veryroundbird.house
1package jetstream
2
3import (
4 "context"
5 "fmt"
6 "log/slog"
7 "os"
8 "os/signal"
9 "sync"
10 "syscall"
11 "time"
12
13 "github.com/bluesky-social/jetstream/pkg/client"
14 "github.com/bluesky-social/jetstream/pkg/client/schedulers/sequential"
15 "github.com/bluesky-social/jetstream/pkg/models"
16 "tangled.sh/tangled.sh/core/log"
17)
18
19type DB interface {
20 GetLastTimeUs() (int64, error)
21 SaveLastTimeUs(int64) error
22}
23
24type Set[T comparable] map[T]struct{}
25
26type JetstreamClient struct {
27 cfg *client.ClientConfig
28 client *client.Client
29 ident string
30 l *slog.Logger
31
32 logDids bool
33 wantedDids Set[string]
34 db DB
35 waitForDid bool
36 mu sync.RWMutex
37
38 cancel context.CancelFunc
39 cancelMu sync.Mutex
40}
41
42func (j *JetstreamClient) AddDid(did string) {
43 if did == "" {
44 return
45 }
46
47 if j.logDids {
48 j.l.Info("adding did to in-memory filter", "did", did)
49 }
50 j.mu.Lock()
51 j.wantedDids[did] = struct{}{}
52 j.mu.Unlock()
53}
54
55func (j *JetstreamClient) RemoveDid(did string) {
56 if did == "" {
57 return
58 }
59
60 if j.logDids {
61 j.l.Info("removing did from in-memory filter", "did", did)
62 }
63 j.mu.Lock()
64 delete(j.wantedDids, did)
65 j.mu.Unlock()
66}
67
68type processor func(context.Context, *models.Event) error
69
70func (j *JetstreamClient) withDidFilter(processFunc processor) processor {
71 // since this closure references j.WantedDids; it should auto-update
72 // existing instances of the closure when j.WantedDids is mutated
73 return func(ctx context.Context, evt *models.Event) error {
74
75 // empty filter => all dids allowed
76 if len(j.wantedDids) == 0 {
77 return processFunc(ctx, evt)
78 }
79
80 if _, ok := j.wantedDids[evt.Did]; ok {
81 return processFunc(ctx, evt)
82 } else {
83 return nil
84 }
85 }
86}
87
88func NewJetstreamClient(endpoint, ident string, collections []string, cfg *client.ClientConfig, logger *slog.Logger, db DB, waitForDid, logDids bool) (*JetstreamClient, error) {
89 if cfg == nil {
90 cfg = client.DefaultClientConfig()
91 cfg.WebsocketURL = endpoint
92 cfg.WantedCollections = collections
93 }
94
95 return &JetstreamClient{
96 cfg: cfg,
97 ident: ident,
98 db: db,
99 l: logger,
100 wantedDids: make(map[string]struct{}),
101
102 logDids: logDids,
103
104 // This will make the goroutine in StartJetstream wait until
105 // j.wantedDids has been populated, typically using addDids.
106 waitForDid: waitForDid,
107 }, nil
108}
109
110// StartJetstream starts the jetstream client and processes events using the provided processFunc.
111// The caller is responsible for saving the last time_us to the database (just use your db.UpdateLastTimeUs).
112func (j *JetstreamClient) StartJetstream(ctx context.Context, processFunc func(context.Context, *models.Event) error) error {
113 logger := j.l
114
115 sched := sequential.NewScheduler(j.ident, logger, j.withDidFilter(processFunc))
116
117 client, err := client.NewClient(j.cfg, log.New("jetstream"), sched)
118 if err != nil {
119 return fmt.Errorf("failed to create jetstream client: %w", err)
120 }
121 j.client = client
122
123 go func() {
124 if j.waitForDid {
125 for len(j.wantedDids) == 0 {
126 time.Sleep(time.Second)
127 }
128 }
129 logger.Info("done waiting for did")
130
131 go j.periodicLastTimeSave(ctx)
132 j.saveIfKilled(ctx)
133
134 j.connectAndRead(ctx)
135 }()
136
137 return nil
138}
139
140func (j *JetstreamClient) connectAndRead(ctx context.Context) {
141 l := log.FromContext(ctx)
142 for {
143 cursor := j.getLastTimeUs(ctx)
144
145 connCtx, cancel := context.WithCancel(ctx)
146 j.cancelMu.Lock()
147 j.cancel = cancel
148 j.cancelMu.Unlock()
149
150 if err := j.client.ConnectAndRead(connCtx, cursor); err != nil {
151 l.Error("error reading jetstream", "error", err)
152 cancel()
153 continue
154 }
155
156 select {
157 case <-ctx.Done():
158 l.Info("context done, stopping jetstream")
159 return
160 case <-connCtx.Done():
161 l.Info("connection context done, reconnecting")
162 continue
163 }
164 }
165}
166
167// save cursor periodically
168func (j *JetstreamClient) periodicLastTimeSave(ctx context.Context) {
169 ticker := time.NewTicker(time.Minute)
170 defer ticker.Stop()
171
172 for {
173 select {
174 case <-ctx.Done():
175 return
176 case <-ticker.C:
177 j.db.SaveLastTimeUs(time.Now().UnixMicro())
178 }
179 }
180}
181
182func (j *JetstreamClient) getLastTimeUs(ctx context.Context) *int64 {
183 l := log.FromContext(ctx)
184 lastTimeUs, err := j.db.GetLastTimeUs()
185 if err != nil {
186 l.Warn("couldn't get last time us, starting from now", "error", err)
187 lastTimeUs = time.Now().UnixMicro()
188 err = j.db.SaveLastTimeUs(lastTimeUs)
189 if err != nil {
190 l.Error("failed to save last time us", "error", err)
191 }
192 }
193
194 // If last time is older than 2 days, start from now
195 if time.Now().UnixMicro()-lastTimeUs > 2*24*60*60*1000*1000 {
196 lastTimeUs = time.Now().UnixMicro()
197 l.Warn("last time us is older than 2 days; discarding that and starting from now")
198 err = j.db.SaveLastTimeUs(lastTimeUs)
199 if err != nil {
200 l.Error("failed to save last time us", "error", err)
201 }
202 }
203
204 l.Info("found last time_us", "time_us", lastTimeUs)
205 return &lastTimeUs
206}
207
208func (j *JetstreamClient) saveIfKilled(ctx context.Context) context.Context {
209 ctxWithCancel, cancel := context.WithCancel(ctx)
210
211 sigChan := make(chan os.Signal, 1)
212
213 signal.Notify(sigChan,
214 syscall.SIGINT,
215 syscall.SIGTERM,
216 syscall.SIGQUIT,
217 syscall.SIGHUP,
218 syscall.SIGKILL,
219 syscall.SIGSTOP,
220 )
221
222 go func() {
223 sig := <-sigChan
224 j.l.Info("Received signal, initiating graceful shutdown", "signal", sig)
225
226 lastTimeUs := time.Now().UnixMicro()
227 if err := j.db.SaveLastTimeUs(lastTimeUs); err != nil {
228 j.l.Error("Failed to save last time during shutdown", "error", err)
229 }
230 j.l.Info("Saved lastTimeUs before shutdown", "lastTimeUs", lastTimeUs)
231
232 j.cancelMu.Lock()
233 if j.cancel != nil {
234 j.cancel()
235 }
236 j.cancelMu.Unlock()
237
238 cancel()
239
240 os.Exit(0)
241 }()
242
243 return ctxWithCancel
244}