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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.

The following information is included below.

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:

Release1.10.5+1.10.41.10.31.10.21.10.11.10.0-patch11.10.0
1.10.5+ YesYesNoNoNoNo
1.10.4Yes YesNoNoNoNo
1.10.3YesYes NoNoNoNo
1.10.2NoNoNo NoNoNo

The following images show how performance has changed from release to release.

 

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_8.txt

Release information for HDF5-1.8.0 through HDF5-1.8.21 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 1.10.11 versus 1.10.10

There are no new or changed items in this release.

Compatibility Notes and Reports

See the API compatibility report for the HDF5 library between 1.10.10 and 1.10.11 for information regarding compatibility with the previous release. The API Compatibility Report page includes all 1.10 compatibility reports.

Release 1.10.10 versus 1.10.9

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

In the main C library

One new API was added, H5Dchunk_iter and one API is removed, H5Treclaim.

Compatibility Notes and Reports

See the API compatibility report for the HDF5 library between 1.10.9 and 1.10.10 for information regarding compatibility with the previous release. The API Compatibility Report page includes all 1.10 compatibility reports.

Release 1.10.9 versus 1.10.8

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

In the Java Wrapper

One Java wrapper was added:

H5.H5export_dataset

Compatibility Notes and Reports

See the API compatibility report for the HDF5 library between 1.10.8 and 1.10.9 for information regarding compatibility with the previous release. The API Compatibility Report page includes all 1.10 compatibility reports.

Release 1.10.8 versus 1.10.7

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

In the C++ Wrapper

One C++ wrapper was added:
DataSet::operator=

Compatibility Notes and Reports

See the API compatibility report for the HDF5 library between 1.10.7 and 1.10.8 for information regarding compatibility with the previous release. The API Compatibility Report page includes all 1.10 compatibility reports.

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:

FunctionDescription
H5P_GET_FAPL_SPLITTER
Retrieves information for a splitter file access property list
H5P_SET_FAPL_SPLITTERSets the file access property list to use the splitter driver
H5P_GET_FILE_LOCKINGGets the file locking property values
H5P_SET_FILE_LOCKINGSets the file locking property values
H5_GET_ALLOC_STATS 
Gets the memory allocation statistics for the library
H5_GET_FREE_LIST_SIZESGets the current size of the free lists used to manage memory
H5S_COMBINE_HYPERSLABPerforms an operation on a hyperslab and an existing selection and returns the resulting selection
H5S_COMBINE_SELECTCombines two hyperslab selections with an operation, returning a dataspace with the resulting selection
H5S_MODIFY_SELECTRefines a hyperslab selection with an operation using a second hyperslab to modify it
H5S_SELECT_ADJUSTAdjusts a selection by subtracting an offset
H5S_SELECT_COPYCopies a selection from one dataspace to another
H5S_SELECT_INTERSECT_BLOCKChecks if current selection intersects with a block
H5S_SELECT_PROJECT_INTERSECTIONProjects the intersection of two source selections to a destination selection
H5S_SELECT_SHAPE_SAME

Checks if two selections are the same shape


In the C++ Wrapper

The following C++ wrappers were added:

WrapperDescription
FileAccPropList::getFileLockingSee H5P_GET_FILE_LOCKING for details
FileAccPropList::setFileLockingSee H5P_SET_FILE_LOCKING for details

Compatibility Notes and Reports

See the API compatibility report for the HDF5 library between 1.10.6 and 1.10.7 for information regarding compatibility with the previous release. The API Compatibility Report page includes all 1.10 compatibility reports.

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:

FunctionDescription
H5P_GET_FAPL_HDFSGets the information of the given Read-Only HDFS virtual file driver
H5P_GET_FAPL_ROS3Gets the information of the given Read-Only S3 virtual file driver
H5P_SET_FAPL_HDFSSets up Read-Only HDFS virtual file driver
H5P_SET_FAPL_ROS3Sets up Read-Only S3 virtual file driver

 

In the C++ Wrapper

The following C++ wrapper was added:

WrapperDescription
LinkCreatPropList::getCreateIntermediateGroup  ( ) const
See H5P_GET_CREATE_INTERMEDIATE_GROUP
LinkCreatPropList::setCreateIntermediateGroup  bool crt_intmd_group ) const
See H5P_SET_CREATE_INTERMEDIATE_GROUP

Compatibility Notes and Reports

See the  API Compatibility Report 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:

FunctionDescription
H5D_GET_CHUNK_INFORetrieves information about a chunk specified by the chunk index
H5D_GET_CHUNK_INFO_BY_COORDRetrieves information about a chunk specified by its coordinates
H5D_GET_NUM_CHUNKSRetrieves number of chunks that have nonempty intersection with a specified selection

H5F_GET_DSET_NO_ATTRS_HINT

Retrieves the setting for determining whether the specified file does or does not create minimized dataset object headers

H5F_SET_DSET_NO_ATTRS_HINT

Sets the flag to create minimized dataset object headers

H5P_GET_DSET_NO_ATTRS_HINT

Retrieves the setting for determining whether the specified DCPL does or does not create minimized dataset object headers

H5P_SET_DSET_NO_ATTRS_HINT

Sets the flag to create minimized dataset object headers

 

The following changed in this release:

FunctionDescription

H5O_GET_INFO, H5O_GET_INFO_BY_NAME, H5O_GET_INFO_BY_IDX, H5O_VISIT, H5O_VISIT_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++ WrapperDescription
H5Object::visit()

Wrapper for the C API H5O_VISIT2. Recursively visit elements reachable from an HDF5 object and perform a common set of operations across all of those elements. See H5O_VISIT2 for more information on this function.

 

In the Fortran Wrapper

The following Fortran wrappers were added or changed:

Fortran WrapperDescription

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 H5F_GET_DSET_NO_ATTRS_HINT, H5F_SET_DSET_NO_ATTRS_HINT, H5P_GET_DSET_NO_ATTRS_HINT, and H5P_SET_DSET_NO_ATTRS_HINT.

h5ovisit_f

h5oget_info_by_name_f

h5oget_info

h5oget_info_by_idx

h5ovisit_by_name_f

Added new Fortran 'fields' optional parameter. See H5O_VISIT2, H5O_GET_INFO_BY_NAME2, H5O_GET_INFO2, H5O_GET_INFO_BY_IDX2, and H5O_VISIT_BY_NAME2.

 

The following Fortran utility function was added:

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

 

A new Fortran derived type was added:

Derived TypeDescription
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 H5O_GET_INFO2.

 

In the Java wrapper

The following Java wrappers were added or changed:

Java WrapperDescription
H5Fset_libver_boundsSee the C API  H5F_SET_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 H5F_GET_DSET_NO_ATTRS_HINT, H5F_SET_DSET_NO_ATTRS_HINT, H5P_GET_DSET_NO_ATTRS_HINT, and H5P_SET_DSET_NO_ATTRS_HINT for more information on these APIs.

Compatibility Notes and Reports

See these API Compatibility Reports for 1.10 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 Report 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:

FunctionDescription
H5D_READ_CHUNKMoved from HDF5 High Level Optimizations library to core library
H5D_WRITE_CHUNKMoved from HDF5 High Level Optimizations library to core library

H5O_GET_INFO

H5O_GET_INFO1

H5O_GET_INFO2

The function H5O_GET_INFO was moved to H5O_GET_INFO1, and the macro H5O_GET_INFO was created that can be mapped to either H5O_GET_INFO1 or H5O_GET_INFO2. For HDF5-1.10 and earlier releases, H5O_GET_INFO is mapped to H5O_GET_INFO1 by default.

H5O_GET_INFO_BY_IDX

H5O_GET_INFO_BY_IDX1

H5O_GET_INFO_BY_IDX2

The function H5O_GET_INFO_BY_IDX was moved to H5O_GET_INFO_BY_IDX1, and the macro H5O_GET_INFO_BY_IDX was created that can be mapped to either H5O_GET_INFO_BY_IDX1 or H5O_GET_INFO_BY_IDX2. For HDF5-1.10 and earlier releases, H5O_GET_INFO_BY_IDX is mapped to H5O_GET_INFO_BY_IDX1 by default.

H5O_GET_INFO_BY_NAME

H5O_GET_INFO_BY_NAME1

H5O_GET_INFO_BY_NAME2

The function H5O_GET_INFO_BY_NAME was moved to H5O_GET_INFO_BY_NAME1, and the macro H5O_GET_INFO_BY_NAME was created that can be mapped to either H5O_GET_INFO_BY_NAME1 or H5O_GET_INFO_BY_NAME2. For HDF5-1.10 and earlier releases, H5O_GET_INFO_BY_NAME is mapped to H5O_GET_INFO_BY_NAME1 by default.

H5O_VISIT

H5O_VISIT1

H5O_VISIT2

The function H5O_VISIT was moved to H5O_VISIT1, and the macro H5O_VISIT was created that can be mapped to either H5O_VISIT1 or H5O_VISIT2. For HDF5-1.10 and earlier releases, H5O_VISIT is mapped to H5O_VISIT1 by default.

H5O_VISIT_BY_NAME

H5O_VISIT_BY_NAME1

H5O_VISIT_BY_NAME2

The function H5O_VISIT_BY_NAME was moved to H5O_VISIT_BY_NAME1, and the macro H5O_VISIT_BY_NAME was created that can be mapped to either H5O_VISIT_BY_NAME1 or H5O_VISIT_BY_NAME2. For HDF5-1.10 and earlier releases, H5O_VISIT_BY_NAME is mapped to H5O_VISIT_BY_NAME1 by default.

 

In the C High Level Interface

The following C functions were deprecated in this release:

FunctionDescription
H5DO_READ_CHUNKDeprecated, moved to H5D_READ_CHUNK
H5DO_WRITE_CHUNKDeprecated, moved to H5D_WRITE_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 Report 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:

FunctionDescription
H5D_GET_CHUNK_STORAGE_SIZEReturns storage amount allocated within a file for a raw data chunk in a dataset
H5F_GET_EOARetrieves the file’s EOA
H5F_INCREMENT_FILESIZE

Sets the file’s EOA to the maximum of (EOA, EOF) + increment

H5F_SET_LIBVER_BOUNDSEnables the switch of version bounds setting for a file
H5FDdriver_queryQueries a VFL driver for its feature flags when a file is not available (not documented in Reference Manual)
H5P_GET_VIRTUAL_PREFIXRetrieves prefix applied to VDS source file paths
H5P_SET_VIRTUAL_PREFIXSets prefix to be applied to VDS source file paths

 

The following C functions changed in this release:

FunctionChange
H5P_SET_LIBVER_BOUNDSHDF5-1.10 was added to the range of versions
H5P_SET_VIRTUALA 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:

FunctionDescription
H5DO_READ_CHUNKReads a raw data chunk directly from a dataset in a file

 

In the C++ Wrapper

The following C++ wrappers were added:

C++ WrapperDescription
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 WrapperDescription
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:

--filesizePrint 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:

--enable-error-stackEnable the error stack

Compatibility Notes and Report

See API Compatibility Reports for 1.10 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:
 

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:
 

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:
 

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:
 

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:

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 API Compatibility Reports for 1.10 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 1.10.0. On this page, we list each feature and its associated C functions and Fortran wrappers.

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

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:
 

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:
 

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:

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:
 

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:
 

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:

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.

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:
 

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:
 

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:
 

H5Pencode   

H5Pdecode 

Additional New Functions:
 

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

 
    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.>/dd>

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 functions 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 compatiblity 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 compatiblity 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 compatiblity 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 API Compatibility Reports for 1.10 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.

--- Last Modified: September 27, 2023 | 12:13 AM