From 89e882e32463c246c95401c9ae8290e9aee72d0d Mon Sep 17 00:00:00 2001
From: syntrust <lundeng@quarkchain.org>
Date: Tue, 27 Aug 2024 18:50:14 +0800
Subject: [PATCH] fix diff

---
 ethstorage/miner/algorithm.go      | 28 ++++++-----
 ethstorage/miner/algorithm_test.go | 78 ++++++++++++++++++++++++++++++
 ethstorage/miner/worker.go         |  7 ++-
 3 files changed, 100 insertions(+), 13 deletions(-)
 create mode 100644 ethstorage/miner/algorithm_test.go

diff --git a/ethstorage/miner/algorithm.go b/ethstorage/miner/algorithm.go
index 7ba2e3d7..90503147 100644
--- a/ethstorage/miner/algorithm.go
+++ b/ethstorage/miner/algorithm.go
@@ -40,23 +40,29 @@ func initHash(miner common.Address, mixedHash common.Hash, nonce uint64) common.
 	)
 }
 
-func expectedDiff(lastMineTime, minedTime uint64, difficulty, cutoff, diffAdjDivisor, minDiff *big.Int) *big.Int {
-	interval := new(big.Int).SetUint64(minedTime - lastMineTime)
-	diff := difficulty
-	if interval.Cmp(cutoff) < 0 {
-		// diff = diff + (diff-interval*diff/cutoff)/diffAdjDivisor
-		diff = new(big.Int).Add(diff, new(big.Int).Div(
-			new(big.Int).Sub(diff, new(big.Int).Div(new(big.Int).Mul(interval, diff), cutoff)), diffAdjDivisor))
+func expectedDiff(interval uint64, difficulty, cutoff, diffAdjDivisor, minDiff *big.Int) *big.Int {
+	diff := new(big.Int).Set(difficulty)
+	x := interval / cutoff.Uint64()
+	if x == 0 {
+		// diff = diff + ((1 - interval / _cutoff) * diff) / _diffAdjDivisor;
+		adjust := new(big.Int).Div(diff, diffAdjDivisor)
+		diff = new(big.Int).Add(diff, adjust)
 		if diff.Cmp(minDiff) < 0 {
 			diff = minDiff
 		}
 	} else {
-		// dec := (interval*diff/cutoff - diff) / diffAdjDivisor
-		dec := new(big.Int).Div(new(big.Int).Sub(new(big.Int).Div(new(big.Int).Mul(interval, diff), cutoff), diff), diffAdjDivisor)
-		if new(big.Int).Add(dec, minDiff).Cmp(diff) > 0 {
+		// diff = diff - ((interval / _cutoff - 1) * diff) / _diffAdjDivisor;
+		adjust := new(big.Int).Div(
+			new(big.Int).Mul(
+				new(big.Int).SetUint64(x-1),
+				diff,
+			),
+			diffAdjDivisor,
+		)
+		if new(big.Int).Add(adjust, minDiff).Cmp(diff) > 0 {
 			diff = minDiff
 		} else {
-			diff = new(big.Int).Sub(diff, dec)
+			diff = new(big.Int).Sub(diff, adjust)
 		}
 	}
 
diff --git a/ethstorage/miner/algorithm_test.go b/ethstorage/miner/algorithm_test.go
new file mode 100644
index 00000000..b99c8b72
--- /dev/null
+++ b/ethstorage/miner/algorithm_test.go
@@ -0,0 +1,78 @@
+// Copyright 2022-2023, EthStorage.
+// For license information, see https://github.com/ethstorage/es-node/blob/main/LICENSE
+
+package miner
+
+import (
+	"fmt"
+	"math/big"
+	"testing"
+)
+
+func Test_expectedDiff(t *testing.T) {
+	type args struct {
+		interval       uint64
+		difficulty     *big.Int
+		cutoff         *big.Int
+		diffAdjDivisor *big.Int
+		minDiff        *big.Int
+	}
+	tests := []struct {
+		name string
+		args args
+		want *big.Int
+	}{
+		{
+			"decrease: diff not match case 1",
+			args{
+				1724219196 - 1724218692,
+				big.NewInt(16933920),
+				big.NewInt(7200),
+				big.NewInt(32),
+				big.NewInt(9437184),
+			},
+			big.NewInt(17463105),
+		},
+		{
+			"decrease: diff not match case 2",
+			args{
+				1724243184 - 1724242128,
+				big.NewInt(71922272),
+				big.NewInt(7200),
+				big.NewInt(32),
+				big.NewInt(9437184),
+			},
+			big.NewInt(74169843),
+		},
+		{
+			"no change",
+			args{
+				1723277844 - 1723267236,
+				big.NewInt(25034417035),
+				big.NewInt(7200),
+				big.NewInt(32),
+				big.NewInt(4718592000),
+			},
+			big.NewInt(25034417035),
+		},
+		{
+			"increase",
+			args{
+				1724507676 - 1724507412,
+				big.NewInt(18788404245),
+				big.NewInt(7200),
+				big.NewInt(32),
+				big.NewInt(4718592000),
+			},
+			big.NewInt(19375541877),
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fmt.Println("tt.args.interval", tt.args.interval)
+			if got := expectedDiff(tt.args.interval, tt.args.difficulty, tt.args.cutoff, tt.args.diffAdjDivisor, tt.args.minDiff); tt.want.Cmp(got) != 0 {
+				t.Errorf("got  = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/ethstorage/miner/worker.go b/ethstorage/miner/worker.go
index 80010026..d94d67f7 100644
--- a/ethstorage/miner/worker.go
+++ b/ethstorage/miner/worker.go
@@ -322,9 +322,12 @@ func (w *worker) updateDifficulty(shardIdx, blockTime uint64) (*big.Int, error)
 		return nil, err
 	}
 	w.lg.Info("Mining info retrieved", "shard", shardIdx, "lastMineTime", info.LastMineTime, "difficulty", info.Difficulty, "proofsSubmitted", info.BlockMined)
+
+	if blockTime <= info.LastMineTime {
+		return nil, errors.New("minedTs too small")
+	}
 	reqDiff := new(big.Int).Div(maxUint256, expectedDiff(
-		info.LastMineTime,
-		blockTime,
+		blockTime-info.LastMineTime,
 		info.Difficulty,
 		w.config.Cutoff,
 		w.config.DiffAdjDivisor,