init block downloader

Cargo.lock

@@ -98,6 +98,16 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
+[[package]]
+name = "async-buffer"
+version = "0.1.0"
+dependencies = [
+ "futures",
+ "pin-project",
+ "thiserror",
+ "tokio",
+]
+
 [[package]]
 name = "async-lock"
 version = "3.3.0"
@@ -580,6 +590,7 @@ dependencies = [
 name = "cuprate-p2p"
 version = "0.1.0"
 dependencies = [
+ "async-buffer",
  "bytes",
  "cuprate-helper",
  "cuprate-test-utils",

p2p/cuprate-p2p/Cargo.toml

@@ -12,6 +12,7 @@ monero-p2p = { path = "../monero-p2p", features = ["borsh"] }
 monero-address-book = { path = "../address-book" }
 monero-pruning = { path = "../../pruning" }
 cuprate-helper = { path = "../../helper", features = ["asynch"] }
+async-buffer = { path = "../async-buffer" }
 
 monero-serai = { workspace = true, features = ["std"] }
 

p2p/cuprate-p2p/src/block_downloader.rs

@@ -0,0 +1,47 @@
+//! # Block Downloader
+//!
+
+use std::sync::Arc;
+
+use monero_serai::{block::Block, transaction::Transaction};
+
+use async_buffer::BufferStream;
+use monero_p2p::{handles::ConnectionHandle, NetworkZone};
+
+use crate::client_pool::ClientPool;
+
+/// A downloaded batch of blocks.
+pub struct BlockBatch {
+    /// The blocks.
+    blocks: (Block, Vec<Transaction>),
+    /// The peer that gave us this block.
+    peer_handle: ConnectionHandle,
+}
+
+/// The block downloader config.
+#[derive(Debug, Copy, Clone, PartialOrd, PartialEq, Ord, Eq)]
+pub struct BlockDownloaderConfig {
+    /// The size of the buffer between the block downloader and the place which
+    /// is consuming the downloaded blocks.
+    buffer_size: usize,
+    /// The size of the in progress queue at which we stop requesting more blocks.
+    in_progress_queue_size: usize,
+}
+
+/// # Block Downloader
+///
+/// This function starts the block downloader and returns a [`BufferStream`] that will produce
+/// a sequential stream of blocks.
+///
+/// The block downloader will pick the longest chain and will follow it for as long as possible,
+/// the blocks given from the [`BufferStream`] will be in order.
+///
+/// The block downloader may fail before the whole chain is downloaded. If this is the case you are
+/// free to call this function again, so it can start the search again.
+pub fn download_blocks<N: NetworkZone, S>(
+    client_pool: Arc<ClientPool<N>>,
+    peer_sync_svc: S,
+    config: BlockDownloaderConfig,
+) -> BufferStream<BlockBatch> {
+    todo!()
+}

p2p/cuprate-p2p/src/lib.rs

@@ -14,6 +14,7 @@ use tracing::{instrument, Instrument, Span};
 
 use monero_p2p::{CoreSyncSvc, NetworkZone, PeerRequestHandler};
 
+mod block_downloader;
 mod broadcast;
 mod client_pool;
 pub mod config;