bitcoin: hash_scid and hash_scidd public functions.

We reimplemented this redundantly: hash_scid was called
short_channel_id_hash, so I obviously missed it.

Rename, and implement hash_scidd helper too.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Author: rustyrussell

bitcoin/short_channel_id.h

@@ -17,7 +17,7 @@ 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)
+static inline size_t hash_scid(struct short_channel_id scid)
 {
 	/* scids cost money to generate, so simple hash works here */
 	return (scid.u64 >> 32) ^ (scid.u64 >> 16) ^ scid.u64;
@@ -46,6 +46,12 @@ static inline bool short_channel_id_dir_eq(const struct short_channel_id_dir *a,
 	return short_channel_id_eq(a->scid, b->scid) && a->dir == b->dir;
 }
 
+static inline size_t hash_scidd(const struct short_channel_id_dir *scidd)
+{
+	/* Bottom bit is common, so use bit 4 for direction */
+	return hash_scid(scidd->scid) | (scidd->dir << 4);
+}
+
 static inline u32 short_channel_id_blocknum(struct short_channel_id scid)
 {
 	return scid.u64 >> 40;

common/gossmap.c

@@ -29,11 +29,7 @@ static bool chanidx_eq_id(const ptrint_t *pidx,
 	struct short_channel_id pidxid = chanidx_id(pidx);
 	return short_channel_id_eq(pidxid, scid);
 }
-static size_t scid_hash(const struct short_channel_id scid)
-{
-	return siphash24(siphash_seed(), &scid, sizeof(scid));
-}
-HTABLE_DEFINE_NODUPS_TYPE(ptrint_t, chanidx_id, scid_hash, chanidx_eq_id,
+HTABLE_DEFINE_NODUPS_TYPE(ptrint_t, chanidx_id, hash_scid, chanidx_eq_id,
 			  chanidx_htable);
 
 static struct node_id nodeidx_id(const ptrint_t *pidx);

connectd/connectd.h

@@ -260,7 +260,7 @@ static bool scid_to_node_id_eq_scid(const struct scid_to_node_id *scid_to_node_i
  * we use this to forward onion messages which specify the next hop by scid/dir. */
 HTABLE_DEFINE_NODUPS_TYPE(struct scid_to_node_id,
 			  scid_to_node_id_keyof,
-			  short_channel_id_hash,
+			  hash_scid,
 			  scid_to_node_id_eq_scid,
 			  scid_htable);
 

lightningd/channel.h

@@ -891,7 +891,7 @@ static inline bool scid_to_channel_eq_scid(const struct scid_to_channel *scidcha
 /* Define channel_scid_map */
 HTABLE_DEFINE_NODUPS_TYPE(struct scid_to_channel,
 			  scid_to_channel_key,
-			  short_channel_id_hash,
+			  hash_scid,
 			  scid_to_channel_eq_scid,
 			  channel_scid_map);
 

plugins/askrene/askrene.h

@@ -95,12 +95,4 @@ static inline struct askrene *get_askrene(struct plugin *plugin)
 {
 	return plugin_get_data(plugin, struct askrene);
 }
-
-/* Convenience routine for hash tables */
-static inline size_t hash_scidd(const struct short_channel_id_dir *scidd)
-{
-	/* scids cost money to generate, so simple hash works here */
-	return (scidd->scid.u64 >> 32) ^ (scidd->scid.u64 >> 16) ^ (scidd->scid.u64 << 1) ^ scidd->dir;
-}
-
 #endif /* LIGHTNING_PLUGINS_ASKRENE_ASKRENE_H */

plugins/askrene/layer.c

@@ -81,12 +81,6 @@ local_channel_scid(const struct local_channel *lc)
 	return lc->scid;
 }
 
-static 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 local_channel_eq_scid(const struct local_channel *lc,
 					 const struct short_channel_id scid)
 {

plugins/channel_hint.c

@@ -3,15 +3,6 @@
 #include <common/memleak.h>
 #include <plugins/channel_hint.h>
 
-size_t channel_hint_hash(const struct short_channel_id_dir *out)
-{
-	struct siphash24_ctx ctx;
-	siphash24_init(&ctx, siphash_seed());
-	siphash24_update(&ctx, &out->scid.u64, sizeof(u64));
-	siphash24_update(&ctx, &out->dir, sizeof(int));
-	return siphash24_done(&ctx);
-}
-
 const struct short_channel_id_dir *channel_hint_keyof(const struct channel_hint *out)
 {
 	return &out->scid;
@@ -20,8 +11,7 @@ const struct short_channel_id_dir *channel_hint_keyof(const struct channel_hint
 bool channel_hint_eq(const struct channel_hint *a,
 		     const struct short_channel_id_dir *b)
 {
-	return short_channel_id_eq(a->scid.scid, b->scid) &&
-		a->scid.dir == b->dir;
+	return short_channel_id_dir_eq(&a->scid, b);
 }
 
 void channel_hint_to_json(const char *name, const struct channel_hint *hint,

plugins/channel_hint.h

@@ -40,15 +40,13 @@ struct channel_hint {
 	struct amount_msat capacity;
 };
 
-size_t channel_hint_hash(const struct short_channel_id_dir *out);
-
 const struct short_channel_id_dir *channel_hint_keyof(const struct channel_hint *out);
 
 bool channel_hint_eq(const struct channel_hint *a,
 		     const struct short_channel_id_dir *b);
 
 HTABLE_DEFINE_NODUPS_TYPE(struct channel_hint, channel_hint_keyof,
-			  channel_hint_hash, channel_hint_eq, channel_hint_map)
+			  hash_scidd, channel_hint_eq, channel_hint_map)
 
 /* A collection of channel_hint instances, allowing us to handle and
  * update them more easily. */

plugins/renepay/chan_extra.h

@@ -50,7 +50,8 @@ static inline bool chan_extra_eq_scid(const struct chan_extra *cd,
 	return short_channel_id_eq(scid, cd->scid);
 }
 
-HTABLE_DEFINE_NODUPS_TYPE(struct chan_extra, chan_extra_scid, short_channel_id_hash,
+HTABLE_DEFINE_NODUPS_TYPE(struct chan_extra, chan_extra_scid,
+			  hash_scid,
 			  chan_extra_eq_scid,
 			  chan_extra_map);
 

plugins/renepay/disabledmap.c

@@ -47,7 +47,7 @@ void disabledmap_add_channel(struct disabledmap *p,
 			     struct short_channel_id_dir scidd)
 {
 	struct short_channel_id_dir *ptr_scidd =
-	    scidd_map_get(p->disabled_map, scidd);
+	    scidd_map_get(p->disabled_map, &scidd);
 	if (ptr_scidd) {
 		/* htable allows for duplicates, but we don't want duplicates.
 		 */
@@ -64,7 +64,7 @@ void disabledmap_warn_channel(struct disabledmap *p,
 			      struct short_channel_id_dir scidd)
 {
 	struct short_channel_id_dir *ptr_scidd =
-	    scidd_map_get(p->warned_map, scidd);
+	    scidd_map_get(p->warned_map, &scidd);
 	if (ptr_scidd) {
 		/* htable allows for duplicates, but we don't want duplicates.
 		 */
@@ -84,7 +84,7 @@ void disabledmap_add_node(struct disabledmap *p, struct node_id node)
 bool disabledmap_channel_is_warned(struct disabledmap *p,
 				   struct short_channel_id_dir scidd)
 {
-	return scidd_map_get(p->warned_map, scidd) != NULL;
+	return scidd_map_get(p->warned_map, &scidd) != NULL;
 }
 
 bitmap *tal_disabledmap_get_bitmap(const tal_t *ctx, struct disabledmap *p,