// hash generates the key for the map from either an id int64 or a code string.
// If both interfaces are nil it returns 0 which is default for website, group or store.
// fnv64a used to calculate the uint64 value of a string, especially website code and store code.
func hash(wID scope.WebsiteIDer, gID scope.GroupIDer, sID scope.StoreIDer) (uint64, error) {
uz := uint64(0)
if nil == wID && nil == gID && nil == sID {
return uz, ErrHashRetrieverNil
}
if wC, ok := wID.(scope.WebsiteCoder); ok {
return hashCode(wC.WebsiteCode()), nil
}
if nil != wID {
return uint64(wID.WebsiteID()), nil
}
if nil != gID {
return uint64(gID.GroupID()), nil
}
if sC, ok := sID.(scope.StoreCoder); ok {
return hashCode(sC.StoreCode()), nil
}
if nil != sID {
return uint64(sID.StoreID()), nil
}
return uz, ErrHashRetrieverNil // unreachable ....
}
// website returns a TableWebsite by using either id or code to find it. If id and code are
// available then the non-empty code has precedence.
func (st *Storage) website(r scope.WebsiteIDer) (*TableWebsite, error) {
if r == nil {
return nil, ErrWebsiteNotFound
}
if c, ok := r.(scope.WebsiteCoder); ok && c.WebsiteCode() != "" {
return st.websites.FindByCode(c.WebsiteCode())
}
return st.websites.FindByWebsiteID(r.WebsiteID())
}