ethers-rs/ethers-middleware/src/transformer/middleware.rs

84 lines
2.3 KiB
Rust

use super::{Transformer, TransformerError};
use async_trait::async_trait;
use ethers_core::types::{transaction::eip2718::TypedTransaction, *};
use ethers_providers::{Middleware, MiddlewareError, PendingTransaction};
use thiserror::Error;
#[derive(Debug)]
/// Middleware used for intercepting transaction requests and transforming them to be executed by
/// the underneath `Transformer` instance.
pub struct TransformerMiddleware<M, T> {
inner: M,
transformer: T,
}
impl<M, T> TransformerMiddleware<M, T>
where
M: Middleware,
T: Transformer,
{
/// Creates a new TransformerMiddleware that intercepts transactions, modifying them to be sent
/// through the Transformer.
pub fn new(inner: M, transformer: T) -> Self {
Self { inner, transformer }
}
}
#[derive(Error, Debug)]
pub enum TransformerMiddlewareError<M: Middleware> {
#[error(transparent)]
TransformerError(#[from] TransformerError),
#[error("{0}")]
MiddlewareError(M::Error),
}
impl<M: Middleware> MiddlewareError for TransformerMiddlewareError<M> {
type Inner = M::Error;
fn from_err(src: M::Error) -> Self {
TransformerMiddlewareError::MiddlewareError(src)
}
fn as_inner(&self) -> Option<&Self::Inner> {
match self {
TransformerMiddlewareError::MiddlewareError(e) => Some(e),
_ => None,
}
}
}
#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
impl<M, T> Middleware for TransformerMiddleware<M, T>
where
M: Middleware,
T: Transformer,
{
type Error = TransformerMiddlewareError<M>;
type Provider = M::Provider;
type Inner = M;
fn inner(&self) -> &M {
&self.inner
}
async fn send_transaction<Tx: Into<TypedTransaction> + Send + Sync>(
&self,
tx: Tx,
block: Option<BlockId>,
) -> Result<PendingTransaction<'_, Self::Provider>, Self::Error> {
let mut tx = tx.into();
// construct the appropriate proxy tx.
self.transformer.transform(&mut tx)?;
self.fill_transaction(&mut tx, block).await?;
// send the proxy tx.
self.inner
.send_transaction(tx, block)
.await
.map_err(TransformerMiddlewareError::MiddlewareError)
}
}