HDF5 version 1.8.19 released on 2017-06-15
================================================================================

INTRODUCTION
============

This document describes the differences between HDF5-1.8.18 and
HDF5-1.8.19, and contains information on the platforms tested and
known problems in HDF5-1.8.19.
For more details, see the files HISTORY-1_0-1_8_0_rc3.txt
and HISTORY-1_8.txt in the release_docs/ directory of the HDF5 source.

Links to the HDF5 1.8.19 source code, documentation, and additional materials
can be found on the HDF5 web page at:

     https://support.hdfgroup.org/HDF5/

The HDF5 1.8.19 release can be obtained from:

     https://support.hdfgroup.org/HDF5/release/obtain518.html

User documentation for 1.8.19 can be accessed directly at this location:

     https://support.hdfgroup.org/HDF5/doc1.8/

New features in the HDF5-1.8.x release series, including brief general
descriptions of some new and modified APIs, are described in the "What's New
in 1.8.0?" document:

     https://support.hdfgroup.org/HDF5/doc/ADGuide/WhatsNew180.html

All new and modified APIs are listed in detail in the "HDF5 Software Changes
from Release to Release" document, in the section "Release 1.8.19 (current
release) versus Release 1.8.18

     https://support.hdfgroup.org/HDF5/doc1.8/ADGuide/Changes.html

If you have any questions or comments, please send them to the HDF Help Desk:

     help@hdfgroup.org


CONTENTS
========

- New Features
- Support for New Platforms, Languages, and Compilers
- Bug Fixes since HDF5-1.8.19
- Supported Platforms
- Supported Configuration Features Summary
- More Tested Platforms
- Known Problems


New Features
============

    Configuration
    --------------
    - CMake in the Tools

      User-defined filters on Windows require that tools be built
      with shared libraries.

      CMake command code added to build tools with
      shared libraries as well as with static libraries.

      (ADB - 2017/02/07, HDFFV-10123)


    Library
    -------
    - H5PL package

      Users would like to be able to set the plugin path programmatically
      instead of through the environment variable.

      H5PL package obtained new APIs for manipulating the entries of
      the plugin path table. The new APIs are;
        H5PLappend  - Insert a plugin path at the end of the list.
        H5PLprepend - Insert a plugin path at the beginning of the list.
        H5PLreplace - Replace the path at the specified index.
        H5PLinsert  - Insert a plugin path at the specified index, moving
                      other paths after the index.
        H5PLremove  - Remove the plugin path at the specifed index and
                      compacting the list.
        H5PLget     - Query the plugin path at the specified index.
        H5PLsize    - Query the size of the current list of plugin paths.

      (ADB - 2017/04/04, HDFFV-10143)

    - H5Dget_chunk_storage_size

      The storage size of a chunk in the file is needed to determine the size
      of the buffer to be allocated for reading a chunk directly from a file.

      New API function gets the size in bytes currently allocated within a
      file for a raw data chunk in a dataset.  This function was added to get
      the chunk size in support of the implementation of H5DOread_chunks, but
      may also be useful for other purposes.

      (VC - 2017/05/02, HDFFV-9934)

    C++ API
    -------
    - The following C++ API wrappers have been added to the C++ Library:
        // Determines if a name exists.
        H5Location::nameExists() - C API H5Lexists()

        // Checks if an ID is valid.
        IdComponent::isValid() - C API H5Iis_valid()

        // Sets the number of soft or user-defined links that can be
        // traversed before a failure occurs.
        LinkAccPropList::setNumLinks() - C API H5Pset_nlinks()

        // Gets the number of soft or user-defined link traversals allowed
        LinkAccPropList::getNumLinks() - C API H5Pget_nlinks()

        // Returns a copy of the creation property list of a datatype.
        DataType::getCreatePlist() - C API H5Tget_create_plist()

        // Opens an object within a location, regarless its type.
        H5Location::openObjId() - C API H5Oopen()
        H5Location::openObjId() - C API H5Oopen()

        // Closes an object opened by openObjId().
        H5Location::closeObjId() - C API H5Oclose()

        // Gets general information about a file.
        H5File::getFileInfo() - C API H5Fget_info()

        // Returns the header version of an HDF5 object.
        H5Object::objVersion() - C API H5Oget_info()

      (BMR, 2017/05/13, HDFFV-10004, HDFFV-10156)

    - New class LinkAccPropList is added for link access proprety list

      (BMR, 2017/05/13, HDFFV-10156)


    High-Level APIs
    ---------------
    - H5DOread_chunk

      Users wanted to read compressed data directly from a file without any
      processing by the HDF5 data transfer pipeline, just as they were able
      to write it directly to a file with H5DOwrite_chunk.
    
      New API function, corresponding to existing function H5DOwrite_chunk.
      H5DOread_chunk reads a raw data chunk directly from a chunked dataset
      in the file into the application buffer, bypassing the library’s internal
      data transfer pipeline, including filters.

      (VC - 2017/05/02, HDFFV-9934)


Support for New Platforms, Languages, and Compilers
===================================================

    - Added OpenMPI 2.0.1 compiled with GCC 4.9.3


Bug Fixes since HDF5-1.8.18
===========================

    Configuration
    -------------
    - Support for Fortran shared libraries on OS X with autotools now
      works. Cmake builds still disables Fortran shared libraries on OS X.
      (MSB - 2017/04/30, HDFFV-2772)


    Library
    -------
    - bitfield datatypes

      bitfield datatypes did not fully support endianness of the data.

      Improved the endianness of bitfield datatypes by adding missing functional
      code. This code used integer types as a template.

      (ADB - 2017/05/12, HDFFV-10186)

    - Newly created datasets with H5D_COMPACT layout failed to open after 
      several H5Dopen/H5Dclose cycles.

      The layout "dirty" flag for a compact dataset is now properly reset 
      before flushing the message.

      (VC - 2017/05/11, HDFFV-10051)

    - Missing #ifdef __cplusplus macros were added to the generated H5Epubgen.h file.

      (DER - 2017/04/25, HDFFV-9638)


    Tools
    -----
    - h5repack

      h5repack did not maintain the creation order flag of the root
      group.

      Improved h5repack by reading the creation order and applying the
      flag to the new root group. Also added arguments to set the
      order and index direction, which applies to the traversing of the
      original file, on the command line.

      (ADB - 2017/05/26, HDFFV-8611)

    - h5diff

      h5diff failed to account for strpad type and null terminators
      of char strings. Also, h5diff failed to account for string length
      differences and would give a different result depending on file
      order in the command line.

      Improved h5diff compare of strings and arrays by adding a check for
      string lengths and if the strpad was null filled.

      (ADB - 2017/05/18, HDFFV-9055, HDFFV-10128)

    - h5diff

      h5diff help text about epsilon comparison was confusing.

      Changed h5diff help text to indicate that the 'a' refers to the
      datapoint in file1 and 'b' refers to the datapoint value in file2.

      (ADB - 2017/05/16, HDFFV-9995)

    - h5diff

      h5diff did not report user-defined filter data differences correctly.

      Improved h5diff compare of user-defined filter data by reporting an
      error if the user-defined filter plugin cannot be found.

      (ADB - 2017/01/18, HDFFV-9994)

    C++ API
    -------
    - The class hierarchy is revised to better reflect the HDF5 model.
      Class H5File is now derived from class Group instead of H5Location.
      Class Attribute is now derived from H5Location instead of IdComponent.
      Wrappers of H5A APIs in H5Location are now duplicated in H5Object,
      the original wrappers in H5Location will be deprecated in future
      releases.

      (BMR - 2017/05/15, HDFFV-10156)



Supported Platforms
===================
The following platforms are supported and have been tested for this release.
They are built with the configure process unless specified otherwise.

    Linux 2.6.32-573.22.1.el6     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (platypus/mayll)              Version 4.4.7 20120313
                                     Versions 4.9.3, 5.2.0, 6.2.0
                                  PGI C, Fortran, C++ for 64-bit target on
                                  x86-64;
                                      Version 16.10-0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.0.098 Build 20160721
                                  MPICH 3.1.4 compiled with GCC 4.9.3
                                  OpenMPI 2.0.1 compiled with GCC 4.9.3

    Linux 2.6.32-573.18.1.el6     gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16)
    #1 SMP ppc64 GNU/Linux        g++ (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16)
    (ostrich)                     GNU Fortran (GCC) 4.4.7 20120313 (Red Hat 4.4.7-16)
                                  IBM XL C/C++ V13.1
                                  IBM XL Fortran V15.1

    Linux 3.10.0-327.10.1.el7     GNU C (gcc), Fortran (gfortran), C++ (g++)
    #1 SMP x86_64 GNU/Linux       compilers:
    (kituo/moohan)                  Version 4.8.5 20150623 (Red Hat 4.8.5-4)
                                    Versions 4.9.3, 5.3.0, 6.2.0
                                  Intel(R) C (icc), C++ (icpc), Fortran (icc)
                                  compilers:
                                     Version 17.0.4.196 Build 20170411
                                  MPICH 3.1.4 compiled with GCC 4.9.3

    SunOS 5.11 32- and 64-bit     Sun C 5.12 SunOS_sparc
    (emu)                         Sun Fortran 95 8.6 SunOS_sparc
                                  Sun C++ 5.12 SunOS_sparc

    Windows 7                     Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Windows 7 x64                 Visual Studio 2012 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2013 w/ Intel Fortran 15 (cmake)
                                  Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Visual Studio 2015 w/ Intel C, Fortran 2017 (cmake)
                                  Visual Studio 2015 w/ MSMPI 8 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.8.0(0.309/5/3)
                                      gcc and gfortran compilers (GCC 5.4.0)
                                      (cmake and autotools)

    Windows 10                    Visual Studio 2015 w/ Intel Fortran 16 (cmake)
                                  Cygwin(CYGWIN_NT-6.1 2.8.0(0.309/5/3)
                                      gcc and gfortran compilers (GCC 5.4.0)
                                      (cmake and autotools)

    Windows 10 x64                Visual Studio 2015 w/ Intel Fortran 16 (cmake)

    Mac OS X Mt. Lion 10.8.5      Apple LLVM version 5.1 (clang-503.0.40)
    64-bit                        gfortran GNU Fortran (GCC) 4.8.2
    (swallow/kite)                Intel icc/icpc/ifort version 15.0.3

    Mac OS X Mavericks 10.9.5     Apple LLVM version 6.0 (clang-600.0.57)
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (wren/quail)                  Intel icc/icpc/ifort version 15.0.3

    Mac OS X Yosemite 10.10.5     Apple LLVM version 6.1 (clang-602.0.53)
    64-bit                        gfortran GNU Fortran (GCC) 4.9.2
    (osx1010dev/osx1010test)      Intel icc/icpc/ifort version 15.0.3

    Mac OS X El Capitan 10.11.4   Apple LLVM version 7.3.0 (clang-703.0.29)
    64-bit                        gfortran GNU Fortran (GCC) 5.2.0
    (VM osx1011dev/osx1011test)   Intel icc/icpc/ifort version 16.0.2


Tested Configuration Features Summary
=====================================

    In the tables below
          y   = tested
          n   = not tested in this release
          C   = Cluster
          W   = Workstation
          x   = not working in this release
          dna = does not apply
          ( ) = footnote appears below second table
          <blank> = testing incomplete on this feature or platform

Platform                              C         F90/   F90      C++  zlib  SZIP
                                      parallel  F2003  parallel
SunOS 5.11 32-bit                       n        y/y    n        y    y     y
SunOS 5.11 64-bit                       n        y/y    n        y    y     y
Windows 7                               y        y/y    n        y    y     y
Windows 7 x64                           y        y/y    n        y    y     y
Windows 7 Cygwin                        n        y/n    n        y    y     y
Windows 7 x64 Cygwin                    n        y/n    n        y    y     y
Windows 10                              y        y/y    n        y    y     y
Windows 10 x64                          y        y/y    n        y    y     y
Mac OS X Mountain Lion 10.8.5 64-bit    n        y/y    n        y    y     y
Mac OS X Mavericks 10.9.5 64-bit        n        y/y    n        y    y     y
Mac OS X Yosemite 10.10.5 64-bit        n        y/y    n        y    y     y
AIX 6.1 32- and 64-bit                  n        y/n    n        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 GNU      y        y/y    y        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 Intel    n        y/y    n        y    y     y
CentOS 6.7 Linux 2.6.32 x86_64 PGI      n        y/y    n        y    y     y
CentOS 7.1 Linux 3.10.0 x86_64 GNU      y        y/y    y        y    y     y
CentOS 7.1 Linux 3.10.0 x86_64 Intel    n        y/y    n        y    y     y
Linux 2.6.32-431.11.2.el6.ppc64         n        y/n    n        y    y     y

Platform                                 Shared  Shared    Shared    Thread-
                                         C libs  F90 libs  C++ libs  safe
SunOS 5.11 32-bit                          y       y         y         y
SunOS 5.11 64-bit                          y       y         y         y
Windows 7                                  y       y         y         y
Windows 7 x64                              y       y         y         y
Windows 7 Cygwin                           n       n         n         y
Windows 7 x64 Cygwin                       n       n         n         y
Windows 10                                 y       y         y         y
Windows 10 x64                             y       y         y         y
Mac OS X Mountain Lion 10.8.5 64-bit       y       n         y         y
Mac OS X Mavericks 10.9.5 64-bit           y       n         y         y
Mac OS X Yosemite 10.10.5 64-bit           y       n         y         y
AIX 6.1 32- and 64-bit                     y       n         n         y
CentOS 6.7 Linux 2.6.32 x86_64 GNU         y       y         y         y
CentOS 6.7 Linux 2.6.32 x86_64 Intel       y       y         y         y
CentOS 6.7 Linux 2.6.32 x86_64 PGI         y       y         y         y
CentOS 7.1 Linux 3.10.0 x86_64 GNU         y       y         y         y
CentOS 7.1 Linux 3.10.0 x86_64 Intel       y       y         y         y
Linux 2.6.32-431.11.2.el6.ppc64            y       y         y         y

Compiler versions for each platform are listed in the preceding
"Supported Platforms" table.


More Tested Platforms
=====================
The following platforms are not supported but have been tested for this release.

    Linux 2.6.32-573.22.1.el6     g95 (GCC 4.0.3 (g95 0.94!)
    #1 SMP x86_64 GNU/Linux
    (mayll)

    Debian8.4.0 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1 x86_64 GNU/Linux
                                  gcc (Debian 4.9.2-10) 4.9.2
                                  GNU Fortran (Debian 4.9.2-10) 4.9.2
                                  (cmake and autotools)

    Fedora24 4.7.2-201.fc24.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc (GCC) 6.1.1 20160621 (Red Hat 6.1.1-3)
                                  GNU Fortran (GCC) 6.1.1 20160621 (Red Hat 6.1.1-3)
                                  (cmake and autotools)

    CentOS 7.2 3.10.0-327.28.2.el7.x86_64 #1 SMP x86_64 x86_64 x86_64 GNU/Linux
                                  gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4)
                                  GNU Fortran (GCC) 4.8.5 20150623 (Red Hat 4.8.5-4)
                                  (cmake and autotools)

    Ubuntu 16.04 4.4.0-38-generic #62-Ubuntu SMP x86_64 GNU/Linux
                                  gcc (Ubuntu 5.4.0-6ubuntu1~16.04.2) 5.4.0
                                  GNU Fortran (Ubuntu 5.4.0-6ubuntu1~16.04.2) 5.4.0
                                  (cmake and autotools)


Known Problems
==============

    The dynamically loaded plugin test libraries require undefined references 
    to HDF5 functions to be resolved at runtime in order to function properly.
    With autotools on CYGWIN this results in build errors, and we have not 
    found a solution that satisfies both.  Therefore the dynamically loaded 
    plugin tests have been disabled on CYGWIN.

    Known problems in previous releases can be found in the HISTORY*.txt files
    in the HDF5 source. Please report any new problems found to
    help@hdfgroup.org.
