Monorepo for Tangled
tangled.org
tangled.org
1package jetstream
2
3import (
4 "context"
5 "fmt"
6 "sync"
7 "time"
8
9 "github.com/bluesky-social/jetstream/pkg/client"
10 "github.com/bluesky-social/jetstream/pkg/client/schedulers/sequential"
11 "github.com/bluesky-social/jetstream/pkg/models"
12 "github.com/sotangled/tangled/log"
13)
14
15type DB interface {
16 GetLastTimeUs() (int64, error)
17 SaveLastTimeUs(int64) error
18}
19
20type JetstreamClient struct {
21 cfg *client.ClientConfig
22 client *client.Client
23 ident string
24
25 db DB
26 reconnectCh chan struct{}
27 waitForDid bool
28 mu sync.RWMutex
29}
30
31func (j *JetstreamClient) AddDid(did string) {
32 j.mu.Lock()
33 j.cfg.WantedDids = append(j.cfg.WantedDids, did)
34 j.mu.Unlock()
35 j.reconnectCh <- struct{}{}
36}
37
38func (j *JetstreamClient) UpdateDids(dids []string) {
39 j.mu.Lock()
40 j.cfg.WantedDids = dids
41 j.mu.Unlock()
42 j.reconnectCh <- struct{}{}
43}
44
45func NewJetstreamClient(ident string, collections []string, cfg *client.ClientConfig, db DB, waitForDid bool) (*JetstreamClient, error) {
46 if cfg == nil {
47 cfg = client.DefaultClientConfig()
48 cfg.WebsocketURL = "wss://jetstream1.us-west.bsky.network/subscribe"
49 cfg.WantedCollections = collections
50 }
51
52 return &JetstreamClient{
53 cfg: cfg,
54 ident: ident,
55 db: db,
56
57 // This will make the goroutine in StartJetstream wait until
58 // cfg.WantedDids has been populated, typically using UpdateDids.
59 waitForDid: waitForDid,
60 reconnectCh: make(chan struct{}, 1),
61 }, nil
62}
63
64// StartJetstream starts the jetstream client and processes events using the provided processFunc.
65// The caller is responsible for saving the last time_us to the database (just use your db.SaveLastTimeUs).
66func (j *JetstreamClient) StartJetstream(ctx context.Context, processFunc func(context.Context, *models.Event) error) error {
67 logger := log.FromContext(ctx)
68
69 sched := sequential.NewScheduler(j.ident, logger, processFunc)
70
71 client, err := client.NewClient(j.cfg, log.New("jetstream"), sched)
72 if err != nil {
73 return fmt.Errorf("failed to create jetstream client: %w", err)
74 }
75 j.client = client
76
77 go func() {
78 lastTimeUs := j.getLastTimeUs(ctx)
79 if j.waitForDid {
80 for len(j.cfg.WantedDids) == 0 {
81 time.Sleep(time.Second)
82 }
83 }
84 logger.Info("done waiting for did")
85 j.connectAndRead(ctx, &lastTimeUs)
86 }()
87
88 return nil
89}
90
91func (j *JetstreamClient) connectAndRead(ctx context.Context, cursor *int64) {
92 l := log.FromContext(ctx)
93 for {
94 select {
95 case <-j.reconnectCh:
96 l.Info("(re)connecting jetstream client")
97 j.client.Scheduler.Shutdown()
98 if err := j.client.ConnectAndRead(ctx, cursor); err != nil {
99 l.Error("error reading jetstream", "error", err)
100 }
101 default:
102 if err := j.client.ConnectAndRead(ctx, cursor); err != nil {
103 l.Error("error reading jetstream", "error", err)
104 }
105 }
106 }
107}
108
109func (j *JetstreamClient) getLastTimeUs(ctx context.Context) int64 {
110 l := log.FromContext(ctx)
111 lastTimeUs, err := j.db.GetLastTimeUs()
112 if err != nil {
113 l.Warn("couldn't get last time us, starting from now", "error", err)
114 lastTimeUs = time.Now().UnixMicro()
115 err = j.db.SaveLastTimeUs(lastTimeUs)
116 if err != nil {
117 l.Error("failed to save last time us")
118 }
119 }
120
121 // If last time is older than a week, start from now
122 if time.Now().UnixMicro()-lastTimeUs > 7*24*60*60*1000*1000 {
123 lastTimeUs = time.Now().UnixMicro()
124 l.Warn("last time us is older than a week. discarding that and starting from now")
125 err = j.db.SaveLastTimeUs(lastTimeUs)
126 if err != nil {
127 l.Error("failed to save last time us")
128 }
129 }
130
131 l.Info("found last time_us", "time_us", lastTimeUs)
132 return lastTimeUs
133}