From 6cf83db13f1cfef9ba3eae9c567eb952f96af004 Mon Sep 17 00:00:00 2001
From: Paul Hauner <paul@paulhauner.com>
Date: Mon, 27 Sep 2021 16:11:54 +1000
Subject: [PATCH] Thread TTD into execution layer

---
 beacon_node/client/src/builder.rs      |  5 +++++
 beacon_node/client/src/config.rs       |  6 +++---
 beacon_node/execution_layer/src/lib.rs | 14 +++++++-------
 beacon_node/src/config.rs              |  4 ++--
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/beacon_node/client/src/builder.rs b/beacon_node/client/src/builder.rs
index 4ae896fd30..4acee035fd 100644
--- a/beacon_node/client/src/builder.rs
+++ b/beacon_node/client/src/builder.rs
@@ -147,10 +147,15 @@ where
             None
         };
 
+        let terminal_total_difficulty = config
+            .terminal_total_difficulty_override
+            .unwrap_or(spec.terminal_total_difficulty);
+
         let execution_layer = if let Some(execution_endpoints) = config.execution_endpoints {
             let context = runtime_context.service_context("exec".into());
             let execution_layer = ExecutionLayer::from_urls(
                 execution_endpoints,
+                terminal_total_difficulty,
                 context.executor.clone(),
                 context.log().clone(),
             )
diff --git a/beacon_node/client/src/config.rs b/beacon_node/client/src/config.rs
index a3791c8a9c..f21becb276 100644
--- a/beacon_node/client/src/config.rs
+++ b/beacon_node/client/src/config.rs
@@ -4,7 +4,7 @@ use sensitive_url::SensitiveUrl;
 use serde_derive::{Deserialize, Serialize};
 use std::fs;
 use std::path::PathBuf;
-use types::{Graffiti, PublicKeyBytes};
+use types::{Graffiti, PublicKeyBytes, Uint256};
 
 /// Default directory name for the freezer database under the top-level data dir.
 const DEFAULT_FREEZER_DB_DIR: &str = "freezer_db";
@@ -75,7 +75,7 @@ pub struct Config {
     pub chain: beacon_chain::ChainConfig,
     pub eth1: eth1::Config,
     pub execution_endpoints: Option<Vec<SensitiveUrl>>,
-    pub total_terminal_difficulty_override: Option<u64>,
+    pub terminal_total_difficulty_override: Option<Uint256>,
     pub http_api: http_api::Config,
     pub http_metrics: http_metrics::Config,
     pub monitoring_api: Option<monitoring_api::Config>,
@@ -97,7 +97,7 @@ impl Default for Config {
             sync_eth1_chain: false,
             eth1: <_>::default(),
             execution_endpoints: None,
-            total_terminal_difficulty_override: None,
+            terminal_total_difficulty_override: None,
             disabled_forks: Vec::new(),
             graffiti: Graffiti::default(),
             http_api: <_>::default(),
diff --git a/beacon_node/execution_layer/src/lib.rs b/beacon_node/execution_layer/src/lib.rs
index da58853a78..525b8fae36 100644
--- a/beacon_node/execution_layer/src/lib.rs
+++ b/beacon_node/execution_layer/src/lib.rs
@@ -30,7 +30,7 @@ impl From<ApiError> for Error {
 
 struct Inner {
     engines: Engines<HttpJsonRpc>,
-    total_terminal_difficulty: Uint256,
+    terminal_total_difficulty: Uint256,
     executor: TaskExecutor,
     log: Logger,
 }
@@ -43,7 +43,7 @@ pub struct ExecutionLayer {
 impl ExecutionLayer {
     pub fn from_urls(
         urls: Vec<SensitiveUrl>,
-        total_terminal_difficulty: Uint256,
+        terminal_total_difficulty: Uint256,
         executor: TaskExecutor,
         log: Logger,
     ) -> Result<Self, Error> {
@@ -61,7 +61,7 @@ impl ExecutionLayer {
                 engines,
                 log: log.clone(),
             },
-            total_terminal_difficulty,
+            terminal_total_difficulty,
             executor,
             log,
         };
@@ -81,8 +81,8 @@ impl ExecutionLayer {
         &self.inner.executor
     }
 
-    fn total_terminal_difficulty(&self) -> Uint256 {
-        self.inner.total_terminal_difficulty
+    fn terminal_total_difficulty(&self) -> Uint256 {
+        self.inner.terminal_total_difficulty
     }
 
     fn log(&self) -> &Logger {
@@ -226,7 +226,7 @@ impl ExecutionLayer {
         }
     }
 
-    pub async fn find_ttd_block_hash(&self) -> Result<Option<Hash256>, Error> {
+    pub async fn get_pow_block_at_total_difficulty(&self) -> Result<Option<Hash256>, Error> {
         self.engines()
             .first_success(|engine| async move {
                 let mut ttd_exceeding_block = None;
@@ -236,7 +236,7 @@ impl ExecutionLayer {
                     .await?;
 
                 loop {
-                    if block.total_difficulty >= self.total_terminal_difficulty() {
+                    if block.total_difficulty >= self.terminal_total_difficulty() {
                         ttd_exceeding_block = Some(block.block_hash);
 
                         block = engine.api.get_block_by_hash(block.parent_hash).await?;
diff --git a/beacon_node/src/config.rs b/beacon_node/src/config.rs
index 6d29d613db..b984d50477 100644
--- a/beacon_node/src/config.rs
+++ b/beacon_node/src/config.rs
@@ -224,7 +224,7 @@ pub fn get_config<E: EthSpec>(
         client_config.execution_endpoints = Some(client_config.eth1.endpoints.clone());
     }
 
-    if let Some(total_terminal_difficulty) =
+    if let Some(terminal_total_difficulty) =
         clap_utils::parse_optional(cli_args, "total-terminal-difficulty-override")?
     {
         if client_config.execution_endpoints.is_none() {
@@ -234,7 +234,7 @@ pub fn get_config<E: EthSpec>(
             );
         }
 
-        client_config.total_terminal_difficulty_override = Some(total_terminal_difficulty);
+        client_config.terminal_total_difficulty_override = Some(terminal_total_difficulty);
     }
 
     if let Some(freezer_dir) = cli_args.value_of("freezer-dir") {