func (p *Provider) GetDBHandle(dbName string) *DBHandle {
	p.mux.Lock()
	defer p.mux.Unlock()
	dbHandle := p.dbHandles[dbName]
	if dbHandle == nil {
		dbHandle = &DBHandle{dbName, p.db}
		p.dbHandles[dbName] = dbHandle
	}
	return dbHandle
}
GetDBHandle returns a handle to a named db
package leveldbhelper
import (
	"bytes"
	"sync"
	"github.com/syndtr/goleveldb/leveldb"
	"github.com/syndtr/goleveldb/leveldb/iterator"
)
var dbNameKeySep = []byte{0x00}
var lastKeyIndicator = byte(0x01)
type Provider struct {
	db        *DB
	dbHandles map[string]*DBHandle
	mux       sync.Mutex
}
func NewProvider(conf *Conf) *Provider {
	db := CreateDB(conf)
	db.Open()
	return &Provider{db, make(map[string]*DBHandle), sync.Mutex{}}
}