tx: remove allocating script fetchers

The pattern of making tal-allocated copies of wally data to pass around
was made redundant after these calls were added by the use of
tal_wally_start/tal_wally_end to parent wally allocations. We can thus
just pass the data directly and avoid the allocations.

Removes redundant allocations when checking tx filters and computing fees.

Signed-off-by: Jon Griffiths <jon_p_griffiths@yahoo.com>

bitcoin/tx.c

@@ -302,28 +302,6 @@ void bitcoin_tx_output_set_amount(struct bitcoin_tx *tx, int outnum,
 	wally_psbt_output_set_amount(&tx->psbt->outputs[outnum], satoshis);
 }
 
-const u8 *cln_wally_tx_output_get_script(const tal_t *ctx,
-					 const struct wally_tx_output *output)
-{
-	if (output->script == NULL) {
-		/* This can happen for coinbase transactions and pegin
-		 * transactions */
-		return NULL;
-	}
-
-	return tal_dup_arr(ctx, u8, output->script, output->script_len, 0);
-}
-
-const u8 *bitcoin_tx_output_get_script(const tal_t *ctx,
-				       const struct bitcoin_tx *tx, int outnum)
-{
-	const struct wally_tx_output *output;
-	assert(outnum < tx->wtx->num_outputs);
-	output = &tx->wtx->outputs[outnum];
-
-	return cln_wally_tx_output_get_script(ctx, output);
-}
-
 u8 *bitcoin_tx_output_get_witscript(const tal_t *ctx, const struct bitcoin_tx *tx,
 				    int outnum)
 {

bitcoin/tx.h

@@ -144,25 +144,6 @@ wally_tx_output_get_amount(const struct wally_tx_output *output);
 void bitcoin_tx_output_set_amount(struct bitcoin_tx *tx, int outnum,
 				  struct amount_sat amount);
 
-/**
- * Helper to get the script of a script's output as a tal_arr
- *
- * Internally we use a `wally_tx` to represent the transaction. The script
- * attached to a `wally_tx_output` is not a `tal_arr`, so in order to keep the
- * comfort of being able to call `tal_bytelen` and similar on a script we just
- * return a `tal_arr` clone of the original script.
- */
-const u8 *bitcoin_tx_output_get_script(const tal_t *ctx, const struct bitcoin_tx *tx, int outnum);
-
-/**
- * Helper to get the script of a script's output as a tal_arr
- *
- * The script attached to a `wally_tx_output` is not a `tal_arr`, so in order to keep the
- * comfort of being able to call `tal_bytelen` and similar on a script we just
- * return a `tal_arr` clone of the original script.
- */
-const u8 *cln_wally_tx_output_get_script(const tal_t *ctx,
-					 const struct wally_tx_output *output);
 /**
  * Helper to get a witness script for an output.
  */

lightningd/chaintopology.c

@@ -61,6 +61,7 @@ static bool we_broadcast(const struct chain_topology *topo,
 
 static void filter_block_txs(struct chain_topology *topo, struct block *b)
 {
+	struct txfilter *filter = topo->bitcoind->ld->owned_txfilter;
 	size_t i;
 	struct amount_sat owned;
 
@@ -89,21 +90,22 @@ static void filter_block_txs(struct chain_topology *topo, struct block *b)
 
 		owned = AMOUNT_SAT(0);
 		txid = b->txids[i];
-		if (txfilter_match(topo->bitcoind->ld->owned_txfilter, tx)) {
+		if (txfilter_match(filter, tx)) {
 			wallet_extract_owned_outputs(topo->bitcoind->ld->wallet,
 						     tx->wtx, is_coinbase, &b->height, &owned);
 			wallet_transaction_add(topo->ld->wallet, tx->wtx,
 					       b->height, i);
 			// invoice_check_onchain_payment(tx);
 			for (size_t k = 0; k < tx->wtx->num_outputs; k++) {
-				const u8 *oscript = bitcoin_tx_output_get_script(tmpctx, tx, k);
-				if (txfilter_scriptpubkey_matches(topo->bitcoind->ld->owned_txfilter, oscript)) {
+				const struct wally_tx_output *txout;
+				txout = &tx->wtx->outputs[k];
+				if (txfilter_scriptpubkey_matches(filter, txout->script)) {
 					struct amount_sat amount;
 					struct bitcoin_outpoint outpoint;
 					outpoint.txid = txid;
 					outpoint.n = k;
 					bitcoin_tx_output_get_amount_sat(tx, k, &amount);
-					invoice_check_onchain_payment(topo->ld, oscript, amount, &outpoint);
+					invoice_check_onchain_payment(topo->ld, txout->script, amount, &outpoint);
 				}
 			}
 

lightningd/closing_control.c

@@ -179,19 +179,15 @@ static struct amount_sat calc_tx_fee(struct amount_sat sat_in,
 {
 	struct amount_asset amt;
 	struct amount_sat fee = sat_in;
-	const u8 *oscript;
-	size_t scriptlen;
-	for (size_t i = 0; i < tx->wtx->num_outputs; i++) {
-		amt = bitcoin_tx_output_get_amount(tx, i);
-		oscript = bitcoin_tx_output_get_script(NULL, tx, i);
-		scriptlen = tal_bytelen(oscript);
-		tal_free(oscript);
 
-		if (chainparams->is_elements && scriptlen == 0)
+	for (size_t i = 0; i < tx->wtx->num_outputs; i++) {
+		const struct wally_tx_output *txout = &tx->wtx->outputs[i];
+		if (chainparams->is_elements && !txout->script_len)
 			continue;
 
 		/* Ignore outputs that are not denominated in our main
 		 * currency. */
+		amt = bitcoin_tx_output_get_amount(tx, i);
 		if (!amount_asset_is_main(&amt))
 			continue;
 

wallet/txfilter.c

@@ -84,19 +84,17 @@ void txfilter_add_derkey(struct txfilter *filter,
 bool txfilter_match(const struct txfilter *filter, const struct bitcoin_tx *tx)
 {
 	for (size_t i = 0; i < tx->wtx->num_outputs; i++) {
-		const u8 *oscript = bitcoin_tx_output_get_script(tmpctx, tx, i);
-
-		if (!oscript)
-			continue;
-
-		if (scriptpubkeyset_get(&filter->scriptpubkeyset, oscript))
+		const struct wally_tx_output *txout = &tx->wtx->outputs[i];
+		if (txfilter_scriptpubkey_matches(filter, txout->script))
 			return true;
 	}
 	return false;
 }
 
 bool txfilter_scriptpubkey_matches(const struct txfilter *filter, const u8 *scriptPubKey)
 {
+	if (!scriptPubKey)
+		return false;
 	return scriptpubkeyset_get(&filter->scriptpubkeyset, scriptPubKey) != NULL;
 }