fs.readFile({
                filePath,
                position: start,
                length: chunkDataLength,
                success(res2) {
                  console.log("file_tcpSocket::1111", file_tcpSocket.write);
                  file_tcpSocket.write(res2.data);
                  console.log("file_tcpSocket::2222", file_tcpSocket.write);
                },
                fail(err) {
                }
              });
            });
报错send socket fail: sent length: 535760 totallength:1048576errno:0 errmsg:Success，我以为是write的字节限制又把发送的字段调低到发送524288，
它又只发送了521280