36 lines
1.2 KiB
Rust
36 lines
1.2 KiB
Rust
use crate::ProviderError;
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use ethers_core::types::U256;
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use futures_timer::Delay;
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use futures_util::{stream, FutureExt, StreamExt};
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use std::{future::Future, pin::Pin};
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/// A simple gas escalation policy
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pub type EscalationPolicy = Box<dyn Fn(U256, usize) -> U256 + Send + Sync>;
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// Helper type alias
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#[cfg(target_arch = "wasm32")]
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pub(crate) type PinBoxFut<'a, T> = Pin<Box<dyn Future<Output = Result<T, ProviderError>> + 'a>>;
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#[cfg(not(target_arch = "wasm32"))]
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pub(crate) type PinBoxFut<'a, T> =
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Pin<Box<dyn Future<Output = Result<T, ProviderError>> + Send + 'a>>;
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/// Calls the future if `item` is None, otherwise returns a `futures::ok`
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pub async fn maybe<F, T, E>(item: Option<T>, f: F) -> Result<T, E>
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where
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F: Future<Output = Result<T, E>>,
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{
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if let Some(item) = item {
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futures_util::future::ok(item).await
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} else {
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f.await
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}
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}
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// https://github.com/tomusdrw/rust-web3/blob/befcb2fb8f3ca0a43e3081f68886fa327e64c8e6/src/api/eth_filter.rs#L20
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/// Create a stream that emits items at a fixed interval. Used for rate control
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pub fn interval(
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duration: instant::Duration,
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) -> impl futures_core::stream::Stream<Item = ()> + Send + Unpin {
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stream::unfold((), move |_| Delay::new(duration).map(|_| Some(((), ())))).map(drop)
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}
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