wallet: Store channel to db whenever something changes

This is as coarse grained as it can get, and therefore slow, but it'll
store the channel (sans HTLCs) to database so we can recover them upon
restart.

lightningd/peer_control.c

@@ -229,7 +229,11 @@ void peer_set_condition(struct peer *peer, enum peer_state old_state,
 		fatal("peer state %s should be %s",
 		      peer_state_name(peer->state), peer_state_name(old_state));
 
-	/* FIXME: save to db */
+	/* TODO(cdecker) Selectively save updated fields to DB */
+	if (!wallet_channel_save(peer->ld->wallet, peer->channel)) {
+		fatal("Could not save channel to database: %s",
+		      peer->ld->wallet->db->err);
+	}
 	peer->state = state;
 }
 
@@ -511,6 +515,37 @@ static void copy_to_parent_log(const char *prefix,
 	tal_free(idstr);
 }
 
+/**
+ * peer_channel_new -- Instantiate a new channel for the given peer and save it
+ *
+ * We are about to open a channel with the peer, either due to a
+ * nongossip message from remote, or because we initiated an
+ * open. This creates the `struct wallet_channel` for the peer and
+ * stores it in the database.
+ *
+ * @w: the wallet to store the information in
+ * @peer: the peer we are opening a channel to
+ *
+ * This currently overwrites peer->channel, so can only be used if we
+ * allow a single channel per peer.
+ */
+static struct wallet_channel *peer_channel_new(struct wallet *w,
+					       struct peer *peer)
+{
+	struct wallet_channel *wc = tal(peer, struct wallet_channel);
+	wc->peer = peer;
+
+	/* TODO(cdecker) See if we already stored this peer in the DB and load if yes */
+	wc->peer_id = 0;
+	wc->id = 0;
+
+	if (!wallet_channel_save(w, wc)) {
+		fatal("Unable to save channel to database: %s", w->db->err);
+	}
+
+	return wc;
+}
+
 void add_peer(struct lightningd *ld, u64 unique_id,
 	      int fd, const struct pubkey *id,
 	      const struct crypto_state *cs)
@@ -551,6 +586,8 @@ void add_peer(struct lightningd *ld, u64 unique_id,
 	peer->htlcs = tal_arr(peer, struct htlc_stub, 0);
 	wallet_shachain_init(ld->wallet, &peer->their_shachain);
 
+	peer->channel = peer_channel_new(ld->wallet, peer);
+
 	idname = type_to_string(peer, struct pubkey, id);
 
 	/* Max 128k per peer. */
@@ -1202,8 +1239,6 @@ static int peer_got_shutdown(struct peer *peer, const u8 *msg)
 		return -1;
 	}
 
-	/* FIXME: Save to db */
-
 	if (peer->local_shutdown_idx == -1) {
 		u8 *scriptpubkey;
 
@@ -1213,7 +1248,6 @@ static int peer_got_shutdown(struct peer *peer, const u8 *msg)
 					    "Can't get local shutdown index");
 			return -1;
 		}
-		/* FIXME: Save to db */
 
 		peer_set_condition(peer, CHANNELD_NORMAL, CHANNELD_SHUTTING_DOWN);
 
@@ -1244,6 +1278,12 @@ static int peer_got_shutdown(struct peer *peer, const u8 *msg)
 								scriptpubkey)));
 	}
 
+	/* TODO(cdecker) Selectively save updated fields to DB */
+	if (!wallet_channel_save(peer->ld->wallet, peer->channel)) {
+		fatal("Could not save channel to database: %s",
+		      peer->ld->wallet->db->err);
+	}
+
 	return 0;
 }
 
@@ -1350,9 +1390,15 @@ static int peer_received_closing_signature(struct peer *peer, const u8 *msg)
 	}
 
 	/* FIXME: Make sure signature is correct! */
+	if (better_closing_fee(peer, tx)) {
+		/* TODO(cdecker) Selectively save updated fields to DB */
+		if (!wallet_channel_save(peer->ld->wallet, peer->channel)) {
+			fatal("Could not save channel to database: %s",
+			      peer->ld->wallet->db->err);
+		}
 
-	if (better_closing_fee(peer, tx))
 		peer_last_tx(peer, tx, &sig);
+	}
 
 	/* OK, you can continue now. */
 	subd_send_msg(peer->owner,
@@ -1702,8 +1748,6 @@ static bool peer_start_channeld(struct peer *peer,
 static bool peer_commit_initial(struct peer *peer)
 {
 	peer->next_index[LOCAL] = peer->next_index[REMOTE] = 1;
-
-	/* FIXME: Db channel_info, etc. */
 	return true;
 }
 
@@ -1728,6 +1772,9 @@ static bool opening_funder_finished(struct subd *opening, const u8 *resp,
 		= tal(fc->peer, struct channel_info);
 	remote_commit = tal(resp, struct bitcoin_tx);
 
+	/* This is a new channel_info->their_config so set its ID to 0 */
+	fc->peer->channel_info->their_config.id = 0;
+
 	if (!fromwire_opening_funder_reply(resp, NULL,
 					   &channel_info->their_config,
 					   remote_commit,
@@ -1830,6 +1877,9 @@ static bool opening_fundee_finished(struct subd *opening,
 
 	/* At this point, we care about peer */
 	peer->channel_info = channel_info = tal(peer, struct channel_info);
+	/* This is a new channel_info->their_config, set its ID to 0 */
+	peer->channel_info->their_config.id = 0;
+
 	peer->funding_txid = tal(peer, struct sha256_double);
 	if (!fromwire_opening_fundee_reply(peer, reply, NULL,
 					   &channel_info->their_config,
@@ -1921,37 +1971,6 @@ static void channel_config(struct lightningd *ld,
 	 ours->channel_reserve_satoshis = 0;
 };
 
-/**
- * peer_channel_new -- Instantiate a new channel for the given peer and save it
- *
- * We are about to open a channel with the peer, either due to a
- * nongossip message from remote, or because we initiated an
- * open. This creates the `struct wallet_channel` for the peer and
- * stores it in the database.
- *
- * @w: the wallet to store the information in
- * @peer: the peer we are opening a channel to
- *
- * This currently overwrites peer->channel, so can only be used if we
- * allow a single channel per peer.
- */
-static struct wallet_channel *peer_channel_new(struct wallet *w,
-					       struct peer *peer)
-{
-	struct wallet_channel *wc = tal(peer, struct wallet_channel);
-	wc->peer = peer;
-
-	/* TODO(cdecker) See if we already stored this peer in the DB and load if yes */
-	wc->peer_id = 0;
-	wc->id = 0;
-
-	if (!wallet_channel_save(w, wc)) {
-		fatal("Unable to save channel to database: %s", w->db->err);
-	}
-
-	return wc;
-}
-
 /* Peer has spontaneously exited from gossip due to msg */
 void peer_fundee_open(struct peer *peer, const u8 *from_peer,
 		      const struct crypto_state *cs,