Function payment_listsendpays_previous

plugins/pay.c:512–634

We are interested in any prior attempts to pay this payment_hash / * invoice so we can set the `groupid` correctly and ensure we don't * already have a pending payment running. We also collect the summary * about an eventual previous complete payment so we can return that * as a no-op. */

 * about an eventual previous complete payment so we can return that
 * as a no-op. */
static struct command_result *
payment_listsendpays_previous(struct command *cmd,
			      const char *method,
			      const char *buf,
			      const jsmntok_t *result,
			      struct payment *p)
{
	size_t i;
	const jsmntok_t *t, *arr, *err;
	/* What was the groupid of an eventual previous attempt? */
	u64 last_group = 0;
	/* Do we have pending sendpays for the previous attempt? */
	bool pending = false;

	/* Group ID of the first pending payment, this will be the one
	 * who's result gets replayed if we end up suspending. */
	u64 pending_group_id = 0;
	/* Did a prior attempt succeed? */
	bool completed = false;

	/* Metadata for a complete payment, if one exists. */
	struct json_stream *ret;
	u32 parts = 0;
	struct preimage preimage;
	struct amount_msat sent, msat;
	struct node_id destination;
	u32 created_at;

	err = json_get_member(buf, result, "error");
	if (err)
		return command_fail(
			   cmd, LIGHTNINGD,
			   "Error retrieving previous pay attempts: %s",
			   json_strdup(tmpctx, buf, err));

			   arr = json_get_member(buf, result, "payments");
	if (!arr || arr->type != JSMN_ARRAY)
		return command_fail(
		    cmd, LIGHTNINGD,
		    "Unexpected non-array result from listsendpays");

	/* We iterate through all prior sendpays, looking for the
	 * latest group and remembering what its state is. */
	json_for_each_arr(i, t, arr)
	{
		u64 groupid;
		const jsmntok_t *status, *grouptok;
		struct amount_msat diff_sent, diff_msat;
		grouptok = json_get_member(buf, t, "groupid");
		json_to_u64(buf, grouptok, &groupid);

		/* New group, reset what we collected. */
		if (last_group != groupid) {
			completed = false;
			pending = false;
			last_group = groupid;

			parts = 1;