askrene: add a dev parameter to switch algorithm

Changelog-None

Signed-off-by: Lagrang3 <lagrang3@protonmail.com>

Author: Lagrang3

plugins/askrene/askrene.c

@@ -347,6 +347,24 @@ static struct amount_msat linear_flows_cost(struct flow **flows,
 	return total;
 }
 
+enum algorithm {
+	ALGO_DEFAULT,
+};
+
+static struct command_result *
+param_algorithm(struct command *cmd, const char *name, const char *buffer,
+		const jsmntok_t *tok, enum algorithm **algo)
+{
+	const char *algo_str = json_strdup(cmd, buffer, tok);
+	*algo = tal(cmd, enum algorithm);
+	if (streq(algo_str, "default"))
+		**algo = ALGO_DEFAULT;
+	else
+		return command_fail_badparam(cmd, name, buffer, tok,
+					     "unknown algorithm");
+	return NULL;
+}
+
 struct getroutes_info {
 	struct command *cmd;
 	struct node_id *source, *dest;
@@ -356,6 +374,8 @@ struct getroutes_info {
 	struct additional_cost_htable *additional_costs;
 	/* Non-NULL if we are told to use "auto.localchans" */
 	struct layer *local_layer;
+	/* algorithm selection, only dev */
+	enum algorithm *dev_algo;
 };
 
 static void apply_layers(struct askrene *askrene, struct route_query *rq,
@@ -582,8 +602,9 @@ static struct command_result *do_getroutes(struct command *cmd,
 	}
 
 	/* Compute the routes. At this point we might select between multiple
-	 * algorithms. */
+	 * algorithms. Right now there is only one algorithm available. */
 	struct timemono time_start = time_mono();
+	assert(*info->dev_algo == ALGO_DEFAULT);
 	err = default_routes(rq, rq, srcnode, dstnode, *info->amount,
 			     /* only one path? = */
 			     have_layer(info->layers, "auto.no_mpp_support"),
@@ -750,6 +771,8 @@ static struct command_result *json_getroutes(struct command *cmd,
 			 p_req("final_cltv", param_u32, &info->finalcltv),
 			 p_opt_def("maxdelay", param_u32, &info->maxdelay,
 				   maxdelay_allowed),
+			 p_opt_dev("dev_algorithm", param_algorithm,
+			 	   &info->dev_algo, ALGO_DEFAULT),
 			 NULL))
 		return command_param_failed();