1 files changed, 111 insertions, 0 deletions
diff --git a/simulation/verification.go b/simulation/verification.go
new file mode 100644
index 0000000..b32d719
--- /dev/null
+++ b/simulation/verification.go
@@ -0,0 +1,111 @@
+// Copyright 2018 The dexon-consensus-core Authors
+// This file is part of the dexon-consensus-core library.
+//
+// The dexon-consensus-core library is free software: you can redistribute it
+// and/or modify it under the terms of the GNU Lesser General Public License as
+// published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The dexon-consensus-core library is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the dexon-consensus-core library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+package simulation
+
+import (
+	"container/heap"
+	"log"
+	"math"
+
+	"github.com/dexon-foundation/dexon-consensus-core/common"
+	"github.com/dexon-foundation/dexon-consensus-core/core/types"
+)
+
+// TotalOrderResult is the object maintaining peer's result of
+// Total Ordering Algorithm.
+type TotalOrderResult struct {
+	hashList         common.Hashes
+	curID            int
+	pendingBlockList PendingBlockList
+}
+
+// PeerTotalOrder stores the TotalOrderResult of each validator.
+type PeerTotalOrder = map[types.ValidatorID]*TotalOrderResult
+
+// NewTotalOrderResult returns pointer to a a new TotalOrderResult instance.
+func NewTotalOrderResult() *TotalOrderResult {
+	totalOrder := &TotalOrderResult{}
+	heap.Init(&totalOrder.pendingBlockList)
+	return totalOrder
+}
+
+// PushBlocks push a BlockList into the TotalOrderResult and return true if
+// there is new blocks ready for verifiy
+func (totalOrder *TotalOrderResult) PushBlocks(blocks BlockList) (ready bool) {
+	if blocks.ID != totalOrder.curID {
+		heap.Push(&totalOrder.pendingBlockList, &blocks)
+		return false
+	}
+
+	// Append all of the consecutive blockList in the pendingBlockList.
+	for {
+		totalOrder.hashList = append(totalOrder.hashList, blocks.BlockHash...)
+		totalOrder.curID++
+		if len(totalOrder.pendingBlockList) == 0 ||
+			totalOrder.pendingBlockList[0].ID != totalOrder.curID {
+			break
+		}
+		blocks = *heap.Pop(&totalOrder.pendingBlockList).(*BlockList)
+	}
+	return true
+}
+
+// VerifyTotalOrder verifies if the result of Total Ordering Algorithm
+// returned by all validators are the same. However, the length of result
+// of each validators may not be the same, so only the common part is verified.
+func VerifyTotalOrder(id types.ValidatorID,
+	totalOrder PeerTotalOrder) (
+	unverifiedMap PeerTotalOrder, correct bool) {
+
+	hasError := false
+
+	// Get the common length from all validators.
+	length := math.MaxInt32
+	for _, peerTotalOrder := range totalOrder {
+		if len(peerTotalOrder.hashList) < length {
+			length = len(peerTotalOrder.hashList)
+		}
+	}
+
+	// Verify if the order of the blocks are the same by comparing
+	// the hash value.
+	for i := 0; i < length; i++ {
+		hash := totalOrder[id].hashList[i]
+		for vid, peerTotalOrder := range totalOrder {
+			if peerTotalOrder.hashList[i] != hash {
+				log.Printf("[%d] Unexpected hash %v from %v\n", i,
+					peerTotalOrder.hashList[i], vid)
+				hasError = true
+			}
+		}
+		if hasError {
+			log.Printf("[%d] Hash is %v from %v\n", i, hash, id)
+		} else {
+			log.Printf("Block %v confirmed\n", hash)
+		}
+	}
+
+	// Remove verified block from list.
+	if length > 0 {
+		for vid := range totalOrder {
+			totalOrder[vid].hashList =
+				totalOrder[vid].hashList[length:]
+		}
+	}
+	return totalOrder, !hasError
+}