fix: make block query cutoff properly configurable

Author: dylanlott

Cargo.lock

@@ -24,6 +24,7 @@ signet-constants = { version = "0.16.0-rc.0" }
 signet-sim = { version = "0.16.0-rc.0" }
 signet-tx-cache = { version = "0.16.0-rc.0" }
 signet-types = { version = "0.16.0-rc.0" }
+signet-bundle = { version = "0.16.0-rc.0" }
 signet-zenith = { version = "0.16.0-rc.0" }
 signet-block-processor = { git = "https://github.com/init4tech/node-components", tag = "v0.16.0-rc.2" }
 signet-genesis = { git = "https://github.com/init4tech/node-components", tag = "v0.16.0-rc.2" }
@@ -64,12 +65,12 @@ alloy-chains = "0.2"
 # comment / uncomment for local dev
 # [patch.crates-io]
 # signet-constants = { path = "../signet-sdk/crates/constants" }
+# signet-sim = { path = "../signet-sdk/crates/sim" }
+# signet-tx-cache = { path = "../signet-sdk/crates/tx-cache" }
 # signet-types = { path = "../signet-sdk/crates/types" }
 # signet-zenith = { path = "../signet-sdk/crates/zenith" }
-# signet-sim = { path = "../signet-sdk/crates/sim" }
+
 # signet-evm = { path = "../signet-sdk/crates/evm" }
 # signet-extract = { path = "../signet-sdk/crates/extract" }
 # signet-journal = { path = "../signet-sdk/crates/journal" }
-# signet-tx-cache = { path = "../signet-sdk/crates/tx-cache" }
 # signet-bundle = { path = "../signet-sdk/crates/bundle" }
-# init4-bin-base = { path = "../bin-base" }

Cargo.toml

@@ -86,7 +86,7 @@ Finally, if it's non-empty, the submit task attempts to get a signature for the
 The Builder is configured via environment variables. The following values are supported for configuration.
 
 Key                           | Required | Description
------------------------------ | -------- | ------------------------------------------------------------------------------
+----------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------
 `RUST_LOG`                    | No       | The log level of the builder
 `CHAIN_NAME`                  | No       | The chain name ("pecorino", or the corresponding name)
 `HOST_RPC_URL`                | Yes      | RPC endpoint for the host chain
@@ -97,7 +97,8 @@ Key                           | Required | Description
 `FLASHBOTS_ENDPOINT`          | No       | Flashbots API to submit blocks to
 `ROLLUP_BLOCK_GAS_LIMIT`      | No       | Override for rollup block gas limit
 `MAX_HOST_GAS_COEFFICIENT`    | No       | Optional maximum host gas coefficient, as a percentage, to use when building blocks
-`BUILDER_KEY`                 | Yes      | AWS KMS key ID _or_ local private key for builder signing
+`BUILDER_KEY`                 | Yes      | AWS KMS key ID _or_ local private key for builder signin
+`BLOCK_QUERY_CUTOFF_BUFFER`   | Yes      | Number of milliseconds before the end of the slot to stop querying for new transactions and start the block signing and submission process
 `AWS_ACCESS_KEY_ID`           | No       | AWS secret access key ID (required if not using `BUILDER_KEY`)
 `AWS_SECRET_ACCESS_KEY`       | No       | AWS secret access key (required if not using `BUILDER_KEY`)
 `AWS_DEFAULT_REGION`          | No       | AWS region for the KMS key in question (required if not using `BUILDER_KEY`)

README.md

@@ -155,6 +155,14 @@ pub struct BuilderConfig {
     )]
     pub max_host_gas_coefficient: Option<u8>,
 
+    /// Number of seconds before the end of the slot to stop querying for new blocks
+    #[from_env(
+        var = "BLOCK_QUERY_CUTOFF_BUFFER",
+        desc = "Number of milliseconds before the end of the slot to stop querying for new transactions and start the block signing and submission process",
+        default = 3000
+    )]
+    pub block_query_cutoff_buffer: u64,
+
     /// The slot calculator for the builder.
     pub slot_calculator: SlotCalculator,
 

src/config.rs

@@ -117,7 +117,9 @@ impl SimulatorTask {
     /// A `Result` containing the built block or an error.
     #[instrument(skip_all, fields(
         tx_count = sim_items.len(),
-        millis_to_deadline = finish_by.duration_since(Instant::now()).as_millis()
+        millis_to_deadline = finish_by.duration_since(Instant::now()).as_millis(),
+        host_block_number = sim_env.rollup_block_number(),
+        rollup_block_number = sim_env.host_block_number(),
     ))]
     pub async fn handle_build(
         &self,
@@ -128,9 +130,12 @@ impl SimulatorTask {
         let concurrency_limit = self.config.concurrency_limit();
 
         let rollup_env = sim_env.sim_rollup_env(self.constants(), self.ru_provider.clone());
-
         let host_env = sim_env.sim_host_env(self.constants(), self.host_provider.clone());
 
+        let ru_number = rollup_env.block().number;
+        let host_number = host_env.block().number;
+        debug!(?ru_number, ?host_number, "starting block simulation");
+
         let block_build = BlockBuild::new(
             rollup_env,
             host_env,
@@ -227,24 +232,31 @@ impl SimulatorTask {
         }
     }
 
-    /// Calculates the deadline for the current block simulation.
+    /// Calculates the deadline for the current block simulation in milliseconds.
     ///
     /// # Returns
     ///
-    /// An `Instant` representing the simulation deadline, as calculated by
-    /// determining the time left in the current slot and adding that to the
-    /// current timestamp in UNIX seconds.
+    /// An `Instant` representing the simulation deadline as calculated by determining
+    /// the milliseconds  left in the current slot and adding that to the current
+    /// timestamp in UNIX seconds.
     pub fn calculate_deadline(&self) -> Instant {
-        // Get the current timepoint within the slot.
-        let timepoint =
-            self.slot_calculator().current_point_within_slot().expect("host chain has started");
+        // Get the current number of milliseconds into the slot.
+        let timepoint_ms =
+            self.slot_calculator().current_point_within_slot_ms().expect("host chain has started");
+        let slot_duration = Duration::from_secs(self.slot_calculator().slot_duration()).as_millis();
+        let elapsed_in_slot = Duration::from_millis(timepoint_ms);
+        let query_cutoff_buffer = Duration::from_millis(self.config.block_query_cutoff_buffer);
 
-        // We have the timepoint in seconds into the slot. To find out what's
-        // remaining, we need to subtract it from the slot duration
-        // we also subtract 3 seconds to account for the sequencer stopping signing.
-        let remaining = (self.slot_calculator().slot_duration() - timepoint).saturating_sub(3);
+        // To find the remaining slot time, subtract the timepoint from the slot duration.
+        // Then subtract the block query cutoff buffer from the slot duration to account for
+        // the sequencer stopping signing.
+        let remaining = slot_duration
+            .saturating_sub(elapsed_in_slot.as_millis())
+            .saturating_sub(query_cutoff_buffer.as_millis());
 
-        let deadline = Instant::now() + Duration::from_secs(remaining);
+        // The deadline is then calculated by adding the remaining time from this instant.
+        // NB: Downcast is okay because u64 will work for 500 million+ years.
+        let deadline = Instant::now() + Duration::from_millis(remaining as u64);
         deadline.max(Instant::now())
     }
 }

src/tasks/block/sim.rs

@@ -5,7 +5,7 @@ use crate::{
 };
 use alloy::{
     consensus::Header,
-    eips::eip1559::BaseFeeParams,
+    eips::{BlockId, eip1559::BaseFeeParams},
     network::Ethereum,
     primitives::{B256, U256},
     providers::{Provider, network::Network},
@@ -64,7 +64,7 @@ impl Environment {
 
     /// Create a new [`AlloyDB`] for this environment using the given provider.
     pub fn alloy_db<N: Network, P: Provider<N>>(&self, provider: P) -> AlloyDB<N, P> {
-        AlloyDB::new(provider, self.prev_header.number.into())
+        AlloyDB::new(provider, BlockId::latest())
     }
 }
 

src/tasks/env.rs

@@ -54,6 +54,7 @@ pub fn setup_test_config() -> &'static BuilderConfig {
                 1740681556, // pecorino start timestamp as sane default
                 0, 1,
             ),
+            block_query_cutoff_buffer: 3000,
             max_host_gas_coefficient: Some(80),
             constants: SignetSystemConstants::parmigiana(),
         }