milvus/internal/streamingcoord/client/assignment/watcher.go

55 lines
1.4 KiB
Go

package assignment
import (
"context"
"sync"
"github.com/cockroachdb/errors"
"github.com/milvus-io/milvus/pkg/streaming/util/types"
"github.com/milvus-io/milvus/pkg/util/syncutil"
"github.com/milvus-io/milvus/pkg/util/typeutil"
)
var ErrWatcherClosed = errors.New("watcher is closed")
// newWatcher creates a new watcher.
func newWatcher() *watcher {
return &watcher{
cond: syncutil.NewContextCond(&sync.Mutex{}),
lastVersionedAssignment: types.VersionedStreamingNodeAssignments{
Version: typeutil.VersionInt64Pair{Global: -1, Local: -1},
Assignments: make(map[int64]types.StreamingNodeAssignment),
},
}
}
// watcher is the watcher for assignment discovery.
type watcher struct {
cond *syncutil.ContextCond
lastVersionedAssignment types.VersionedStreamingNodeAssignments
}
// AssignmentDiscover watches the assignment discovery.
func (w *watcher) AssignmentDiscover(ctx context.Context, cb func(*types.VersionedStreamingNodeAssignments) error) error {
w.cond.L.Lock()
for {
if err := cb(&w.lastVersionedAssignment); err != nil {
w.cond.L.Unlock()
return err
}
if err := w.cond.Wait(ctx); err != nil {
return err
}
}
}
// Update updates the assignment.
func (w *watcher) Update(assignments types.VersionedStreamingNodeAssignments) {
w.cond.LockAndBroadcast()
if assignments.Version.GT(w.lastVersionedAssignment.Version) {
w.lastVersionedAssignment = assignments
}
w.cond.L.Unlock()
}