Ilia Denisov
80 lines
2.1 KiB
Go
80 lines
2.1 KiB
Go
package redisstate
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import (
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"context"
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"errors"
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"fmt"
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"time"
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"github.com/redis/go-redis/v9"
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)
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// StreamOffsetStore provides the Redis-backed storage used for persisted
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// plain-XREAD consumer progress.
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type StreamOffsetStore struct {
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client *redis.Client
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keys Keyspace
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}
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// NewStreamOffsetStore constructs one Redis-backed stream-offset store.
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func NewStreamOffsetStore(client *redis.Client) (*StreamOffsetStore, error) {
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if client == nil {
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return nil, errors.New("new stream offset store: nil redis client")
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}
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return &StreamOffsetStore{
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client: client,
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keys: Keyspace{},
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}, nil
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}
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// Load returns the last processed entry id for stream when one is stored.
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func (store *StreamOffsetStore) Load(ctx context.Context, stream string) (string, bool, error) {
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if store == nil || store.client == nil {
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return "", false, errors.New("load stream offset: nil store")
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}
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if ctx == nil {
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return "", false, errors.New("load stream offset: nil context")
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}
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payload, err := store.client.Get(ctx, store.keys.StreamOffset(stream)).Bytes()
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switch {
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case errors.Is(err, redis.Nil):
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return "", false, nil
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case err != nil:
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return "", false, fmt.Errorf("load stream offset: %w", err)
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}
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offset, err := UnmarshalStreamOffset(payload)
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if err != nil {
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return "", false, fmt.Errorf("load stream offset: %w", err)
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}
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return offset.LastProcessedEntryID, true, nil
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}
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// Save stores the last processed entry id for stream.
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func (store *StreamOffsetStore) Save(ctx context.Context, stream string, entryID string) error {
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if store == nil || store.client == nil {
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return errors.New("save stream offset: nil store")
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}
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if ctx == nil {
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return errors.New("save stream offset: nil context")
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}
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offset := StreamOffset{
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Stream: stream,
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LastProcessedEntryID: entryID,
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UpdatedAt: time.Now().UTC().Truncate(time.Millisecond),
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}
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payload, err := MarshalStreamOffset(offset)
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if err != nil {
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return fmt.Errorf("save stream offset: %w", err)
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}
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if err := store.client.Set(ctx, store.keys.StreamOffset(stream), payload, 0).Err(); err != nil {
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return fmt.Errorf("save stream offset: %w", err)
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}
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return nil
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}
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