Added transaction event pubsub with test case (#385)

state/state.go

@@ -620,4 +620,10 @@ func (st *state) publishEvents(height uint32, block *block.Block) {
 	}
 	blockEvent := event.CreateBlockEvent(block.Hash(), height)
 	st.eventCh <- blockEvent
+
+	for i := 1; i < block.Transactions().Len(); i++ {
+		tx := block.Transactions().Get(i)
+		TxEvent := event.CreateNewTransactionEvent(tx.ID(), height)
+		st.eventCh <- TxEvent
+	}
 }

types/block/txs.go

@@ -45,3 +45,7 @@ func (txs Txs) IsEmpty() bool {
 func (txs Txs) Len() int {
 	return len(txs)
 }
+
+func (txs Txs) Get(i int) *tx.Tx {
+	return txs[i]
+}

types/block/txs_test.go

@@ -49,3 +49,12 @@ func TestIsEmpty(t *testing.T) {
 	txs.Append(trx)
 	assert.False(t, txs.IsEmpty())
 }
+
+func TestGetTransaction(t *testing.T) {
+	txs := NewTxs()
+	trx1, _ := tx.GenerateTestSendTx()
+	trx2, _ := tx.GenerateTestSendTx()
+	txs.Append(trx1)
+	txs.Append(trx2)
+	assert.Equal(t, trx1, txs.Get(0))
+}

www/nanomsg/event/event.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 
 	"github.com/pactus-project/pactus/crypto/hash"
+	"github.com/pactus-project/pactus/types/tx"
 	"github.com/pactus-project/pactus/util/encoding"
 	"github.com/pactus-project/pactus/util/logger"
 )
@@ -25,3 +26,16 @@ func CreateBlockEvent(blockHash hash.Hash, height uint32) Event {
 	}
 	return w.Bytes()
 }
+
+// CreateBlockEvent creates an event when the new block is committed.
+// The block event structure is like :
+// <topic_id><tx_hash><height><sequence_number>
+func CreateNewTransactionEvent(txHash tx.ID, height uint32) Event {
+	buf := make([]byte, 0, 42)
+	w := bytes.NewBuffer(buf)
+	err := encoding.WriteElements(w, TopicNewTransaction, txHash, height)
+	if err != nil {
+		logger.Error("error on encoding event in transaction event", "err", err)
+	}
+	return w.Bytes()
+}

www/nanomsg/event/event_test.go

@@ -15,3 +15,11 @@ func TestCreateBlockEvent(t *testing.T) {
 		0xa, 0xb, 0xc, 0xd, 0xe, 0xf, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8,
 		0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf, 0x34, 0x21, 0x0, 0x0})
 }
+func TestCreateNewTransactionEvent(t *testing.T) {
+	hash, _ := hash.FromString("000102030405060708090a0b0c0d0e0f000102030405060708090a0b0c0d0e0f")
+	height := uint32(0x2134)
+	e := CreateNewTransactionEvent(hash, height)
+	assert.Equal(t, e, Event{0x1, 0x2, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9,
+		0xa, 0xb, 0xc, 0xd, 0xe, 0xf, 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8,
+		0x9, 0xa, 0xb, 0xc, 0xd, 0xe, 0xf, 0x34, 0x21, 0x0, 0x0})
+}