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