12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758 |
- // Copyright 2016 The go-ethereum Authors
- // This file is part of the go-ethereum library.
- //
- // The go-ethereum library is free software: you can redistribute it and/or modify
- // it under the terms of the GNU Lesser General Public License as published by
- // the Free Software Foundation, either version 3 of the License, or
- // (at your option) any later version.
- //
- // The go-ethereum library is distributed in the hope that it will be useful,
- // but WITHOUT ANY WARRANTY; without even the implied warranty of
- // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- // GNU Lesser General Public License for more details.
- //
- // You should have received a copy of the GNU Lesser General Public License
- // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
- // Contains the Whisper protocol Topic element.
- package whisperv6
- import (
- "github.com/ethereum/go-ethereum/common"
- "github.com/ethereum/go-ethereum/common/hexutil"
- )
- // TopicType 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 TopicType [TopicLength]byte
- // BytesToTopic converts from the byte array representation of a topic
- // into the TopicType type.
- func BytesToTopic(b []byte) (t TopicType) {
- sz := TopicLength
- if x := len(b); x < TopicLength {
- sz = x
- }
- for i := 0; i < sz; i++ {
- t[i] = b[i]
- }
- return t
- }
- // String converts a topic byte array to a string representation.
- func (t *TopicType) String() string {
- return common.ToHex(t[:])
- }
- // MarshalText returns the hex representation of t.
- func (t TopicType) MarshalText() ([]byte, error) {
- return hexutil.Bytes(t[:]).MarshalText()
- }
- // UnmarshalText parses a hex representation to a topic.
- func (t *TopicType) UnmarshalText(input []byte) error {
- return hexutil.UnmarshalFixedText("Topic", input, t[:])
- }
|