We first introduced auto-update as a separate struct AutoClient, which
was wrapping Client and calling Update periodically.
// AutoClient can auto update itself by fetching headers every N seconds.
type AutoClient struct {
base *Client
updatePeriod time.Duration
quit chan struct{}
trustedHeaders chan *types.SignedHeader
errs chan error
}
// NewAutoClient creates a new client and starts a polling goroutine.
func NewAutoClient(base *Client, updatePeriod time.Duration) *AutoClient {
c := &AutoClient{
base: base,
updatePeriod: updatePeriod,
quit: make(chan struct{}),
trustedHeaders: make(chan *types.SignedHeader),
errs: make(chan error),
}
go c.autoUpdate()
return c
}
// TrustedHeaders returns a channel onto which new trusted headers are posted.
func (c *AutoClient) TrustedHeaders() <-chan *types.SignedHeader {
return c.trustedHeaders
}
// Err returns a channel onto which errors are posted.
func (c *AutoClient) Errs() <-chan error {
return c.errs
}
// Stop stops the client.
func (c *AutoClient) Stop() {
close(c.quit)
}
func (c *AutoClient) autoUpdate() {
ticker := time.NewTicker(c.updatePeriod)
defer ticker.Stop()
for {
select {
case <-ticker.C:
lastTrustedHeight, err := c.base.LastTrustedHeight()
if err != nil {
c.errs <- err
continue
}
if lastTrustedHeight == -1 {
// no headers yet => wait
continue
}
newTrustedHeader, err := c.base.Update(time.Now())
if err != nil {
c.errs <- err
continue
}
if newTrustedHeader != nil {
c.trustedHeaders <- newTrustedHeader
}
case <-c.quit:
return
}
}
}
Later we merged it into the Client itself with the assumption that most clients will want it.
But now I am not sure. Neither IBC nor cosmos/relayer are using it. It increases complexity (Start/Stop methods).
That said, I think it makes sense to remove it until we see a need for it (until we better understand usage behavior). We can always introduce it later 😅. Maybe in the form of AutoClient.
Anton Kaliaev
431618cef6