1 files changed, 265 insertions, 0 deletions
diff --git a/promisor-remote.c b/promisor-remote.c
new file mode 100644
index 0000000000..9f338c945f
--- /dev/null
+++ b/promisor-remote.c
@@ -0,0 +1,265 @@
+#include "cache.h"
+#include "object-store.h"
+#include "promisor-remote.h"
+#include "config.h"
+#include "transport.h"
+
+static char *repository_format_partial_clone;
+static const char *core_partial_clone_filter_default;
+
+void set_repository_format_partial_clone(char *partial_clone)
+{
+	repository_format_partial_clone = xstrdup_or_null(partial_clone);
+}
+
+static int fetch_refs(const char *remote_name, struct ref *ref)
+{
+	struct remote *remote;
+	struct transport *transport;
+	int res;
+
+	remote = remote_get(remote_name);
+	if (!remote->url[0])
+		die(_("Remote with no URL"));
+	transport = transport_get(remote, remote->url[0]);
+
+	transport_set_option(transport, TRANS_OPT_FROM_PROMISOR, "1");
+	transport_set_option(transport, TRANS_OPT_NO_DEPENDENTS, "1");
+	res = transport_fetch_refs(transport, ref);
+
+	return res;
+}
+
+static int fetch_objects(const char *remote_name,
+			 const struct object_id *oids,
+			 int oid_nr)
+{
+	struct ref *ref = NULL;
+	int i;
+
+	for (i = 0; i < oid_nr; i++) {
+		struct ref *new_ref = alloc_ref(oid_to_hex(&oids[i]));
+		oidcpy(&new_ref->old_oid, &oids[i]);
+		new_ref->exact_oid = 1;
+		new_ref->next = ref;
+		ref = new_ref;
+	}
+	return fetch_refs(remote_name, ref);
+}
+
+static struct promisor_remote *promisors;
+static struct promisor_remote **promisors_tail = &promisors;
+
+static struct promisor_remote *promisor_remote_new(const char *remote_name)
+{
+	struct promisor_remote *r;
+
+	if (*remote_name == '/') {
+		warning(_("promisor remote name cannot begin with '/': %s"),
+			remote_name);
+		return NULL;
+	}
+
+	FLEX_ALLOC_STR(r, name, remote_name);
+
+	*promisors_tail = r;
+	promisors_tail = &r->next;
+
+	return r;
+}
+
+static struct promisor_remote *promisor_remote_lookup(const char *remote_name,
+						      struct promisor_remote **previous)
+{
+	struct promisor_remote *r, *p;
+
+	for (p = NULL, r = promisors; r; p = r, r = r->next)
+		if (!strcmp(r->name, remote_name)) {
+			if (previous)
+				*previous = p;
+			return r;
+		}
+
+	return NULL;
+}
+
+static void promisor_remote_move_to_tail(struct promisor_remote *r,
+					 struct promisor_remote *previous)
+{
+	if (r->next == NULL)
+		return;
+
+	if (previous)
+		previous->next = r->next;
+	else
+		promisors = r->next ? r->next : r;
+	r->next = NULL;
+	*promisors_tail = r;
+	promisors_tail = &r->next;
+}
+
+static int promisor_remote_config(const char *var, const char *value, void *data)
+{
+	const char *name;
+	int namelen;
+	const char *subkey;
+
+	if (!strcmp(var, "core.partialclonefilter"))
+		return git_config_string(&core_partial_clone_filter_default,
+					 var, value);
+
+	if (parse_config_key(var, "remote", &name, &namelen, &subkey) < 0)
+		return 0;
+
+	if (!strcmp(subkey, "promisor")) {
+		char *remote_name;
+
+		if (!git_config_bool(var, value))
+			return 0;
+
+		remote_name = xmemdupz(name, namelen);
+
+		if (!promisor_remote_lookup(remote_name, NULL))
+			promisor_remote_new(remote_name);
+
+		free(remote_name);
+		return 0;
+	}
+	if (!strcmp(subkey, "partialclonefilter")) {
+		struct promisor_remote *r;
+		char *remote_name = xmemdupz(name, namelen);
+
+		r = promisor_remote_lookup(remote_name, NULL);
+		if (!r)
+			r = promisor_remote_new(remote_name);
+
+		free(remote_name);
+
+		if (!r)
+			return 0;
+
+		return git_config_string(&r->partial_clone_filter, var, value);
+	}
+
+	return 0;
+}
+
+static int initialized;
+
+static void promisor_remote_init(void)
+{
+	if (initialized)
+		return;
+	initialized = 1;
+
+	git_config(promisor_remote_config, NULL);
+
+	if (repository_format_partial_clone) {
+		struct promisor_remote *o, *previous;
+
+		o = promisor_remote_lookup(repository_format_partial_clone,
+					   &previous);
+		if (o)
+			promisor_remote_move_to_tail(o, previous);
+		else
+			promisor_remote_new(repository_format_partial_clone);
+	}
+}
+
+static void promisor_remote_clear(void)
+{
+	while (promisors) {
+		struct promisor_remote *r = promisors;
+		promisors = promisors->next;
+		free(r);
+	}
+
+	promisors_tail = &promisors;
+}
+
+void promisor_remote_reinit(void)
+{
+	initialized = 0;
+	promisor_remote_clear();
+	promisor_remote_init();
+}
+
+struct promisor_remote *promisor_remote_find(const char *remote_name)
+{
+	promisor_remote_init();
+
+	if (!remote_name)
+		return promisors;
+
+	return promisor_remote_lookup(remote_name, NULL);
+}
+
+int has_promisor_remote(void)
+{
+	return !!promisor_remote_find(NULL);
+}
+
+static int remove_fetched_oids(struct repository *repo,
+			       struct object_id **oids,
+			       int oid_nr, int to_free)
+{
+	int i, remaining_nr = 0;
+	int *remaining = xcalloc(oid_nr, sizeof(*remaining));
+	struct object_id *old_oids = *oids;
+	struct object_id *new_oids;
+
+	for (i = 0; i < oid_nr; i++)
+		if (oid_object_info_extended(repo, &old_oids[i], NULL,
+					     OBJECT_INFO_SKIP_FETCH_OBJECT)) {
+			remaining[i] = 1;
+			remaining_nr++;
+		}
+
+	if (remaining_nr) {
+		int j = 0;
+		new_oids = xcalloc(remaining_nr, sizeof(*new_oids));
+		for (i = 0; i < oid_nr; i++)
+			if (remaining[i])
+				oidcpy(&new_oids[j++], &old_oids[i]);
+		*oids = new_oids;
+		if (to_free)
+			free(old_oids);
+	}
+
+	free(remaining);
+
+	return remaining_nr;
+}
+
+int promisor_remote_get_direct(struct repository *repo,
+			       const struct object_id *oids,
+			       int oid_nr)
+{
+	struct promisor_remote *r;
+	struct object_id *remaining_oids = (struct object_id *)oids;
+	int remaining_nr = oid_nr;
+	int to_free = 0;
+	int res = -1;
+
+	promisor_remote_init();
+
+	for (r = promisors; r; r = r->next) {
+		if (fetch_objects(r->name, remaining_oids, remaining_nr) < 0) {
+			if (remaining_nr == 1)
+				continue;
+			remaining_nr = remove_fetched_oids(repo, &remaining_oids,
+							 remaining_nr, to_free);
+			if (remaining_nr) {
+				to_free = 1;
+				continue;
+			}
+		}
+		res = 0;
+		break;
+	}
+
+	if (to_free)
+		free(remaining_oids);
+
+	return res;
+}