ethers_middleware/gas_oracle/
etherchain.rs

1use super::{from_gwei_f64, GasCategory, GasOracle, GasOracleError, Result};
2use async_trait::async_trait;
3use ethers_core::types::U256;
4use reqwest::Client;
5use serde::Deserialize;
6use url::Url;
7
8const URL: &str = "https://www.etherchain.org/api/gasPriceOracle";
9
10/// A client over HTTP for the [Etherchain](https://www.etherchain.org/api/gasPriceOracle) gas tracker API
11/// that implements the `GasOracle` trait.
12#[derive(Clone, Debug)]
13#[must_use]
14pub struct Etherchain {
15    client: Client,
16    url: Url,
17    gas_category: GasCategory,
18}
19
20#[derive(Clone, Copy, Debug, Deserialize, PartialEq)]
21#[serde(rename_all = "camelCase")]
22pub struct Response {
23    pub safe_low: f64,
24    pub standard: f64,
25    pub fast: f64,
26    pub fastest: f64,
27    pub current_base_fee: f64,
28    pub recommended_base_fee: f64,
29}
30
31impl Response {
32    #[inline]
33    pub fn gas_from_category(&self, gas_category: GasCategory) -> f64 {
34        match gas_category {
35            GasCategory::SafeLow => self.safe_low,
36            GasCategory::Standard => self.standard,
37            GasCategory::Fast => self.fast,
38            GasCategory::Fastest => self.fastest,
39        }
40    }
41}
42
43impl Default for Etherchain {
44    fn default() -> Self {
45        Self::new()
46    }
47}
48
49#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
50#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
51impl GasOracle for Etherchain {
52    async fn fetch(&self) -> Result<U256> {
53        let res = self.query().await?;
54        let gas_price = res.gas_from_category(self.gas_category);
55        Ok(from_gwei_f64(gas_price))
56    }
57
58    async fn estimate_eip1559_fees(&self) -> Result<(U256, U256)> {
59        Err(GasOracleError::Eip1559EstimationNotSupported)
60    }
61}
62
63impl Etherchain {
64    /// Creates a new [Etherchain](https://etherchain.org/tools/gasPriceOracle) gas price oracle.
65    pub fn new() -> Self {
66        Self::with_client(Client::new())
67    }
68
69    /// Same as [`Self::new`] but with a custom [`Client`].
70    pub fn with_client(client: Client) -> Self {
71        let url = Url::parse(URL).unwrap();
72        Etherchain { client, url, gas_category: GasCategory::Standard }
73    }
74
75    /// Sets the gas price category to be used when fetching the gas price.
76    pub fn category(mut self, gas_category: GasCategory) -> Self {
77        self.gas_category = gas_category;
78        self
79    }
80
81    /// Perform a request to the gas price API and deserialize the response.
82    pub async fn query(&self) -> Result<Response> {
83        let response =
84            self.client.get(self.url.clone()).send().await?.error_for_status()?.json().await?;
85        Ok(response)
86    }
87}
ethers_middleware/gas_oracle/etherchain.rs

ethers_middleware/gas_oracle/
etherchain.rs
