refactor needle write for different versions

weed/storage/needle/needle_write_v1.go

@@ -0,0 +1,54 @@
+package needle
+
+import (
+	"fmt"
+
+	"github.com/seaweedfs/seaweedfs/weed/storage/backend"
+	. "github.com/seaweedfs/seaweedfs/weed/storage/types"
+	"github.com/seaweedfs/seaweedfs/weed/util"
+	"github.com/seaweedfs/seaweedfs/weed/util/buffer_pool"
+)
+
+func writeNeedleV1(w backend.BackendStorageFile, n *Needle) (offset uint64, size Size, actualSize int64, err error) {
+	if end, _, e := w.GetStat(); e == nil {
+		defer func(w backend.BackendStorageFile, off int64) {
+			if err != nil {
+				if te := w.Truncate(end); te != nil {
+					// handle error
+				}
+			}
+		}(w, end)
+		offset = uint64(end)
+	} else {
+		err = fmt.Errorf("Cannot Read Current Volume Position: %w", e)
+		return
+	}
+	if offset >= MaxPossibleVolumeSize && len(n.Data) != 0 {
+		err = fmt.Errorf("Volume Size %d Exceeded %d", offset, MaxPossibleVolumeSize)
+		return
+	}
+
+	bytesBuffer := buffer_pool.SyncPoolGetBuffer()
+	defer buffer_pool.SyncPoolPutBuffer(bytesBuffer)
+
+	bytesBuffer.Reset()
+	header := make([]byte, NeedleHeaderSize)
+	CookieToBytes(header[0:CookieSize], n.Cookie)
+	NeedleIdToBytes(header[CookieSize:CookieSize+NeedleIdSize], n.Id)
+	n.Size = Size(len(n.Data))
+	SizeToBytes(header[CookieSize+NeedleIdSize:CookieSize+NeedleIdSize+SizeSize], n.Size)
+	size = n.Size
+	actualSize = NeedleHeaderSize + int64(n.Size)
+	bytesBuffer.Write(header)
+	bytesBuffer.Write(n.Data)
+	padding := PaddingLength(n.Size, Version1)
+	util.Uint32toBytes(header[0:NeedleChecksumSize], uint32(n.Checksum))
+	bytesBuffer.Write(header[0 : NeedleChecksumSize+padding])
+
+	_, err = w.WriteAt(bytesBuffer.Bytes(), int64(offset))
+	if err != nil {
+		err = fmt.Errorf("failed to write %d bytes to %s at offset %d: %w", actualSize, w.Name(), offset, err)
+	}
+
+	return offset, size, actualSize, err
+}