From 34052f996021e9c5848205c2f9694026f0fd43cd Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Tue, 9 Jul 2024 18:11:44 +0930
Subject: [PATCH] bitcoin: hoist scid hash into common code.

A second user is coming.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 bitcoin/short_channel_id.h   | 7 ++++++-
 plugins/renepay/chan_extra.h | 8 +-------
 2 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/bitcoin/short_channel_id.h b/bitcoin/short_channel_id.h
index 46133e0d9..8dd2dacb5 100644
--- a/bitcoin/short_channel_id.h
+++ b/bitcoin/short_channel_id.h
@@ -3,7 +3,6 @@
 #include "config.h"
 #include <ccan/compiler/compiler.h>
 #include <ccan/short_types/short_types.h>
-#include <ccan/structeq/structeq.h>
 #include <ccan/tal/tal.h>
 #include <common/gossip_constants.h>
 
@@ -19,6 +18,12 @@ static inline bool short_channel_id_eq(struct short_channel_id a,
 	return a.u64 == b.u64;
 }
 
+static inline size_t short_channel_id_hash(struct short_channel_id scid)
+{
+	/* scids cost money to generate, so simple hash works here */
+	return (scid.u64 >> 32) ^ (scid.u64 >> 16) ^ scid.u64;
+}
+
 /* BOLT #7:
  *
  * - MUST set `node_id_1` and `node_id_2` to the public keys of the two nodes
diff --git a/plugins/renepay/chan_extra.h b/plugins/renepay/chan_extra.h
index 478e5904f..7a3982358 100644
--- a/plugins/renepay/chan_extra.h
+++ b/plugins/renepay/chan_extra.h
@@ -44,19 +44,13 @@ chan_extra_scid(const struct chan_extra *cd)
 	return cd->scid;
 }
 
-static inline size_t hash_scid(const struct short_channel_id scid)
-{
-	/* scids cost money to generate, so simple hash works here */
-	return (scid.u64 >> 32) ^ (scid.u64 >> 16) ^ scid.u64;
-}
-
 static inline bool chan_extra_eq_scid(const struct chan_extra *cd,
 				      const struct short_channel_id scid)
 {
 	return short_channel_id_eq(scid, cd->scid);
 }
 
-HTABLE_DEFINE_TYPE(struct chan_extra, chan_extra_scid, hash_scid,
+HTABLE_DEFINE_TYPE(struct chan_extra, chan_extra_scid, short_channel_id_hash,
 		   chan_extra_eq_scid, chan_extra_map);
 
 /* Helpers for chan_extra_map */