From 695e473784cfc8841049e263eac9ea30c203fc2a Mon Sep 17 00:00:00 2001
From: Rongjian Lan <rongjian.lan@gmail.com>
Date: Mon, 3 Sep 2018 16:48:49 -0700
Subject: [PATCH] Create state block from utxo pool

---
 blockchain/block.go    | 18 ++++++++++++++++++
 blockchain/utxopool.go |  5 +++++
 2 files changed, 23 insertions(+)

diff --git a/blockchain/block.go b/blockchain/block.go
index 805631d19..696630db8 100644
--- a/blockchain/block.go
+++ b/blockchain/block.go
@@ -112,3 +112,21 @@ func NewBlock(transactions []*Transaction, prevBlockHash [32]byte, shardId uint3
 func NewGenesisBlock(coinbase *Transaction, shardId uint32) *Block {
 	return NewBlock([]*Transaction{coinbase}, [32]byte{}, shardId)
 }
+
+// NewStateBlock creates and returns a state Block based on utxo pool.
+func NewStateBlock(utxoPool *UTXOPool) *Block {
+	stateTransactions := []*Transaction{}
+	for address, txHash2Vout2AmountMap := range utxoPool.UtxoMap {
+		stateTransaction := Transaction{}
+		for _, vout2AmountMap := range txHash2Vout2AmountMap {
+			for _, amount := range vout2AmountMap {
+				stateTransaction.TxOutput = append(stateTransaction.TxOutput, TXOutput{Amount: amount, Address: address, ShardID: utxoPool.ShardID})
+			}
+		}
+		if len(stateTransaction.TxOutput) != 0 {
+			stateTransaction.SetID()
+			stateTransactions = append(stateTransactions, &stateTransaction)
+		}
+	}
+	return NewBlock(stateTransactions, [32]byte{}, utxoPool.ShardID)
+}
diff --git a/blockchain/utxopool.go b/blockchain/utxopool.go
index 0b08fbe83..184027362 100644
--- a/blockchain/utxopool.go
+++ b/blockchain/utxopool.go
@@ -456,3 +456,8 @@ func (utxoPool *UTXOPool) GetSizeInByteOfUtxoMap() int {
 	encoder.Encode(utxoPool.UtxoMap)
 	return len(byteBuffer.Bytes())
 }
+
+// Create state block based on the utxos.
+func (utxoPool *UTXOPool) CreateStateBlock() *Block {
+	return NewStateBlock(utxoPool)
+}