lightningd: only trim old UTXO entries after gossipd acks block.

If it gets really far behind, then we restart, it could miss some.

Signed-off-by: Rusty Russell <[email protected]>

Author: rustyrussell

lightningd/gossip_control.c

@@ -222,6 +222,10 @@ static void gossipd_new_blockheight_reply(struct subd *gossipd,
 
 	/* Now, finally update getinfo's blockheight */
 	gossipd->ld->gossip_blockheight = ptr2int(blockheight);
+
+	/* And use that to trim old entries in the UTXO set */
+	wallet_utxoset_prune(gossipd->ld->wallet,
+			     gossipd->ld->gossip_blockheight);
 }
 
 void gossip_notify_new_block(struct lightningd *ld, u32 blockheight)

wallet/wallet.c

@@ -4198,7 +4198,7 @@ bool wallet_sanity_check(struct wallet *w)
 /**
  * wallet_utxoset_prune -- Remove spent UTXO entries that are old
  */
-static void wallet_utxoset_prune(struct wallet *w, const u32 blockheight)
+void wallet_utxoset_prune(struct wallet *w, u32 blockheight)
 {
 	struct db_stmt *stmt;
 
@@ -4236,9 +4236,6 @@ void wallet_block_add(struct wallet *w, struct block *b)
 		db_bind_null(stmt);
 	}
 	db_exec_prepared_v2(take(stmt));
-
-	/* Now cleanup UTXOs that we don't care about anymore */
-	wallet_utxoset_prune(w, b->height);
 }
 
 void wallet_block_remove(struct wallet *w, struct block *b)

wallet/wallet.h

@@ -1135,6 +1135,9 @@ void wallet_utxoset_add(struct wallet *w,
 const struct short_channel_id *
 wallet_utxoset_get_spent(const tal_t *ctx, struct wallet *w, u32 blockheight);
 
+/* Prune all UTXO entries spent (far) below this block height */
+void wallet_utxoset_prune(struct wallet *w, u32 blockheight);
+
 /**
  * Retrieve all UTXO entries that were created at a given blockheight.
  */