milvus/pkg/util/syncutil/future.go
Zhen Ye f18aa85083
enhance: vchannel fair balance policy for streaming (#40959)
issue: #40638 

- Add `ChannelID` for streaming replica in future.
- Remove the pchannel count fair balance policy for streaming.
- Add Score based vchannel fair balance policy for streaming.
- Add pchannel stats manager to collect the stats of pchannel for
balancer.
- Add configuration and metrics for new balance policy

---------

Signed-off-by: chyezh <chyezh@outlook.com>
2025-04-04 10:12:22 +08:00

65 lines
1.2 KiB
Go

package syncutil
import (
"context"
)
// Future is a future value that can be set and retrieved.
type Future[T any] struct {
ch chan struct{}
value T
}
// NewFuture creates a new future.
func NewFuture[T any]() *Future[T] {
return &Future[T]{
ch: make(chan struct{}),
}
}
// Set sets the value of the future.
func (f *Future[T]) Set(value T) {
f.value = value
close(f.ch)
}
// GetWithContext retrieves the value of the future if set, otherwise block until set or the context is done.
func (f *Future[T]) GetWithContext(ctx context.Context) (T, error) {
select {
case <-ctx.Done():
var val T
return val, ctx.Err()
case <-f.ch:
return f.value, nil
}
}
// MustGet retrieves the value of the future if set, otherwise panic if the ready yet.
func (f *Future[T]) MustGet() T {
if !f.Ready() {
panic("future is not ready")
}
return f.Get()
}
// Get retrieves the value of the future if set, otherwise block until set.
func (f *Future[T]) Get() T {
<-f.ch
return f.value
}
// Done returns a channel that is closed when the future is set.
func (f *Future[T]) Done() <-chan struct{} {
return f.ch
}
// Ready returns true if the future is set.
func (f *Future[T]) Ready() bool {
select {
case <-f.ch:
return true
default:
return false
}
}