115 lines
3.1 KiB
Go
115 lines
3.1 KiB
Go
// Copyright 2019 The Waku Library Authors.
|
|
//
|
|
// The Waku 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 Waku library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty off
|
|
// 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 Waku library. If not, see <http://www.gnu.org/licenses/>.
|
|
//
|
|
// This software uses the go-ethereum library, which is licensed
|
|
// under the GNU Lesser General Public Library, version 3 or any later.
|
|
|
|
package common
|
|
|
|
import (
|
|
"errors"
|
|
"strings"
|
|
|
|
"golang.org/x/exp/maps"
|
|
|
|
"github.com/ethereum/go-ethereum/common/hexutil"
|
|
)
|
|
|
|
// TopicType represents a cryptographically secure, probabilistic partial
|
|
// classifications of a message, determined as the first (leftmost) 4 bytes of the
|
|
// SHA3 hash of some arbitrary data given by the original author of the message.
|
|
type TopicType [TopicLength]byte
|
|
|
|
type TopicSet map[TopicType]struct{}
|
|
|
|
func NewTopicSet(topics []TopicType) TopicSet {
|
|
s := make(TopicSet, len(topics))
|
|
for _, t := range topics {
|
|
s[t] = struct{}{}
|
|
}
|
|
return s
|
|
}
|
|
|
|
func NewTopicSetFromBytes(byteArrays [][]byte) TopicSet {
|
|
topics := make([]TopicType, len(byteArrays))
|
|
for i, byteArr := range byteArrays {
|
|
topics[i] = BytesToTopic(byteArr)
|
|
}
|
|
return NewTopicSet(topics)
|
|
}
|
|
|
|
// 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
|
|
}
|
|
|
|
func StringToTopic(s string) (t TopicType) {
|
|
str, _ := hexutil.Decode(s)
|
|
return BytesToTopic(str)
|
|
}
|
|
|
|
// String converts a topic byte array to a string representation.
|
|
func (t *TopicType) String() string {
|
|
return hexutil.Encode(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[:])
|
|
}
|
|
|
|
// Converts a topic to its 23/WAKU2-TOPICS representation
|
|
func (t TopicType) ContentTopic() string {
|
|
enc := hexutil.Encode(t[:])
|
|
return "/waku/1/" + enc + "/rfc26"
|
|
}
|
|
|
|
func ExtractTopicFromContentTopic(s string) (TopicType, error) {
|
|
p := strings.Split(s, "/")
|
|
|
|
if len(p) != 5 || p[1] != "waku" || p[2] != "1" || p[4] != "rfc26" {
|
|
return TopicType{}, errors.New("invalid content topic format")
|
|
}
|
|
|
|
str, err := hexutil.Decode(p[3])
|
|
if err != nil {
|
|
return TopicType{}, err
|
|
}
|
|
|
|
result := BytesToTopic(str)
|
|
return result, nil
|
|
}
|
|
|
|
func (t TopicSet) ContentTopics() []string {
|
|
contentTopics := make([]string, len(t))
|
|
for i, ct := range maps.Keys(t) {
|
|
contentTopics[i] = ct.ContentTopic()
|
|
}
|
|
return contentTopics
|
|
}
|