Monero time_for_block, dust

processor/monero/src/lib.rs

@@ -54,64 +54,6 @@ impl SignableTransactionTrait for SignableTransaction {
   }
 }
 
-#[async_trait]
-impl BlockTrait<Monero> for Block {
-  type Id = [u8; 32];
-  fn id(&self) -> Self::Id {
-    self.hash()
-  }
-
-  fn parent(&self) -> Self::Id {
-    self.header.previous
-  }
-
-  async fn time(&self, rpc: &Monero) -> u64 {
-    // Constant from Monero
-    const BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW: usize = 60;
-
-    // If Monero doesn't have enough blocks to build a window, it doesn't define a network time
-    if (self.number().unwrap() + 1) < BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW {
-      // Use the block number as the time
-      return u64::try_from(self.number().unwrap()).unwrap();
-    }
-
-    let mut timestamps = vec![self.header.timestamp];
-    let mut parent = self.parent();
-    while timestamps.len() < BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW {
-      let mut parent_block;
-      while {
-        parent_block = rpc.rpc.get_block(parent).await;
-        parent_block.is_err()
-      } {
-        log::error!("couldn't get parent block when trying to get block time: {parent_block:?}");
-        sleep(Duration::from_secs(5)).await;
-      }
-      let parent_block = parent_block.unwrap();
-      timestamps.push(parent_block.header.timestamp);
-      parent = parent_block.parent();
-
-      if parent_block.number().unwrap() == 0 {
-        break;
-      }
-    }
-    timestamps.sort();
-
-    // Because 60 has two medians, Monero's epee picks the in-between value, calculated by the
-    // following formula (from the "get_mid" function)
-    let n = timestamps.len() / 2;
-    let a = timestamps[n - 1];
-    let b = timestamps[n];
-    #[rustfmt::skip] // Enables Ctrl+F'ing for everything after the `= `
-    let res = (a/2) + (b/2) + ((a - 2*(a/2)) + (b - 2*(b/2)))/2;
-    // Technically, res may be 1 if all prior blocks had a timestamp by 0, which would break
-    // monotonicity with our above definition of height as time
-    // Monero also solely requires the block's time not be less than the median, it doesn't ensure
-    // it advances the median forward
-    // Ensure monotonicity despite both these issues by adding the block number to the median time
-    res + u64::try_from(self.number().unwrap()).unwrap()
-  }
-}
-
 enum MakeSignableTransactionResult {
   Fee(u64),
   SignableTransaction(MSignableTransaction),
@@ -330,9 +272,6 @@ impl Network for Monero {
 
   const MAX_OUTPUTS: usize = 16;
 
-  // 0.01 XMR
-  const DUST: u64 = 10000000000;
-
   // TODO
   const COST_TO_AGGREGATE: u64 = 0;
 

processor/monero/src/primitives/block.rs

@@ -5,8 +5,8 @@ use zeroize::Zeroizing;
 use ciphersuite::{Ciphersuite, Ed25519};
 
 use monero_wallet::{
-  block::Block as MBlock, rpc::ScannableBlock as MScannableBlock,
-  ViewPairError, GuaranteedViewPair, ScanError, GuaranteedScanner,
+  block::Block as MBlock, rpc::ScannableBlock as MScannableBlock, ViewPairError,
+  GuaranteedViewPair, ScanError, GuaranteedScanner,
 };
 
 use serai_client::networks::monero::Address;
@@ -58,8 +58,12 @@ impl primitives::Block for Block {
     scanner.register_subaddress(FORWARDED_SUBADDRESS.unwrap());
     match scanner.scan(self.0.clone()) {
       Ok(outputs) => outputs.not_additionally_locked().into_iter().map(Output).collect(),
-      Err(ScanError::UnsupportedProtocol(version)) => panic!("Monero unexpectedly hard-forked (version {version})"),
-      Err(ScanError::InvalidScannableBlock(reason)) => panic!("fetched an invalid scannable block from the RPC: {reason}"),
+      Err(ScanError::UnsupportedProtocol(version)) => {
+        panic!("Monero unexpectedly hard-forked (version {version})")
+      }
+      Err(ScanError::InvalidScannableBlock(reason)) => {
+        panic!("fetched an invalid scannable block from the RPC: {reason}")
+      }
     }
   }
 
@@ -76,10 +80,7 @@ impl primitives::Block for Block {
     for (hash, tx) in self.0.block.transactions.iter().zip(&self.0.transactions) {
       if let Some(eventuality) = eventualities.active_eventualities.get(&tx.prefix().extra) {
         if eventuality.eventuality.matches(tx) {
-          res.insert(
-            *hash,
-            eventualities.active_eventualities.remove(&tx.prefix().extra).unwrap(),
-          );
+          res.insert(*hash, eventualities.active_eventualities.remove(&tx.prefix().extra).unwrap());
         }
       }
     }

processor/monero/src/rpc.rs

@@ -54,7 +54,38 @@ impl ScannerFeed for Rpc {
     &self,
     number: u64,
   ) -> impl Send + Future<Output = Result<u64, Self::EphemeralError>> {
-    async move { todo!("TODO") }
+    async move {
+      // Constant from Monero
+      const BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW: u64 = 60;
+
+      // If Monero doesn't have enough blocks to build a window, it doesn't define a network time
+      if (number + 1) < BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW {
+        return Ok(0);
+      }
+
+      // Fetch all the timestamps within the window
+      let block_for_time_of = self.rpc.get_block_by_number(number.try_into().unwrap()).await?;
+      let mut timestamps = vec![block_for_time_of.header.timestamp];
+      let mut parent = block_for_time_of.header.previous;
+      for _ in 1 .. BLOCKCHAIN_TIMESTAMP_CHECK_WINDOW {
+        let parent_block = self.rpc.get_block(parent).await?;
+        timestamps.push(parent_block.header.timestamp);
+        parent = parent_block.header.previous;
+      }
+      timestamps.sort();
+
+      // Because there are two timestamps equidistance from the ends, Monero's epee picks the
+      // in-between value, calculated by the following formula (from the "get_mid" function)
+      let n = timestamps.len() / 2;
+      let a = timestamps[n - 1];
+      let b = timestamps[n];
+      #[rustfmt::skip] // Enables Ctrl+F'ing for everything after the `= `
+      let res = (a/2) + (b/2) + ((a - 2*(a/2)) + (b - 2*(b/2)))/2;
+
+      // Monero does check that the new block's time is greater than the median, causing the median
+      // to be monotonic
+      Ok(res)
+    }
   }
 
   fn unchecked_block_header_by_number(
@@ -66,17 +97,21 @@ impl ScannerFeed for Rpc {
     async move { Ok(BlockHeader(self.rpc.get_block_by_number(number.try_into().unwrap()).await?)) }
   }
 
+  #[rustfmt::skip] // It wants to improperly format the `async move` to a single line
   fn unchecked_block_by_number(
     &self,
     number: u64,
   ) -> impl Send + Future<Output = Result<Self::Block, Self::EphemeralError>> {
-    async move { todo!("TODO") }
+    async move {
+      Ok(Block(self.rpc.get_scannable_block_by_number(number.try_into().unwrap()).await?))
+    }
   }
 
   fn dust(coin: Coin) -> Amount {
     assert_eq!(coin, Coin::Monero);
 
-    todo!("TODO")
+    // 0.01 XMR
+    Amount(10_000_000_000)
   }
 
   fn cost_to_aggregate(