Function firstEvent

onchain/eth_subscribe.go:56–100

(ctx context.Context, source chan interface{})

)

func firstEvent(ctx context.Context, source chan interface{}) (out chan interface{}) {
	out = make(chan interface{})

	go func() {
		defer close(out)
		visited := make(map[string]uint64)
		for {
			select {
			case <-ctx.Done():
				return
			case event, ok := <-source:
				if !ok {
					return
				}
				if content, ok := event.(*LogCommon); ok {
					if content.Removed {
						continue
					}
					var bytes []byte
					bytes = append(bytes, content.Raw.Data...)
					bytes = append(bytes, new(big.Int).SetUint64(content.BlockN).Bytes()...)
					nHash := sha256.Sum256(bytes)

					identity := string(nHash[:])
					if visited[identity] == 0 {
						visited[identity] = content.BlockN
						select {
						case out <- content.log:
						case <-ctx.Done():
						}
						go func(identity string) {
							select {
							case <-ctx.Done():
							case <-time.After(100 * 15 * time.Second):
								delete(visited, identity)
							}
						}(identity)
					}
				}
			}
		}
	}()

	return
}

// SubscribeEvent is a log subscription operation
func (e *ethAdaptor) SubscribeEvent(subscribeTypes []int) (chan interface{}, chan error) {