Bitcoin ScannerFeed

Cargo.lock

@@ -8141,6 +8141,7 @@ dependencies = [
  "serai-message-queue",
  "serai-processor-messages",
  "serai-processor-primitives",
+ "serai-processor-scanner",
  "serai-processor-scheduler-primitives",
  "tokio",
  "zalloc",

processor/bitcoin/Cargo.toml

@@ -44,6 +44,7 @@ messages = { package = "serai-processor-messages", path = "../messages" }
 
 primitives = { package = "serai-processor-primitives", path = "../primitives" }
 scheduler = { package = "serai-processor-scheduler-primitives", path = "../scheduler/primitives" }
+scanner = { package = "serai-processor-scanner", path = "../scanner" }
 
 message-queue = { package = "serai-message-queue", path = "../../message-queue" }
 

processor/bitcoin/src/block.rs

@@ -8,10 +8,10 @@ use serai_client::networks::bitcoin::Address;
 
 use primitives::{ReceivedOutput, EventualityTracker};
 
-use crate::{hash_bytes, scanner::scanner, output::Output, transaction::Eventuality};
+use crate::{hash_bytes, scan::scanner, output::Output, transaction::Eventuality};
 
 #[derive(Clone, Debug)]
-pub(crate) struct BlockHeader(Header);
+pub(crate) struct BlockHeader(pub(crate) Header);
 impl primitives::BlockHeader for BlockHeader {
   fn id(&self) -> [u8; 32] {
     hash_bytes(self.0.block_hash().to_raw_hash())
@@ -22,7 +22,7 @@ impl primitives::BlockHeader for BlockHeader {
 }
 
 #[derive(Clone, Debug)]
-pub(crate) struct Block(BBlock);
+pub(crate) struct Block(pub(crate) BBlock);
 
 #[async_trait::async_trait]
 impl primitives::Block for Block {

processor/bitcoin/src/lib.rs

@@ -6,12 +6,19 @@
 static ALLOCATOR: zalloc::ZeroizingAlloc<std::alloc::System> =
   zalloc::ZeroizingAlloc(std::alloc::System);
 
-mod scanner;
+// Internal utilities for scanning transactions
+mod scan;
 
+// Output trait satisfaction
 mod output;
+// Transaction/SignableTransaction/Eventuality trait satisfaction
 mod transaction;
+// Block trait satisfaction
 mod block;
 
+// ScannerFeed trait satisfaction
+mod scanner_feed;
+
 pub(crate) fn hash_bytes(hash: bitcoin_serai::bitcoin::hashes::sha256d::Hash) -> [u8; 32] {
   use bitcoin_serai::bitcoin::hashes::Hash;
 

processor/bitcoin/src/output.rs

@@ -23,7 +23,7 @@ use serai_client::{
 
 use primitives::{OutputType, ReceivedOutput};
 
-use crate::scanner::{offsets_for_key, presumed_origin, extract_serai_data};
+use crate::scan::{offsets_for_key, presumed_origin, extract_serai_data};
 
 #[derive(Clone, PartialEq, Eq, Hash, Debug, Encode, Decode, BorshSerialize, BorshDeserialize)]
 pub(crate) struct OutputId([u8; 36]);

processor/bitcoin/src/scanner_feed.rs

@@ -0,0 +1,62 @@
+use bitcoin_serai::rpc::{RpcError, Rpc as BRpc};
+
+use serai_client::primitives::{NetworkId, Coin, Amount};
+
+use scanner::ScannerFeed;
+
+use crate::block::{BlockHeader, Block};
+
+#[derive(Clone)]
+pub(crate) struct Rpc(BRpc);
+
+#[async_trait::async_trait]
+impl ScannerFeed for Rpc {
+  const NETWORK: NetworkId = NetworkId::Bitcoin;
+  const CONFIRMATIONS: u64 = 6;
+  const WINDOW_LENGTH: u64 = 6;
+
+  const TEN_MINUTES: u64 = 1;
+
+  type Block = Block;
+
+  type EphemeralError = RpcError;
+
+  async fn latest_finalized_block_number(&self) -> Result<u64, Self::EphemeralError> {
+    u64::try_from(self.0.get_latest_block_number().await?)
+      .unwrap()
+      .checked_sub(Self::CONFIRMATIONS)
+      .ok_or(RpcError::ConnectionError)
+  }
+
+  async fn unchecked_block_header_by_number(
+    &self,
+    number: u64,
+  ) -> Result<<Self::Block as primitives::Block>::Header, Self::EphemeralError> {
+    Ok(BlockHeader(
+      self.0.get_block(&self.0.get_block_hash(number.try_into().unwrap()).await?).await?.header,
+    ))
+  }
+
+  async fn unchecked_block_by_number(
+    &self,
+    number: u64,
+  ) -> Result<Self::Block, Self::EphemeralError> {
+    Ok(Block(self.0.get_block(&self.0.get_block_hash(number.try_into().unwrap()).await?).await?))
+  }
+
+  fn dust(coin: Coin) -> Amount {
+    assert_eq!(coin, Coin::Bitcoin);
+    // 10,000 satoshis, or $5 if 1 BTC = 50,000 USD
+    Amount(10_000)
+  }
+
+  async fn cost_to_aggregate(
+    &self,
+    coin: Coin,
+    _reference_block: &Self::Block,
+  ) -> Result<Amount, Self::EphemeralError> {
+    assert_eq!(coin, Coin::Bitcoin);
+    // TODO
+    Ok(Amount(0))
+  }
+}

processor/scanner/src/lib.rs

@@ -71,8 +71,14 @@ pub trait ScannerFeed: 'static + Send + Sync + Clone {
 
   /// The amount of blocks to process in parallel.
   ///
-  /// This must be at least `1`. This value should be the worst-case latency to handle a block
-  /// divided by the expected block time.
+  /// This must be at least `1`. This value MUST be at least the worst-case latency to publish a
+  /// Batch for a block divided by the expected block time. Setting this value too low will risk a
+  /// backlog forming. Setting this value too high will only delay key rotation and forwarded
+  /// outputs.
+  // The latency to publish a Batch for a block is the latency of a provided transaction
+  // (1 minute), the latency of a signing protocol (1 minute), the latency of Serai to finalize a
+  // block (1 minute), and the latency to cosign such a block (5 minutes for the cosign distance
+  // plus 1 minute). Accordingly, this should be at least ~30 minutes, ideally 60 minutes.
   const WINDOW_LENGTH: u64;
 
   /// The amount of blocks which will occur in 10 minutes (approximate).