init: PoC

* only supports legacy transactions

cmd/gorge.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"math/big"
+	"time"
+
+	"git.grassecon.net/chaintool/gorge/pkg/block"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/lmittmann/w3"
+)
+
+func main() {
+	client := w3.MustDial("https://rpc.ankr.com/eth")
+	defer client.Close()
+
+	defer traceExecTime(time.Now())
+	blockFetcher := block.NewBlockFetcher(block.BlockFetcherOpts{
+		W3Client: client,
+		Signer:   types.NewEIP155Signer(big.NewInt(1)),
+	})
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
+	defer cancel()
+
+	// https://etherscan.io/block/16031266
+	res, err := blockFetcher.FetchBlock(ctx, big.NewInt(5000000))
+	if err != nil {
+		log.Fatalf("Could not fetch block: %v", err)
+	}
+
+	resJson, err := json.Marshal(res)
+	if err != nil {
+		log.Fatalf("json.Marshal failed: %v", err)
+	}
+
+	if err := ioutil.WriteFile("block.json", resJson, 0644); err != nil {
+		log.Fatalf("Write file failed: %v", err)
+	}
+
+	log.Printf("Block successfully obtained")
+}

cmd/trace.go

@@ -0,0 +1,12 @@
+package main
+
+import (
+	"log"
+	"time"
+)
+
+func traceExecTime(start time.Time) {
+	elapsed := time.Since(start)
+
+	log.Printf("Exec time: %s", elapsed)
+}