seaweedfs/weed/mount/filehandle_read.go
2024-11-05 08:41:14 -08:00

101 lines
2.8 KiB
Go

package mount
import (
"context"
"fmt"
"io"
"github.com/seaweedfs/seaweedfs/weed/filer"
"github.com/seaweedfs/seaweedfs/weed/glog"
"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
)
func (fh *FileHandle) lockForRead(startOffset int64, size int) {
fh.dirtyPages.LockForRead(startOffset, startOffset+int64(size))
}
func (fh *FileHandle) unlockForRead(startOffset int64, size int) {
fh.dirtyPages.UnlockForRead(startOffset, startOffset+int64(size))
}
func (fh *FileHandle) readFromDirtyPages(buff []byte, startOffset int64, tsNs int64) (maxStop int64) {
maxStop = fh.dirtyPages.ReadDirtyDataAt(buff, startOffset, tsNs)
return
}
func (fh *FileHandle) readFromChunks(buff []byte, offset int64) (int64, int64, error) {
fh.entryLock.RLock()
defer fh.entryLock.RUnlock()
fileFullPath := fh.FullPath()
entry := fh.GetEntry()
if entry.IsInRemoteOnly() {
glog.V(4).Infof("download remote entry %s", fileFullPath)
err := fh.downloadRemoteEntry(entry)
if err != nil {
glog.V(1).Infof("download remote entry %s: %v", fileFullPath, err)
return 0, 0, err
}
}
fileSize := int64(entry.Attributes.FileSize)
if fileSize == 0 {
fileSize = int64(filer.FileSize(entry.GetEntry()))
}
if fileSize == 0 {
glog.V(1).Infof("empty fh %v", fileFullPath)
return 0, 0, io.EOF
} else if offset == fileSize {
return 0, 0, io.EOF
} else if offset >= fileSize {
glog.V(1).Infof("invalid read, fileSize %d, offset %d for %s", fileSize, offset, fileFullPath)
return 0, 0, io.EOF
}
if offset < int64(len(entry.Content)) {
totalRead := copy(buff, entry.Content[offset:])
glog.V(4).Infof("file handle read cached %s [%d,%d] %d", fileFullPath, offset, offset+int64(totalRead), totalRead)
return int64(totalRead), 0, nil
}
totalRead, ts, err := fh.entryChunkGroup.ReadDataAt(fileSize, buff, offset)
if err != nil && err != io.EOF {
glog.Errorf("file handle read %s: %v", fileFullPath, err)
}
// glog.V(4).Infof("file handle read %s [%d,%d] %d : %v", fileFullPath, offset, offset+int64(totalRead), totalRead, err)
return int64(totalRead), ts, err
}
func (fh *FileHandle) downloadRemoteEntry(entry *LockedEntry) error {
fileFullPath := fh.FullPath()
dir, _ := fileFullPath.DirAndName()
err := fh.wfs.WithFilerClient(false, func(client filer_pb.SeaweedFilerClient) error {
request := &filer_pb.CacheRemoteObjectToLocalClusterRequest{
Directory: string(dir),
Name: entry.Name,
}
glog.V(4).Infof("download entry: %v", request)
resp, err := client.CacheRemoteObjectToLocalCluster(context.Background(), request)
if err != nil {
return fmt.Errorf("CacheRemoteObjectToLocalCluster file %s: %v", fileFullPath, err)
}
entry.SetEntry(resp.Entry)
fh.wfs.metaCache.InsertEntry(context.Background(), filer.FromPbEntry(request.Directory, resp.Entry))
return nil
})
return err
}