wallet: Track some channel usage statistics.

Fixes: #1049

lightningd/peer_control.c

@@ -625,6 +625,7 @@ static void gossipd_getpeers_complete(struct subd *gossip, const u8 *msg,
 	list_for_each(&gpa->cmd->ld->peers, p, list) {
 		bool connected;
 		struct channel *channel;
+		struct channel_stats channel_stats;
 
 		if (gpa->specific_id && !pubkey_eq(gpa->specific_id, &p->id))
 			continue;
@@ -712,6 +713,28 @@ static void gossipd_getpeers_complete(struct subd *gossip, const u8 *msg,
 				json_add_string(response, NULL,
 						channel->billboard.transient);
 			json_array_end(response);
+
+			/* Provide channel statistics */
+			wallet_channel_stats_load(gpa->cmd->ld->wallet,
+						  channel->dbid,
+						  &channel_stats);
+			json_add_u64(response, "in_payments_offered",
+				     channel_stats.in_payments_offered);
+			json_add_u64(response, "in_msatoshi_offered",
+				     channel_stats.in_msatoshi_offered);
+			json_add_u64(response, "in_payments_fulfilled",
+				     channel_stats.in_payments_fulfilled);
+			json_add_u64(response, "in_msatoshi_fulfilled",
+				     channel_stats.in_msatoshi_fulfilled);
+			json_add_u64(response, "out_payments_offered",
+				     channel_stats.out_payments_offered);
+			json_add_u64(response, "out_msatoshi_offered",
+				     channel_stats.out_msatoshi_offered);
+			json_add_u64(response, "out_payments_fulfilled",
+				     channel_stats.out_payments_fulfilled);
+			json_add_u64(response, "out_msatoshi_fulfilled",
+				     channel_stats.out_msatoshi_fulfilled);
+
 			json_object_end(response);
 		}
 		json_array_end(response);

lightningd/peer_htlcs.c

@@ -199,26 +199,32 @@ static bool check_cltv(struct htlc_in *hin,
 static void fulfill_htlc(struct htlc_in *hin, const struct preimage *preimage)
 {
 	u8 *msg;
+	struct channel *channel = hin->key.channel;
+	struct wallet *wallet = channel->peer->ld->wallet;
 
 	hin->preimage = tal_dup(hin, struct preimage, preimage);
 	htlc_in_check(hin, __func__);
 
 	/* We update state now to signal it's in progress, for persistence. */
-	htlc_in_update_state(hin->key.channel, hin, SENT_REMOVE_HTLC);
+	htlc_in_update_state(channel, hin, SENT_REMOVE_HTLC);
+	/* Update channel stats */
+	wallet_channel_stats_incr_in_fulfilled(wallet,
+					       channel->dbid,
+					       hin->msatoshi);
 
 	/* No owner?  We'll either send to channeld in peer_htlcs, or
 	 * onchaind in onchaind_tell_fulfill. */
-	if (!hin->key.channel->owner) {
+	if (!channel->owner) {
-		log_debug(hin->key.channel->log, "HTLC fulfilled, but no owner.");
+		log_debug(channel->log, "HTLC fulfilled, but no owner.");
 		return;
 	}
 
-	if (channel_on_chain(hin->key.channel)) {
+	if (channel_on_chain(channel)) {
 		msg = towire_onchain_known_preimage(hin, preimage);
 	} else {
 		msg = towire_channel_fulfill_htlc(hin, hin->key.id, preimage);
 	}
-	subd_send_msg(hin->key.channel->owner, take(msg));
+	subd_send_msg(channel->owner, take(msg));
 }
 
 static void handle_localpay(struct htlc_in *hin,
@@ -665,6 +671,10 @@ static void fulfill_our_htlc_out(struct channel *channel, struct htlc_out *hout,
 	htlc_out_check(hout, __func__);
 
 	wallet_htlc_update(ld->wallet, hout->dbid, hout->hstate, preimage);
+	/* Update channel stats */
+	wallet_channel_stats_incr_out_fulfilled(ld->wallet,
+						channel->dbid,
+						hout->msatoshi);
 
 	if (hout->in)
 		fulfill_htlc(hout->in, preimage);
@@ -889,6 +899,10 @@ static bool update_out_htlc(struct channel *channel,
 
 	if (!hout->dbid) {
 		wallet_htlc_save_out(ld->wallet, channel, hout);
+		/* Update channel stats */
+		wallet_channel_stats_incr_out_offered(ld->wallet,
+						      channel->dbid,
+						      hout->msatoshi);
 
 		/* For our own HTLCs, we commit payment to db lazily */
 		if (hout->origin_htlc_id == 0)
@@ -1053,6 +1067,9 @@ static bool channel_added_their_htlc(struct channel *channel,
 
 	/* Save an incoming htlc to the wallet */
 	wallet_htlc_save_in(ld->wallet, channel, hin);
+	/* Update channel stats */
+	wallet_channel_stats_incr_in_offered(ld->wallet, channel->dbid,
+					     added->amount_msat);
 
 	log_debug(channel->log, "Adding their HTLC %"PRIu64, added->id);
 	connect_htlc_in(&channel->peer->ld->htlcs_in, hin);

wallet/db.c

@@ -251,6 +251,22 @@ char *dbmigrations[] = {
     "     , route_nodes = NULL"
     "     , route_channels = NULL"
     " WHERE status <> 0;", /* PAYMENT_PENDING */
+    /* -- Routing statistics -- */
+    "ALTER TABLE channels ADD in_payments_offered INTEGER;",
+    "ALTER TABLE channels ADD in_payments_fulfilled INTEGER;",
+    "ALTER TABLE channels ADD in_msatoshi_offered INTEGER;",
+    "ALTER TABLE channels ADD in_msatoshi_fulfilled INTEGER;",
+    "ALTER TABLE channels ADD out_payments_offered INTEGER;",
+    "ALTER TABLE channels ADD out_payments_fulfilled INTEGER;",
+    "ALTER TABLE channels ADD out_msatoshi_offered INTEGER;",
+    "ALTER TABLE channels ADD out_msatoshi_fulfilled INTEGER;",
+    "UPDATE channels"
+    "   SET  in_payments_offered = 0,  in_payments_fulfilled = 0"
+    "     ,  in_msatoshi_offered = 0,  in_msatoshi_fulfilled = 0"
+    "     , out_payments_offered = 0, out_payments_fulfilled = 0"
+    "     , out_msatoshi_offered = 0, out_msatoshi_fulfilled = 0"
+    "     ;",
+    /* -- Routing statistics ends --*/
     NULL,
 };
 

wallet/wallet.c

@@ -719,6 +719,68 @@ bool wallet_channels_load_active(const tal_t *ctx, struct wallet *w)
 	return ok;
 }
 
+static
+void wallet_channel_stats_incr_x(struct wallet *w,
+				 char const *dir,
+				 char const *typ,
+				 u64 cdbid,
+				 u64 msatoshi)
+{
+	char const *payments_stat = tal_fmt(tmpctx, "%s_payments_%s",
+					    dir, typ);
+	char const *msatoshi_stat = tal_fmt(tmpctx, "%s_msatoshi_%s",
+					    dir, typ);
+	char const *qry = tal_fmt(tmpctx,
+				  "UPDATE channels"
+				  "   SET %s = COALESCE(%s, 0) + 1"
+				  "     , %s = COALESCE(%s, 0) + %"PRIu64""
+				  " WHERE id = %"PRIu64";",
+				  payments_stat, payments_stat,
+				  msatoshi_stat, msatoshi_stat, msatoshi,
+				  cdbid);
+	sqlite3_stmt *stmt = db_prepare(w->db, qry);
+	db_exec_prepared(w->db, stmt);
+}
+void wallet_channel_stats_incr_in_offered(struct wallet *w, u64 id, u64 m)
+{
+	wallet_channel_stats_incr_x(w, "in", "offered", id, m);
+}
+void wallet_channel_stats_incr_in_fulfilled(struct wallet *w, u64 id, u64 m)
+{
+	wallet_channel_stats_incr_x(w, "in", "fulfilled", id, m);
+}
+void wallet_channel_stats_incr_out_offered(struct wallet *w, u64 id, u64 m)
+{
+	wallet_channel_stats_incr_x(w, "out", "offered", id, m);
+}
+void wallet_channel_stats_incr_out_fulfilled(struct wallet *w, u64 id, u64 m)
+{
+	wallet_channel_stats_incr_x(w, "out", "fulfilled", id, m);
+}
+
+void wallet_channel_stats_load(struct wallet *w,
+			       u64 id,
+			       struct channel_stats *stats)
+{
+	sqlite3_stmt *stmt;
+	stmt = db_prepare(w->db,
+			  "SELECT  in_payments_offered,  in_payments_fulfilled"
+			  "     ,  in_msatoshi_offered,  in_msatoshi_fulfilled"
+			  "     , out_payments_offered, out_payments_fulfilled"
+			  "     , out_msatoshi_offered, out_msatoshi_fulfilled"
+			  "  FROM channels"
+			  " WHERE id = ?");
+	sqlite3_bind_int64(stmt, 1, id);
+	stats->in_payments_offered = sqlite3_column_int64(stmt, 0);
+	stats->in_payments_fulfilled = sqlite3_column_int64(stmt, 1);
+	stats->in_msatoshi_offered = sqlite3_column_int64(stmt, 2);
+	stats->in_msatoshi_fulfilled = sqlite3_column_int64(stmt, 3);
+	stats->out_payments_offered = sqlite3_column_int64(stmt, 4);
+	stats->out_payments_fulfilled = sqlite3_column_int64(stmt, 5);
+	stats->out_msatoshi_offered = sqlite3_column_int64(stmt, 6);
+	stats->out_msatoshi_fulfilled = sqlite3_column_int64(stmt, 7);
+}
+
 #ifdef COMPAT_V052
 /* Upgrade of db (or initial create): do we have anything to scan for? */
 static bool wallet_ever_used(struct wallet *w)

wallet/wallet.h

@@ -119,6 +119,14 @@ struct outpoint {
 	u32 spendheight;
 };
 
+/* Statistics for a channel */
+struct channel_stats {
+	u64  in_payments_offered,  in_payments_fulfilled;
+	u64  in_msatoshi_offered,  in_msatoshi_fulfilled;
+	u64 out_payments_offered, out_payments_fulfilled;
+	u64 out_msatoshi_offered, out_msatoshi_fulfilled;
+};
+
 /**
  * wallet_new - Constructor for a new sqlite3 based wallet
  *
@@ -286,6 +294,27 @@ bool wallet_peer_by_nodeid(struct wallet *w, const struct pubkey *nodeid,
  */
 bool wallet_channels_load_active(const tal_t *ctx, struct wallet *w);
 
+/**
+ * wallet_channel_stats_incr_* - Increase channel statistics.
+ *
+ * @w: wallet containing the channel
+ * @cdbid: channel database id
+ * @msatoshi: amount in msatoshi being transferred
+ */
+void wallet_channel_stats_incr_in_offered(struct wallet *w, u64 cdbid, u64 msatoshi);
+void wallet_channel_stats_incr_in_fulfilled(struct wallet *w, u64 cdbid, u64 msatoshi);
+void wallet_channel_stats_incr_out_offered(struct wallet *w, u64 cdbid, u64 msatoshi);
+void wallet_channel_stats_incr_out_fulfilled(struct wallet *w, u64 cdbid, u64 msatoshi);
+
+/**
+ * wallet_channel_stats_load - Load channel statistics
+ *
+ * @w: wallet containing the channel
+ * @cdbid: channel database id
+ * @stats: location to load statistics to
+ */
+void wallet_channel_stats_load(struct wallet *w, u64 cdbid, struct channel_stats *stats);
+
 /**
  * wallet_first_blocknum - get first block we're interested in.
  *