forked from cwtch.im/cwtch
92 lines
2.0 KiB
Go
92 lines
2.0 KiB
Go
package model
|
|
|
|
import (
|
|
"sort"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
// Timeline encapsulates a collection of ordered messages, and a mechanism to access them
|
|
// in a threadsafe manner.
|
|
type Timeline struct {
|
|
Messages []Message
|
|
SignedGroupID []byte
|
|
lock sync.Mutex
|
|
}
|
|
|
|
// Message is a local representation of a given message sent over a group chat channel.
|
|
type Message struct {
|
|
Timestamp time.Time
|
|
Received time.Time
|
|
PeerID string
|
|
Message string
|
|
Signature []byte
|
|
Verified bool
|
|
PreviousMessageSig []byte
|
|
}
|
|
|
|
func compareSignatures(a []byte, b []byte) bool {
|
|
if len(a) != len(b) {
|
|
return false
|
|
}
|
|
for i := range a {
|
|
if a[i] != b[i] {
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
}
|
|
|
|
// GetMessages returns a copy of the entire timeline
|
|
func (t *Timeline) GetMessages() []Message {
|
|
t.lock.Lock()
|
|
messages := make([]Message, len(t.Messages))
|
|
copy(messages[:], t.Messages[:])
|
|
t.lock.Unlock()
|
|
return messages
|
|
}
|
|
|
|
// Len gets the length of the timeline
|
|
func (t *Timeline) Len() int {
|
|
return len(t.Messages)
|
|
}
|
|
|
|
// Swap swaps 2 messages on the timeline.
|
|
func (t *Timeline) Swap(i, j int) {
|
|
t.Messages[i], t.Messages[j] = t.Messages[j], t.Messages[i]
|
|
}
|
|
|
|
// Less checks 2 messages (i and j) in the timeline and returns true if i occcured before j, else false
|
|
func (t *Timeline) Less(i, j int) bool {
|
|
|
|
if t.Messages[i].Timestamp.Before(t.Messages[j].Timestamp) {
|
|
return true
|
|
}
|
|
|
|
if compareSignatures(t.Messages[i].PreviousMessageSig, t.SignedGroupID) {
|
|
return true
|
|
}
|
|
|
|
if compareSignatures(t.Messages[i].Signature, t.Messages[j].PreviousMessageSig) {
|
|
return true
|
|
}
|
|
|
|
return false
|
|
}
|
|
|
|
// Insert inserts a message into the timeline in a thread safe way.
|
|
func (t *Timeline) Insert(mi *Message) {
|
|
t.lock.Lock()
|
|
defer t.lock.Unlock()
|
|
|
|
for _, m := range t.Messages {
|
|
// If the message already exists, then we don't add it
|
|
if compareSignatures(m.Signature, mi.Signature) {
|
|
return
|
|
}
|
|
}
|
|
|
|
t.Messages = append(t.Messages, *mi)
|
|
sort.Sort(t)
|
|
}
|