1 files changed, 113 insertions, 0 deletions
diff --git a/third_party/git/ls-refs.c b/third_party/git/ls-refs.c
new file mode 100644
index 000000000000..818aef70a09e
--- /dev/null
+++ b/third_party/git/ls-refs.c
@@ -0,0 +1,113 @@
+#include "cache.h"
+#include "repository.h"
+#include "refs.h"
+#include "remote.h"
+#include "argv-array.h"
+#include "ls-refs.h"
+#include "pkt-line.h"
+#include "config.h"
+
+/*
+ * Check if one of the prefixes is a prefix of the ref.
+ * If no prefixes were provided, all refs match.
+ */
+static int ref_match(const struct argv_array *prefixes, const char *refname)
+{
+	int i;
+
+	if (!prefixes->argc)
+		return 1; /* no restriction */
+
+	for (i = 0; i < prefixes->argc; i++) {
+		const char *prefix = prefixes->argv[i];
+
+		if (starts_with(refname, prefix))
+			return 1;
+	}
+
+	return 0;
+}
+
+struct ls_refs_data {
+	unsigned peel;
+	unsigned symrefs;
+	struct argv_array prefixes;
+};
+
+static int send_ref(const char *refname, const struct object_id *oid,
+		    int flag, void *cb_data)
+{
+	struct ls_refs_data *data = cb_data;
+	const char *refname_nons = strip_namespace(refname);
+	struct strbuf refline = STRBUF_INIT;
+
+	if (ref_is_hidden(refname_nons, refname))
+		return 0;
+
+	if (!ref_match(&data->prefixes, refname_nons))
+		return 0;
+
+	strbuf_addf(&refline, "%s %s", oid_to_hex(oid), refname_nons);
+	if (data->symrefs && flag & REF_ISSYMREF) {
+		struct object_id unused;
+		const char *symref_target = resolve_ref_unsafe(refname, 0,
+							       &unused,
+							       &flag);
+
+		if (!symref_target)
+			die("'%s' is a symref but it is not?", refname);
+
+		strbuf_addf(&refline, " symref-target:%s",
+			    strip_namespace(symref_target));
+	}
+
+	if (data->peel) {
+		struct object_id peeled;
+		if (!peel_ref(refname, &peeled))
+			strbuf_addf(&refline, " peeled:%s", oid_to_hex(&peeled));
+	}
+
+	strbuf_addch(&refline, '\n');
+	packet_write(1, refline.buf, refline.len);
+
+	strbuf_release(&refline);
+	return 0;
+}
+
+static int ls_refs_config(const char *var, const char *value, void *data)
+{
+	/*
+	 * We only serve fetches over v2 for now, so respect only "uploadpack"
+	 * config. This may need to eventually be expanded to "receive", but we
+	 * don't yet know how that information will be passed to ls-refs.
+	 */
+	return parse_hide_refs_config(var, value, "uploadpack");
+}
+
+int ls_refs(struct repository *r, struct argv_array *keys,
+	    struct packet_reader *request)
+{
+	struct ls_refs_data data;
+
+	memset(&data, 0, sizeof(data));
+
+	git_config(ls_refs_config, NULL);
+
+	while (packet_reader_read(request) != PACKET_READ_FLUSH) {
+		const char *arg = request->line;
+		const char *out;
+
+		if (!strcmp("peel", arg))
+			data.peel = 1;
+		else if (!strcmp("symrefs", arg))
+			data.symrefs = 1;
+		else if (skip_prefix(arg, "ref-prefix ", &out))
+			argv_array_push(&data.prefixes, out);
+	}
+
+	head_ref_namespaced(send_ref, &data);
+	for_each_namespaced_ref(send_ref, &data);
+	packet_flush(1);
+	argv_array_clear(&data.prefixes);
+	return 0;
+}