Software Changes from Release to Release for HDF5-1.10

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(For a description of the major new features that were introduced, please see New Features in HDF5 Release 1.10.)

This page provides information on the changes that a maintenance developer needs to be aware of between successive releases of HDF5, such as:

  • New or changed features or tools
  • Syntax and behavioral changes in the existing application programming interface (the API)
  • Certain types of changes in configuration or build processes

Note that bug fixes and performance enhancements in the C library are automatically picked up by the C++, Fortran, and Java libraries.


Contents

Compatibility and Performance Issues

Not all HDF5-1.10 releases are compatible. Users should NOT be using 1.10 releases prior to HDF5-1.10.3. See the compatibility matrix below for details on compatibility between 1.10 releases:

Release 1.10.5+ 1.10.4 1.10.3 1.10.2 1.10.1 1.10.1-patch1 1.10.0
1.10.5+ -- Yes Yes No No No No
1.10.4 Yes -- Yes No No No No
1.10.3 Yes Yes -- No No No No
1.10.2 No No No -- No No No


The following images show how performance has changed from release to release. Many performance improvements were added in HDF5-1.10.3:

cgns.png

writeLgNumDsets.png

The release notes also list changes made to the library, but these notes tend to be more at a more detail-oriented level. The release notes may include new features, bugs fixed, supported configuration features, platforms on which the library has been tested, and known problems. The release note files are listed below and can be found at the top level of the HDF5 source code tree in the release_docs directory.

Release Notes Technical notes regarding the current release of the HDF5 library (RELEASE.txt in the source code)
HISTORY-1_10.txt Release information for all HDF5-1.10 releases
HISTORY-1_8_0-1_10_0.txt Development history between the HDF5-1.8.0 and HDF5-1.10.0 releases
HISTORY-1_10.txt Release information for HDF5-1.8.0 through HDF5-1.8.17 releases
HISTORY-1_0-1_8_0_rc3.txt Technical notes starting with HDF5-1.0.0 and ending with HDF5-1.8.0-rc3 (the state of the code prior to the HDF5-1.8.0 release)

Release 1.10.7 versus 1.10.6

New and Changed Functions, Classes, Subroutines, Wrappers, and Macros

In the C Interface (main library)

The following are new C functions in this release:

Function Description
H5Pget_fapl_splitter() Retrieves information for a splitter file access property list
H5Pset_fapl_splitter() Sets the file access property list to use the splitter driver
H5Pget_file_locking() Gets the file locking property values
H5Pset_file_locking() Sets the file locking property values
H5get_alloc_stats() Gets the memory allocation statistics for the library
H5get_free_list_sizes() Gets the current size of the free lists used to manage memory
H5Scombine_hyperslab() Performs an operation on a hyperslab and an existing selection and returns the resulting selection
H5Scombine_select() Combines two hyperslab selections with an operation, returning a dataspace with the resulting selection
H5Smodify_select() Refines a hyperslab selection with an operation using a second hyperslab to modify it
H5Sselect_adjust() Adjusts a selection by subtracting an offset
H5Sselect_copy() Copies a selection from one dataspace to another
H5Sselect_intersect_block() Checks if current selection intersects with a block
H5Sselect_project_intersection()   Projects the intersection of two source selections to a destination selection
H5Sselect_shape_name() Checks if two selections are the same shape

In the C++ Wrapper

The following C++ wrappers were added:

Wrapper Description
FileAccPropList::getFileLocking()   See H5Pget_file_locking() for details
FileAccPropList::setFileLocking() See H5Pset_file_locking() for details

Compatibility Notes and Reports

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Release 1.10.6 versus 1.10.5

New and Changed Functions, Classes, Subroutines, Wrappers, and Macros

In the C Interface (main library)

The following are new C functions in this release:

Function Description
H5Pget_fapl_hdfs()   Gets the information of the given Read-Only HDFS virtual file driver
H5Pget_fapl_ros3() Gets the information of the given Read-Only S3 virtual file driver
H5Pset_fapl_hdfs() Sets up Read-Only HDFS virtual file driver
H5Pset_fapl_ros3() Sets up Read-Only S3 virtual file driver

In the C++ Wrapper

The following C++ wrapper was added:

Wrapper Description
LinkCreatPropList::getCreateIntermediateGroup ( ) const See H5Pget_create_intermediate_group()
LinkCreatPropList::setCreateIntermediateGroup ( bool crt_intmd_group ) const   See H5Pset_create_intermediate_group()

Compatibility Notes and Reports

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Release 1.10.5 versus 1.10.4, 1.10.3, and 1.10.2

New and Changed Functions, Classes, Subroutines, Wrappers, and Macros

In the C Interface (main library)

The following are new C functions in this release:

Function Description
H5Dget_chunk_info() Retrieves information about a chunk specified by the chunk index
H5Dget_chunk_info_by_coord() Retrieves information about a chunk specified by its coordinates
H5Dget_num_chunks() Retrieves number of chunks that have nonempty intersection with a specified selection
H5Fget_dset_no_attrs_hint() Retrieves the setting for determining whether the specified file does or does not create minimized dataset object headers
H5Fset_dset_no_attrs_hint() Sets the flag to create minimized dataset object headers
H5Pget_dset_no_attrs_hint() Retrieves the setting for determining whether the specified DCPL does or does not create minimized dataset object headers
H5Pset_dset_no_attrs_hint() Sets the flag to create minimized dataset object headers

The following changed in this release:

Function Description
H5Oget_info(), H5Oget_info_by_name(), H5Oget_info_by_idx(), H5Ovisit(), H5Ovisit_by_name() In 1.10.3 the original functions were versioned to H5Oget_info*1 and H5Ovisit*1 and the macros H5Oget_info* and H5Ovisit* were created. This broke the API compatibility for a maintenance release. In HDF5-1.10.5, the macros introduced in HDF5-1.10.3 were removed. The H5Oget_info*1 and H5Ovisit*1 APIs were copied to H5Oget_Info* and H5Ovisit*. As an example, H5Oget_info and H5Oget_info1 are identical in this release.

In the C++ Wrapper

The following C++ wrapper was added:

C++ Wrapper Description
H5Object::visit()  Wrapper for the C API H5Ovisit2(). Recursively visit elements reachable from an HDF5 object and perform a common set of operations across all of those elements. See H5Ovisit2() for more information on this function.

In the Fortran Wrapper

The following Fortran wrappers were added or changed:

Fortran Wrapper Description
h5fget_dset_no_attrs_hint_f(), h5fset_dset_no_attrs_hint_f(),

h5pget_dset_no_attrs_hint_f(),h5pset_dset_no_attrs_hint_f()

Wrappers for the dataset object header minimization calls. See H5Fget_dset_no_attrs_hint(), H5Fset_dset_no_attrs_hint(), H5Pget_dset_no_attrs_hint(), and H5Pset_dset_no_attrs_hint().
h5ovisit_f(),h5oget_info_by_name_f(),

h5oget_info_f(),h5oget_info_by_idx_f(),h5ovisit_by_name_f()

Added new Fortran 'fields' optional parameter. See H5Ovisit2(), H5Oget_info_by_name2(), H5Oget_info2(), H5Oget_info_by_idx2(), and H5Ovisit_by_name2().


The following Fortran utility function was added:

Function Description
h5gmtime() converts (C) 'time_t' structure to Fortran DATE AND TIME storage format


A new Fortran derived type was added:

Derived Type Description
c_h5o_info_t This is interoperable with C's h5o_info_t. This is needed for callback functions which pass C's h5o_info_t data type definition. See the Fortran signature for H5Oget_info2().

In the Java wrapper

The following Java wrappers were added or changed:

Java Wrapper Description
H5Fset_libver_bounds() See the C API H5Fset_libver_bounds() for information on this function
H5Fget_dset_no_attrs_hint,H5Fset_dset_no_attrs_hint

H5Pget_dset_no_attrs_hint,H5Pset_dset_no_attrs_hint

Wrappers for the dataset object header minimization calls. See H5Fget_dset_no_attrs_hint(), H5Fset_dset_no_attrs_hint(),

H5Pget_dset_no_attrs_hint(), and H5Pset_dset_no_attrs_hint() for more information on these APIs.

Compatibility Notes and Reports

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases. Reports are available comparing HDF5-1.10.5 vs 1.10.2, HDF5-1.10.5 vs 1.10.3, and HDF5-1.10.5 vs 1.10.4.


Release 1.10.4 versus Release 1.10.3

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Release 1.10.3 versus Release 1.10.2

New and Changed Functions, Classes, Subroutines, Wrappers, and Macros

In the C Interface (main library)

The following are new C functions in this release:

Function Description
H5Dread_chunk() Moved from HDF5 High Level Optimizations library to core library
H5Dwrite_chunk() Moved from HDF5 High Level Optimizations library to core library
H5Oget_info(),

H5Oget_info1(), H5Oget_info2()

The function H5Oget_info() was moved to H5Oget_info1(), and the macro H5Oget_info() was created that

can be mapped to either H5Oget_info1()or H5Oget_info2(). For HDF5-1.10 and earlier releases, H5Oget_info() is mapped to H5Oget_info1() by default.

H5Oget_info_by_idx(),

H5Oget_info_by_idx1(), H5Oget_info_by_idx2()

The function H5Oget_info_by_idx() was moved to get_info_by_idx1(), and the macro H5Oget_info_by_idx() was created that can be mapped to

either H5Oget_info_by_idx1() or H5Oget_info_by_idx2(). For HDF5-1.10 and earlier releases, H5Oget_info_by_idx() is mapped to H5Oget_info_by_idx1() by default.

H5Oget_info_by_name(),

H5Oget_info_by_name1(), H5Oget_info_by_name2()

The function H5Oget_info_by_name() was moved to H5Oget_info_by_name1(), and the macro H5Oget_info_by_name() was created that can be mapped to either

H5Oget_info_by_name1() or H5Oget_info_by_name2(). For HDF5-1.10 and earlier releases, H5Oget_info_by_name() is mapped to H5Oget_info_by_name1() by default.

H5Ovisit(),

H5Ovisit1(), H5Ovisit2()

The function H5Ovisit() was moved to H5Ovisit1(), and the macro H5Ovisit() was created that can be mapped to either H5Ovisit1()

or H5Ovisit2(). For HDF5-1.10 and earlier releases, H5Ovisit() is mapped to H5Ovisit1() by default.

H5Ovisit_by_name(),

H5Ovisit_by_name1(), H5Ovisit_by_name2()

The function H5Ovisit_by_name() was moved to H5Ovisit_by_name1(), and the macro H5Ovisit_by_name() was created that can be mapped

to either H5Ovisit_by_name1() or H5Ovisit_by_name2(). For HDF5-1.10 and earlier releases, H5Ovisit_by_name() is mapped to H5Ovisit_by_name1() by default.

In the C High Level Interface

The following C functions were deprecated in this release:

Function Description
H5DOread_chunk() Deprecated, moved to H5Dread_chunk()
H5DOwrite_chunk() Deprecated, moved to H5Dwrite_chunk()

In the C++ Wrapper

Several C++ wrappers were added or modified to provide additional support. See the API Compatibility Report for details.

Compatibility Notes and Report

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Release 1.10.2 versus Release 1.10.1

This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.10.1 to Release 1.10.2.

New and Changed Functions, Classes, Subroutines, Wrappers, and Macros

In the C Interface (main library)

The following are new C functions in this release:

Function Description
H5Dget_chunk_storage_size() Returns storage amount allocated within a file for a raw data chunk in a dataset
H5Fget_eoa() Retrieves the file’s EOA
H5Fincrement_filesize() Sets the file’s EOA to the maximum of (EOA, EOF) + increment
H5Fset_libver_bounds() Enables the switch of version bounds setting for a file
H5FDdriver_query() Queries a VFL driver for its feature flags when a file is not available (not documented in Reference Manual)
H5Pget_virtual_prefix() Retrieves prefix applied to VDS source file paths
H5Pset_virtual_prefix() Sets prefix to be applied to VDS source file paths


The following C functions changed in this release:

Function Description
H5Pset_libver_bounds() HDF5-1.10 was added to the range of versions
H5Pset_virtual() A change was made to the method of searching for VDS source files
H5PL* The parameters for many of the H5PL APIs were renamed

In the C High Level Interface

The following new C function was added to this release:

Function Description
H5DOread_chunk() Reads a raw data chunk directly from a dataset in a file

In the C++ Wrapper

The following C++ wrappers were added:

C++ Wrapper Description
H5Lcreate_soft() Creates a soft link from link_name to target_name
H5Lcreate_hard() Creates a hard link from new_name to curr_name
H5Lcopy() Copy an object from a group of file
H5Lmove() Rename an object in a group or file
H5Ldelete() Removes the specified link from this location
H5Tencode() Creates a binary object description of this datatype
H5Tdecode() Returns the decoded type from the binary object description
H5Lget_info() Returns the information of the named link


These were also added:

  • Class LinkCreatPropList for link create property list
  • Overloaded functions H5Location::createGroup to take a link creation property list

See the API Compatibility report for complete details.

In the Java Wrapper

The following Java wrappers were added:

Java Wrapper Description
H5Pset_evict_on_close() Controls the library's behavior of evicting metadata associated with a closed object
H5Pget_evict_on_close() Retrieves the file access property list setting that determines whether an HDF5 object will be evicted from the library's metadata cache when closed
H5Pset_chunk_opts() Sets the edge chunk option in a dataset creation property list
H5Pget_chunk_opts() Retrieves the edge chunk option setting from a dataset creation property list
H5Pset_efile_prefix() Sets the external dataset storage file prefix in the dataset access property list
H5Pget_efile_prefix() Retrieves the prefix for external raw data storage files as set in the dataset access property list
H5Pset_virtual_prefix() Sets prefix to be applied to VDS source file paths
H5Pget_virtual_prefix() Retrieves prefix applied to VDS source file paths

See the Release.txt file for details.

Tools

New options were added to the h5clear utility:

Option Decription
--filesize Print the file’s EOA and EOF
--increment=C Set the file’s EOA to the maximum of (EOA, EOF) + C for the file. C is >= 0; C is optional and will default to 1M when not set


A new option was added to h5diff:

Option Decription
--enable-error-stack Enable the error stack

Compatibility Notes and Report

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Release 1.10.1 versus Release 1.10.0 (and 1.10.0-patch1)

This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.10.0 (and HDF5-1.10.0-patch1) to Release 1.10.1.

New Features

Several new features are introduced in HDF5 Release 1.10.1.

  • Metadata Cache Image
  • Metadata Cache Evict on Close
  • Paged Aggregation
  • Page Buffering

New Features, including associated C Functions

The following features are described and documented in New Features in HDF5 Release 1.10. Each new feature in 1.10.1 is listed below along with the associated C functions:

Metadata Cache Image:

Function Description
H5Pget_mdc_image_config() Retrieves the metadata cache image configuration values for a file access property list.
H5Pset_mdc_image_config() Sets the metadata cache image option for a file access property list.
H5Fget_mdc_image_info() Gets information about a metadata cache image if it exists.

Metadata Cache Evict on Close:

Function Description
H5Pget_evict_on_close() Retrieves the property list setting that determines whether an HDF5 object will be evicted from the library's metadata cache when it is closed.
H5Pset_evict_on_close() Controls the library's behavior of evicting metadata associated with a closed object.

Paged Aggregation:

Function Description
H5Pget_file_space_page_size() Retrieves the file space page size for a file creation property list.
H5Pset_file_space_page_size() Sets the file space page size (used with paged aggregation) for a file creation property list.
H5Pget_file_space_strategy() Retrieves the file space handling strategy for a file creation property list.
H5Pset_file_space_strategy() Sets the file space allocation strategy for a file creation property list.

Page Buffering:

Function Description
H5Pget_page_buffer_size() Retrieves the maximum size for the page buffer and the minimum percentage for metadata and raw data pages.
H5Pset_page_buffer_size() Sets the maximum size for the page buffer and the minimum percentage for metadata and raw data pages.
H5Fget_page_buffering_stats() Retrieves statistics about page access when it is enabled.
H5Freset_page_buffering_stats() Resets the page buffer statistics.

New and Changed Functions, Classes, Subroutines, Wrappers, and Macros

In the C Interface (main library)

The following new C functions were added:

Function
H5PLappend()
H5PLget()
H5PLinsert()
H5PLprepend()
H5PLremove()
H5PLreplace()
H5PLsize()

In the C++ Wrapper

New member functions were added to provide const versions. For example, these methods,

  • ArrayType::getArrayDims ( hsize_t* dims ) const
  • ArrayType::getArrayNDims ( ) const


replace these:

  • ArrayType::getArrayDims ( hsize_t* dims )
  • ArrayType::getArrayNDims ( )


Several functions were moved to other classes. For example, this method,

  • H5Location::openDataSet ( char const* name ) const


replaces:

  • CommonFG::openDataSet ( char const* name ) const


PLEASE review the Compatibility report below for complete information on the C++ changes in this release. Compatibility Report

Compatibility report for Release 1.10.1 versus Release 1.10.0-patch1

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Release 1.10.0 of March 2016 versus Release 1.8.16

This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.16 to Release 1.10.0.

Changed Type

hid_t Changed from a 32-bit to a 64-bit value.

hid_t is the type is used for all HDF5 identifiers. This change, which is necessary to accomodate the capacities of modern computing systems, therefore affects all HDF5 applications. If an application has been using HDF5’s hid_t the type, recompilation will normally be sufficient to take advantage of HDF5 Release 1.10.0. If an application uses an integer type instead of HDF5’s hid_t type, those identifiers must be changed to a 64-bit type when the application is ported to the 1.10.x series.

New Features and Feature Sets

Several new features are introduced in HDF5 Release 1.10.0.

  • Single-Writer / Multiple-Reader or SWMR
  • Collective Metadata I/O
  • Fine-tuning the metadata cache
  • File Space Management
  • Virtual Datasets or VDS
  • Partial Edge Chunk Options
  • Relative Pathnames for External Links
  • Property List Encoding and Decoding

More substantial lists follow, including new and modified C functions and Fortran subroutines.

New Features, including associated C Functions and Fortran Wrappers

The following features are described and documented in [New Features in HDF5 Release 1.10]. On this page, we list each feature and its associated C functions and Fortran wrappers.

Single-writer / Multiple-reader, commonly called SWMR:

Function Description
H5Fstart_swmr_write() Enables SWMR writing mode for a file.
H5DOappend() Appends data to a dataset along a specified dimension. (This is a high-level API.)
H5Pget_append_flush() Retrieves the values of the append property that is set up in the dataset access property list.
H5Pset_append_flush() Sets two actions to perform when the size of a dataset’s dimension being appended reaches a specified boundary.
H5Pget_object_flush_cb() Retrieves the object flush property values from the file access property list.
H5Pset_object_flush_cb() Sets a callback function to invoke when an object flush occurs in the file.
H5Odisable_mdc_flushes() Prevents metadata entries for an HDF5 object from being flushed from the metadata cache to storage.
H5Oenable_mdc_flushes() Returns the cache entries associated with an HDF5 object to the default metadata flush and eviction algorithm.
H5Oare_mdc_flushes_disabled() Determines if an HDF5 object (dataset, group, committed datatype) has had flushes of metadata entries disabled.
H5Fdisable_mdc_flushes() Globally prevents dirty metadata entries from being flushed from the metadata cache to storage.
H5Fenable_mdc_flushes() Returns a file’s metadata cache to the standard eviction and flushing algorithm.
H5Fare_mdc_flushes_disabled() Determines if flushes have been globally disabled for a file’s metadata cache.
H5Fget_mdc_flush_disabled_obj_ids() Returns a list of all object identifiers for which flushes have been disabled in a file’s metadata cache.
Command-line Tools:
h5watch Allows users to output new records appended to a dataset under SWMR access as it grows. The functionality is similar to the Unix user command tail with the follow option, which outputs appended data as the file grows.
h5format_convert This tool allows users to convert the indexing type of a chunked dataset made with a 1.10.x version of the HDF5 Library when the latest file format is used to the 1.8.x version 1 B-tree indexing type. For example, datasets created using SWMR access, can be converted to be accessed by the HDF5 1.18 library and tools. The tool does not rewrite raw data, but it does rewrite HDF5 metadata.

Collective Metadata I/O:

Function Description
H5Pset_coll_metadata_write()

h5pset_coll_metadata_write_f()

Establishes I/O mode property setting, collective or independent, for metadata writes.
H5Pget_coll_metadata_write()

h5pget_coll_metadata_write_f()

Retrieves I/O mode property setting for metadata writes.
H5Pset_all_coll_metadata_ops()

h5pset_all_coll_metadata_ops_f()

Establishes I/O mode, collective or independent, for metadata read operations.
H5Pget_all_coll_metadata_ops()

h5pget_all_coll_metadata_ops_f()

Retrieves I/O mode for metadata read operations.

Fine-tuning the Metadata Cache:

Function Description
H5Fget_metadata_read_retries_info() Retrieves the collection of read retries for metadata items with checksum.
H5Pget_metadata_read_attempts() Retrieves the number of read attempts from a file access property list.
H5Pset_metadata_read_attempts() Sets the number of read attempts in a file access property list.
H5Dflush() Causes all buffers associated with a dataset to be immediately written to disk without removing the data from the cache.
H5Drefresh() Causes all buffers associated with a dataset to be cleared and immediately re-loaded with updated contents from disk storage.
H5Gflush() Causes all buffers associated with a group to be immediately flushed to disk without removing the data from the cache.
H5Grefresh() Causes all buffers associated with a group to be cleared and immediately re-loaded with updated contents from disk storage.
H5Oflush() Causes all buffers associated with an object to be immediately flushed to disk without removing the data from the cache.
H5Orefresh() Causes all buffers associated with an object to be cleared and immediately re-loaded with updated contents from disk storage.
H5Tflush() Causes all buffers associated with a committed datatype to be immediately flushed to disk without removing the data from the cache.
H5Trefresh() Causes all buffers associated with a committed datatype to be cleared and immediately re-loaded with updated contents from disk storage.
H5Fget_intent() Determines the read/write or read-only status of a file.
Logging APIs:
Function Description
H5Pset_mdc_log_options() Sets metadata cache logging options.
H5Pget_mdc_log_options() Gets metadata cache logging options.
H5Fstart_mdc_logging() Starts logging metadata cache events if logging was previously enabled.
H5Fstop_mdc_logging() Stops logging metadata cache events if logging was previously enabled and is currently ongoing.
H5Pget_mdc_logging_status() Gets the current metadata cache logging status.

File Space Management:

Function Description
H5Fget_free_sections() Retrieves free-space section information for a file.
H5Fget_freespace() Returns the amount of free space in a file.
H5Fget_info2() Returns global information for a file.
H5Pset_file_space() Sets the file space management strategy and/or the free-space section threshold for an HDF5 file.
H5Pget_file_space() Retrieves the file space management strategy and/or the free-space section threshold for an HDF5 file.

The following tool has been modified to preserve or modify file freepace information appropriately when processing files employing the VDS feature:

h5repack Repacks HDF5 files with various options, including the ability to change the applied filters. This version of h5repack understands the file free space feature and handles the file and metadata appropriately.

Virtual Dataset or VDS:

Function Description
H5Pset_virtual(), h5pset_virtual_f() Sets the mapping between virtual and source datasets.
H5Pget_virtual_count(), h5pget_virtual_count_f() Retrieves the number of mappings for the virtual dataset.
H5Pget_virtual_vspace(), h5pget_virtual_vspace_f() Retrieves a dataspace identifier for the selection within the virtual dataset used in the mapping.
H5Pget_virtual_srcspace(), h5pget_virtual_srcspace_f() Retrieves a dataspace identifier for the selection within the source dataset used in the mapping.
H5Pget_virtual_dsetname(), h5pget_virtual_dsetname_f() Retrieves the name of a source dataset used in the mapping.
H5Pget_virtual_filename(), h5pget_virtual_filename_f() Retrieves the filename of a source dataset used in the mapping.
H5Pset_virtual_printf_gap(), h5pset_virtual_printf_gap_f() Sets maximum number of missing source files and/or datasets with printf-style names when getting the extent of an unlimited virtual dataset.
H5Pget_virtual_printf_gap(), h5pget_virtual_printf_gap_f() Returns maximum number of missing source files and/or datasets with printf-style names when getting the extent for an unlimited virtual dataset.
H5Pset_virtual_view(), h5pset_virtual_view_f() Sets the view of the virtual dataset to include or exclude missing mapped elements.
H5Pget_virtual_view(), h5pget_virtual_view_f() Retrieves the view of a virtual dataset.
Supporting Functions:
Function Description
H5Sis_regular_hyperslab(), h5sis_regular_hyperslab_f() Determines whether a hyperslab selection is regular.
H5Sget_regular_hyperslab(), h5sget_regular_hyperslab_f() Retrieves a regular hyperslab selection.
Modified Functions:

The following pre-exising functions have been modified to understand virtual datasets.

Function Description
H5Pset_layout(), h5pset_layout_f() Specifies the layout to be used for a dataset.

Virtual dataset, H5D_VIRTUAL, has been added to the list of layouts available through this function.

H5Pget_layout(), h5pget_layout_f() Retrieves the layout in use for a dataset.

Virtual dataset, H5D_VIRTUAL, has been added to the list of layouts.

Partial Edge Chunks:

Function Description
H5Pset_chunk_opts() Sets a partial edge chunk option in a dataset access property list.
H5Pget_chunk_opts() Retrieves partial edge chunk option setting from a dataset access property list.

Relative Pathnames for External Links:

Function Description
H5Pset_elink_prefix() These functions enable the user to specify the locations of external files.

(These functions are not yet documented.)

H5Pget_elink_prefix

Property List Encoding and Decoding:

Function
H5Pencode()
H5Pdecode()

Additional New Functions:

The following new functions appear in HDF5 Release 1.10.0 but are not yet documented:

Function
H5Dformat_convert()
H5Dget_chunk_index_type()
H5FDlock()
H5FDunlock()
H5Fformat_convert()
H5LDget_dset_dims()
H5LDget_dset_elmts()
H5LDget_dset_type_size()

New and Changed Elements of the Packet Table (H5PT) High-level API

In the C Interface

Replacement functions:

H5PTcreate() Takes a property list identifier to provide flexibility on creation properties.

H5PTcreate_fl has been removed.

H5PTfree_vlen_buff() Replaces H5PTfree_vlen_readbuff.

New functions:

Two accessor functions have been added.

H5PTget_dataset() Returns the identifier of the dataset associated a packet table.
H5PTget_type() Returns the identifier of the datatype used by a packet table.
H5PTis_varlen() Determines whether a type is variable-length.

In the C++ Interface

Overloaded constructor

An overloaded constructor has been added.

FL_PacketTable Takes a property list identifier to provide flexibility on creation properties.
H5PTfree_vlen_buff Replaces H5PTfree_vlen_readbuff.
Accessor wrappers

Two accessor wrappers are added to class PacketTable.

PacketTable::GetDataset() Returns the identifier of the dataset associated a packet table.
PacketTable::GetDatatype() Returns the identifier of the datatype used by a packet table.
Other wrappers
PacketTable::FreeBuff() Replaces VL_PacketTable::FreeReadBuff().
PacketTable::IsVariableLength() Replaces VL_PacketTable::IsVariableLength().
Overloaded functions:

Where a member functions has a char* as an argument, an overloaded function has been added to provide the const char* argument.

The existing version will be deprecated in a future release.

Java Interface Changes

Integration into Main HDF5 Library

The Java HDF5 JNI library has been integrated into the HDF5 repository.

  • Configure option: --enable-java
  • CMake option: HDF5_BUILD_JAVA:BOOL=ON

Prior to the 1.10.x series, the HDF5 Java tools were built from an independent repository and were not as fully integrated with HDF5. were built from an independent repository and were not as fully integrated with HDF5.

Package Hierarchy Change

The package hierarchy has changed to hdf.hdflib.hdf5.

Prior to the 1.10.x series, the hierarchy was ncsa.hdf.hdflib.hdf5.

New Java APIs

A number of new APIs have been added in the Java interface, including APIs for the VDS and SWMR features.

Functions with Changed Behavior

H5Lexists()

 The behavior of this function has changed in this release. When testing the pathname / (a slash representing the root of an HDF5 file) 
 H5Lexists() now returns successfully with the value 1 (one). 
 See the entry in the HDF5 Reference Manual for H5Lexists() for more information.

API Compatibility

See API Compatibility Macros in HDF5 for details on the following.

New API Compatibility Flag

A new v18 flag was added enabling the building of HDF5 such that the default API is compatible with the HDF5 Release 1.8.x API:

   --with-default-api-version=v18

New versioned functions and associated compatibility macros

Two functions and a struct have been converted to a versioned form in this release. Compatibility macros have been created for each.

  • H5Fget_info()
 The original function is renamed to H5Fget_info1() and deprecated. 
 A new version of the function, H5Fget_info2(), is introduced
 The compatibility macro H5Fget_info is introduced.
  • H5F_info_t
 This is the struct used by the H5Fget_info() functions and macro.
 The original struct is renamed to H5F_info1_t and deprecated.
 A new version of the struct, H5F_info2_t, is introduced.
 The compatibility macro H5F_info_t is introduced.
  • H5Rdereference()
 The original function is renamed to H5Rdereference1() and deprecated.
 A new version of the function, H5Rdereference2(), is introduced.
 The compatibility macro H5Rdereference is introduced.

Autotools Configuration and Large File Support

Autotools configuration has been extensively reworked and autotool’s handling of large file support has been overhauled in this release.

See the following sections in RELEASE.txt:

  • Autotools Configuration Has Been Extensively Reworked
  • LFS Changes

RELEASE.txt is found in the release_docs/ subdirectory at the root level of the HDF5 code distribution.

Compatibility Report and Comments

Compatibility report for Release 1.10.0 versus Release 1.8.16

See the API Compatibility reports on the Release Information page for information regarding compatibility with previous releases.

Comments regarding the report

In the C interface, the hid_t change from 32-bit to 64-bit was made in order to address a performance problem that arose when the library “ran out” of valid object identifiers to issue and thus needed to employ an expensive algorithm to find previously issued identifiers that could be re-issued. This problem is avoided by switching the size of the hid_t type to 64-bit integers instead of 32-bit integers in order to make the pool of available integers significantly larger. (H5E_major_t and H5E_minor_t are aliased to hid_t which is why they changed size as well). (An alternate solution to this problem was applied in release HDF5 1.8.5 but this is the cleaner/preferred solution and had to wait until 1.10.0 to be included).

hbool_t will now be defined as a _Bool type when configure determines that it’s available.

Public structs that have members of type hid_t or hbool_t are affected by the above changes accordingly.

The H5Fget_info() function was renamed due to the introduction of a newer version of the function which returns additional information. The H5Rdereference() function was renamed due to the introduction of a newer version of the function which allows a data access property list to be passed in. Both changes are accompanied with compatibility macros, so while existing code will need to be recompiled in order to use the newer library version, these functions do not need to be changed in application code using them provided that the HDF5 API compatibility macros are configured appropriately.