!> @defgroup FH5O Fortran Object (H5O) Interface
!!
!! @see H5O, C-API
!!
!! @see @ref H5O_UG, User Guide
!!

!> @ingroup FH5O
!!
!!  @brief This module contains Fortran interfaces for H5O functions.
!
! COPYRIGHT
! * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
!   Copyright by The HDF Group.                                               *
!   All rights reserved.                                                      *
!                                                                             *
!   This file is part of HDF5.  The full HDF5 copyright notice, including     *
!   terms governing use, modification, and redistribution, is contained in    *
!   the COPYING file, which can be found at the root of the source code       *
!   distribution tree, or in https://www.hdfgroup.org/licenses.               *
!   If you do not have access to either file, you may request a copy from     *
!   help@hdfgroup.org.                                                        *
! * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
!
! NOTES
!       _____ __  __ _____   ____  _____ _______       _   _ _______
!      |_   _|  \/  |  __ \ / __ \|  __ \__   __|/\   | \ | |__   __|
! ****   | | | \  / | |__) | |  | | |__) | | |  /  \  |  \| |  | |    ****
! ****   | | | |\/| |  ___/| |  | |  _  /  | | / /\ \ | . ` |  | |    ****
! ****  _| |_| |  | | |    | |__| | | \ \  | |/ ____ \| |\  |  | |    ****
!      |_____|_|  |_|_|     \____/|_|  \_\ |_/_/    \_\_| \_|  |_|
!
!  If you add a new H5O function you must add the function name to the
!  Windows dll file 'hdf5_fortrandll.def.in' in the fortran/src directory.
!  This is needed for Windows based operating systems.
!

MODULE H5O

  USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_PTR, C_FUNPTR, C_CHAR, C_INT64_T, C_LONG, C_INT, C_LOC
  USE H5GLOBAL
  IMPLICIT NONE

!> @brief h5o_info_t derived type. The time values are an integer array as specified in the Fortran intrinsic DATE_AND_TIME(VALUES).
  TYPE, BIND(C) :: h5o_info_t
     INTEGER(C_LONG)     :: fileno     !< File number that object is located in
     TYPE(H5O_TOKEN_T_F) :: token      !< Token for object in file
     INTEGER(C_INT)      :: type       !< Basic object type (group, dataset, etc.)
     INTEGER             :: rc         !< Reference count of object
     !    -- NOTE --
     ! Returns an integer array
     ! as specified in the Fortran
     ! intrinsic DATE_AND_TIME(VALUES)
     INTEGER, DIMENSION(8) :: atime !<  Access time
     INTEGER, DIMENSION(8) :: mtime !<  Modification time
     INTEGER, DIMENSION(8) :: ctime !<  Change time
     INTEGER, DIMENSION(8) :: btime !<  Birth time

     INTEGER(hsize_t) :: num_attrs  !<  Number of attributes attached to object
  END TYPE h5o_info_t

!> @brief C interoperable structure for h5o_info_t. The Fortran derived type returns the time
!! values as an integer array as specified in the Fortran intrinsic DATE_AND_TIME(VALUES).
!! Whereas, this derived type does not.

  TYPE, BIND(C) :: c_h5o_info_t
     INTEGER(C_LONG)  :: fileno     !<  File number that object is located in
     TYPE(H5O_TOKEN_T_F) :: token   !<  Token for object in file
     INTEGER(C_INT)   :: type       !<  Basic object type (group, dataset, etc.)
     INTEGER(C_INT)   :: rc         !<  Reference count of object

     INTEGER(KIND=TIME_T) :: atime  !<  Access time
     INTEGER(KIND=TIME_T) :: mtime  !<  Modify time
     INTEGER(KIND=TIME_T) :: ctime  !<  Create time
     INTEGER(KIND=TIME_T) :: btime  !<  Birth time

     INTEGER(hsize_t) :: num_attrs  !<  Number of attributes attached to object
  END TYPE c_h5o_info_t

!> @brief space_t derived type
  TYPE, BIND(C) :: space_t
     INTEGER(hsize_t) :: total !<  Total space for storing object header in file
     INTEGER(hsize_t) :: meta  !<  Space within header for object header metadata information
     INTEGER(hsize_t) :: mesg  !<  Space within header for actual message information
     INTEGER(hsize_t) :: free  !<  Free space within object header
  END TYPE space_t

!> @brief mesg_t derived type
  TYPE, BIND(C) :: mesg_t
     INTEGER(c_int64_t) :: present !<  Flags to indicate presence of message type in header
     INTEGER(c_int64_t) :: shared  !<  Flags to indicate message type is shared in header
  END TYPE mesg_t

!> @brief hdr_t derived type
  TYPE, BIND(C) :: hdr_t
     INTEGER :: version !<  Version number of header format in file
     INTEGER :: nmesgs  !<  Number of object header messages
     INTEGER :: nchunks !<  Number of object header chunks
     INTEGER :: flags   !<  Object header status flags
     TYPE(space_t)  :: space
     TYPE(mesg_t)   :: mesg
  END TYPE hdr_t

!> @brief c_hdr_t derived type
  TYPE, BIND(C) :: c_hdr_t
     INTEGER(C_INT) :: version !<  Version number of header format in file
     INTEGER(C_INT) :: nmesgs  !<  Number of object header messages
     INTEGER(C_INT) :: nchunks !<  Number of object header chunks
     INTEGER(C_INT) :: flags   !<  Object header status flags
     TYPE(space_t)  :: space
     TYPE(mesg_t)   :: mesg
  END TYPE c_hdr_t

!> @brief Extra metadata storage for obj & attributes
  TYPE, BIND(C) :: H5_ih_info_t
     INTEGER(hsize_t) :: index_size !<  btree and/or list
     INTEGER(hsize_t) :: heap_size  !<  heap
  END TYPE H5_ih_info_t

!> @brief meta_size_t derived type
  TYPE, BIND(C) :: meta_size_t
     TYPE(H5_ih_info_t) :: obj  !<  v1/v2 B-tree & local/fractal heap for groups, B-tree for chunked datasets
     TYPE(H5_ih_info_t) :: attr !<  v2 B-tree & heap for attributes
  ENDTYPE meta_size_t

!> @brief h5o_native_info_t derived type
  TYPE, BIND(C) :: h5o_native_info_t
     TYPE(hdr_t) :: hdr
     TYPE(meta_size_t) :: meta_size
  END TYPE h5o_native_info_t

! @brief C interoperable structure for h5o_native_info_t.
  TYPE, BIND(C) :: c_h5o_native_info_t
     TYPE(c_hdr_t) :: hdr
     TYPE(meta_size_t) :: meta_size
  END TYPE c_h5o_native_info_t


CONTAINS

!>
!! \ingroup FH5O
!!
!! \brief Creates a hard link to an object in an HDF5 file.
!!
!! \param object_id     Object to be linked.
!! \param new_loc_id    File or group identifier specifying location at which object is to be linked.
!! \param new_link_name Name of link to be created, relative to new_loc_id.
!! \param hdferr        \fortran_error
!! \param lcpl_id       Link creation property list identifier.
!! \param lapl_id       Link access property list identifier.
!!
!! See C API: @ref H5Olink()
!!
  SUBROUTINE h5olink_f(object_id, new_loc_id, new_link_name, hdferr, lcpl_id, lapl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: object_id
    INTEGER(HID_T)  , INTENT(IN)  :: new_loc_id
    CHARACTER(LEN=*), INTENT(IN)  :: new_link_name
    INTEGER         , INTENT(OUT) :: hdferr
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: lcpl_id
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: lapl_id
    INTEGER(HID_T) :: lapl_id_default
    INTEGER(HID_T) :: lcpl_id_default

    INTEGER(SIZE_T) :: new_link_namelen

    INTERFACE
       INTEGER FUNCTION h5olink_c(object_id, new_loc_id, new_link_name, new_link_namelen, &
            lcpl_id_default, lapl_id_default) BIND(C,NAME='h5olink_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN) :: object_id
         INTEGER(HID_T), INTENT(IN) :: new_loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: new_link_name
         INTEGER(SIZE_T) :: new_link_namelen
         INTEGER(HID_T) :: lapl_id_default
         INTEGER(HID_T) :: lcpl_id_default
       END FUNCTION h5olink_c
    END INTERFACE

    new_link_namelen = LEN(new_link_name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id
    lcpl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lcpl_id)) lcpl_id_default = lcpl_id

    hdferr = h5olink_c(object_id, new_loc_id, new_link_name, new_link_namelen, &
         lcpl_id_default, lapl_id_default)

  END SUBROUTINE h5olink_f

!>
!! \ingroup FH5O
!!
!! \brief Opens an object in an HDF5 file by location identifier and path name.
!!
!! \param loc_id  File or group identifier.
!! \param name    Path to the object, relative to loc_id.
!! \param obj_id  Object identifier for the opened object.
!! \param hdferr  \fortran_error
!! \param lapl_id Access property list identifier for the link pointing to the object.
!!
!! See C API: @ref H5Oopen()
!!
  SUBROUTINE h5oopen_f(loc_id, name, obj_id, hdferr, lapl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: loc_id
    CHARACTER(LEN=*), INTENT(IN)  :: name
    INTEGER(HID_T)  , INTENT(OUT) :: obj_id
    INTEGER         , INTENT(OUT) :: hdferr
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: lapl_id
    INTEGER(HID_T) :: lapl_id_default
    INTEGER(SIZE_T) :: namelen

    INTERFACE
       INTEGER FUNCTION h5oopen_c(loc_id, name, namelen, lapl_id_default, obj_id) BIND(C,NAME='h5oopen_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN) :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: name
         INTEGER(HID_T) :: lapl_id_default
         INTEGER(SIZE_T) :: namelen
         INTEGER(HID_T), INTENT(OUT) :: obj_id
       END FUNCTION h5oopen_c
    END INTERFACE

    namelen = LEN(name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    hdferr = h5oopen_c(loc_id, name, namelen, lapl_id_default, obj_id)

  END SUBROUTINE h5oopen_f
!>
!! \ingroup FH5O
!!
!! \brief Closes an object in an HDF5 file.
!!
!! \param object_id Object identifier.
!! \param hdferr    \fortran_error
!!
!! See C API: @ref H5Oclose()
!!
  SUBROUTINE h5oclose_f(object_id, hdferr)
    IMPLICIT NONE
    INTEGER(HID_T), INTENT(IN)   :: object_id
    INTEGER       , INTENT(OUT) :: hdferr
    INTERFACE
       INTEGER FUNCTION h5oclose_c(object_id) BIND(C,NAME='h5oclose_c')
         IMPORT :: HID_T
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN) :: object_id
       END FUNCTION h5oclose_c
    END INTERFACE

    hdferr = h5oclose_c(object_id)
  END SUBROUTINE h5oclose_f

!>
!! \ingroup FH5O
!!
!! \brief Opens an object using its token within an HDF5 file.
!!
!! \param loc_id File or group identifier.
!! \param token  Object’s token in the file.
!! \param obj_id Object identifier for the opened object.
!! \param hdferr \fortran_error
!!
!! See C API: @ref H5Oopen_by_token()
!!
  SUBROUTINE h5oopen_by_token_f(loc_id, token, obj_id, hdferr)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)        :: loc_id
    TYPE(H5O_TOKEN_T_F), INTENT(IN)     :: token
    INTEGER(HID_T)  , INTENT(OUT)       :: obj_id
    INTEGER         , INTENT(OUT)       :: hdferr
    INTERFACE
       INTEGER FUNCTION h5oopen_by_token_c(loc_id, token, obj_id) BIND(C,NAME='h5oopen_by_token_c')
         IMPORT :: HID_T, H5O_TOKEN_T_F
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN) :: loc_id
         TYPE(H5O_TOKEN_T_F), INTENT(IN) :: token
         INTEGER(HID_T), INTENT(OUT) :: obj_id
       END FUNCTION h5oopen_by_token_c
    END INTERFACE

    hdferr = h5oopen_by_token_c(loc_id, token, obj_id)

  END SUBROUTINE h5oopen_by_token_f

!>
!! \ingroup FH5O
!!
!! \brief Copies an object in an HDF5 file.
!!
!! \param src_loc_id Object identifier indicating the location of the source object to be copied.
!! \param src_name   Name of the source object to be copied.
!! \param dst_loc_id Location identifier specifying the destination.
!! \param dst_name   Name to be assigned to the new copy.
!! \param ocpypl_id  Object copy property list.
!! \param lcpl_id    Link creation property list for the new hard link.
!! \param hdferr     \fortran_error
!!
!! See C API: @ref H5Ocopy()
!!
  SUBROUTINE h5ocopy_f(src_loc_id, src_name, dst_loc_id, dst_name, hdferr, ocpypl_id, lcpl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: src_loc_id
    CHARACTER(LEN=*), INTENT(IN)  :: src_name
    INTEGER(HID_T)  , INTENT(IN)  :: dst_loc_id
    CHARACTER(LEN=*), INTENT(IN)  :: dst_name
    INTEGER         , INTENT(OUT) :: hdferr
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: ocpypl_id
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: lcpl_id

    INTEGER(SIZE_T) :: src_name_len, dst_name_len
    INTEGER(HID_T)  :: ocpypl_id_default, lcpl_id_default

    INTERFACE
       INTEGER FUNCTION h5ocopy_c(src_loc_id, src_name, src_name_len, &
            dst_loc_id, dst_name, dst_name_len, ocpypl_id_default, lcpl_id_default) &
            BIND(C,NAME='h5ocopy_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: src_loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: src_name
         INTEGER(HID_T)  , INTENT(IN) :: dst_loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: dst_name
         INTEGER(HID_T)  , INTENT(IN) :: ocpypl_id_default
         INTEGER(HID_T)  , INTENT(IN) :: lcpl_id_default
         INTEGER(SIZE_T)              :: src_name_len, dst_name_len

       END FUNCTION h5ocopy_c
    END INTERFACE

    src_name_len = LEN(src_name)
    dst_name_len = LEN(dst_name)

    ocpypl_id_default = H5P_DEFAULT_F
    IF(PRESENT(ocpypl_id)) ocpypl_id_default = ocpypl_id
    lcpl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lcpl_id)) lcpl_id_default = lcpl_id

    hdferr = h5ocopy_c(src_loc_id, src_name, src_name_len, &
         dst_loc_id, dst_name, dst_name_len, ocpypl_id_default, lcpl_id_default)

  END SUBROUTINE h5ocopy_f

!>
!! \ingroup FH5O
!!
!! \brief Decrements an object reference count.
!!
!! \param object_id Object identifier.
!! \param hdferr    \fortran_error
!!
!! See C API: @ref H5Odecr_refcount()
!!
  SUBROUTINE h5odecr_refcount_f(object_id, hdferr)
    IMPLICIT NONE
    INTEGER(HID_T), INTENT(IN)  :: object_id
    INTEGER       , INTENT(OUT) :: hdferr

    INTERFACE
       INTEGER FUNCTION h5odecr_refcount_c(object_id) BIND(C,NAME='h5odecr_refcount_c')
         IMPORT :: HID_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: object_id
       END FUNCTION h5odecr_refcount_c
    END INTERFACE

    hdferr = h5odecr_refcount_c(object_id)

  END SUBROUTINE h5odecr_refcount_f

!>
!! \ingroup FH5O
!!
!! \brief Determines whether a link resolves to an actual object.
!!
!! \param loc_id   IdeIdentifier of the file or group to query.
!! \param name     TheThe name of the link to check.
!!
!!
!! \param lapl_id     Link access property list identifier.
!! \param link_exists Existing link resolves to an object.
!! \param hdferr      \fortran_error
!!
!! See C API: @ref H5Oexists_by_name()
!!
  SUBROUTINE h5oexists_by_name_f(loc_id, name, link_exists, hdferr, lapl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: loc_id
    CHARACTER(LEN=*), INTENT(IN)  :: name
    LOGICAL         , INTENT(OUT) :: link_exists
    INTEGER         , INTENT(OUT) :: hdferr
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: lapl_id

    INTEGER(size_t) :: namelen
    INTEGER :: status
    INTEGER(HID_T) :: lapl_id_default

    INTERFACE
       INTEGER FUNCTION h5oexists_by_name_c(loc_id, name, namelen, lapl_id) &
            BIND(C,NAME='h5oexists_by_name_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: name
         INTEGER(SIZE_T) , INTENT(IN) :: namelen
         INTEGER(HID_T)  , INTENT(IN) :: lapl_id

       END FUNCTION h5oexists_by_name_c
    END INTERFACE

    namelen = LEN(name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    status = h5oexists_by_name_c(loc_id, name, namelen, lapl_id_default)

    link_exists = .FALSE.
    IF(status.EQ.1)THEN
       link_exists = .TRUE.
    ENDIF

    hdferr = 0
    IF(status.LT.0)THEN
       hdferr = -1
    ENDIF

  END SUBROUTINE h5oexists_by_name_f

!>
!! \ingroup FH5O
!!
!! \brief Retrieves comment for specified object.
!!
!! \param obj_id  Identifier for the target object.
!! \param bufsize Size of the comment buffer.
!! \param comment The comment.
!! \param hdferr  \fortran_error
!!
!! See C API: @ref H5Oget_comment()
!!
  SUBROUTINE h5oget_comment_f(obj_id, comment, hdferr, bufsize)
    IMPLICIT NONE
    INTEGER(HID_T)   , INTENT(IN)            :: obj_id
    CHARACTER(LEN=*) , INTENT(OUT)           :: comment
    INTEGER          , INTENT(OUT)           :: hdferr
    INTEGER(HSSIZE_T), INTENT(OUT), OPTIONAL :: bufsize

    INTEGER(SIZE_T)   :: commentsize_default
    INTEGER(HSSIZE_T) :: bufsize_default

    INTERFACE
       INTEGER FUNCTION h5oget_comment_c(obj_id, comment, commentsize_default, bufsize) &
            BIND(C,NAME='h5oget_comment_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T, HSSIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN)  :: obj_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(OUT) :: comment
         INTEGER(SIZE_T) , INTENT(IN)  :: commentsize_default
         INTEGER(HSSIZE_T) , INTENT(OUT) :: bufsize
       END FUNCTION h5oget_comment_c
    END INTERFACE

    commentsize_default = LEN(comment)

    hdferr = h5oget_comment_c(obj_id, comment, commentsize_default, bufsize_default)

    IF(PRESENT(bufsize)) bufsize = bufsize_default

  END SUBROUTINE h5oget_comment_f

!>
!! \ingroup FH5O
!!
!! \brief Retrieves comment for specified object.
!!
!! \param loc_id  Identifier of a file, group, dataset, or named datatype.
!! \param name    Name of the object whose comment is to be retrieved, specified as a path relative to loc_id.
!! \param comment The comment.
!! \param hdferr  \fortran_error
!! \param bufsize Size of the comment buffer.
!! \param lapl_id File access property list identifier.
!!
!! See C API: @ref H5Oget_comment_by_name()
!!
  SUBROUTINE h5oget_comment_by_name_f(loc_id, name, comment, hdferr, bufsize, lapl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)            :: loc_id
    CHARACTER(LEN=*), INTENT(IN)            :: name
    CHARACTER(LEN=*), INTENT(OUT)           :: comment
    INTEGER         , INTENT(OUT)           :: hdferr
    INTEGER(SIZE_T) , INTENT(OUT), OPTIONAL :: bufsize
    INTEGER(HID_T)  , INTENT(IN) , OPTIONAL :: lapl_id

    INTEGER(SIZE_T) :: commentsize_default
    INTEGER(SIZE_T) :: name_size
    INTEGER(SIZE_T) :: bufsize_default
    INTEGER(HID_T)  :: lapl_id_default
    INTERFACE
       INTEGER FUNCTION h5oget_comment_by_name_c(loc_id, name, name_size, &
            comment, commentsize_default, bufsize_default, lapl_id) BIND(C,NAME='h5oget_comment_by_name_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN)  :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN)  :: name
         INTEGER(SIZE_T) , INTENT(IN)  :: name_size
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(OUT) :: comment
         INTEGER(SIZE_T) , INTENT(IN)  :: commentsize_default
         INTEGER(SIZE_T) , INTENT(OUT) :: bufsize_default
         INTEGER(HID_T)  , INTENT(IN)  :: lapl_id
       END FUNCTION h5oget_comment_by_name_c
    END INTERFACE

    commentsize_default = LEN(comment)
    name_size = LEN(name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    hdferr = h5oget_comment_by_name_c(loc_id, name, name_size, &
         comment, commentsize_default, bufsize_default, lapl_id_default)

    IF(PRESENT(bufsize)) bufsize = bufsize_default

  END SUBROUTINE h5oget_comment_by_name_f

!>
!! \ingroup FH5O
!!
!! \brief Increments an object reference count.
!!
!! \param obj_id Object identifier.
!! \param hdferr \fortran_error
!!
!! See C API: @ref H5Oincr_refcount()
!!
  SUBROUTINE h5oincr_refcount_f(obj_id, hdferr)
    IMPLICIT NONE
    INTEGER(HID_T), INTENT(IN)  :: obj_id
    INTEGER       , INTENT(OUT) :: hdferr

    INTERFACE
       INTEGER FUNCTION h5oincr_refcount_c(obj_id) BIND(C,NAME='h5oincr_refcount_c')
         IMPORT :: HID_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: obj_id
       END FUNCTION h5oincr_refcount_c
    END INTERFACE

    hdferr = h5oincr_refcount_c(obj_id)

  END SUBROUTINE h5oincr_refcount_f

!>
!! \ingroup FH5O
!!
!! \brief Open the nth object in a group.
!!
!! \param loc_id     A file or group identifier.
!! \param group_name Name of group, relative to loc_id, in which object is located.
!! \param index_type Type of index by which objects are ordered.
!! \param order      Order of iteration within index, NOTE: zero-based.
!! \param n          Object to open.
!! \param obj_id     An object identifier for the opened object.
!! \param hdferr     \fortran_error
!!
!! \param lapl_id    Link access property list.
!!
!! See C API: @ref H5Oopen_by_idx()
!!
  SUBROUTINE h5oopen_by_idx_f(loc_id, group_name, index_type, order, n, obj_id, &
       hdferr, lapl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)            :: loc_id
    CHARACTER(LEN=*), INTENT(IN)            :: group_name
    INTEGER         , INTENT(IN)            :: index_type
    INTEGER         , INTENT(IN)            :: order
    INTEGER(HSIZE_T), INTENT(IN)            :: n
    INTEGER(HID_T)  , INTENT(OUT)           :: obj_id
    INTEGER         , INTENT(OUT)           :: hdferr
    INTEGER(HID_T)  , INTENT(IN) , OPTIONAL :: lapl_id
    INTEGER(SIZE_T) :: group_namelen
    INTEGER(HID_T)  :: lapl_id_default

    INTERFACE
       INTEGER FUNCTION h5oopen_by_idx_c(loc_id, group_name, group_namelen, index_type, order, n, obj_id, lapl_id_default) &
            BIND(C,NAME='h5oopen_by_idx_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T, HSIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN)  :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN)  :: group_name
         INTEGER(SIZE_T) , INTENT(IN)  :: group_namelen
         INTEGER         , INTENT(IN)  :: index_type
         INTEGER         , INTENT(IN)  :: order
         INTEGER(HSIZE_T), INTENT(IN)  :: n
         INTEGER(HID_T)  , INTENT(OUT) :: obj_id
         INTEGER(HID_T)  , INTENT(IN)  :: lapl_id_default

       END FUNCTION h5oopen_by_idx_c
    END INTERFACE

    group_namelen = LEN(group_name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    hdferr = h5oopen_by_idx_c(loc_id, group_name, group_namelen, index_type, order, n, obj_id, lapl_id_default)

  END SUBROUTINE H5Oopen_by_idx_f

!>
!! \ingroup FH5O
!!
!! \brief Sets comment for specified object.
!!
!! \param obj_id  Identifier of the target object.
!! \param comment The new comment.
!! \param hdferr  \fortran_error
!!
!! See C API: @ref H5Oset_comment()
!!
  SUBROUTINE h5oset_comment_f(obj_id, comment, hdferr)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: obj_id
    CHARACTER(LEN=*), INTENT(IN)  :: comment
    INTEGER         , INTENT(OUT) :: hdferr
    INTEGER(SIZE_T) :: commentlen

    INTERFACE
       INTEGER FUNCTION h5oset_comment_c(obj_id, comment, commentlen) BIND(C,NAME='h5oset_comment_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: obj_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: comment
         INTEGER(SIZE_T) , INTENT(IN) :: commentlen

       END FUNCTION h5oset_comment_c
    END INTERFACE

    commentlen = LEN(comment)

    hdferr = h5oset_comment_c(obj_id, comment, commentlen)

  END SUBROUTINE h5oset_comment_f

!>
!! \ingroup FH5O
!!
!! \brief Sets comment for specified object.
!!
!! \param loc_id  Identifier of a file, group, dataset, or named datatype.
!! \param name    Name of the object whose comment is to be set or reset, specified as a path relative to loc_id.
!! \param comment The new comment.
!! \param hdferr  \fortran_error
!! \param lapl_id Link access property list identifier.
!!
!! See C API: @ref H5Oset_comment_by_name()
!!
  SUBROUTINE h5oset_comment_by_name_f(loc_id, name, comment, hdferr, lapl_id)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: loc_id
    CHARACTER(LEN=*), INTENT(IN)  :: name
    CHARACTER(LEN=*), INTENT(IN)  :: comment
    INTEGER         , INTENT(OUT) :: hdferr
    INTEGER(HID_T)  , INTENT(IN), OPTIONAL :: lapl_id
    INTEGER(SIZE_T) :: commentlen
    INTEGER(SIZE_T) :: namelen
    INTEGER(HID_T) :: lapl_id_default

    INTERFACE
       INTEGER FUNCTION h5oset_comment_by_name_c(loc_id, name, namelen, comment, commentlen, lapl_id) &
            BIND(C,NAME='h5oset_comment_by_name_c')
         IMPORT :: C_CHAR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: comment
         INTEGER(SIZE_T) , INTENT(IN) :: commentlen
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: name
         INTEGER(SIZE_T) , INTENT(IN) :: namelen
         INTEGER(HID_T)  , INTENT(IN) :: lapl_id
       END FUNCTION h5oset_comment_by_name_c
    END INTERFACE

    commentlen = LEN(comment)
    namelen = LEN(name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    hdferr = h5oset_comment_by_name_c(loc_id, name, namelen, comment, commentlen, lapl_id_default)

  END SUBROUTINE h5oset_comment_by_name_f

!>
!! \ingroup FH5O
!!
!! \brief Recursively visits all objects starting from a specified object.
!!
!! \param object_id    Identifier of the object at which the recursive iteration begins.
!! \param index_type   Type of index; valid values include:
!!                     \li H5_INDEX_NAME_F
!!                     \li H5_INDEX_CRT_ORDER_F
!! \param order        Order in which index is traversed; valid values include:
!!                     \li H5_ITER_DEC_F
!!                     \li H5_ITER_INC_F
!!                     \li H5_ITER_NATIVE_F
!! \param op           Callback function passing data regarding the group to the calling application.
!! \param op_data      User-defined pointer to data required by the application for its processing of the group.
!! \param return_value Returns the return value of the first operator that returns a positive value, or
!!                     zero if all members were processed with no operator returning non-zero.
!! \param hdferr       \fortran_error
!! \param fields       Flags specifying the fields to include in object_info.
!!
!! See C API: @ref H5Ovisit3()
!!
  SUBROUTINE h5ovisit_f(object_id, index_type, order, op, op_data, return_value, hdferr, fields)
    IMPLICIT NONE
    INTEGER(HID_T), INTENT(IN) :: object_id
    INTEGER, INTENT(IN) :: index_type
    INTEGER, INTENT(IN) :: order

    TYPE(C_FUNPTR):: op
    TYPE(C_PTR)   :: op_data
    INTEGER, INTENT(OUT) :: return_value
    INTEGER, INTENT(OUT) :: hdferr
    INTEGER, INTENT(IN), OPTIONAL  :: fields
    INTEGER :: fields_c

    INTERFACE
       INTEGER FUNCTION h5ovisit_c(object_id, index_type, order, op, op_data, fields) &
            BIND(C, NAME='h5ovisit_c')
         IMPORT :: C_FUNPTR, C_PTR
         IMPORT :: HID_T
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN) :: object_id
         INTEGER, INTENT(IN) :: index_type
         INTEGER, INTENT(IN) :: order
         TYPE(C_FUNPTR), VALUE :: op
         TYPE(C_PTR), VALUE :: op_data
         INTEGER, INTENT(IN) :: fields
       END FUNCTION h5ovisit_c
    END INTERFACE

    fields_c = H5O_INFO_ALL_F
    IF(PRESENT(fields)) fields_c = fields

    return_value = h5ovisit_c(object_id, index_type, order, op, op_data, fields_c)

    IF(return_value.GE.0)THEN
       hdferr = 0
    ELSE
       hdferr = -1
    END IF

  END SUBROUTINE h5ovisit_f

!>
!! \ingroup FH5O
!!
!! \brief Retrieves the metadata for an object, identifying the object by location and relative name.
!!
!! \param loc_id      File or group identifier specifying location of group in which object is located.
!! \param name        Name of group, relative to loc_id.
!! \param object_info Buffer in which to return object information.
!! \param hdferr      \fortran_error
!! \param lapl_id     Link access property list.
!! \param fields      Flags specifying the fields to include in object_info.
!!
!! See C API: @ref H5Oget_info_by_name3()
!!
  SUBROUTINE h5oget_info_by_name_f(loc_id, name, object_info, hdferr, lapl_id, fields)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)            :: loc_id
    CHARACTER(LEN=*), INTENT(IN)            :: name
    TYPE(h5o_info_t), INTENT(OUT), TARGET   :: object_info
    INTEGER         , INTENT(OUT)           :: hdferr
    INTEGER(HID_T)  , INTENT(IN) , OPTIONAL :: lapl_id
    INTEGER         , INTENT(IN) , OPTIONAL :: fields

    INTEGER(SIZE_T) :: namelen
    INTEGER(HID_T)  :: lapl_id_default
    TYPE(C_PTR)     :: ptr
    INTEGER :: fields_c

    INTERFACE
       INTEGER FUNCTION h5oget_info_by_name_c(loc_id, name, namelen, lapl_id_default, object_info, fields) &
            BIND(C, NAME='h5oget_info_by_name_c')
         IMPORT :: c_char, c_ptr
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN)  :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: name
         INTEGER(SIZE_T) , INTENT(IN)  :: namelen
         INTEGER(HID_T)  , INTENT(IN)  :: lapl_id_default
         TYPE(C_PTR), VALUE            :: object_info
         INTEGER         , INTENT(IN)  :: fields
       END FUNCTION h5oget_info_by_name_c
    END INTERFACE

    fields_c = H5O_INFO_ALL_F
    IF(PRESENT(fields)) fields_c = fields

    namelen = LEN(name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    ptr = C_LOC(object_info)

    hdferr = H5Oget_info_by_name_c(loc_id, name, namelen, lapl_id_default, ptr, fields_c)

  END SUBROUTINE H5Oget_info_by_name_f

!>
!! \ingroup FH5O
!!
!! \brief Retrieves the metadata for an object specified by an identifier.
!!
!! \param object_id   Identifier for target object.
!! \param object_info Buffer in which to return object information.
!! \param hdferr      \fortran_error
!! \param fields      Flags specifying the fields to include in object_info.
!!
!! See C API: @ref H5Oget_info3()
!!
  SUBROUTINE h5oget_info_f(object_id, object_info, hdferr, fields)

    USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_PTR
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)            :: object_id
    TYPE(h5o_info_t), INTENT(OUT), TARGET   :: object_info
    INTEGER         , INTENT(OUT)           :: hdferr
    INTEGER         , INTENT(IN), OPTIONAL  :: fields
    TYPE(C_PTR) :: ptr
    INTEGER :: fields_c

    INTERFACE
       INTEGER FUNCTION h5oget_info_c(object_id, object_info, fields) &
            BIND(C, NAME='h5oget_info_c')
         IMPORT :: C_PTR
         IMPORT :: HID_T
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN)  :: object_id
         TYPE(C_PTR), VALUE          :: object_info
         INTEGER, INTENT(IN)         :: fields
       END FUNCTION h5oget_info_c
    END INTERFACE

    fields_c = H5O_INFO_ALL_F
    IF(PRESENT(fields)) fields_c = fields

    ptr = C_LOC(object_info)
    hdferr = H5Oget_info_c(object_id, ptr, fields_c)

  END SUBROUTINE H5Oget_info_f

!>
!! \ingroup FH5O
!!
!! \brief Retrieves the metadata for an object, identifying the object by an index position.
!!
!! \param loc_id      File or group identifier specifying location of group in which object is located.
!! \param group_name  Name of group in which object is located.
!! \param index_field Index or field that determines the order.
!! \param order       Order within field or index.
!! \param n           Object for which information is to be returned.
!! \param object_info Buffer in which to return object information.
!! \param hdferr      \fortran_error
!!
!! \param lapl_id     Link access property list. (Not currently used.).
!! \param fields      Flags specifying the fields to include in object_info.
!!
!! See C API: @ref H5Oget_info_by_idx3()
!!
  SUBROUTINE h5oget_info_by_idx_f(loc_id, group_name, index_field, order, n, &
       object_info, hdferr, lapl_id, fields)

    USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_PTR
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)            :: loc_id
    CHARACTER(LEN=*), INTENT(IN)            :: group_name
    INTEGER         , INTENT(IN)            :: index_field
    INTEGER         , INTENT(IN)            :: order
    INTEGER(HSIZE_T), INTENT(IN)            :: n
    TYPE(h5o_info_t), INTENT(OUT), TARGET   :: object_info
    INTEGER         , INTENT(OUT)           :: hdferr
    INTEGER(HID_T)  , INTENT(IN) , OPTIONAL :: lapl_id
    INTEGER         , INTENT(IN) , OPTIONAL :: fields
    INTEGER(SIZE_T) :: namelen
    INTEGER(HID_T)  :: lapl_id_default
    TYPE(C_PTR)     :: ptr
    INTEGER         :: fields_c

    INTERFACE
       INTEGER FUNCTION h5oget_info_by_idx_c(loc_id, group_name, namelen, &
            index_field, order, n, lapl_id_default, object_info, fields) BIND(C, NAME='h5oget_info_by_idx_c')
         IMPORT :: c_char, c_ptr, c_funptr
         IMPORT :: HID_T, SIZE_T, HSIZE_T
         INTEGER(HID_T)  , INTENT(IN)  :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: group_name
         INTEGER(SIZE_T) , INTENT(IN)  :: namelen
         INTEGER         , INTENT(IN)  :: index_field
         INTEGER         , INTENT(IN)  :: order
         INTEGER(HSIZE_T), INTENT(IN)  :: n
         INTEGER(HID_T)  , INTENT(IN)  :: lapl_id_default
         TYPE(C_PTR), VALUE            :: object_info
         INTEGER, INTENT(IN)           :: fields
       END FUNCTION h5oget_info_by_idx_c
    END INTERFACE

    fields_c = H5O_INFO_ALL_F
    IF(PRESENT(fields)) fields_c = fields

    namelen = LEN(group_name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    ptr = C_LOC(object_info)
    hdferr = H5Oget_info_by_idx_c(loc_id, group_name, namelen, index_field, order, n, lapl_id_default, ptr, fields_c)

  END SUBROUTINE H5Oget_info_by_idx_f


!>
!! \ingroup FH5O
!!
!! \brief Recursively visits all objects starting from a specified object.
!!
!! \param loc_id       Identifier of a file or group.
!! \param object_name  Name of the object, generally relative to loc_id, that will serve as root of the iteration.
!! \param index_type   Type of index; valid values include:
!!                     \li H5_INDEX_NAME_F
!!                     \li H5_INDEX_CRT_ORDER_F
!! \param order        Order in which index is traversed; valid values include:
!!                     \li H5_ITER_DEC_F
!!                     \li H5_ITER_INC_F
!!                     \li H5_ITER_NATIVE_F
!! \param op           Callback function passing data regarding the group to the calling application.
!! \param op_data      User-defined pointer to data required by the application for its processing of the group.
!! \param return_value Returns the return value of the first operator that returns a positive value, or
!!                     zero if all members were processed with no operator returning non-zero.
!! \param hdferr       \fortran_error
!! \param lapl_id      Link access property list identifier.
!! \param fields       Flags specifying the fields to include in object_info.
!!
!! See C API: @ref H5Ovisit_by_name3()
!!
  SUBROUTINE h5ovisit_by_name_f(loc_id, object_name, index_type, order, op, op_data, &
       return_value, hdferr, lapl_id, fields)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)             :: loc_id
    CHARACTER(LEN=*), INTENT(IN)             :: object_name
    INTEGER         , INTENT(IN)             :: index_type
    INTEGER         , INTENT(IN)             :: order

    TYPE(C_FUNPTR)                           :: op
    TYPE(C_PTR)                              :: op_data
    INTEGER         , INTENT(OUT)            :: return_value
    INTEGER         , INTENT(OUT)            :: hdferr
    INTEGER(HID_T)  , INTENT(IN) , OPTIONAL  :: lapl_id
    INTEGER         , INTENT(IN) , OPTIONAL  :: fields

    INTEGER(SIZE_T) :: namelen
    INTEGER(HID_T)  :: lapl_id_default
    INTEGER :: fields_c

    INTERFACE
       INTEGER FUNCTION h5ovisit_by_name_c(loc_id, object_name, namelen, index_type, order, &
            op, op_data, lapl_id, fields) BIND(C, NAME='h5ovisit_by_name_c')
         IMPORT :: C_CHAR, C_PTR, C_FUNPTR
         IMPORT :: HID_T, SIZE_T
         IMPLICIT NONE
         INTEGER(HID_T)  , INTENT(IN) :: loc_id
         CHARACTER(KIND=C_CHAR), DIMENSION(*), INTENT(IN) :: object_name
         INTEGER(SIZE_T)              :: namelen
         INTEGER         , INTENT(IN) :: index_type
         INTEGER         , INTENT(IN) :: order
         TYPE(C_FUNPTR)  , VALUE      :: op
         TYPE(C_PTR)     , VALUE      :: op_data
         INTEGER(HID_T)  , INTENT(IN) :: lapl_id
         INTEGER         , INTENT(IN) :: fields
       END FUNCTION h5ovisit_by_name_c
    END INTERFACE

    fields_c = H5O_INFO_ALL_F
    IF(PRESENT(fields)) fields_c = fields

    namelen = LEN(object_name)

    lapl_id_default = H5P_DEFAULT_F
    IF(PRESENT(lapl_id)) lapl_id_default = lapl_id

    return_value = h5ovisit_by_name_c(loc_id, object_name, namelen, index_type, order, &
         op, op_data, lapl_id_default, fields_c)

    IF(return_value.GE.0)THEN
       hdferr = 0
    ELSE
       hdferr = -1
    END IF

  END SUBROUTINE h5ovisit_by_name_f

!>
!! \ingroup FH5O
!!
!! \brief Compare two tokens, which must be from the same file / containers.
!!
!! \param loc_id    Identifier of an object in the file / container.
!! \param token1    The first token to compare.
!! \param token2    The second token to compare.
!! \param cmp_value Returns 0 if tokens are equal, non-zero for unequal tokens.
!! \param hdferr    \fortran_error
!!
!! See C API: @ref H5Otoken_cmp()
!!
  SUBROUTINE h5otoken_cmp_f(loc_id, token1, token2, cmp_value, hdferr)
    IMPLICIT NONE
    INTEGER(HID_T)  , INTENT(IN)  :: loc_id
    TYPE(H5O_TOKEN_T_F), INTENT(IN) :: token1
    TYPE(H5O_TOKEN_T_F), INTENT(IN) :: token2
    INTEGER         , INTENT(OUT) :: cmp_value
    INTEGER         , INTENT(OUT) :: hdferr
    INTERFACE
       INTEGER FUNCTION h5otoken_cmp_c(loc_id, token1, token2, cmp_value) BIND(C,NAME='h5otoken_cmp_c')
         IMPORT :: HID_T, C_PTR, H5O_TOKEN_T_F
         IMPLICIT NONE
         INTEGER(HID_T), INTENT(IN)     :: loc_id
         TYPE(H5O_TOKEN_T_F), INTENT(IN) :: token1
         TYPE(H5O_TOKEN_T_F), INTENT(IN) :: token2
         INTEGER, INTENT(OUT)           :: cmp_value

       END FUNCTION h5otoken_cmp_c
    END INTERFACE

    hdferr = h5otoken_cmp_c(loc_id, token1, token2, cmp_value)

  END SUBROUTINE h5otoken_cmp_f

END MODULE H5O