ethers_middleware/gas_oracle/
eth_gas_station.rs

1#![allow(deprecated)]
2
3use super::{GasCategory, GasOracle, GasOracleError, Result, GWEI_TO_WEI_U256};
4use async_trait::async_trait;
5use ethers_core::types::U256;
6use reqwest::Client;
7use serde::Deserialize;
8use std::collections::HashMap;
9use url::Url;
10
11const URL: &str = "https://ethgasstation.info/api/ethgasAPI.json";
12
13/// A client over HTTP for the [EthGasStation](https://ethgasstation.info) gas tracker API
14/// that implements the `GasOracle` trait.
15#[derive(Clone, Debug)]
16#[deprecated = "ETHGasStation is shutting down: https://twitter.com/ETHGasStation/status/1597341610777317376"]
17#[must_use]
18pub struct EthGasStation {
19    client: Client,
20    url: Url,
21    gas_category: GasCategory,
22}
23
24/// Eth Gas Station's response for the current recommended fast, standard and
25/// safe low gas prices on the Ethereum network, along with the current block
26/// and wait times for each "speed".
27#[derive(Clone, Debug, Deserialize, PartialEq)]
28#[serde(rename_all = "camelCase")]
29pub struct Response {
30    /// Recommended safe (expected to be mined in < 30 minutes).
31    ///
32    /// In gwei * 10 (divide by 10 to convert it to gwei).
33    pub safe_low: u64,
34    /// Recommended average (expected to be mined in < 5 minutes).
35    ///
36    /// In gwei * 10 (divide by 10 to convert it to gwei).
37    pub average: u64,
38    /// Recommended fast (expected to be mined in < 2 minutes).
39    ///
40    /// In gwei * 10 (divide by 10 to convert it to gwei).
41    pub fast: u64,
42    /// Recommended fastest (expected to be mined in < 30 seconds).
43    ///
44    /// In gwei * 10 (divide by 10 to convert it to gwei).
45    pub fastest: u64,
46
47    // post eip-1559 fields
48    /// Average time (in seconds) to mine a single block.
49    #[serde(rename = "block_time")] // inconsistent json response naming...
50    pub block_time: f64,
51    /// The latest block number.
52    pub block_num: u64,
53    /// Smallest value of `gasUsed / gaslimit` from the last 10 blocks.
54    pub speed: f64,
55    /// Waiting time (in minutes) for the `safe_low` gas price.
56    pub safe_low_wait: f64,
57    /// Waiting time (in minutes) for the `average` gas price.
58    pub avg_wait: f64,
59    /// Waiting time (in minutes) for the `fast` gas price.
60    pub fast_wait: f64,
61    /// Waiting time (in minutes) for the `fastest` gas price.
62    pub fastest_wait: f64,
63    // What is this?
64    pub gas_price_range: HashMap<u64, f64>,
65}
66
67impl Response {
68    #[inline]
69    pub fn gas_from_category(&self, gas_category: GasCategory) -> u64 {
70        match gas_category {
71            GasCategory::SafeLow => self.safe_low,
72            GasCategory::Standard => self.average,
73            GasCategory::Fast => self.fast,
74            GasCategory::Fastest => self.fastest,
75        }
76    }
77}
78
79impl Default for EthGasStation {
80    fn default() -> Self {
81        Self::new(None)
82    }
83}
84
85#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
86#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
87impl GasOracle for EthGasStation {
88    async fn fetch(&self) -> Result<U256> {
89        let res = self.query().await?;
90        let gas_price = res.gas_from_category(self.gas_category);
91        // gas_price is in `gwei * 10`
92        Ok(U256::from(gas_price) * GWEI_TO_WEI_U256 / U256::from(10_u64))
93    }
94
95    async fn estimate_eip1559_fees(&self) -> Result<(U256, U256)> {
96        Err(GasOracleError::Eip1559EstimationNotSupported)
97    }
98}
99
100impl EthGasStation {
101    /// Creates a new [EthGasStation](https://docs.ethgasstation.info/) gas oracle.
102    pub fn new(api_key: Option<&str>) -> Self {
103        Self::with_client(Client::new(), api_key)
104    }
105
106    /// Same as [`Self::new`] but with a custom [`Client`].
107    pub fn with_client(client: Client, api_key: Option<&str>) -> Self {
108        let mut url = Url::parse(URL).unwrap();
109        if let Some(key) = api_key {
110            url.query_pairs_mut().append_pair("api-key", key);
111        }
112        EthGasStation { client, url, gas_category: GasCategory::Standard }
113    }
114
115    /// Sets the gas price category to be used when fetching the gas price.
116    pub fn category(mut self, gas_category: GasCategory) -> Self {
117        self.gas_category = gas_category;
118        self
119    }
120
121    /// Perform a request to the gas price API and deserialize the response.
122    pub async fn query(&self) -> Result<Response> {
123        let response =
124            self.client.get(self.url.clone()).send().await?.error_for_status()?.json().await?;
125        Ok(response)
126    }
127}
ethers_middleware/gas_oracle/eth_gas_station.rs

ethers_middleware/gas_oracle/
eth_gas_station.rs
