From b24b7f90c434ee3532e54f74a5e7838bc7e37479 Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 13 Oct 2021 14:15:36 +1030
Subject: [PATCH] lightningd: use bitcoin_outpoint in watch.

This makes more sense than two args.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 lightningd/chaintopology.c |  4 ++--
 lightningd/watch.c         | 22 +++++++++++-----------
 lightningd/watch.h         | 12 +++---------
 3 files changed, 16 insertions(+), 22 deletions(-)

diff --git a/lightningd/chaintopology.c b/lightningd/chaintopology.c
index 17244bb02..09702f179 100644
--- a/lightningd/chaintopology.c
+++ b/lightningd/chaintopology.c
@@ -72,10 +72,10 @@ static void filter_block_txs(struct chain_topology *topo, struct block *b)
 
 		/* Tell them if it spends a txo we care about. */
 		for (j = 0; j < tx->wtx->num_inputs; j++) {
-			struct txwatch_output out;
+			struct bitcoin_outpoint out;
 			struct txowatch *txo;
 			bitcoin_tx_input_get_txid(tx, j, &out.txid);
-			out.index = tx->wtx->inputs[j].index;
+			out.n = tx->wtx->inputs[j].index;
 
 			txo = txowatch_hash_get(&topo->txowatches, &out);
 			if (txo) {
diff --git a/lightningd/watch.c b/lightningd/watch.c
index 34cc8ce4e..123d6e036 100644
--- a/lightningd/watch.c
+++ b/lightningd/watch.c
@@ -40,7 +40,7 @@ struct txowatch {
 	struct channel *channel;
 
 	/* Output to watch. */
-	struct txwatch_output out;
+	struct bitcoin_outpoint out;
 
 	/* A new tx. */
 	enum watch_result (*cb)(struct channel *channel,
@@ -71,24 +71,24 @@ struct txwatch {
 				unsigned int depth);
 };
 
-const struct txwatch_output *txowatch_keyof(const struct txowatch *w)
+const struct bitcoin_outpoint *txowatch_keyof(const struct txowatch *w)
 {
 	return &w->out;
 }
 
-size_t txo_hash(const struct txwatch_output *out)
+size_t txo_hash(const struct bitcoin_outpoint *out)
 {
 	/* This hash-in-one-go trick only works if they're consecutive. */
-	BUILD_ASSERT(offsetof(struct txwatch_output, index)
-		     == sizeof(((struct txwatch_output *)NULL)->txid));
-	return siphash24(siphash_seed(), &out->txid,
-			 sizeof(out->txid) + sizeof(out->index));
+	BUILD_ASSERT(offsetof(struct bitcoin_outpoint, n)
+		     == sizeof(((struct bitcoin_outpoint *)NULL)->txid));
+	return siphash24(siphash_seed(), out,
+			 sizeof(out->txid) + sizeof(out->n));
 }
 
-bool txowatch_eq(const struct txowatch *w, const struct txwatch_output *out)
+bool txowatch_eq(const struct txowatch *w, const struct bitcoin_outpoint *out)
 {
 	return bitcoin_txid_eq(&w->out.txid, &out->txid)
-		&& w->out.index == out->index;
+		&& w->out.n == out->n;
 }
 
 static void destroy_txowatch(struct txowatch *w)
@@ -198,7 +198,7 @@ struct txowatch *watch_txo(const tal_t *ctx,
 
 	w->topo = topo;
 	w->out.txid = *txid;
-	w->out.index = output;
+	w->out.n = output;
 	w->channel = channel;
 	w->cb = cb;
 
@@ -266,7 +266,7 @@ void txowatch_fire(const struct txowatch *txow,
 	log_debug(txow->channel->log,
 		  "Got UTXO spend for %s:%u: %s",
 		  type_to_string(tmpctx, struct bitcoin_txid, &txow->out.txid),
-		  txow->out.index,
+		  txow->out.n,
 		  type_to_string(tmpctx, struct bitcoin_txid, &txid));
 
 	r = txow->cb(txow->channel, tx, input_num, block);
diff --git a/lightningd/watch.h b/lightningd/watch.h
index fc67b43c1..348c50fbf 100644
--- a/lightningd/watch.h
+++ b/lightningd/watch.h
@@ -4,7 +4,6 @@
 #include <bitcoin/tx.h>
 #include <ccan/htable/htable_type.h>
 
-struct bitcoin_tx;
 struct block;
 struct channel;
 struct chain_topology;
@@ -17,14 +16,9 @@ enum watch_result {
 	KEEP_WATCHING = -2
 };
 
-struct txwatch_output {
-	struct bitcoin_txid txid;
-	unsigned int index;
-};
-
-const struct txwatch_output *txowatch_keyof(const struct txowatch *w);
-size_t txo_hash(const struct txwatch_output *out);
-bool txowatch_eq(const struct txowatch *w, const struct txwatch_output *out);
+const struct bitcoin_outpoint *txowatch_keyof(const struct txowatch *w);
+size_t txo_hash(const struct bitcoin_outpoint *out);
+bool txowatch_eq(const struct txowatch *w, const struct bitcoin_outpoint *out);
 
 HTABLE_DEFINE_TYPE(struct txowatch, txowatch_keyof, txo_hash, txowatch_eq,
 		   txowatch_hash);