refactor: store both found mempool txs and hashes of txs not found in…

…-memory

mempoolexplorer.go

@@ -2,26 +2,18 @@ package mempoolexplorer
 
 import (
 	"context"
-	"fmt"
 	"github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethclient/gethclient"
 	"log"
 )
 
 var missingTxs = make([]common.Hash, 0, 20)
+var txs = make(map[common.Hash]*types.Transaction)
 
-func main() {
-	pendingTxs := streamMemPoolTxs(createGethClient(), 5)
-	for {
-		fmt.Println("Channel length: ", len(pendingTxs))
-		fmt.Println("Channel capacity: ", cap(pendingTxs))
-		fmt.Println(<-pendingTxs)
-	}
-}
-
-// streamMemPoolTxs listens to all pending TXs that underlying ethereum node receives from incoming RPC requests and other nodes
-func streamMemPoolTxs(geth *gethclient.Client, bufferLength int) chan common.Hash {
+// streamMemPoolTxHashes listens to all pending TXs that underlying ethereum node receives from incoming RPC requests and other nodes
+func streamMemPoolTxHashes(geth *gethclient.Client, bufferLength int) chan common.Hash {
 	pendingTxs := make(chan common.Hash, bufferLength)
 	_, err := geth.SubscribePendingTransactions(context.Background(), pendingTxs)
 	if err != nil {
@@ -30,27 +22,19 @@ func streamMemPoolTxs(geth *gethclient.Client, bufferLength int) chan common.Has
 	return pendingTxs
 }
 
-func printTxDetails(txHash common.Hash) {
+func storeTxDetails(txHash common.Hash) {
 	client := createEthClient()
-	tx, isPending, err := client.TransactionByHash(context.Background(), txHash)
+	tx, _, err := client.TransactionByHash(context.Background(), txHash)
 
-	// If TX is not found, just print the error and return so the rest of the program can continue. If there's an other error then log and exit.
+	// If TX is not found, print the error, store the hash and return so the rest of the program can continue.
 	if err == ethereum.NotFound {
 		log.Println(err)
 		storeMissingTxHashes(txHash)
 		return
 	} else if err != nil {
 		log.Fatal(err)
 	}
-
-	fmt.Println(tx.Hash().Hex())          // 0x5d49fcaa394c97ec8a9c3e7bd9e8388d420fb050a52083ca52ff24b3b65bc9c2
-	fmt.Println(tx.Value().String())      // 10000000000000000
-	fmt.Println(tx.Gas())                 // 105000
-	fmt.Println(tx.GasPrice().Uint64())   // 102000000000
-	fmt.Println(tx.Nonce())               // 110644
-	fmt.Println(tx.Data())                // []
-	fmt.Println(tx.To().Hex())            // 0x55fE59D8Ad77035154dDd0AD0388D09Dd4047A8e
-	fmt.Println("isPending: ", isPending) // true
+	txs[txHash] = tx
 }
 
 func storeMissingTxHashes(txHash common.Hash) {

mempoolexplorer_test.go

@@ -6,8 +6,8 @@ import (
 	"testing"
 )
 
-func TestMain_streamMemPoolTxs(t *testing.T) {
-	pendingTxs := streamMemPoolTxs(createGethClient(), 100)
+func TestMempoolExplorer_streamMemPoolTxs(t *testing.T) {
+	pendingTxs := streamMemPoolTxHashes(createGethClient(), 100)
 	for {
 		fmt.Println("Channel length: ", len(pendingTxs))
 		fmt.Println("Channel capacity: ", cap(pendingTxs))
@@ -16,22 +16,33 @@ func TestMain_streamMemPoolTxs(t *testing.T) {
 	}
 }
 
-func TestMain_getTxDetails(t *testing.T) {
+func TestMempoolExplorer_storeTxDetails(t *testing.T) {
 	// 0xaf745220755919ee3386ca28cc207e87388841832ee4bd67d7260b06b914af85
-	printTxDetails(common.HexToHash("0xaf745220755919ee3386ca28cc207e87388841832ee4bd67d7260b06b914af85"))
+	storeTxDetails(common.HexToHash("0xaf745220755919ee3386ca28cc207e87388841832ee4bd67d7260b06b914af85"))
 }
 
-func TestMain_getTxDetails_Live(t *testing.T) {
-	pendingTxs := streamMemPoolTxs(createGethClient(), 10)
+func TestMempoolExplorer_storeTxDetails_Live(t *testing.T) {
+	pendingTxs := streamMemPoolTxHashes(createGethClient(), 10)
 	for i := 1; i < 25; i++ {
 		currentTxHash := <-pendingTxs
 		fmt.Println(currentTxHash)
-		printTxDetails(currentTxHash)
+		storeTxDetails(currentTxHash)
 	}
 
-	fmt.Println("Pending TXs not found on geth node:")
+	fmt.Println(len(txs), " stored mempool TXs found on geth node:")
+	for _, tx := range txs {
+		fmt.Println("------------------------------------------------------")
+		fmt.Println(tx.Hash().Hex())        // 0x5d49fcaa394c97ec8a9c3e7bd9e8388d420fb050a52083ca52ff24b3b65bc9c2
+		fmt.Println(tx.Value().String())    // 10000000000000000
+		fmt.Println(tx.Gas())               // 105000
+		fmt.Println(tx.GasPrice().Uint64()) // 102000000000
+		fmt.Println(tx.Nonce())             // 110644
+		fmt.Println(tx.Data())              // []
+		fmt.Println(tx.To().Hex())          // 0x55fE59D8Ad77035154dDd0AD0388D09Dd4047A8e
+	}
+
+	fmt.Println(len(missingTxs), " pending TXs not found on geth node:")
 	for _, txHash := range missingTxs {
 		fmt.Println(txHash.Hex())
 	}
-
 }