mirror of https://github.com/status-im/op-geth.git
36 lines
1.1 KiB
Go
36 lines
1.1 KiB
Go
// Contains the Whisper protocol Topic element. For formal details please see
|
|
// the specs at https://github.com/ethereum/wiki/wiki/Whisper-PoC-1-Protocol-Spec#topics.
|
|
|
|
package whisper
|
|
|
|
import "github.com/ethereum/go-ethereum/crypto"
|
|
|
|
// Topic represents a cryptographically secure, probabilistic partial
|
|
// classifications of a message, determined as the first (left) 4 bytes of the
|
|
// SHA3 hash of some arbitrary data given by the original author of the message.
|
|
type Topic [4]byte
|
|
|
|
// NewTopic creates a topic from the 4 byte prefix of the SHA3 hash of the data.
|
|
func NewTopic(data []byte) Topic {
|
|
prefix := [4]byte{}
|
|
copy(prefix[:], crypto.Sha3(data)[:4])
|
|
return Topic(prefix)
|
|
}
|
|
|
|
// String converts a topic byte array to a string representation.
|
|
func (self *Topic) String() string {
|
|
return string(self[:])
|
|
}
|
|
|
|
// TopicSet represents a hash set to check if a topic exists or not.
|
|
type TopicSet map[string]struct{}
|
|
|
|
// NewTopicSet creates a topic hash set from a slice of topics.
|
|
func NewTopicSet(topics []Topic) TopicSet {
|
|
set := make(map[string]struct{})
|
|
for _, topic := range topics {
|
|
set[topic.String()] = struct{}{}
|
|
}
|
|
return TopicSet(set)
|
|
}
|