executor: vmstats in json

executor/executor.go

@@ -1,6 +1,7 @@
 package executor
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -33,13 +34,25 @@ type Config struct {
 }
 
 type Result struct {
-	Status          int64
-	GasUsed         uint64
-	SyscallCount    int64
-	ExecDur         time.Duration
-	PagesBeforeExec int
-	PagesUsed       int
-	StartTime       time.Time
+	Status          int64         `json:"status"`
+	GasUsed         uint64        `json:"gas_used"`
+	SyscallCount    int64         `json:"syscall_count"`
+	ExecDur         time.Duration `json:"exec_dur"`
+	PagesBeforeExec int           `json:"pages_before_exec"`
+	PagesUsed       int           `json:"pages_used"`
+	StartTime       time.Time     `json:"start_time"`
+}
+
+func (r Result) StatsJSONFile() txtar.File {
+	data, err := json.MarshalIndent(r, "", "  ")
+	if err != nil /* unlikely */ {
+		panic(err)
+	}
+
+	return txtar.File{
+		Name: "vmstats.json",
+		Data: data,
+	}
 }
 
 func (r Result) StatsFile() txtar.File {