ntfy/server/cache_mem.go
2021-12-09 10:23:17 -05:00

101 lines
2.1 KiB
Go

package server
import (
"sync"
"time"
)
type memCache struct {
messages map[string][]*message
nop bool
mu sync.Mutex
}
var _ cache = (*memCache)(nil)
// newMemCache creates an in-memory cache
func newMemCache() *memCache {
return &memCache{
messages: make(map[string][]*message),
nop: false,
}
}
// newNopCache creates an in-memory cache that discards all messages;
// it is always empty and can be used if caching is entirely disabled
func newNopCache() *memCache {
return &memCache{
messages: make(map[string][]*message),
nop: true,
}
}
func (s *memCache) AddMessage(m *message) error {
s.mu.Lock()
defer s.mu.Unlock()
if s.nop {
return nil
}
if m.Event != messageEvent {
return errUnexpectedMessageType
}
if _, ok := s.messages[m.Topic]; !ok {
s.messages[m.Topic] = make([]*message, 0)
}
s.messages[m.Topic] = append(s.messages[m.Topic], m)
return nil
}
func (s *memCache) Messages(topic string, since sinceTime) ([]*message, error) {
s.mu.Lock()
defer s.mu.Unlock()
if _, ok := s.messages[topic]; !ok || since.IsNone() {
return make([]*message, 0), nil
}
messages := make([]*message, 0) // copy!
for _, m := range s.messages[topic] {
msgTime := time.Unix(m.Time, 0)
if msgTime == since.Time() || msgTime.After(since.Time()) {
messages = append(messages, m)
}
}
return messages, nil
}
func (s *memCache) MessageCount(topic string) (int, error) {
s.mu.Lock()
defer s.mu.Unlock()
if _, ok := s.messages[topic]; !ok {
return 0, nil
}
return len(s.messages[topic]), nil
}
func (s *memCache) Topics() (map[string]*topic, error) {
s.mu.Lock()
defer s.mu.Unlock()
topics := make(map[string]*topic)
for topic := range s.messages {
topics[topic] = newTopic(topic)
}
return topics, nil
}
func (s *memCache) Prune(olderThan time.Time) error {
s.mu.Lock()
defer s.mu.Unlock()
for topic := range s.messages {
s.pruneTopic(topic, olderThan)
}
return nil
}
func (s *memCache) pruneTopic(topic string, olderThan time.Time) {
messages := make([]*message, 0)
for _, m := range s.messages[topic] {
if m.Time >= olderThan.Unix() {
messages = append(messages, m)
}
}
s.messages[topic] = messages
}