|
| 1 | +package common |
| 2 | + |
| 3 | +import ( |
| 4 | + "context" |
| 5 | + "fmt" |
| 6 | + "github.com/nats-io/nats.go" |
| 7 | + "github.com/nats-io/nats.go/jetstream" |
| 8 | + "log" |
| 9 | + "sync" |
| 10 | + "time" |
| 11 | +) |
| 12 | + |
| 13 | +const ( |
| 14 | + DefaultStream = "defaultStream" |
| 15 | +) |
| 16 | + |
| 17 | +var ( |
| 18 | + streamRegistry = make(map[string]*JetStreamManager) |
| 19 | + registryLock sync.RWMutex |
| 20 | + streamInstances = make(map[string]jetstream.Stream) |
| 21 | + streamInstLock sync.RWMutex |
| 22 | +) |
| 23 | + |
| 24 | +// RegisterManager registers a JetStreamManager with the specified streamID. |
| 25 | +func RegisterManager(streamID string, mgr *JetStreamManager) { |
| 26 | + registryLock.Lock() |
| 27 | + defer registryLock.Unlock() |
| 28 | + streamRegistry[streamID] = mgr |
| 29 | +} |
| 30 | + |
| 31 | +// GetManager retrieves the JetStreamManager for the given streamID. |
| 32 | +// Returns the manager and true if found; otherwise returns nil and false. |
| 33 | +func GetManager(streamID string) (*JetStreamManager, bool) { |
| 34 | + registryLock.RLock() |
| 35 | + defer registryLock.RUnlock() |
| 36 | + mgr, ok := streamRegistry[streamID] |
| 37 | + return mgr, ok |
| 38 | +} |
| 39 | + |
| 40 | +// RegisterStreamInstances initializes the JetStream contexts (if needed), |
| 41 | +// creates or updates streams based on the provided JetStream configurations, |
| 42 | +// and stores the stream instances in a global map for later usage. |
| 43 | +// Parameters: |
| 44 | +// |
| 45 | +// nc - pointer to the NATS connection |
| 46 | +// cfgs - list of JetStreamConfig configurations to register |
| 47 | +func RegisterStreamInstances(nc *nats.Conn, cfgs []*JetStreamConfig) { |
| 48 | + // Register managers for each provided configuration if not already registered. |
| 49 | + if len(cfgs) > 0 { |
| 50 | + for _, cfg := range cfgs { |
| 51 | + if _, ok := GetManager(cfg.Name); !ok { |
| 52 | + mgr := NewJetStream(cfg) |
| 53 | + RegisterManager(cfg.Name, mgr) |
| 54 | + } else { |
| 55 | + log.Printf("manager for stream %q already registered", cfg.Name) |
| 56 | + } |
| 57 | + } |
| 58 | + } |
| 59 | + |
| 60 | + // Iterate through all registered stream managers to initialize JetStream and create stream instances. |
| 61 | + for streamName, streamMgr := range streamRegistry { |
| 62 | + streamInstLock.RLock() |
| 63 | + _, exists := streamInstances[streamName] |
| 64 | + streamInstLock.RUnlock() |
| 65 | + if exists { |
| 66 | + log.Printf("streamInstance %q already created", streamName) |
| 67 | + continue |
| 68 | + } |
| 69 | + // Initialize JetStream context |
| 70 | + if err := streamMgr.InitJetStream(nc); err != nil { |
| 71 | + log.Printf("failed to initialize jetstream for stream %q: %v", streamName, err) |
| 72 | + continue |
| 73 | + } |
| 74 | + ctx := context.Background() |
| 75 | + stream, err := streamMgr.CreateStream(ctx) |
| 76 | + if err != nil { |
| 77 | + log.Printf("failed to create stream %q: %v", streamName, err) |
| 78 | + continue |
| 79 | + } |
| 80 | + streamInstLock.Lock() |
| 81 | + streamInstances[streamName] = stream |
| 82 | + streamInstLock.Unlock() |
| 83 | + log.Printf("streamInstance %q created", streamName) |
| 84 | + } |
| 85 | +} |
| 86 | + |
| 87 | +// GetStream retrieves a JetStream stream instance by streamID. |
| 88 | +// Returns the stream instance and true if found. |
| 89 | +func GetStream(streamID string) (jetstream.Stream, bool) { |
| 90 | + streamInstLock.RLock() |
| 91 | + defer streamInstLock.RUnlock() |
| 92 | + stream, ok := streamInstances[streamID] |
| 93 | + return stream, ok |
| 94 | +} |
| 95 | + |
| 96 | +func init() { |
| 97 | + // Registers a default stream manager if one hasn't been registered. |
| 98 | + if _, ok := GetManager(DefaultStream); !ok { |
| 99 | + defaultCfg := &JetStreamConfig{ |
| 100 | + Name: DefaultStream, |
| 101 | + Subjects: []string{"subject.*.*"}, |
| 102 | + Description: DefaultStream, |
| 103 | + Retention: 0, |
| 104 | + MaxConsumers: 30, |
| 105 | + MaxMsgs: -1, |
| 106 | + MaxBytes: -1, |
| 107 | + Discard: 0, |
| 108 | + DiscardNewPerSubject: false, |
| 109 | + MaxAge: 0, |
| 110 | + MaxMsgsPerSubject: 10000, |
| 111 | + MaxMsgSize: 10000, |
| 112 | + NoAck: false, |
| 113 | + } |
| 114 | + defaultManager := NewJetStream(defaultCfg) |
| 115 | + RegisterManager(DefaultStream, defaultManager) |
| 116 | + log.Printf("default stream %q registered", DefaultStream) |
| 117 | + } |
| 118 | +} |
| 119 | + |
| 120 | +// InitJetStream initializes the JetStream context for the manager using the given NATS connection. |
| 121 | +// Parameters: |
| 122 | +// |
| 123 | +// nc - pointer to the NATS connection |
| 124 | +// |
| 125 | +// Returns: |
| 126 | +// |
| 127 | +// error - non-nil error if JetStream context creation fails |
| 128 | +func (jsm *JetStreamManager) InitJetStream(nc *nats.Conn) error { |
| 129 | + js, err := jetstream.New(nc) |
| 130 | + if err != nil { |
| 131 | + nc.Close() |
| 132 | + return fmt.Errorf("failed to create JetStream context: %w", err) |
| 133 | + } |
| 134 | + jsm.JS = js |
| 135 | + return nil |
| 136 | +} |
| 137 | + |
| 138 | +// CreateStream creates or updates a JetStream stream using the manager's configuration. |
| 139 | +// Parameters: |
| 140 | +// |
| 141 | +// ctx - context to control request timeout |
| 142 | +// |
| 143 | +// Returns: |
| 144 | +// |
| 145 | +// jetstream.Stream - the created/updated stream instance |
| 146 | +// error - non-nil error if stream creation fails |
| 147 | +func (jsm *JetStreamManager) CreateStream(ctx context.Context) (jetstream.Stream, error) { |
| 148 | + streamCtx, cancel := context.WithTimeout(ctx, 30*time.Second) |
| 149 | + defer cancel() |
| 150 | + stream, err := jsm.JS.CreateOrUpdateStream(streamCtx, jsm.streamConf) |
| 151 | + if err != nil { |
| 152 | + return nil, err |
| 153 | + } |
| 154 | + return stream, nil |
| 155 | +} |
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