getting an event payload from the strfry database directly from Go

strfry_access.go

package main

import (
	"encoding/hex"
	"fmt"

	"github.com/bmatsuo/lmdb-go/lmdb"
	"github.com/bmatsuo/lmdb-go/lmdbscan"
)

func main() {
	fmt.Println(getEvent(
		"/home/fiatjaf/comp/strfry/strfry-db/",
		"ff80c31dc005d0ff6aa55daf2e15e9cd804aea781c85bafd17091587aeadaf37",
	))
}

func getEvent(lmdbPath, id string) string {
	var eventJson string

	env, err := lmdb.NewEnv()
	if err != nil {
		panic(err)
	}

	env.SetMaxDBs(2)

	err = env.Open(lmdbPath, 0, 0644)
	if err != nil {
		panic(err)
	}
	defer env.Close()

	var eventsByIdIndexDbi lmdb.DBI
	var eventsDbi lmdb.DBI

	env.Update(func(txn *lmdb.Txn) error {
		db1, err := txn.OpenDBI("rasgueadb_defaultDb__Event__id", 0)
		if err != nil {
			panic(err)
		}
		eventsByIdIndexDbi = db1

		db2, err := txn.OpenDBI("rasgueadb_defaultDb__EventPayload", 0)
		if err != nil {
			panic(err)
		}
		eventsDbi = db2

		return nil
	})

	env.View(func(txn *lmdb.Txn) error {
		txn.RawRead = true

		eventId, err := hex.DecodeString(id)
		if err != nil {
			panic(err)
		}

		scanner := lmdbscan.New(txn, eventsByIdIndexDbi)
		cursor := scanner.Cursor()
		_, val, err := cursor.Get(eventId, nil, lmdb.SetRange)
		if err != nil {
			panic(err)
		}
		defer scanner.Close()

		res, err := txn.Get(eventsDbi, val)
		if err != nil {
			return nil
		}
		eventJson = string(res[1:])

		return nil
	})

	return eventJson
}