reth_network_p2p/headers/
client.rs

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1use crate::{download::DownloadClient, error::PeerRequestResult, priority::Priority};
2use alloy_consensus::Header;
3use alloy_eips::BlockHashOrNumber;
4use futures::{Future, FutureExt};
5pub use reth_eth_wire_types::{BlockHeaders, HeadersDirection};
6use reth_primitives_traits::BlockHeader;
7use std::{
8    fmt::Debug,
9    pin::Pin,
10    task::{ready, Context, Poll},
11};
12
13/// The header request struct to be sent to connected peers, which
14/// will proceed to ask them to stream the requested headers to us.
15#[derive(Clone, Debug)]
16pub struct HeadersRequest {
17    /// The starting block
18    pub start: BlockHashOrNumber,
19    /// The response max size
20    pub limit: u64,
21    /// The direction in which headers should be returned.
22    pub direction: HeadersDirection,
23}
24
25impl HeadersRequest {
26    /// Creates a request for a single header (direction doesn't matter).
27    ///
28    /// # Arguments
29    /// * `start` - The block hash or number to start from
30    pub const fn one(start: BlockHashOrNumber) -> Self {
31        Self { direction: HeadersDirection::Rising, limit: 1, start }
32    }
33
34    /// Creates a request for headers in rising direction (ascending block numbers).
35    ///
36    /// # Arguments
37    /// * `start` - The block hash or number to start from
38    /// * `limit` - Maximum number of headers to retrieve
39    pub const fn rising(start: BlockHashOrNumber, limit: u64) -> Self {
40        Self { direction: HeadersDirection::Rising, limit, start }
41    }
42
43    /// Creates a request for headers in falling direction (descending block numbers).
44    ///
45    /// # Arguments
46    /// * `start` - The block hash or number to start from
47    /// * `limit` - Maximum number of headers to retrieve
48    pub const fn falling(start: BlockHashOrNumber, limit: u64) -> Self {
49        Self { direction: HeadersDirection::Falling, limit, start }
50    }
51}
52
53/// The headers future type
54pub type HeadersFut<H = Header> =
55    Pin<Box<dyn Future<Output = PeerRequestResult<Vec<H>>> + Send + Sync>>;
56
57/// The block headers downloader client
58#[auto_impl::auto_impl(&, Arc, Box)]
59pub trait HeadersClient: DownloadClient {
60    /// The header type this client fetches.
61    type Header: BlockHeader;
62    /// The headers future type
63    type Output: Future<Output = PeerRequestResult<Vec<Self::Header>>> + Sync + Send + Unpin;
64
65    /// Sends the header request to the p2p network and returns the header response received from a
66    /// peer.
67    fn get_headers(&self, request: HeadersRequest) -> Self::Output {
68        self.get_headers_with_priority(request, Priority::Normal)
69    }
70
71    /// Sends the header request to the p2p network with priority set and returns the header
72    /// response received from a peer.
73    fn get_headers_with_priority(
74        &self,
75        request: HeadersRequest,
76        priority: Priority,
77    ) -> Self::Output;
78
79    /// Fetches a single header for the requested number or hash.
80    fn get_header(&self, start: BlockHashOrNumber) -> SingleHeaderRequest<Self::Output> {
81        self.get_header_with_priority(start, Priority::Normal)
82    }
83
84    /// Fetches a single header for the requested number or hash with priority
85    fn get_header_with_priority(
86        &self,
87        start: BlockHashOrNumber,
88        priority: Priority,
89    ) -> SingleHeaderRequest<Self::Output> {
90        let req = HeadersRequest::one(start);
91        let fut = self.get_headers_with_priority(req, priority);
92        SingleHeaderRequest { fut }
93    }
94}
95
96/// A Future that resolves to a single block body.
97///
98/// Returns `None` if the peer responded with an empty header response.
99#[derive(Debug)]
100#[must_use = "futures do nothing unless polled"]
101pub struct SingleHeaderRequest<Fut> {
102    fut: Fut,
103}
104
105impl<Fut, H> Future for SingleHeaderRequest<Fut>
106where
107    Fut: Future<Output = PeerRequestResult<Vec<H>>> + Sync + Send + Unpin,
108{
109    type Output = PeerRequestResult<Option<H>>;
110
111    fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
112        let resp = ready!(self.get_mut().fut.poll_unpin(cx));
113        let resp = resp.map(|res| res.map(|headers| headers.into_iter().next()));
114        Poll::Ready(resp)
115    }
116}
reth_network_p2p/headers/client.rs

reth_network_p2p/headers/
client.rs
