seaweedfs/weed/filesys/meta_cache/meta_cache_subscribe.go
2020-09-09 11:21:23 -07:00

80 lines
2 KiB
Go

package meta_cache
import (
"context"
"fmt"
"io"
"time"
"github.com/chrislusf/seaweedfs/weed/filer"
"github.com/chrislusf/seaweedfs/weed/glog"
"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
"github.com/chrislusf/seaweedfs/weed/util"
)
func SubscribeMetaEvents(mc *MetaCache, selfSignature int32, client filer_pb.FilerClient, dir string, lastTsNs int64) error {
processEventFn := func(resp *filer_pb.SubscribeMetadataResponse) error {
message := resp.EventNotification
for _, sig := range message.Signatures {
if sig == selfSignature && selfSignature != 0 {
return nil
}
}
var oldPath util.FullPath
var newEntry *filer.Entry
if message.OldEntry != nil {
oldPath = util.NewFullPath(resp.Directory, message.OldEntry.Name)
glog.V(4).Infof("deleting %v", oldPath)
}
if message.NewEntry != nil {
dir := resp.Directory
if message.NewParentPath != "" {
dir = message.NewParentPath
}
key := util.NewFullPath(dir, message.NewEntry.Name)
glog.V(4).Infof("creating %v", key)
newEntry = filer.FromPbEntry(dir, message.NewEntry)
}
return mc.AtomicUpdateEntryFromFiler(context.Background(), oldPath, newEntry)
}
for {
err := client.WithFilerClient(func(client filer_pb.SeaweedFilerClient) error {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
stream, err := client.SubscribeMetadata(ctx, &filer_pb.SubscribeMetadataRequest{
ClientName: "mount",
PathPrefix: dir,
SinceNs: lastTsNs,
Signature: selfSignature,
})
if err != nil {
return fmt.Errorf("subscribe: %v", err)
}
for {
resp, listenErr := stream.Recv()
if listenErr == io.EOF {
return nil
}
if listenErr != nil {
return listenErr
}
if err := processEventFn(resp); err != nil {
glog.Fatalf("process %v: %v", resp, err)
}
lastTsNs = resp.TsNs
}
})
if err != nil {
glog.Errorf("subscribing filer meta change: %v", err)
}
time.Sleep(time.Second)
}
}