Update weights

The existing transaction weights were placeholder values.

This PR updates the weights to be more representative of their cost in
disk and bandwidth usage.

A single input is 57 bytes, and output is 737 B and a kernel is 147 B.
Normalising an input weight to one, an output would be 12.9 and a kernel 2.6.

There is one kernel per transaction; and one header per block. We can't
know what the header contribution is per transaction, but by rounding
the kernel weight to 3, each transaction can "pay" for a little part of
the header.

Rounding the output weight to 13 makes very little difference to
the overall arithmetic.

Overall, this makes every transaction, regardless of number of in- or
outputs roughly the same weight per byte; around 57 ±  bytes/weight.

Several tests were updated that used fees in theor assertions to account
for the new weights; typically by reducing the fee per gram specified in
the test transactions.

base_layer/core/src/mempool/orphan_pool/orphan_pool.rs

@@ -168,12 +168,12 @@ mod test {
 
     #[test]
     fn test_insert_rlu_and_ttl() {
-        let tx1 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(500), lock: 4000, inputs: 2, outputs: 1).0);
-        let tx2 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(300), lock: 3000, inputs: 2, outputs: 1).0);
-        let tx3 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(100), lock: 2500, inputs: 2, outputs: 1).0);
-        let tx4 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(200), lock: 1000, inputs: 2, outputs: 1).0);
-        let tx5 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(500), lock: 2000, inputs: 2, outputs: 1).0);
-        let tx6 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(600), lock: 5500, inputs: 2, outputs: 1).0);
+        let tx1 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(500), lock: 4000, inputs: 2, outputs: 1).0);
+        let tx2 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(300), lock: 3000, inputs: 2, outputs: 1).0);
+        let tx3 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(100), lock: 2500, inputs: 2, outputs: 1).0);
+        let tx4 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(200), lock: 1000, inputs: 2, outputs: 1).0);
+        let tx5 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(500), lock: 2000, inputs: 2, outputs: 1).0);
+        let tx6 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(600), lock: 5500, inputs: 2, outputs: 1).0);
         let network = Network::LocalNet;
         let consensus_manager = ConsensusManagerBuilder::new(network).build();
         let store = create_mem_db(&consensus_manager);

base_layer/core/src/mempool/pending_pool/pending_pool.rs

@@ -254,7 +254,7 @@ mod test {
 
     #[test]
     fn test_insert_and_lru() {
-        let tx1 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(50), lock: 500, inputs: 2, outputs: 1).0);
+        let tx1 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(49), lock: 500, inputs: 2, outputs: 1).0);
         let tx2 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(20), lock: 2150, inputs: 1, outputs: 2).0);
         let tx3 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(100), lock: 1000, inputs: 2, outputs: 1).0);
         let tx4 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(30), lock: 2450, inputs: 2, outputs: 2).0);
@@ -276,7 +276,7 @@ mod test {
         assert_eq!(pending_pool.len(), 3);
         assert_eq!(
             pending_pool.has_tx_with_excess_sig(&tx1.body.kernels()[0].excess_sig),
-            true
+            false
         );
         assert_eq!(
             pending_pool.has_tx_with_excess_sig(&tx2.body.kernels()[0].excess_sig),
@@ -292,7 +292,7 @@ mod test {
         );
         assert_eq!(
             pending_pool.has_tx_with_excess_sig(&tx5.body.kernels()[0].excess_sig),
-            false
+            true
         );
         assert_eq!(
             pending_pool.has_tx_with_excess_sig(&tx6.body.kernels()[0].excess_sig),

base_layer/core/src/mempool/priority/prioritized_transaction.rs

@@ -32,6 +32,7 @@ pub struct FeePriority(Vec<u8>);
 
 impl FeePriority {
     pub fn try_from(transaction: &Transaction) -> Result<Self, PriorityError> {
+        // The weights have been normalised, so the fee priority is now equal to the fee per gram ± a few pct points
         let fee_per_byte = (transaction.calculate_ave_fee_per_gram() * 1000.0) as usize; // Include 3 decimal places before flooring
         let mut fee_priority = fee_per_byte.to_binary()?;
         fee_priority.reverse(); // Requires Big-endian for BtreeMap sorting

base_layer/core/src/mempool/reorg_pool/reorg_pool.rs

@@ -146,12 +146,12 @@ mod test {
 
     #[test]
     fn test_insert_rlu_and_ttl() {
-        let tx1 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(500), lock: 4000, inputs: 2, outputs: 1).0);
-        let tx2 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(300), lock: 3000, inputs: 2, outputs: 1).0);
-        let tx3 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(100), lock: 2500, inputs: 2, outputs: 1).0);
-        let tx4 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(200), lock: 1000, inputs: 2, outputs: 1).0);
-        let tx5 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(500), lock: 2000, inputs: 2, outputs: 1).0);
-        let tx6 = Arc::new(tx!(MicroTari(10_000), fee: MicroTari(600), lock: 5500, inputs: 2, outputs: 1).0);
+        let tx1 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(500), lock: 4000, inputs: 2, outputs: 1).0);
+        let tx2 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(300), lock: 3000, inputs: 2, outputs: 1).0);
+        let tx3 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(100), lock: 2500, inputs: 2, outputs: 1).0);
+        let tx4 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(200), lock: 1000, inputs: 2, outputs: 1).0);
+        let tx5 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(500), lock: 2000, inputs: 2, outputs: 1).0);
+        let tx6 = Arc::new(tx!(MicroTari(100_000), fee: MicroTari(600), lock: 5500, inputs: 2, outputs: 1).0);
 
         let reorg_pool = ReorgPool::new(ReorgPoolConfig {
             storage_capacity: 3,

base_layer/core/src/mempool/unconfirmed_pool/unconfirmed_pool.rs

@@ -239,7 +239,7 @@ mod test {
         let tx2 = Arc::new(tx!(MicroTari(5_000), fee: MicroTari(20), inputs: 4, outputs: 1).0);
         let tx3 = Arc::new(tx!(MicroTari(5_000), fee: MicroTari(100), inputs: 5, outputs: 1).0);
         let tx4 = Arc::new(tx!(MicroTari(5_000), fee: MicroTari(30), inputs: 3, outputs: 1).0);
-        let tx5 = Arc::new(tx!(MicroTari(5_000), fee: MicroTari(50), inputs: 5, outputs: 1).0);
+        let tx5 = Arc::new(tx!(MicroTari(5_000), fee: MicroTari(55), inputs: 5, outputs: 1).0);
 
         let mut unconfirmed_pool = UnconfirmedPool::new(UnconfirmedPoolConfig {
             storage_capacity: 4,
@@ -270,12 +270,12 @@ mod test {
             true
         );
         // Retrieve the set of highest priority unspent transactions
-        let desired_weight = tx1.calculate_weight() + tx3.calculate_weight() + tx4.calculate_weight();
+        let desired_weight = tx1.calculate_weight() + tx3.calculate_weight() + tx5.calculate_weight();
         let selected_txs = unconfirmed_pool.highest_priority_txs(desired_weight).unwrap();
         assert_eq!(selected_txs.len(), 3);
         assert!(selected_txs.contains(&tx1));
         assert!(selected_txs.contains(&tx3));
-        assert!(selected_txs.contains(&tx4));
+        assert!(selected_txs.contains(&tx5));
         // Note that transaction tx5 could not be included as its weight was to big to fit into the remaining allocated
         // space, the second best transaction was then included
 

base_layer/core/src/transactions/aggregated_body.rs

@@ -270,7 +270,7 @@ impl AggregateBody {
 
     /// Returns the byte size or weight of a body
     pub fn calculate_weight(&self) -> u64 {
-        Fee::calculate_weight(self.inputs().len(), self.outputs().len())
+        Fee::calculate_weight(self.kernels().len(), self.inputs().len(), self.outputs().len())
     }
 }
 

base_layer/core/src/transactions/fee.rs

@@ -25,19 +25,25 @@ use crate::transactions::{tari_amount::*, transaction::MINIMUM_TRANSACTION_FEE};
 pub struct Fee {}
 
 pub const WEIGHT_PER_INPUT: u64 = 1;
-pub const WEIGHT_PER_OUTPUT: u64 = 4;
-pub const BASE_COST: u64 = 1;
+pub const WEIGHT_PER_OUTPUT: u64 = 13;
+pub const KERNEL_WEIGHT: u64 = 3; // Constant weight per transaction; covers kernel and part of header.
 
 impl Fee {
     /// Computes the absolute transaction fee given the fee-per-gram, and the size of the transaction
-    pub fn calculate(fee_per_gram: MicroTari, num_inputs: usize, num_outputs: usize) -> MicroTari {
-        (BASE_COST + Fee::calculate_weight(num_inputs, num_outputs) * u64::from(fee_per_gram)).into()
+    pub fn calculate(fee_per_gram: MicroTari, num_kernels: usize, num_inputs: usize, num_outputs: usize) -> MicroTari {
+        (Fee::calculate_weight(num_kernels, num_inputs, num_outputs) * u64::from(fee_per_gram)).into()
     }
 
     /// Computes the absolute transaction fee using `calculate`, but the resulting fee will always be at least the
     /// minimum network transaction fee.
-    pub fn calculate_with_minimum(fee_per_gram: MicroTari, num_inputs: usize, num_outputs: usize) -> MicroTari {
-        let fee = Fee::calculate(fee_per_gram, num_inputs, num_outputs);
+    pub fn calculate_with_minimum(
+        fee_per_gram: MicroTari,
+        num_kernels: usize,
+        num_inputs: usize,
+        num_outputs: usize,
+    ) -> MicroTari
+    {
+        let fee = Fee::calculate(fee_per_gram, num_kernels, num_inputs, num_outputs);
         if fee < MINIMUM_TRANSACTION_FEE {
             MINIMUM_TRANSACTION_FEE
         } else {
@@ -46,7 +52,9 @@ impl Fee {
     }
 
     /// Calculate the weight of a transaction based on the number of inputs and outputs
-    pub fn calculate_weight(num_inputs: usize, num_outputs: usize) -> u64 {
-        WEIGHT_PER_INPUT * num_inputs as u64 + WEIGHT_PER_OUTPUT * num_outputs as u64
+    pub fn calculate_weight(num_kernels: usize, num_inputs: usize, num_outputs: usize) -> u64 {
+        KERNEL_WEIGHT * num_kernels as u64 +
+            WEIGHT_PER_INPUT * num_inputs as u64 +
+            WEIGHT_PER_OUTPUT * num_outputs as u64
     }
 }

base_layer/core/src/transactions/helpers.rs

@@ -264,7 +264,7 @@ pub fn create_tx(
     unblinded_inputs.push(input.clone());
     stx_builder.with_input(utxo, input);
 
-    let estimated_fee = Fee::calculate(fee_per_gram, input_count as usize, output_count as usize);
+    let estimated_fee = Fee::calculate(fee_per_gram, 1, input_count as usize, output_count as usize);
     let amount_per_output = (amount - estimated_fee) / output_count;
     let amount_for_last_output = (amount - estimated_fee) - amount_per_output * (output_count - 1);
     for i in 0..output_count {

base_layer/core/src/transactions/transaction_protocol/sender.rs

@@ -557,7 +557,7 @@ mod test {
         let b = TestParams::new();
         let (utxo, input) = make_input(&mut OsRng, MicroTari(1200), &factories.commitment);
         let mut builder = SenderTransactionProtocol::builder(1);
-        let fee = Fee::calculate(MicroTari(20), 1, 1);
+        let fee = Fee::calculate(MicroTari(20), 1, 1, 1);
         builder
             .with_lock_height(0)
             .with_fee_per_gram(MicroTari(20))
@@ -615,7 +615,7 @@ mod test {
         let b = TestParams::new();
         let (utxo, input) = make_input(&mut OsRng, MicroTari(2500), &factories.commitment);
         let mut builder = SenderTransactionProtocol::builder(1);
-        let fee = Fee::calculate(MicroTari(20), 1, 2);
+        let fee = Fee::calculate(MicroTari(20), 1, 1, 2);
         builder
             .with_lock_height(0)
             .with_fee_per_gram(MicroTari(20))

base_layer/core/src/transactions/transaction_protocol/transaction_initializer.rs

@@ -169,8 +169,8 @@ impl SenderTransactionInitializer {
 
         let total_amount = self.amounts.sum().ok_or_else(|| "Not all amounts have been provided")?;
         let fee_per_gram = self.fee_per_gram.ok_or_else(|| "Fee per gram was not provided")?;
-        let fee_without_change = Fee::calculate(fee_per_gram, num_inputs, num_outputs);
-        let fee_with_change = Fee::calculate(fee_per_gram, num_inputs, num_outputs + 1);
+        let fee_without_change = Fee::calculate(fee_per_gram, 1, num_inputs, num_outputs);
+        let fee_with_change = Fee::calculate(fee_per_gram, 1, num_inputs, num_outputs + 1);
         let extra_fee = fee_with_change - fee_without_change;
         // Subtract with a check on going negative
         let change_amount = total_being_spent.checked_sub(total_to_self + total_amount + fee_without_change);
@@ -313,7 +313,7 @@ impl SenderTransactionInitializer {
 #[cfg(test)]
 mod test {
     use crate::transactions::{
-        fee::{Fee, BASE_COST, WEIGHT_PER_INPUT, WEIGHT_PER_OUTPUT},
+        fee::{Fee, KERNEL_WEIGHT, WEIGHT_PER_INPUT, WEIGHT_PER_OUTPUT},
         helpers::{make_input, TestParams},
         tari_amount::*,
         transaction::{UnblindedOutput, MAX_TRANSACTION_INPUTS},
@@ -347,10 +347,10 @@ mod test {
             .with_offset(p.offset)
             .with_private_nonce(p.nonce);
         builder.with_output(UnblindedOutput::new(MicroTari(100), p.spend_key, None));
-        let (utxo, input) = make_input(&mut OsRng, MicroTari(500), &factories.commitment);
+        let (utxo, input) = make_input(&mut OsRng, MicroTari(5_000), &factories.commitment);
         builder.with_input(utxo, input);
         builder.with_fee_per_gram(MicroTari(20));
-        let expected_fee = Fee::calculate(MicroTari(20), 1, 2);
+        let expected_fee = Fee::calculate(MicroTari(20), 1, 1, 2);
         // We needed a change input, so this should fail
         let err = builder.build::<Blake256>(&factories).unwrap_err();
         assert_eq!(err.message, "Change spending key was not provided");
@@ -380,7 +380,7 @@ mod test {
         let factories = CryptoFactories::default();
         let p = TestParams::new();
         let (utxo, input) = make_input(&mut OsRng, MicroTari(500), &factories.commitment);
-        let expected_fee = Fee::calculate(MicroTari(20), 1, 1);
+        let expected_fee = Fee::calculate(MicroTari(20), 1, 1, 1);
         let output = UnblindedOutput::new(MicroTari(500) - expected_fee, p.spend_key, None);
         // Start the builder
         let mut builder = SenderTransactionInitializer::new(0);
@@ -414,8 +414,9 @@ mod test {
         let factories = CryptoFactories::default();
         let p = TestParams::new();
         let (utxo, input) = make_input(&mut OsRng, MicroTari(500), &factories.commitment);
-        let expected_fee = MicroTari::from(BASE_COST + (WEIGHT_PER_INPUT + 1 * WEIGHT_PER_OUTPUT) * 20); // 101, output = 80
-                                                                                                         // Pay out so that I should get change, but not enough to pay for the output
+        let expected_fee = MicroTari::from((KERNEL_WEIGHT + WEIGHT_PER_INPUT + 1 * WEIGHT_PER_OUTPUT) * 20);
+        // fee == 340, output = 80
+        // Pay out so that I should get change, but not enough to pay for the output
         let output = UnblindedOutput::new(MicroTari(500) - expected_fee - MicroTari(50), p.spend_key, None);
         // Start the builder
         let mut builder = SenderTransactionInitializer::new(0);
@@ -511,7 +512,7 @@ mod test {
         // Create some inputs
         let factories = CryptoFactories::default();
         let p = TestParams::new();
-        let (utxo, input) = make_input(&mut OsRng, MicroTari(1000), &factories.commitment);
+        let (utxo, input) = make_input(&mut OsRng, MicroTari(100_000), &factories.commitment);
         let output = UnblindedOutput::new(MicroTari(150), p.spend_key, None);
         // Start the builder
         let mut builder = SenderTransactionInitializer::new(2);
@@ -542,7 +543,7 @@ mod test {
         let (utxo1, input1) = make_input(&mut OsRng, MicroTari(2000), &factories.commitment);
         let (utxo2, input2) = make_input(&mut OsRng, MicroTari(3000), &factories.commitment);
         let weight = MicroTari(30);
-        let expected_fee = Fee::calculate(weight, 2, 3);
+        let expected_fee = Fee::calculate(weight, 1, 2, 3);
         let output = UnblindedOutput::new(MicroTari(1500) - expected_fee, p.spend_key, None);
         // Start the builder
         let mut builder = SenderTransactionInitializer::new(1);

base_layer/core/tests/mempool.rs

@@ -164,7 +164,7 @@ fn test_insert_and_process_published_block() {
     assert_eq!(stats.orphan_txs, 1);
     assert_eq!(stats.timelocked_txs, 2);
     assert_eq!(stats.published_txs, 0);
-    assert_eq!(stats.total_weight, 36);
+    assert_eq!(stats.total_weight, 120);
 
     // Spend tx2, so it goes in Reorg pool, tx5 matures, so goes in Unconfirmed pool
     generate_block(
@@ -219,7 +219,7 @@ fn test_insert_and_process_published_block() {
     assert_eq!(stats.orphan_txs, 1);
     assert_eq!(stats.timelocked_txs, 1);
     assert_eq!(stats.published_txs, 1);
-    assert_eq!(stats.total_weight, 36);
+    assert_eq!(stats.total_weight, 120);
 }
 
 #[test]
@@ -501,15 +501,15 @@ fn request_response_get_stats() {
     bob.mempool.insert(orphan1.clone()).unwrap();
     bob.mempool.insert(orphan2.clone()).unwrap();
 
-    // The coinbase tx cannot be spent until maturity, so rxn1 will be in the timelocked pool. The other 2 txns are
+    // The coinbase tx cannot be spent until maturity, so txn1 will be in the timelocked pool. The other 2 txns are
     // orphans.
     let stats = bob.mempool.stats().unwrap();
     assert_eq!(stats.total_txs, 3);
     assert_eq!(stats.orphan_txs, 2);
     assert_eq!(stats.unconfirmed_txs, 0);
     assert_eq!(stats.timelocked_txs, 1);
     assert_eq!(stats.published_txs, 0);
-    assert_eq!(stats.total_weight, 35);
+    assert_eq!(stats.total_weight, 116);
 
     runtime.block_on(async {
         // Alice will request mempool stats from Bob, and thus should be identical
@@ -519,7 +519,7 @@ fn request_response_get_stats() {
         assert_eq!(received_stats.orphan_txs, 2);
         assert_eq!(received_stats.timelocked_txs, 1);
         assert_eq!(received_stats.published_txs, 0);
-        assert_eq!(received_stats.total_weight, 35);
+        assert_eq!(received_stats.total_weight, 116);
 
         alice.comms.shutdown().await;
         bob.comms.shutdown().await;

base_layer/wallet/src/output_manager_service/service.rs

@@ -545,7 +545,7 @@ where
             );
         }
 
-        let fee_without_change = Fee::calculate(fee_per_gram, outputs.len(), 1);
+        let fee_without_change = Fee::calculate(fee_per_gram, 1, outputs.len(), 1);
         let mut change_key: Option<PrivateKey> = None;
         // If the input values > the amount to be sent + fees_without_change then we will need to include a change
         // output
@@ -681,8 +681,8 @@ where
             outputs.push(o.clone());
             total += o.value;
             // I am assuming that the only output will be the payment output and change if required
-            fee_without_change = Fee::calculate(fee_per_gram, outputs.len(), 1);
-            fee_with_change = Fee::calculate(fee_per_gram, outputs.len(), 2);
+            fee_without_change = Fee::calculate(fee_per_gram, 1, outputs.len(), 1);
+            fee_with_change = Fee::calculate(fee_per_gram, 1, outputs.len(), 2);
 
             if total == amount + fee_without_change || total >= amount + fee_with_change {
                 break;

base_layer/wallet/src/testnet_utils.rs

@@ -678,7 +678,7 @@ pub fn receive_test_transaction<
         .runtime
         .block_on(wallet.transaction_service.test_accept_transaction(
             OsRng.next_u64(),
-            MicroTari::from(10_000 + OsRng.next_u64() % 10_1000),
+            MicroTari::from(10_000 + OsRng.next_u64() % 101_000),
             public_key,
         ))?;
 

base_layer/wallet/src/transaction_service/service.rs

@@ -1718,7 +1718,7 @@ where
         fake_oms.add_output(uo).await?;
 
         let mut stp = fake_oms
-            .prepare_transaction_to_send(amount, MicroTari::from(100), None, "".to_string())
+            .prepare_transaction_to_send(amount, MicroTari::from(25), None, "".to_string())
             .await?;
 
         let msg = stp.build_single_round_message()?;

base_layer/wallet/tests/output_manager_service/service.rs

@@ -273,7 +273,7 @@ fn send_no_change<T: OutputManagerBackend + 'static>(backend: T) {
     let (mut oms, _, _shutdown, _) = setup_output_manager_service(&mut runtime, backend);
 
     let fee_per_gram = MicroTari::from(20);
-    let fee_without_change = Fee::calculate(fee_per_gram, 2, 1);
+    let fee_without_change = Fee::calculate(fee_per_gram, 1, 2, 1);
     let key1 = PrivateKey::random(&mut OsRng);
     let value1 = 500;
     runtime
@@ -347,7 +347,7 @@ fn send_not_enough_for_change<T: OutputManagerBackend + 'static>(backend: T) {
     let (mut oms, _, _shutdown, _) = setup_output_manager_service(&mut runtime, backend);
 
     let fee_per_gram = MicroTari::from(20);
-    let fee_without_change = Fee::calculate(fee_per_gram, 2, 1);
+    let fee_without_change = Fee::calculate(fee_per_gram, 1, 2, 1);
     let key1 = PrivateKey::random(&mut OsRng);
     let value1 = 500;
     runtime