package whisper import "github.com/ethereum/go-ethereum/crypto" func hashTopic(topic []byte) []byte { return crypto.Sha3(topic)[:4] } // NOTE this isn't DRY, but I don't want to iterate twice. // Returns a formatted topics byte slice. // data: unformatted data (e.g., no hashes needed) func Topics(data [][]byte) [][]byte { d := make([][]byte, len(data)) for i, byts := range data { d[i] = hashTopic(byts) } return d } func TopicsFromString(data []string) [][]byte { d := make([][]byte, len(data)) for i, str := range data { d[i] = hashTopic([]byte(str)) } return d }