core, core/vm: added structure logging

This also reduces the time required spend in the VM

core/vm_logger.go

@@ -0,0 +1,40 @@
+package core
+
+import (
+	"fmt"
+	"os"
+	"unicode/utf8"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/vm"
+)
+
+func VmStdErrFormat(logs []vm.StructLog) {
+	fmt.Fprintf(os.Stderr, "VM Stats %d ops\n", len(logs))
+	for _, log := range logs {
+		fmt.Fprintf(os.Stderr, "PC %-3d - %-14s\n", log.Pc, log.Op)
+		fmt.Fprintln(os.Stderr, "STACK =", len(log.Stack))
+		for i, item := range log.Stack {
+			fmt.Fprintf(os.Stderr, "%04d: %x\n", i, common.LeftPadBytes(item.Bytes(), 32))
+		}
+
+		const maxMem = 10
+		addr := 0
+		fmt.Fprintln(os.Stderr, "MEM =", len(log.Memory))
+		for i := 0; i+16 <= len(log.Memory) && addr < maxMem; i += 16 {
+			data := log.Memory[i : i+16]
+			str := fmt.Sprintf("%04d: % x  ", addr*16, data)
+			for _, r := range data {
+				if r == 0 {
+					str += "."
+				} else if utf8.ValidRune(rune(r)) {
+					str += fmt.Sprintf("%s", string(r))
+				} else {
+					str += "?"
+				}
+			}
+			addr++
+			fmt.Fprintln(os.Stderr, str)
+		}
+	}
+}