ethers-rs/ethers-middleware/src/gas_oracle/polygon.rs

117 lines
3.7 KiB
Rust

use super::{from_gwei_f64, GasCategory, GasOracle, GasOracleError, Result};
use async_trait::async_trait;
use ethers_core::types::{Chain, U256};
use reqwest::Client;
use serde::Deserialize;
use url::Url;
const MAINNET_URL: &str = "https://gasstation-mainnet.matic.network/v2";
const MUMBAI_URL: &str = "https://gasstation-mumbai.matic.today/v2";
/// The [Polygon](https://docs.polygon.technology/docs/develop/tools/polygon-gas-station/) gas station API
/// Queries over HTTP and implements the `GasOracle` trait.
#[derive(Clone, Debug)]
#[must_use]
pub struct Polygon {
client: Client,
url: Url,
gas_category: GasCategory,
}
/// The response from the Polygon gas station API.
///
/// Gas prices are in __Gwei__.
#[derive(Debug, Deserialize, PartialEq)]
#[serde(rename_all = "camelCase")]
pub struct Response {
pub estimated_base_fee: f64,
pub safe_low: GasEstimate,
pub standard: GasEstimate,
pub fast: GasEstimate,
}
#[derive(Clone, Copy, Debug, Deserialize, PartialEq)]
#[serde(rename_all = "camelCase")]
pub struct GasEstimate {
pub max_priority_fee: f64,
pub max_fee: f64,
}
impl Response {
#[inline]
pub fn estimate_from_category(&self, gas_category: GasCategory) -> GasEstimate {
match gas_category {
GasCategory::SafeLow => self.safe_low,
GasCategory::Standard => self.standard,
GasCategory::Fast => self.fast,
GasCategory::Fastest => self.fast,
}
}
}
impl Default for Polygon {
fn default() -> Self {
Self::new(Chain::Polygon).unwrap()
}
}
#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
impl GasOracle for Polygon {
async fn fetch(&self) -> Result<U256> {
let response = self.query().await?;
let base = response.estimated_base_fee;
let prio = response.estimate_from_category(self.gas_category).max_priority_fee;
let fee = base + prio;
Ok(from_gwei_f64(fee))
}
async fn estimate_eip1559_fees(&self) -> Result<(U256, U256)> {
let response = self.query().await?;
let estimate = response.estimate_from_category(self.gas_category);
let max = from_gwei_f64(estimate.max_fee);
let prio = from_gwei_f64(estimate.max_priority_fee);
Ok((max, prio))
}
}
impl Polygon {
pub fn new(chain: Chain) -> Result<Self> {
Self::with_client(Client::new(), chain)
}
pub fn with_client(client: Client, chain: Chain) -> Result<Self> {
// TODO: Sniff chain from chain id.
let url = match chain {
Chain::Polygon => MAINNET_URL,
Chain::PolygonMumbai => MUMBAI_URL,
_ => return Err(GasOracleError::UnsupportedChain),
};
Ok(Self { client, url: Url::parse(url).unwrap(), gas_category: GasCategory::Standard })
}
/// Sets the gas price category to be used when fetching the gas price.
pub fn category(mut self, gas_category: GasCategory) -> Self {
self.gas_category = gas_category;
self
}
/// Perform a request to the gas price API and deserialize the response.
pub async fn query(&self) -> Result<Response> {
let response =
self.client.get(self.url.clone()).send().await?.error_for_status()?.json().await?;
Ok(response)
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn parse_polygon_gas_station_response() {
let s = r#"{"safeLow":{"maxPriorityFee":2.1267086610666666,"maxFee":2.1267086760666665},"standard":{"maxPriorityFee":2.3482958369333335,"maxFee":2.3482958519333335},"fast":{"maxPriorityFee":2.793454819,"maxFee":2.793454834},"estimatedBaseFee":1.5e-8,"blockTime":2,"blockNumber":30328888}"#;
let _resp: Response = serde_json::from_str(s).unwrap();
}
}