lightningd: Load persisted channels on startup

This is the big one, and it's completely anticlimactic: it loads all
channels that have reached opening and are not marked as
closingd_complete into memory, that's it.

Signed-off-by: Christian Decker <decker.christian@gmail.com>

lightningd/lightningd.c

@@ -267,6 +267,15 @@ int main(int argc, char *argv[])
 		       /* FIXME: Load from peers. */
 		       0);
 
+	/* Load peers from database */
+	wallet_channels_load_active(ld->wallet, &ld->peers);
+	struct peer *peer;
+	list_for_each(&ld->peers, peer, list) {
+		populate_peer(ld, peer);
+		peer->seed = tal(peer, struct privkey);
+		derive_peer_seed(ld, peer->seed, &peer->id);
+	}
+
 	/* Create RPC socket (if any) */
 	setup_jsonrpc(&ld->dstate, ld->dstate.rpc_filename);
 

lightningd/peer_control.c

@@ -550,6 +550,23 @@ static struct wallet_channel *peer_channel_new(struct wallet *w,
 	return wc;
 }
 
+void populate_peer(struct lightningd *ld, struct peer *peer)
+{
+	const char *idname;
+	struct pubkey *id = &peer->id;
+	idname = type_to_string(peer, struct pubkey, id);
+
+	peer->ld = ld;
+
+	/* Max 128k per peer. */
+	peer->log_book = new_log_book(peer, 128*1024,
+				      get_log_level(ld->dstate.log_book));
+	peer->log = new_log(peer, peer->log_book, "peer %s:", idname);
+	set_log_outfn(peer->log_book, copy_to_parent_log, peer);
+	tal_free(idname);
+	tal_add_destructor(peer, destroy_peer);
+}
+
 void add_peer(struct lightningd *ld, u64 unique_id,
 	      int fd, const struct pubkey *id,
 	      const struct crypto_state *cs)
@@ -598,14 +615,6 @@ void add_peer(struct lightningd *ld, u64 unique_id,
 	/* peer->channel gets populated as soon as we start opening a channel */
 	peer->channel = NULL;
 
-	idname = type_to_string(peer, struct pubkey, id);
-
-	/* Max 128k per peer. */
-	peer->log_book = new_log_book(peer, 128*1024,
-				      get_log_level(ld->dstate.log_book));
-	peer->log = new_log(peer, peer->log_book, "peer %s:", idname);
-	set_log_outfn(peer->log_book, copy_to_parent_log, peer);
-
 	/* FIXME: Don't assume protocol here! */
 	if (!netaddr_from_fd(fd, SOCK_STREAM, IPPROTO_TCP, &peer->netaddr)) {
 		log_unusual(ld->log, "Failed to get netaddr for outgoing: %s",
@@ -613,11 +622,14 @@ void add_peer(struct lightningd *ld, u64 unique_id,
 		tal_free(peer);
 		return;
 	}
+	list_add_tail(&ld->peers, &peer->list);
+	populate_peer(ld, peer);
+
+	idname = type_to_string(peer, struct pubkey, id);
 	netname = netaddr_name(idname, &peer->netaddr);
 	log_info(peer->log, "Connected from %s", netname);
+
 	tal_free(idname);
-	list_add_tail(&ld->peers, &peer->list);
-	tal_add_destructor(peer, destroy_peer);
 
 	/* Let gossip handle it from here. */
 	peer->owner = peer->ld->gossip;

lightningd/peer_control.h

@@ -158,6 +158,18 @@ void add_peer(struct lightningd *ld, u64 unique_id,
 	      int fd, const struct pubkey *id,
 	      const struct crypto_state *cs);
 
+/**
+ * populate_peer -- Populate daemon fields in a peer
+ *
+ * @ld: the daemon to wire the peer into
+ * @peer: the peer to populate
+ *
+ * Creating a new peer, or loading a peer from the database we need to
+ * populate a number of fields, e.g., the logging handler and the
+ * pointer to the daemon. populate_peer does exactly that.
+ */
+void populate_peer(struct lightningd *ld, struct peer *peer);
+
 /* Could be configurable. */
 #define OUR_CHANNEL_FLAGS CHANNEL_FLAGS_ANNOUNCE_CHANNEL
 

tests/test_lightningd.py

@@ -47,10 +47,10 @@ def setupBitcoind():
         bitcoind.rpc.generate(1)
 
 
-def wait_for(success, timeout=30):
+def wait_for(success, timeout=30, interval=0.1):
     start_time = time.time()
     while not success() and time.time() < start_time + timeout:
-        pass
+        time.sleep(interval)
     if time.time() > start_time + timeout:
         raise ValueError("Error waiting for {}", success)
 
@@ -875,17 +875,21 @@ class LightningDTests(BaseLightningDTests):
         for n in (l1, l2):
             assert(n.db_query('SELECT COUNT(id) as count FROM channels;')[0]['count'] == 1)
 
-        l1.daemon.stop()
+        l2.daemon.stop()
 
         # Let the other side notice, then stop it
-        wait_for(lambda: not l2.rpc.getpeers()['peers'][0]['connected'])
-        l2.daemon.stop()
+        wait_for(lambda: not l1.rpc.getpeers()['peers'][0]['connected'])
+        #l1.daemon.stop()
 
         # Now restart l1 and it should reload peers/channels from the DB
-        l1.daemon.start()
+        l2.daemon.start()
+        wait_for(lambda: len(l2.rpc.getpeers()['peers']) == 1)
 
-        #wait_for(lambda: len(l1.rpc.getpeers()['peers']) == 1)
+        wait_for(lambda: len([p for p in l1.rpc.getpeers()['peers'] if p['connected']]), interval=1)
+        wait_for(lambda: len([p for p in l2.rpc.getpeers()['peers'] if p['connected']]), interval=1)
 
+        # Now make sure this is really functional by sending a payment
+        self.pay(l1, l2, 10000)
 
 class LegacyLightningDTests(BaseLightningDTests):
 

wallet/wallet.c

@@ -591,6 +591,27 @@ bool wallet_channel_load(struct wallet *w, const u64 id,
 	return ok;
 }
 
+bool wallet_channels_load_active(struct wallet *w, struct list_head *peers)
+{
+	bool ok = true;
+	/* Channels are active if they have reached at least the
+	 * opening state and they are not marked as complete */
+	sqlite3_stmt *stmt = db_query(
+	    __func__, w->db, "SELECT %s FROM channels WHERE state >= %d AND state != %d;",
+	    channel_fields, OPENINGD, CLOSINGD_COMPLETE);
+
+	int count = 0;
+	while (ok && stmt && sqlite3_step(stmt) == SQLITE_ROW) {
+		struct wallet_channel *c = talz(w, struct wallet_channel);
+		ok &= wallet_stmt2channel(w, stmt, c);
+		list_add(peers, &c->peer->list);
+		count++;
+	}
+	log_debug(w->log, "Loaded %d channels from DB", count);
+	sqlite3_finalize(stmt);
+	return ok;
+}
+
 static char* db_serialize_signature(const tal_t *ctx, secp256k1_ecdsa_signature* sig)
 {
 	u8 buf[64];

wallet/wallet.h

@@ -4,6 +4,7 @@
 #include "config.h"
 #include "db.h"
 #include <ccan/crypto/shachain/shachain.h>
+#include <ccan/list/list.h>
 #include <ccan/tal/tal.h>
 #include <lightningd/channel_config.h>
 #include <lightningd/utxo.h>
@@ -197,4 +198,16 @@ bool wallet_channel_config_load(struct wallet *w, const u64 id,
  */
 bool wallet_peer_by_nodeid(struct wallet *w, const struct pubkey *nodeid,
 			   struct peer *peer);
+
+/**
+ * wlalet_channels_load_active -- Load persisted active channels into the peers
+ *
+ * @w: wallet to load from
+ * @peers: list_head to load channels/peers into
+ *
+ * Be sure to call this only once on startup since it'll append peers
+ * loaded from the database to the list without checking.
+ */
+bool wallet_channels_load_active(struct wallet *w, struct list_head *peers);
+
 #endif /* WALLET_WALLET_H */