Ryan
fb30e8e884
Move lesson source into the teaching structure, align the course path with the learner's Go and DevOps experience, and add the interactive lesson guides. Add advanced DevOps lifecycle study as a separate section. Bound MQTT message work and drain accepted jobs during shutdown; align the backend implementation with the revised course through Section 6.
73 lines
1.6 KiB
Go
73 lines
1.6 KiB
Go
package deviceview
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import (
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"fmt"
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"sync"
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"time"
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"example.com/mqtt5-learning/internal/contracts"
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)
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type Snapshot struct {
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DeviceID string
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MessageID string
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ReportedAt time.Time
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ReceivedAt time.Time
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Temperature float64
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TemperatureSet bool
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}
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type Status struct {
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Snapshot Snapshot
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HeartbeatFresh bool
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}
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type Store struct {
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mu sync.RWMutex
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latest map[string]Snapshot
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}
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func NewStore() *Store {
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return &Store{latest: make(map[string]Snapshot)}
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}
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func (s *Store) RecordHeartbeat(message contracts.Heartbeat, receivedAt time.Time) (bool, error) {
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reportedAt, err := time.Parse(time.RFC3339, message.OccurredAt)
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if err != nil {
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// Decode already validates this timestamp. Keep the store defensive too.
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return false, fmt.Errorf("parse heartbeat timestamp: %w", err)
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}
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snapshot := Snapshot{
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DeviceID: message.DeviceID,
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MessageID: message.MessageID,
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ReportedAt: reportedAt,
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ReceivedAt: receivedAt,
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}
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if message.Temperature != nil {
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snapshot.Temperature = *message.Temperature
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snapshot.TemperatureSet = true
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}
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s.mu.Lock()
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defer s.mu.Unlock()
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previous, exists := s.latest[message.DeviceID]
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if exists && !reportedAt.After(previous.ReportedAt) {
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return false, nil
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}
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s.latest[message.DeviceID] = snapshot
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return true, nil
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}
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func (s *Store) GetStatus(deviceID string, now time.Time, freshFor time.Duration) (Status, bool) {
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s.mu.RLock()
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snapshot, exists := s.latest[deviceID]
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s.mu.RUnlock()
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if !exists {
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return Status{}, false
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}
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fresh := freshFor > 0 && !now.Before(snapshot.ReceivedAt) && now.Sub(snapshot.ReceivedAt) <= freshFor
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return Status{Snapshot: snapshot, HeartbeatFresh: fresh}, true
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}
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