133 lines
3.6 kB
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package jetstream
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import (
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"context"
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"fmt"
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"sync"
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"time"
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"github.com/bluesky-social/jetstream/pkg/client"
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"github.com/bluesky-social/jetstream/pkg/client/schedulers/sequential"
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"github.com/bluesky-social/jetstream/pkg/models"
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"github.com/sotangled/tangled/log"
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)
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type DB interface {
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GetLastTimeUs() (int64, error)
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SaveLastTimeUs(int64) error
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}
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type JetstreamClient struct {
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cfg *client.ClientConfig
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client *client.Client
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ident string
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db DB
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reconnectCh chan struct{}
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waitForDid bool
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mu sync.RWMutex
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}
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func (j *JetstreamClient) AddDid(did string) {
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j.mu.Lock()
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j.cfg.WantedDids = append(j.cfg.WantedDids, did)
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j.mu.Unlock()
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j.reconnectCh <- struct{}{}
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}
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func (j *JetstreamClient) UpdateDids(dids []string) {
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j.mu.Lock()
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j.cfg.WantedDids = dids
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j.mu.Unlock()
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j.reconnectCh <- struct{}{}
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}
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func NewJetstreamClient(ident string, collections []string, cfg *client.ClientConfig, db DB, waitForDid bool) (*JetstreamClient, error) {
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if cfg == nil {
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cfg = client.DefaultClientConfig()
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cfg.WebsocketURL = "wss://jetstream1.us-west.bsky.network/subscribe"
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cfg.WantedCollections = collections
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}
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return &JetstreamClient{
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cfg: cfg,
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ident: ident,
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db: db,
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// This will make the goroutine in StartJetstream wait until
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// cfg.WantedDids has been populated, typically using UpdateDids.
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waitForDid: waitForDid,
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reconnectCh: make(chan struct{}, 1),
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}, nil
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}
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// StartJetstream starts the jetstream client and processes events using the provided processFunc.
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// The caller is responsible for saving the last time_us to the database (just use your db.SaveLastTimeUs).
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func (j *JetstreamClient) StartJetstream(ctx context.Context, processFunc func(context.Context, *models.Event) error) error {
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logger := log.FromContext(ctx)
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sched := sequential.NewScheduler(j.ident, logger, processFunc)
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client, err := client.NewClient(j.cfg, log.New("jetstream"), sched)
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if err != nil {
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return fmt.Errorf("failed to create jetstream client: %w", err)
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}
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j.client = client
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go func() {
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lastTimeUs := j.getLastTimeUs(ctx)
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if j.waitForDid {
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for len(j.cfg.WantedDids) == 0 {
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time.Sleep(time.Second)
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}
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}
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logger.Info("done waiting for did")
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j.connectAndRead(ctx, &lastTimeUs)
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}()
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return nil
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}
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func (j *JetstreamClient) connectAndRead(ctx context.Context, cursor *int64) {
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l := log.FromContext(ctx)
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for {
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select {
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case <-j.reconnectCh:
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l.Info("(re)connecting jetstream client")
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j.client.Scheduler.Shutdown()
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if err := j.client.ConnectAndRead(ctx, cursor); err != nil {
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l.Error("error reading jetstream", "error", err)
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}
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default:
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if err := j.client.ConnectAndRead(ctx, cursor); err != nil {
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l.Error("error reading jetstream", "error", err)
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}
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}
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}
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}
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func (j *JetstreamClient) getLastTimeUs(ctx context.Context) int64 {
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l := log.FromContext(ctx)
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lastTimeUs, err := j.db.GetLastTimeUs()
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if err != nil {
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l.Warn("couldn't get last time us, starting from now", "error", err)
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lastTimeUs = time.Now().UnixMicro()
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err = j.db.SaveLastTimeUs(lastTimeUs)
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if err != nil {
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l.Error("failed to save last time us")
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}
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}
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// If last time is older than a week, start from now
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if time.Now().UnixMicro()-lastTimeUs > 7*24*60*60*1000*1000 {
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lastTimeUs = time.Now().UnixMicro()
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l.Warn("last time us is older than a week. discarding that and starting from now")
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err = j.db.SaveLastTimeUs(lastTimeUs)
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if err != nil {
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l.Error("failed to save last time us")
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}
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}
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l.Info("found last time_us", "time_us", lastTimeUs)
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return lastTimeUs
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}
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