From cbc845460969ef0fdbf7d588b8d171aa3ef5252e Mon Sep 17 00:00:00 2001
From: FiveMovesAhead <ying@tig.foundation>
Date: Mon, 31 Mar 2025 18:39:49 +0800
Subject: [PATCH] Implement hash_threshold update logic.

---
 tig-protocol/src/context.rs              |  6 +----
 tig-protocol/src/contracts/benchmarks.rs |  9 ++++----
 tig-protocol/src/contracts/opow.rs       | 28 ++++++++++++++++++++++++
 tig-structs/src/config.rs                |  2 ++
 4 files changed, 36 insertions(+), 9 deletions(-)

diff --git a/tig-protocol/src/context.rs b/tig-protocol/src/context.rs
index 73a54579..0ff1e897 100644
--- a/tig-protocol/src/context.rs
+++ b/tig-protocol/src/context.rs
@@ -38,11 +38,6 @@ pub trait Context {
         challenge_id: &String,
         block_id: &String,
     ) -> Option<ChallengeBlockData>;
-    async fn get_hash_threshold(
-        &self,
-        block_id: &String,
-        challenge_id: &String,
-    ) -> Option<MerkleHash>;
     async fn get_config(&self) -> ProtocolConfig;
     async fn add_deposit_to_mempool(&self, details: DepositDetails) -> Result<String>;
     async fn get_player_details(&self, player_id: &String) -> Option<PlayerDetails>;
@@ -108,4 +103,5 @@ pub struct AddBlockCache {
     pub active_breakthroughs_details: HashMap<String, BreakthroughDetails>,
     pub active_breakthroughs_block_data: HashMap<String, BreakthroughBlockData>,
     pub active_solutions: Vec<(BenchmarkSettings, u32, u32)>,
+    pub confirmed_num_solutions: HashMap<String, u32>,
 }
diff --git a/tig-protocol/src/contracts/benchmarks.rs b/tig-protocol/src/contracts/benchmarks.rs
index 403efdd1..0b2bd234 100644
--- a/tig-protocol/src/contracts/benchmarks.rs
+++ b/tig-protocol/src/contracts/benchmarks.rs
@@ -214,12 +214,13 @@ pub async fn submit_proof<T: Context>(
     }
 
     // verify merkle_proofs
+    let hash_threshold = ctx
+        .get_challenge_block_data(&settings.challenge_id, &settings.block_id)
+        .await
+        .ok_or_else(|| anyhow!("Block too old"))?
+        .hash_threshold;
     let mut verification_result = Ok(());
     let max_branch_len = (64 - (num_nonces - 1).leading_zeros()) as usize;
-    let hash_threshold = ctx
-        .get_hash_threshold(&settings.block_id, &settings.challenge_id)
-        .await
-        .unwrap();
     for merkle_proof in merkle_proofs.iter() {
         if merkle_proof.branch.0.len() > max_branch_len
             || merkle_proof
diff --git a/tig-protocol/src/contracts/opow.rs b/tig-protocol/src/contracts/opow.rs
index b07fd1f1..45c0fde1 100644
--- a/tig-protocol/src/contracts/opow.rs
+++ b/tig-protocol/src/contracts/opow.rs
@@ -19,6 +19,7 @@ pub(crate) async fn update(cache: &mut AddBlockCache) {
         active_players_state,
         active_players_block_data,
         active_opow_block_data,
+        confirmed_num_solutions,
         ..
     } = cache;
 
@@ -93,6 +94,33 @@ pub(crate) async fn update(cache: &mut AddBlockCache) {
         opow_data.cutoff = cutoff;
     }
 
+    // update hash threshold
+    let max_threshold = U256::MAX;
+    let denominator: u64 = 1_000_000_000;
+    for challenge_id in active_challenge_ids.iter() {
+        let prev_hash_threshold = active_challenges_prev_block_data
+            .get(challenge_id)
+            .map(|x| U256::from(x.hash_threshold.clone().0))
+            .unwrap_or(max_threshold.clone());
+        let percentage_error = 1.0
+            - *confirmed_num_solutions.get(challenge_id).unwrap_or(&0) as f64
+                / config.benchmarks.target_solution_rate;
+        let percent_delta = percentage_error
+            .abs()
+            .min(config.benchmarks.hash_threshold_max_percent_delta);
+
+        let numerator = (percent_delta * denominator as f64) as u64;
+        let delta = max_threshold / U256::from(denominator) * U256::from(numerator);
+
+        let challenge_data = active_challenges_block_data.get_mut(challenge_id).unwrap();
+        let hash_threshold = if percentage_error >= 0.0 {
+            prev_hash_threshold.saturating_add(delta)
+        } else {
+            prev_hash_threshold.saturating_sub(delta)
+        };
+        hash_threshold.to_big_endian(&mut challenge_data.hash_threshold.0);
+    }
+
     // update qualifiers
     let mut solutions_by_challenge =
         HashMap::<String, Vec<(&BenchmarkSettings, &u32, &u32)>>::new();
diff --git a/tig-structs/src/config.rs b/tig-structs/src/config.rs
index 734caf25..2523c4a2 100644
--- a/tig-structs/src/config.rs
+++ b/tig-structs/src/config.rs
@@ -68,6 +68,8 @@ serializable_struct_with_getters! {
         min_per_nonce_fee: PreciseNumber,
         min_base_fee: PreciseNumber,
         runtime_configs: HashMap<AlgorithmType, RuntimeConfig>,
+        target_solution_rate: f64,
+        hash_threshold_max_percent_delta: f64,
     }
 }
 serializable_struct_with_getters! {