You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: db.go
    path of file: ./repos/wgnetwork/vendor/go.etcd.io/bbolt
    
    the code of the file until where you have to start completion: package bbolt

import (
	"errors"
	"fmt"
	"hash/fnv"
	"io"
	"os"
	"runtime"
	"sort"
	"sync"
	"time"
	"unsafe"
)

// The largest step that can be taken when remapping the mmap.
const maxMmapStep = 1 << 30 // 1GB

// The data
    
func (db *DB) loadFreelist() {
	db.freelistLoad.Do(func() {
		db.freelist = newFreelist(db.FreelistType)
		if !db.hasSyncedFreelist() {
			// Reconstruct free list by scanning the DB.
			db.freelist.readIDs(db.freepages())
		} else {
			// Read free list from freelist page.
			db.freelist.read(db.page(db.meta().freelist))
		}
		db.stats.FreePageN = db.freelist.free_count()
	})
}