ObjectStore: Modify read function can handle fadvise flags.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
PGBackend: Make objects_read_sync can handle fadvise flags

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
encoding: Add type boost::tuple<A,B,C> encoding/decode func.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
types: Add operator<< for type boost::tuple<A, B, C>.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
include: Remove unused code: class triple.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
osd: Make async-read can handle fadvise flags.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
PGTransaction: Modify append/write function can handle fadvise flags.
ObjectStore/Transaction: Add fadvise_flags to track write fadvise flags.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
ECBackend: Make parity data don't cache.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>
FileStore: Implement fadvise handle for read-operation.

Signed-off-by: Jianpeng Ma <jianpeng.ma@intel.com>