1 files changed, 113 insertions, 0 deletions
diff --git a/weed/mount/filehandle_read.go b/weed/mount/filehandle_read.go
new file mode 100644
index 000000000..5439b8bfd
--- /dev/null
+++ b/weed/mount/filehandle_read.go
@@ -0,0 +1,113 @@
+package mount
+
+import (
+	"context"
+	"fmt"
+	"github.com/chrislusf/seaweedfs/weed/filer"
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/chrislusf/seaweedfs/weed/pb/filer_pb"
+	"io"
+)
+
+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) (maxStop int64) {
+	maxStop = fh.dirtyPages.ReadDirtyDataAt(buff, startOffset)
+	return
+}
+
+func (fh *FileHandle) readFromChunks(buff []byte, offset int64) (int64, error) {
+
+	fileFullPath := fh.FullPath()
+
+	entry := fh.entry
+	if entry == nil {
+		return 0, io.EOF
+	}
+
+	if entry.IsInRemoteOnly() {
+		glog.V(4).Infof("download remote entry %s", fileFullPath)
+		newEntry, err := fh.downloadRemoteEntry(entry)
+		if err != nil {
+			glog.V(1).Infof("download remote entry %s: %v", fileFullPath, err)
+			return 0, err
+		}
+		entry = newEntry
+	}
+
+	fileSize := int64(filer.FileSize(entry))
+
+	if fileSize == 0 {
+		glog.V(1).Infof("empty fh %v", fileFullPath)
+		return 0, io.EOF
+	}
+
+	if offset+int64(len(buff)) <= 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), nil
+	}
+
+	var chunkResolveErr error
+	if fh.entryViewCache == nil {
+		fh.entryViewCache, chunkResolveErr = filer.NonOverlappingVisibleIntervals(fh.wfs.LookupFn(), entry.Chunks, 0, fileSize)
+		if chunkResolveErr != nil {
+			return 0, fmt.Errorf("fail to resolve chunk manifest: %v", chunkResolveErr)
+		}
+		fh.reader = nil
+	}
+
+	reader := fh.reader
+	if reader == nil {
+		chunkViews := filer.ViewFromVisibleIntervals(fh.entryViewCache, 0, fileSize)
+		glog.V(4).Infof("file handle read %s [%d,%d) from %d views", fileFullPath, offset, offset+int64(len(buff)), len(chunkViews))
+		for _, chunkView := range chunkViews {
+			glog.V(4).Infof("  read %s [%d,%d) from chunk %+v", fileFullPath, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size), chunkView.FileId)
+		}
+		reader = filer.NewChunkReaderAtFromClient(fh.wfs.LookupFn(), chunkViews, fh.wfs.chunkCache, fileSize)
+	}
+	fh.reader = reader
+
+	totalRead, err := reader.ReadAt(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), err
+}
+
+func (fh *FileHandle) downloadRemoteEntry(entry *filer_pb.Entry) (*filer_pb.Entry, 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 = resp.Entry
+
+		fh.wfs.metaCache.InsertEntry(context.Background(), filer.FromPbEntry(request.Directory, resp.Entry))
+
+		return nil
+	})
+
+	return entry, err
+}