Mempool tweaks (#524)

* Some mempool tweaks

* Change mempool tx eviction policy

* Add test_evict

* Some fixes

* clippy

* move to estimated size

* remove estimated_size field

* remove clippy allow

* Fix clippy warnings

* Mempool evict policy -- a few fixes  (#7)

* comments and logs

* validate in context before execute rbf + note

* use a dedicated mempool_estimated_bytes fn

* fix redeemers check

* make sure we found enough space (not sure about this, might be better to remove the assert in the calling function and turn into if)

* reorganize checks

* include tx itself in redeemers

* Add comment to test_evict

* Add case to test_evict

* Remove explicit check for too big transactions

* Raise DEFAULT_MEMPOOL_SIZE_LIMIT to 1GB

---------

Co-authored-by: Michael Sutton <mikisiton2@gmail.com>

consensus/core/src/tx.rs

@@ -8,6 +8,7 @@ pub use script_public_key::{
     scriptvec, ScriptPublicKey, ScriptPublicKeyT, ScriptPublicKeyVersion, ScriptPublicKeys, ScriptVec, SCRIPT_VECTOR_SIZE,
 };
 use serde::{Deserialize, Serialize};
+use std::collections::HashSet;
 use std::sync::atomic::AtomicU64;
 use std::sync::atomic::Ordering::SeqCst;
 use std::{
@@ -437,6 +438,37 @@ impl<T: AsRef<Transaction>> MutableTransaction<T> {
             None
         }
     }
+
+    /// A function for estimating the amount of memory bytes used by this transaction (dedicated to mempool usage).
+    /// We need consistency between estimation calls so only this function should be used for this purpose since
+    /// `estimate_mem_bytes` is sensitive to pointer wrappers such as Arc
+    pub fn mempool_estimated_bytes(&self) -> usize {
+        self.estimate_mem_bytes()
+    }
+
+    pub fn has_parent(&self, possible_parent: TransactionId) -> bool {
+        self.tx.as_ref().inputs.iter().any(|x| x.previous_outpoint.transaction_id == possible_parent)
+    }
+
+    pub fn has_parent_in_set(&self, possible_parents: &HashSet<TransactionId>) -> bool {
+        self.tx.as_ref().inputs.iter().any(|x| possible_parents.contains(&x.previous_outpoint.transaction_id))
+    }
+}
+
+impl<T: AsRef<Transaction>> MemSizeEstimator for MutableTransaction<T> {
+    fn estimate_mem_bytes(&self) -> usize {
+        size_of::<Self>()
+            + self
+                .entries
+                .iter()
+                .map(|op| {
+                    // size_of::<Option<UtxoEntry>>() already counts SCRIPT_VECTOR_SIZE bytes within, so we only add the delta
+                    size_of::<Option<UtxoEntry>>()
+                        + op.as_ref().map_or(0, |e| e.script_public_key.script().len().saturating_sub(SCRIPT_VECTOR_SIZE))
+                })
+                .sum::<usize>()
+            + self.tx.as_ref().estimate_mem_bytes()
+    }
 }
 
 impl<T: AsRef<Transaction>> AsRef<Transaction> for MutableTransaction<T> {

mining/errors/src/mempool.rs

@@ -33,9 +33,9 @@ pub enum RuleError {
     #[error("replace by fee found more than one double spending transaction in the mempool")]
     RejectRbfTooManyDoubleSpendingTransactions,
 
-    /// New behavior: a transaction is rejected if the mempool is full
-    #[error("number of high-priority transactions in mempool ({0}) has reached the maximum allowed ({1})")]
-    RejectMempoolIsFull(usize, u64),
+    /// a transaction is rejected if the mempool is full
+    #[error("transaction could not be added to the mempool because it's full with transactions with higher priority")]
+    RejectMempoolIsFull,
 
     /// An error emitted by mining\src\mempool\check_transaction_standard.rs
     #[error("transaction {0} is not standard: {1}")]

mining/src/manager.rs

@@ -836,6 +836,11 @@ impl MiningManager {
     pub fn unknown_transactions(&self, transactions: Vec<TransactionId>) -> Vec<TransactionId> {
         self.mempool.read().unknown_transactions(transactions)
     }
+
+    #[cfg(test)]
+    pub(crate) fn get_estimated_size(&self) -> usize {
+        self.mempool.read().get_estimated_size()
+    }
 }
 
 /// Async proxy for the mining manager

mining/src/manager_tests.rs

@@ -10,7 +10,7 @@ mod tests {
             model::frontier::selectors::TakeAllSelector,
             tx::{Orphan, Priority, RbfPolicy},
         },
-        model::tx_query::TransactionQuery,
+        model::{tx_insert::TransactionInsertion, tx_query::TransactionQuery},
         testutils::consensus_mock::ConsensusMock,
         MiningCounters,
     };
@@ -35,6 +35,7 @@ mod tests {
         pay_to_address_script, pay_to_script_hash_signature_script,
         test_helpers::{create_transaction, create_transaction_with_change, op_true_script},
     };
+    use kaspa_utils::mem_size::MemSizeEstimator;
     use std::{iter::once, sync::Arc};
     use tokio::sync::mpsc::{error::TryRecvError, unbounded_channel};
 
@@ -1116,6 +1117,71 @@ mod tests {
         // TODO: extend the test according to the golang scenario
     }
 
+    // This is a sanity test for the mempool eviction policy. We check that if the mempool reached to its maximum
+    // (in bytes) a high paying transaction will evict as much transactions as needed so it can enter the
+    // mempool.
+    // TODO: Add a test where we try to add a heavy transaction with fee rate that's higher than some of the mempool
+    // transactions, but not enough, so the transaction will be rejected nonetheless.
+    #[test]
+    fn test_evict() {
+        const TX_COUNT: usize = 10;
+        let txs = (0..TX_COUNT).map(|i| create_transaction_with_utxo_entry(i as u32, 0)).collect_vec();
+
+        let consensus = Arc::new(ConsensusMock::new());
+        let counters = Arc::new(MiningCounters::default());
+        let mut config = Config::build_default(TARGET_TIME_PER_BLOCK, false, MAX_BLOCK_MASS);
+        let tx_size = txs[0].mempool_estimated_bytes();
+        let size_limit = TX_COUNT * tx_size;
+        config.mempool_size_limit = size_limit;
+        let mining_manager = MiningManager::with_config(config, None, counters);
+
+        for tx in txs {
+            validate_and_insert_mutable_transaction(&mining_manager, consensus.as_ref(), tx).unwrap();
+        }
+        assert_eq!(mining_manager.get_all_transactions(TransactionQuery::TransactionsOnly).0.len(), TX_COUNT);
+
+        let heavy_tx_low_fee = {
+            let mut heavy_tx = create_transaction_with_utxo_entry(TX_COUNT as u32, 0);
+            let mut inner_tx = (*(heavy_tx.tx)).clone();
+            inner_tx.payload = vec![0u8; TX_COUNT / 2 * tx_size - inner_tx.estimate_mem_bytes()];
+            heavy_tx.tx = inner_tx.into();
+            heavy_tx.calculated_fee = Some(2081);
+            heavy_tx
+        };
+        assert!(validate_and_insert_mutable_transaction(&mining_manager, consensus.as_ref(), heavy_tx_low_fee.clone()).is_err());
+        assert_eq!(mining_manager.get_all_transactions(TransactionQuery::TransactionsOnly).0.len(), TX_COUNT);
+
+        let heavy_tx_high_fee = {
+            let mut heavy_tx = create_transaction_with_utxo_entry(TX_COUNT as u32 + 1, 0);
+            let mut inner_tx = (*(heavy_tx.tx)).clone();
+            inner_tx.payload = vec![0u8; TX_COUNT / 2 * tx_size - inner_tx.estimate_mem_bytes()];
+            heavy_tx.tx = inner_tx.into();
+            heavy_tx.calculated_fee = Some(500_000);
+            heavy_tx
+        };
+        validate_and_insert_mutable_transaction(&mining_manager, consensus.as_ref(), heavy_tx_high_fee.clone()).unwrap();
+        assert_eq!(mining_manager.get_all_transactions(TransactionQuery::TransactionsOnly).0.len(), TX_COUNT - 5);
+        assert!(mining_manager.get_estimated_size() <= size_limit);
+
+        let too_big_tx = {
+            let mut heavy_tx = create_transaction_with_utxo_entry(TX_COUNT as u32 + 2, 0);
+            let mut inner_tx = (*(heavy_tx.tx)).clone();
+            inner_tx.payload = vec![0u8; size_limit];
+            heavy_tx.tx = inner_tx.into();
+            heavy_tx.calculated_fee = Some(500_000);
+            heavy_tx
+        };
+        assert!(validate_and_insert_mutable_transaction(&mining_manager, consensus.as_ref(), too_big_tx.clone()).is_err());
+    }
+
+    fn validate_and_insert_mutable_transaction(
+        mining_manager: &MiningManager,
+        consensus: &dyn ConsensusApi,
+        tx: MutableTransaction,
+    ) -> Result<TransactionInsertion, MiningManagerError> {
+        mining_manager.validate_and_insert_mutable_transaction(consensus, tx, Priority::Low, Orphan::Allowed, RbfPolicy::Forbidden)
+    }
+
     fn sweep_compare_modified_template_to_built(
         consensus: &dyn ConsensusApi,
         address_prefix: Prefix,

mining/src/mempool/config.rs

@@ -1,19 +1,18 @@
 use kaspa_consensus_core::constants::TX_VERSION;
 
-pub(crate) const DEFAULT_MAXIMUM_TRANSACTION_COUNT: u32 = 1_000_000;
+pub(crate) const DEFAULT_MAXIMUM_TRANSACTION_COUNT: usize = 1_000_000;
+pub(crate) const DEFAULT_MEMPOOL_SIZE_LIMIT: usize = 1_000_000_000;
 pub(crate) const DEFAULT_MAXIMUM_BUILD_BLOCK_TEMPLATE_ATTEMPTS: u64 = 5;
 
-pub(crate) const DEFAULT_TRANSACTION_EXPIRE_INTERVAL_SECONDS: u64 = 60;
+pub(crate) const DEFAULT_TRANSACTION_EXPIRE_INTERVAL_SECONDS: u64 = 24 * 60 * 60;
 pub(crate) const DEFAULT_TRANSACTION_EXPIRE_SCAN_INTERVAL_SECONDS: u64 = 10;
 pub(crate) const DEFAULT_ACCEPTED_TRANSACTION_EXPIRE_INTERVAL_SECONDS: u64 = 120;
 pub(crate) const DEFAULT_ACCEPTED_TRANSACTION_EXPIRE_SCAN_INTERVAL_SECONDS: u64 = 10;
 pub(crate) const DEFAULT_ORPHAN_EXPIRE_INTERVAL_SECONDS: u64 = 60;
 pub(crate) const DEFAULT_ORPHAN_EXPIRE_SCAN_INTERVAL_SECONDS: u64 = 10;
 
 pub(crate) const DEFAULT_MAXIMUM_ORPHAN_TRANSACTION_MASS: u64 = 100_000;
-
-// TODO: when rusty-kaspa nodes run most of the network, consider increasing this value
-pub(crate) const DEFAULT_MAXIMUM_ORPHAN_TRANSACTION_COUNT: u64 = 50;
+pub(crate) const DEFAULT_MAXIMUM_ORPHAN_TRANSACTION_COUNT: u64 = 500;
 
 /// DEFAULT_MINIMUM_RELAY_TRANSACTION_FEE specifies the minimum transaction fee for a transaction to be accepted to
 /// the mempool and relayed. It is specified in sompi per 1kg (or 1000 grams) of transaction mass.
@@ -28,7 +27,8 @@ pub(crate) const DEFAULT_MAXIMUM_STANDARD_TRANSACTION_VERSION: u16 = TX_VERSION;
 
 #[derive(Clone, Debug)]
 pub struct Config {
-    pub maximum_transaction_count: u32,
+    pub maximum_transaction_count: usize,
+    pub mempool_size_limit: usize,
     pub maximum_build_block_template_attempts: u64,
     pub transaction_expire_interval_daa_score: u64,
     pub transaction_expire_scan_interval_daa_score: u64,
@@ -51,7 +51,8 @@ pub struct Config {
 impl Config {
     #[allow(clippy::too_many_arguments)]
     pub fn new(
-        maximum_transaction_count: u32,
+        maximum_transaction_count: usize,
+        mempool_size_limit: usize,
         maximum_build_block_template_attempts: u64,
         transaction_expire_interval_daa_score: u64,
         transaction_expire_scan_interval_daa_score: u64,
@@ -72,6 +73,7 @@ impl Config {
     ) -> Self {
         Self {
             maximum_transaction_count,
+            mempool_size_limit,
             maximum_build_block_template_attempts,
             transaction_expire_interval_daa_score,
             transaction_expire_scan_interval_daa_score,
@@ -97,6 +99,7 @@ impl Config {
     pub const fn build_default(target_milliseconds_per_block: u64, relay_non_std_transactions: bool, max_block_mass: u64) -> Self {
         Self {
             maximum_transaction_count: DEFAULT_MAXIMUM_TRANSACTION_COUNT,
+            mempool_size_limit: DEFAULT_MEMPOOL_SIZE_LIMIT,
             maximum_build_block_template_attempts: DEFAULT_MAXIMUM_BUILD_BLOCK_TEMPLATE_ATTEMPTS,
             transaction_expire_interval_daa_score: DEFAULT_TRANSACTION_EXPIRE_INTERVAL_SECONDS * 1000 / target_milliseconds_per_block,
             transaction_expire_scan_interval_daa_score: DEFAULT_TRANSACTION_EXPIRE_SCAN_INTERVAL_SECONDS * 1000
@@ -121,7 +124,7 @@ impl Config {
     }
 
     pub fn apply_ram_scale(mut self, ram_scale: f64) -> Self {
-        self.maximum_transaction_count = (self.maximum_transaction_count as f64 * ram_scale.min(1.0)) as u32; // Allow only scaling down
+        self.maximum_transaction_count = (self.maximum_transaction_count as f64 * ram_scale.min(1.0)) as usize; // Allow only scaling down
         self
     }
 

mining/src/mempool/mod.rs

@@ -162,6 +162,11 @@ impl Mempool {
             .filter(|transaction_id| !(self.transaction_pool.has(transaction_id) || self.orphan_pool.has(transaction_id)));
         self.accepted_transactions.unaccepted(&mut not_in_pools_txs)
     }
+
+    #[cfg(test)]
+    pub(crate) fn get_estimated_size(&self) -> usize {
+        self.transaction_pool.get_estimated_size()
+    }
 }
 
 pub mod tx {

mining/src/mempool/model/frontier.rs

@@ -5,12 +5,12 @@ use crate::{
 };
 
 use feerate_key::FeerateTransactionKey;
-use kaspa_consensus_core::block::TemplateTransactionSelector;
+use kaspa_consensus_core::{block::TemplateTransactionSelector, tx::Transaction};
 use kaspa_core::trace;
 use rand::{distributions::Uniform, prelude::Distribution, Rng};
 use search_tree::SearchTree;
 use selectors::{SequenceSelector, SequenceSelectorInput, TakeAllSelector};
-use std::collections::HashSet;
+use std::{collections::HashSet, iter::FusedIterator, sync::Arc};
 
 pub(crate) mod feerate_key;
 pub(crate) mod search_tree;
@@ -254,6 +254,11 @@ impl Frontier {
         }
         estimator
     }
+
+    /// Returns an iterator to the transactions in the frontier in increasing feerate order
+    pub fn ascending_iter(&self) -> impl DoubleEndedIterator<Item = &Arc<Transaction>> + ExactSizeIterator + FusedIterator {
+        self.search_tree.ascending_iter().map(|key| &key.tx)
+    }
 }
 
 #[cfg(test)]