
+		 * in full (e.g. "refs/remotes/origin/master") or at
+		 * least from the toplevel (e.g. "remotes/origin/master");
+		 * otherwise "git push $URL master" would result in
+		 * ambiguity between remotes/origin/master and heads/master
+		 * at the remote site.
+		 */
+		if (namelen != patlen &&
+		    patlen != namelen - 5 &&
+		    prefixcmp(name, "refs/heads/") &&
+		    prefixcmp(name, "refs/tags/")) {
+			/* We want to catch the case where only weak
+			 * matches are found and there are multiple
+			 * matches, and where more than one strong
+			 * matches are found, as ambiguous.  One
+			 * strong match with zero or more weak matches
+			 * are acceptable as a unique match.
+			 */
+			matched_weak = refs;
+			weak_match++;
+		}
+		else {
+			matched = refs;
+			match++;
+		}
+	}
+	if (!matched) {
+		*matched_ref = matched_weak;
+		return weak_match;
+	}
+	else {
+		*matched_ref = matched;
+		return match;
+	}
+}
+
+static void link_dst_tail(struct ref *ref, struct ref ***tail)
+{
+	**tail = ref;
+	*tail = &ref->next;
+	**tail = NULL;
+}
+
+static struct ref *try_explicit_object_name(const char *name)
+{
+	unsigned char sha1[20];
+	struct ref *ref;
+	int len;
+
+	if (!*name) {
+		ref = xcalloc(1, sizeof(*ref) + 20);
+		strcpy(ref->name, "(delete)");
+		hashclr(ref->new_sha1);
+		return ref;
+	}
+	if (get_sha1(name, sha1))
+		return NULL;
+	len = strlen(name) + 1;
+	ref = xcalloc(1, sizeof(*ref) + len);
+	memcpy(ref->name, name, len);
+	hashcpy(ref->new_sha1, sha1);
+	return ref;
+}
+
+static int match_explicit_refs(struct ref *src, struct ref *dst,
+			       struct ref ***dst_tail, struct refspec *rs,
+			       int rs_nr)
+{
+	int i, errs;
+	for (i = errs = 0; i < rs_nr; i++) {
+		struct ref *matched_src, *matched_dst;
+
+		const char *dst_value = rs[i].dst;
+		if (dst_value == NULL)
+			dst_value = rs[i].src;
+
+		matched_src = matched_dst = NULL;
+		switch (count_refspec_match(rs[i].src, src, &matched_src)) {
+		case 1:
+			break;
+		case 0:
+			/* The source could be in the get_sha1() format
+			 * not a reference name.  :refs/other is a
+			 * way to delete 'other' ref at the remote end.
+			 */
+			matched_src = try_explicit_object_name(rs[i].src);
+			if (matched_src)
+				break;
+			errs = 1;
+			error("src refspec %s does not match any.",
+			      rs[i].src);
+			break;
+		default:
+			errs = 1;
+			error("src refspec %s matches more than one.",
+			      rs[i].src);
+			break;
+		}
+		switch (count_refspec_match(dst_value, dst, &matched_dst)) {
+		case 1:
+			break;
+		case 0:
+			if (!memcmp(dst_value, "refs/", 5)) {
+				int len = strlen(dst_value) + 1;
+				matched_dst = xcalloc(1, sizeof(*dst) + len);
+				memcpy(matched_dst->name, dst_value, len);
+				link_dst_tail(matched_dst, dst_tail);
+			}
+			else if (!strcmp(rs[i].src, dst_value) &&
+				 matched_src) {
+				/* pushing "master:master" when
+				 * remote does not have master yet.
+				 */
+				int len = strlen(matched_src->name) + 1;
+				matched_dst = xcalloc(1, sizeof(*dst) + len);
+				memcpy(matched_dst->name, matched_src->name,
+				       len);
+				link_dst_tail(matched_dst, dst_tail);
+			}
+			else {
+				errs = 1;
+				error("dst refspec %s does not match any "
+				      "existing ref on the remote and does "
+				      "not start with refs/.", dst_value);
+			}
+			break;
+		default:
+			errs = 1;
+			error("dst refspec %s matches more than one.",
+			      dst_value);
+			break;
+		}
+		if (errs)
+			continue;
+		if (matched_dst->peer_ref) {
+			errs = 1;
+			error("dst ref %s receives from more than one src.",
+			      matched_dst->name);
+		}
+		else {
+			matched_dst->peer_ref = matched_src;
+			matched_dst->force = rs[i].force;
+		}
+	}
+	return -errs;
+}
+
+static struct ref *find_ref_by_name(struct ref *list, const char *name)
+{
+	for ( ; list; list = list->next)
+		if (!strcmp(list->name, name))
+			return list;
+	return NULL;
+}
+
+int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
+	       int nr_refspec, char **refspec, int all)
+{
+	struct refspec *rs =
+		parse_ref_spec(nr_refspec, (const char **) refspec);
+
+	if (nr_refspec)
+		return match_explicit_refs(src, dst, dst_tail, rs, nr_refspec);
+
+	/* pick the remainder */
+	for ( ; src; src = src->next) {
+		struct ref *dst_peer;
+		if (src->peer_ref)
+			continue;
+		dst_peer = find_ref_by_name(dst, src->name);
+		if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all))
+			continue;
+		if (!dst_peer) {
+			/* Create a new one and link it */
+			int len = strlen(src->name) + 1;
+			dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
+			memcpy(dst_peer->name, src->name, len);
+			hashcpy(dst_peer->new_sha1, src->new_sha1);
+			link_dst_tail(dst_peer, dst_tail);
+		}
+		dst_peer->peer_ref = src;
+	}
+	return 0;
+}