parity-common/transaction-pool/src/replace.rs

54 lines
2.0 KiB
Rust

// Copyright 2015-2019 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
//! When queue limits are reached, decide whether to replace an existing transaction from the pool
use pool::Transaction;
use scoring::Choice;
/// Encapsulates a transaction to be compared, along with pooled transactions from the same sender
pub struct ReplaceTransaction<'a, T> {
/// The transaction to be compared for replacement
pub transaction: &'a Transaction<T>,
/// Other transactions currently in the pool for the same sender
pub pooled_by_sender: Option<&'a [Transaction<T>]>,
}
impl<'a, T> ReplaceTransaction<'a, T> {
/// Creates a new `ReplaceTransaction`
pub fn new(transaction: &'a Transaction<T>, pooled_by_sender: Option<&'a [Transaction<T>]>) -> Self {
ReplaceTransaction {
transaction,
pooled_by_sender,
}
}
}
impl<'a, T> ::std::ops::Deref for ReplaceTransaction<'a, T> {
type Target = Transaction<T>;
fn deref(&self) -> &Self::Target {
&self.transaction
}
}
/// Chooses whether a new transaction should replace an existing transaction if the pool is full.
pub trait ShouldReplace<T> {
/// Decides if `new` should push out `old` transaction from the pool.
///
/// NOTE returning `InsertNew` here can lead to some transactions being accepted above pool limits.
fn should_replace(&self, old: &ReplaceTransaction<T>, new: &ReplaceTransaction<T>) -> Choice;
}