channel_hint: minor cleanups.

1. short_channel_id_dir should be passed by pointer, unlike short_channel_id.
2. "scid" is not a good name for a field which is not (just) an scid
   (The spec used sciddir_or_pubkey in drafts, so use sciddir).
3. ... nor is it a good member name, so fix that (we use scidd usually).
4. json_add_channel_hint is a more expected name than channel_hint_to_json.
5. Use amount_sat_to_msat instead of warning suppression.
6. Rename "total_amount" in "struct route_hop" to "capacity".

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

common/json_parse.c

@@ -5,6 +5,7 @@
 #include <bitcoin/privkey.h>
 #include <bitcoin/psbt.h>
 #include <bitcoin/pubkey.h>
+#include <bitcoin/short_channel_id.h>
 #include <bitcoin/tx.h>
 #include <ccan/json_escape/json_escape.h>
 #include <ccan/mem/mem.h>

common/json_parse.h

@@ -1,7 +1,6 @@
 #ifndef LIGHTNING_COMMON_JSON_PARSE_H
 #define LIGHTNING_COMMON_JSON_PARSE_H
 #include "config.h"
-#include <bitcoin/short_channel_id.h>
 #include <ccan/crypto/sha256/sha256.h>
 #include <common/coin_mvt.h>
 #include <common/errcode.h>
@@ -18,6 +17,7 @@ struct secret;
 struct pubkey;
 struct node_id;
 struct short_channel_id;
+struct short_channel_id_dir;
 struct amount_sat;
 struct amount_msat;
 struct bitcoin_txid;

common/json_stream.c

@@ -485,13 +485,13 @@ void json_add_short_channel_id(struct json_stream *response,
 }
 
 void json_add_short_channel_id_dir(struct json_stream *response,
-			       const char *fieldname,
-			       struct short_channel_id_dir scidd)
+				   const char *fieldname,
+				   const struct short_channel_id_dir *scidd)
 {
 	json_add_str_fmt(response, fieldname, "%dx%dx%d/%d",
-			 short_channel_id_blocknum(scidd.scid),
-			 short_channel_id_txnum(scidd.scid),
-			 short_channel_id_outnum(scidd.scid), scidd.dir);
+			 short_channel_id_blocknum(scidd->scid),
+			 short_channel_id_txnum(scidd->scid),
+			 short_channel_id_outnum(scidd->scid), scidd->dir);
 }
 
 static void json_add_address_fields(struct json_stream *response,

common/json_stream.h

@@ -28,7 +28,6 @@ struct channel_id;
 struct channel_type;
 struct bitcoin_txid;
 struct bitcoin_outpoint;
-struct short_channel_id;
 struct sha256;
 struct preimage;
 struct bitcoin_tx;
@@ -317,7 +316,7 @@ void json_add_short_channel_id(struct json_stream *response,
 /* '"fieldname" : "1234:5:6/1"' */
 void json_add_short_channel_id_dir(struct json_stream *response,
 				   const char *fieldname,
-				   struct short_channel_id_dir idd);
+				   const struct short_channel_id_dir *scidd);
 
 /* JSON serialize a network address for a node */
 void json_add_address(struct json_stream *response, const char *fieldname,

common/route.c

@@ -110,7 +110,8 @@ static bool dijkstra_to_hops(struct route_hop **hops,
 		return false;
 
 	gossmap_chan_get_capacity(gossmap, c, &total);
-	(*hops)[num_hops].total_amount.millisatoshis = total.satoshis * 1000; /* Raw: simpler. */
+	if (!amount_sat_to_msat(&(*hops)[num_hops].capacity, total))
+		abort();
 	(*hops)[num_hops].amount = *amount;
 	(*hops)[num_hops].delay = *cltv;
 

common/route.h

@@ -18,15 +18,15 @@ struct gossmap_node;
  * @direction: 0 (dest node_id < src node_id), 1 (dest node_id > src).
  * @node_id: the node_id of the destination of this hop.
  * @amount: amount to send through this hop.
- * @total_amount: The amount the channel was funded with.
+ * @capacity: The amount the channel was funded with.
  * @delay: total cltv delay at this hop.
  */
 struct route_hop {
 	struct short_channel_id scid;
 	int direction;
 	struct node_id node_id;
 	struct amount_msat amount;
-	struct amount_msat total_amount;
+	struct amount_msat capacity;
 	u32 delay;
 };
 

plugins/channel_hint.c

@@ -1,18 +1,19 @@
 #include "config.h"
 #include <plugins/channel_hint.h>
 
-void channel_hint_to_json(const char *name, const struct channel_hint *hint,
-			  struct json_stream *dest)
+void json_add_channel_hint(struct json_stream *js,
+			   const char *fieldname,
+			   const struct channel_hint *hint)
 {
-	json_object_start(dest, name);
-	json_add_u32(dest, "timestamp", hint->timestamp);
-	json_add_short_channel_id_dir(dest, "scid", hint->scid);
-	json_add_amount_msat(dest, "estimated_capacity_msat",
+	json_object_start(js, fieldname);
+	json_add_u32(js, "timestamp", hint->timestamp);
+	json_add_short_channel_id_dir(js, "sciddir", &hint->scidd);
+	json_add_amount_msat(js, "estimated_capacity_msat",
 			     hint->estimated_capacity);
-	json_add_amount_msat(dest, "overall_capacity_msat",
+	json_add_amount_msat(js, "overall_capacity_msat",
 			     hint->overall_capacity);
-	json_add_bool(dest, "enabled", hint->enabled);
-	json_object_end(dest);
+	json_add_bool(js, "enabled", hint->enabled);
+	json_object_end(js);
 }
 
 #define PAY_REFILL_TIME 7200
@@ -83,9 +84,9 @@ struct channel_hint *channel_hint_from_json(const tal_t *ctx,
 	const char *ret;
 	struct channel_hint *hint = tal(ctx, struct channel_hint);
 	ret = json_scan(ctx, buffer, toks,
-			"{timestamp:%,scid:%,estimated_capacity_msat:%,overall_capacity_msat:%,enabled:%}",
+			"{timestamp:%,sciddir:%,estimated_capacity_msat:%,overall_capacity_msat:%,enabled:%}",
 			JSON_SCAN(json_to_u32, &hint->timestamp),
-			JSON_SCAN(json_to_short_channel_id_dir, &hint->scid),
+			JSON_SCAN(json_to_short_channel_id_dir, &hint->scidd),
 			JSON_SCAN(json_to_msat, &hint->estimated_capacity),
 			JSON_SCAN(json_to_bool, &hint->enabled));
 

plugins/channel_hint.h

@@ -29,7 +29,7 @@ struct channel_hint {
 	 * local alias. The `pay` algorithm doesn't really care which
 	 * one it is, but we'll prefer the scid as that's likely more
 	 * readable than the alias. */
-	struct short_channel_id_dir scid;
+	struct short_channel_id_dir scidd;
 
 	/* Upper bound on remove channels inferred from payment failures. */
 	struct amount_msat estimated_capacity;
@@ -54,8 +54,10 @@ struct channel_hint_set {
 };
 
 bool channel_hint_update(const struct timeabs now,
-				struct channel_hint *hint);
+			 struct channel_hint *hint);
 
-void channel_hint_to_json(const char *name, const struct channel_hint *hint, struct json_stream *dest);
+void json_add_channel_hint(struct json_stream *js,
+			   const char *fieldname,
+			   const struct channel_hint *hint);
 
 #endif /* LIGHTNING_PLUGINS_CHANNEL_HINT_H */

plugins/libplugin-pay.c

@@ -401,12 +401,12 @@ static void channel_hint_notify(struct plugin *plugin,
 	    plugin_notification_start(plugin, "channel_hint_update");
 
 	/* The timestamp used to decay the observation over time. */
-	channel_hint_to_json("channel_hint", hint, js);
+	json_add_channel_hint(js, "channel_hint", hint);
 	plugin_notification_end(plugin, js);
 }
 
 static void channel_hints_update(struct payment *p,
-				 const struct short_channel_id scid,
+				 struct short_channel_id scid,
 				 int direction, bool enabled, bool local,
 				 const struct amount_msat *estimated_capacity,
 				 const struct amount_msat overall_capacity,
@@ -423,8 +423,8 @@ static void channel_hints_update(struct payment *p,
 	/* Try and look for an existing hint: */
 	for (size_t i=0; i<tal_count(root->channel_hints); i++) {
 		struct channel_hint *hint = &root->channel_hints[i];
-		if (short_channel_id_eq(hint->scid.scid, scid) &&
-		    hint->scid.dir == direction) {
+		if (short_channel_id_eq(hint->scidd.scid, scid) &&
+		    hint->scidd.dir == direction) {
 			bool modified = false;
 			/* Prefer to disable a channel. */
 			if (!enabled && hint->enabled) {
@@ -452,7 +452,7 @@ static void channel_hints_update(struct payment *p,
 					   "enabled %s, "
 					   "estimated capacity %s",
 					   fmt_short_channel_id_dir(tmpctx,
-						&hint->scid),
+						&hint->scidd),
 					   hint->enabled ? "true" : "false",
 					   fmt_amount_msat(tmpctx,
 						hint->estimated_capacity));
@@ -465,8 +465,8 @@ static void channel_hints_update(struct payment *p,
 	/* No hint found, create one. */
 	newhint.enabled = enabled;
 	newhint.timestamp = timestamp;
-	newhint.scid.scid = scid;
-	newhint.scid.dir = direction;
+	newhint.scidd.scid = scid;
+	newhint.scidd.dir = direction;
 	newhint.overall_capacity = overall_capacity;
 	if (local) {
 		newhint.local = tal(root->channel_hints, struct local_hint);
@@ -484,7 +484,7 @@ static void channel_hints_update(struct payment *p,
 	paymod_log(
 	    p, LOG_DBG,
 	    "Added a channel hint for %s: enabled %s, estimated capacity %s",
-	    fmt_short_channel_id_dir(tmpctx, &newhint.scid),
+	    fmt_short_channel_id_dir(tmpctx, &newhint.scidd),
 	    newhint.enabled ? "true" : "false",
 	    fmt_amount_msat(tmpctx, newhint.estimated_capacity));
 	channel_hint_notify(p->plugin, &newhint);
@@ -505,7 +505,7 @@ static void payment_exclude_most_expensive(struct payment *p)
 		}
 	}
 	channel_hints_update(p, e->scid, e->direction, false, false, NULL,
-			     e->total_amount, NULL);
+			     e->capacity, NULL);
 }
 
 static void payment_exclude_longest_delay(struct payment *p)
@@ -521,7 +521,7 @@ static void payment_exclude_longest_delay(struct payment *p)
 		}
 	}
 	channel_hints_update(p, e->scid, e->direction, false, false, NULL,
-			     e->total_amount, NULL);
+			     e->capacity, NULL);
 }
 
 static struct amount_msat payment_route_fee(struct payment *p)
@@ -565,8 +565,8 @@ static struct channel_hint *payment_chanhints_get(struct payment *p,
 	struct channel_hint *curhint;
 	for (size_t j = 0; j < tal_count(root->channel_hints); j++) {
 		curhint = &root->channel_hints[j];
-		if (short_channel_id_eq(curhint->scid.scid, h->scid) &&
-		    curhint->scid.dir == h->direction) {
+		if (short_channel_id_eq(curhint->scidd.scid, h->scid) &&
+		    curhint->scidd.dir == h->direction) {
 			return curhint;
 		}
 	}
@@ -619,7 +619,7 @@ static bool payment_chanhints_apply_route(struct payment *p)
 				   "for %s. Could be a concurrent "
 				   "`getroute` call.",
 				   fmt_short_channel_id_dir(tmpctx,
-							    &curhint->scid));
+							    &curhint->scidd));
 			paymod_log(
 			    p, LOG_DBG,
 			    "Capacity: estimated_capacity=%s, hop_amount=%s. "
@@ -701,16 +701,16 @@ payment_get_excluded_channels(const tal_t *ctx, struct payment *p)
 		hint = &root->channel_hints[i];
 
 		if (!hint->enabled)
-			tal_arr_expand(&res, hint->scid);
+			tal_arr_expand(&res, hint->scidd);
 
 		else if (amount_msat_greater(p->our_amount,
 					     hint->estimated_capacity))
-			tal_arr_expand(&res, hint->scid);
+			tal_arr_expand(&res, hint->scidd);
 
 		else if (hint->local && hint->local->htlc_budget == 0)
 			/* If we cannot add any HTLCs to the channel we
 			 * shouldn't look for a route through that channel */
-			tal_arr_expand(&res, hint->scid);
+			tal_arr_expand(&res, hint->scidd);
 	}
 	return res;
 }
@@ -728,8 +728,8 @@ static const struct channel_hint *find_hint(const struct channel_hint *hints,
 					    int dir)
 {
 	for (size_t i = 0; i < tal_count(hints); i++) {
-		if (short_channel_id_eq(scid, hints[i].scid.scid)
-		    && dir == hints[i].scid.dir)
+		if (short_channel_id_eq(scid, hints[i].scidd.scid)
+		    && dir == hints[i].scidd.dir)
 			return &hints[i];
 	}
 	return NULL;
@@ -1536,7 +1536,7 @@ handle_intermediate_failure(struct command *cmd,
 	case WIRE_REQUIRED_CHANNEL_FEATURE_MISSING:
 		/* All of these result in the channel being marked as disabled. */
 		channel_hints_update(root, errchan->scid, errchan->direction,
-				     false, false, NULL, errchan->total_amount,
+				     false, false, NULL, errchan->capacity,
 				     NULL);
 		break;
 
@@ -1555,7 +1555,7 @@ handle_intermediate_failure(struct command *cmd,
 		 * remember the amount we tried as an estimate. */
 		channel_hints_update(root, errchan->scid, errchan->direction,
 				     true, false, &estimated,
-				     errchan->total_amount, NULL);
+				     errchan->capacity, NULL);
 		goto error;
 	}
 
@@ -2876,7 +2876,7 @@ static bool routehint_excluded(struct payment *p,
 		 * channel, which is greater than the destination.
 		 */
 		for (size_t j = 0; j < tal_count(hints); j++) {
-			if (!short_channel_id_eq(hints[j].scid.scid, r->short_channel_id))
+			if (!short_channel_id_eq(hints[j].scidd.scid, r->short_channel_id))
 				continue;
 			/* We exclude on equality because we set the estimate
 			 * to the smallest failed attempt.  */
@@ -3173,7 +3173,7 @@ static void routehint_step_cb(struct routehints_data *d, struct payment *p)
 			hop.amount = dest_amount;
 			hop.delay = route_cltv(d->final_cltv, routehint + i + 1,
 					       tal_count(routehint) - i - 1);
-			hop.total_amount = estimate;
+			hop.capacity = estimate;
 
 			/* Should we get a failure inside the routehint we'll
 			 * need the direction so we can exclude it. Luckily
@@ -3525,7 +3525,7 @@ static void direct_pay_override(struct payment *p) {
 	/* If we have a channel we need to make sure that it still has
 	 * sufficient capacity. Look it up in the channel_hints. */
 	for (size_t i=0; i<tal_count(root->channel_hints); i++) {
-		struct short_channel_id_dir *cur = &root->channel_hints[i].scid;
+		struct short_channel_id_dir *cur = &root->channel_hints[i].scidd;
 		if (short_channel_id_eq(cur->scid, d->chan->scid) &&
 		    cur->dir == d->chan->dir) {
 			hint = &root->channel_hints[i];
@@ -3539,14 +3539,14 @@ static void direct_pay_override(struct payment *p) {
 		p->route = tal_arr(p, struct route_hop, 1);
 		p->route[0].amount = p->our_amount;
 		p->route[0].delay = p->getroute->cltv;
-		p->route[0].scid = hint->scid.scid;
-		p->route[0].direction = hint->scid.dir;
+		p->route[0].scid = hint->scidd.scid;
+		p->route[0].direction = hint->scidd.dir;
 		p->route[0].node_id = *p->route_destination;
-		p->route[0].total_amount = hint->overall_capacity;
+		p->route[0].capacity = hint->overall_capacity;
 		paymod_log(p, LOG_DBG,
 			   "Found a direct channel (%s) with sufficient "
 			   "capacity, skipping route computation.",
-			   fmt_short_channel_id_dir(tmpctx, &hint->scid));
+			   fmt_short_channel_id_dir(tmpctx, &hint->scidd));
 
 		payment_set_step(p, PAYMENT_STEP_GOT_ROUTE);
 	}

plugins/test/run-route-calc.c

@@ -123,7 +123,7 @@ void json_add_short_channel_id(struct json_stream *response UNNEEDED,
 /* Generated stub for json_add_short_channel_id_dir */
 void json_add_short_channel_id_dir(struct json_stream *response UNNEEDED,
 				   const char *fieldname UNNEEDED,
-				   struct short_channel_id_dir idd UNNEEDED)
+				   const struct short_channel_id_dir *scidd UNNEEDED)
 { fprintf(stderr, "json_add_short_channel_id_dir called!\n"); abort(); }
 /* Generated stub for json_add_string */
 void json_add_string(struct json_stream *js UNNEEDED,

plugins/test/run-route-overlong.c

@@ -121,7 +121,7 @@ void json_add_short_channel_id(struct json_stream *response UNNEEDED,
 /* Generated stub for json_add_short_channel_id_dir */
 void json_add_short_channel_id_dir(struct json_stream *response UNNEEDED,
 				   const char *fieldname UNNEEDED,
-				   struct short_channel_id_dir idd UNNEEDED)
+				   const struct short_channel_id_dir *scidd UNNEEDED)
 { fprintf(stderr, "json_add_short_channel_id_dir called!\n"); abort(); }
 /* Generated stub for json_add_string */
 void json_add_string(struct json_stream *js UNNEEDED,

wallet/test/run-wallet.c

@@ -1002,7 +1002,7 @@ void topology_add_sync_waiter_(const tal_t *ctx UNNEEDED,
 u8 *towire_announcement_signatures(const tal_t *ctx UNNEEDED, const struct channel_id *channel_id UNNEEDED, struct short_channel_id short_channel_id UNNEEDED, const secp256k1_ecdsa_signature *node_signature UNNEEDED, const secp256k1_ecdsa_signature *bitcoin_signature UNNEEDED)
 { fprintf(stderr, "towire_announcement_signatures called!\n"); abort(); }
 /* Generated stub for towire_channel_reestablish */
-u8 *towire_channel_reestablish(const tal_t *ctx UNNEEDED, const struct channel_id *channel_id UNNEEDED, u64 next_commitment_number UNNEEDED, u64 next_revocation_number UNNEEDED, const struct secret *your_last_per_commitment_secret UNNEEDED, const struct pubkey *my_current_per_commitment_point UNNEEDED, const struct tlv_channel_reestablish_tlvs *tlvs UNNEEDED)
+u8 *towire_channel_reestablish(const tal_t *ctx UNNEEDED, const struct channel_id *channel_id UNNEEDED, u64 next_commitment_number UNNEEDED, u64 next_revocation_number UNNEEDED, const struct secret *your_last_per_commitment_secret UNNEEDED, const struct pubkey *my_current_per_commitment_point UNNEEDED, const struct tlv_channel_reestablish_tlvs *channel_reestablish UNNEEDED)
 { fprintf(stderr, "towire_channel_reestablish called!\n"); abort(); }
 /* Generated stub for towire_channeld_dev_memleak */
 u8 *towire_channeld_dev_memleak(const tal_t *ctx UNNEEDED)