balance snap: first pass

common/coin_mvt.c

@@ -7,7 +7,6 @@
 #include <common/type_to_string.h>
 #include <wire/wire.h>
 
-#define WALLET "wallet"
 #define EXTERNAL "external"
 
 static const char *mvt_types[] = { "chain_mvt", "channel_mvt" };

common/coin_mvt.h

@@ -7,6 +7,7 @@
 #include <common/utils.h>
 
 #define COIN_MVT_VERSION 2
+#define WALLET "wallet"
 
 enum mvt_type {
 	CHAIN_MVT = 0,

lightningd/chaintopology.c

@@ -629,6 +629,10 @@ static void updates_complete(struct chain_topology *topo)
 			      "last_processed_block", topo->tip->height);
 
 		topo->prev_tip = topo->tip->blkid;
+
+		/* Send out an account balance snapshot */
+		/* FIXME: only issue on first updates_complete call */
+		send_account_balance_snapshot(topo->ld, topo->tip->height);
 	}
 
 	/* If bitcoind is synced, we're now synced. */

lightningd/coin_mvts.c

@@ -1,8 +1,12 @@
 #include "config.h"
+#include <ccan/array_size/array_size.h>
 #include <common/onion.h>
+#include <common/type_to_string.h>
 #include <lightningd/channel.h>
 #include <lightningd/coin_mvts.h>
 #include <lightningd/notification.h>
+#include <lightningd/peer_control.h>
+
 
 void notify_channel_mvt(struct lightningd *ld, const struct channel_coin_mvt *mvt)
 {
@@ -76,3 +80,55 @@ struct channel_coin_mvt *new_channel_mvt_routed_hout(const tal_t *ctx,
 				    false,
 				    hout->fees);
 }
+
+void send_account_balance_snapshot(struct lightningd *ld, u32 blockheight)
+{
+	struct balance_snapshot *snap = tal(NULL, struct balance_snapshot);
+	struct account_balance *bal;
+	struct utxo **utxos;
+	struct channel *chan;
+	struct peer *p;
+	/* Available + reserved utxos are A+, as reserved things have not yet
+	 * been spent */
+	enum output_status utxo_states[] = {OUTPUT_STATE_AVAILABLE,
+					    OUTPUT_STATE_RESERVED};
+
+	snap->blockheight = blockheight;
+	snap->timestamp = time_now().ts.tv_sec;
+	snap->node_id = &ld->id;
+
+	/* Add the 'wallet' account balance */
+	snap->accts = tal_arr(snap, struct account_balance *, 1);
+	bal = tal(snap, struct account_balance);
+	bal->acct_id = WALLET;
+	bal->bip173_name = chainparams->lightning_hrp;
+
+	for (size_t i = 0; i < ARRAY_SIZE(utxo_states); i++) {
+		utxos = wallet_get_utxos(NULL, ld->wallet, utxo_states[i]);
+		for (size_t j = 0; j < tal_count(utxos); j++) {
+			if (!amount_msat_add_sat(&bal->balance,
+						 bal->balance, utxos[j]->amount))
+				fatal("Overflow adding node balance");
+		}
+		tal_free(utxos);
+	}
+	snap->accts[0] = bal;
+
+	/* Add channel balances */
+	list_for_each(&ld->peers, p, list) {
+		list_for_each(&p->channels, chan, list) {
+			if (channel_active(chan)) {
+				bal = tal(snap, struct account_balance);
+				bal->bip173_name = chainparams->lightning_hrp;
+				bal->acct_id = type_to_string(bal,
+							   struct channel_id,
+							   &chan->cid);
+				bal->balance = chan->our_msat;
+				tal_arr_expand(&snap->accts, bal);
+			}
+		}
+	}
+
+	notify_balance_snapshot(ld, snap);
+	tal_free(snap);
+}

lightningd/coin_mvts.h

@@ -5,6 +5,20 @@
 #include <common/coin_mvt.h>
 #include <lightningd/lightningd.h>
 
+struct account_balance {
+	const char *acct_id;
+	const char *bip173_name;
+	struct amount_msat balance;
+};
+
+struct balance_snapshot {
+	struct node_id *node_id;
+	u32 blockheight;
+	u32 timestamp;
+
+	struct account_balance **accts;
+};
+
 void notify_channel_mvt(struct lightningd *ld, const struct channel_coin_mvt *mvt);
 void notify_chain_mvt(struct lightningd *ld, const struct chain_coin_mvt *mvt);
 
@@ -21,4 +35,5 @@ struct channel_coin_mvt *new_channel_mvt_routed_hout(const tal_t *ctx,
 						     struct htlc_out *hout,
 						     struct channel *channel);
 
+void send_account_balance_snapshot(struct lightningd *ld, u32 blockheight);
 #endif /* LIGHTNING_LIGHTNINGD_COIN_MVTS_H */

lightningd/notification.c

@@ -2,6 +2,7 @@
 #include <common/json_helpers.h>
 #include <common/type_to_string.h>
 #include <lightningd/channel.h>
+#include <lightningd/coin_mvts.h>
 #include <lightningd/notification.h>
 
 static struct notification *find_notification_by_topic(const char* topic)
@@ -513,6 +514,43 @@ void notify_coin_mvt(struct lightningd *ld,
 	plugins_notify(ld->plugins, take(n));
 }
 
+static void balance_snapshot_notification_serialize(struct json_stream *stream, struct balance_snapshot *snap)
+{
+	json_object_start(stream, "balance_snapshot");
+	json_add_node_id(stream, "node_id", snap->node_id);
+	json_add_u32(stream, "blockheight", snap->blockheight);
+	json_add_u32(stream, "timestamp", snap->timestamp);
+
+	json_array_start(stream, "accounts");
+	for (size_t i = 0; i < tal_count(snap->accts); i++) {
+		json_object_start(stream, NULL);
+		json_add_string(stream, "account_id",
+				snap->accts[i]->acct_id);
+		json_add_amount_msat_only(stream, "balance",
+					  snap->accts[i]->balance);
+		json_add_string(stream, "coin_type", snap->accts[i]->bip173_name);
+		json_object_end(stream);
+	}
+	json_array_end(stream);
+	json_object_end(stream);
+}
+
+REGISTER_NOTIFICATION(balance_snapshot,
+		      balance_snapshot_notification_serialize);
+
+void notify_balance_snapshot(struct lightningd *ld,
+			     const struct balance_snapshot *snap)
+{
+	void (*serialize)(struct json_stream *,
+			  const struct balance_snapshot *) = balance_snapshot_notification_gen.serialize;
+
+	struct jsonrpc_notification *n =
+		jsonrpc_notification_start(NULL, "balance_snapshot");
+	serialize(n->stream, snap);
+	jsonrpc_notification_end(n);
+	plugins_notify(ld->plugins, take(n));
+}
+
 static void openchannel_peer_sigs_serialize(struct json_stream *stream,
 					    const struct channel_id *cid,
 					    const struct wally_psbt *psbt)

lightningd/notification.h

@@ -5,6 +5,7 @@
 #include <lightningd/pay.h>
 #include <lightningd/plugin.h>
 
+struct balance_snapshot;
 struct onionreply;
 struct wally_psbt;
 
@@ -81,6 +82,9 @@ void notify_sendpay_failure(struct lightningd *ld,
 void notify_coin_mvt(struct lightningd *ld,
 		     const struct coin_mvt *mvt);
 
+void notify_balance_snapshot(struct lightningd *ld,
+			     const struct balance_snapshot *snap);
+
 void notify_openchannel_peer_sigs(struct lightningd *ld,
 				  const struct channel_id *cid,
 				  const struct wally_psbt *psbt);