path: root/release_docs/HISTORY.txt

HDF5 HISTORY
============

CONTENTS
I.   Release Information for hdf5-1.4.1
II.   Release Information for hdf5-1.4.0
III.  Release Information for hdf5-1.2.2
IV. Release Information for hdf5-1.2.1
V.  Release Information for hdf5-1.2.0
     A. Platforms Supported
     B. Known Problems
     C. Changes Since Version 1.0.1  
        1. Documentation
        2. Configuration
        3. Debugging
        4. Datatypes
        5. Dataspaces
        6. Persistent Pointers
        7. Parallel Support
        8. New API Functions
           a. Property List Interface
           b. Dataset Interface
           c. Dataspace Interface
           d. Datatype Interface
           e. Identifier Interface
           f. Reference Interface
           g. Ragged Arrays
        9. Tools

VI.    Changes from Release 1.0.0 to Release 1.0.1
VII.   Changes from the Beta 1.0.0 Release to Release 1.0.0
VIII.  Changes from the Second Alpha 1.0.0 Release to the Beta 1.0.0 Release
IX. Changes from the First Alpha 1.0.0 Release to the 
         Second Alpha 1.0.0 Release

[Search on the string '%%%%' for per-release section breaks.]

-----------------------------------------------------------------------


%%%%1.4.1%%%%   Release Information for hdf5-1.4.1 (April/01)



 
                       HDF5 Release 1.4.1


INTRODUCTION

This document describes the differences between HDF5-1.4.0 and
HDF5-1.4.1, and contains information on the platforms tested and
known problems in HDF5-1.4.1. For more details check the HISTORY.txt
file in the HDF5 source.

The HDF5 documentation can be found on the NCSA ftp server
(ftp.ncsa.uiuc.edu) in the directory:

     /HDF/HDF5/docs/

For more information look at the HDF5 home page at:
   
    http://hdf.ncsa.uiuc.edu/HDF5/

If you have any questions or comments, please send them to:

    hdfhelp@ncsa.uiuc.edu


CONTENTS

- New Features
- Bug Fixes since HDF5-1.4.0
- Documentation
- Platforms Tested
- Supported Configuration Features
- Known Problems


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

   * XML output option for h5dump utility.
  
     A new option --xml to output data in XML format has been added. The
     XML output contains a complete description of the file, marked up in
     XML. 

     The XML conforms to the HDF5 Document Type Definition (DTD), which
     is available at:

       http://hdf.ncsa.uiuc.edu/DTDs/HDF5-File.dtd

     The XML output is suitable for use with other tools, including the
     Java Tools:

       http://hdf.ncsa.uiuc.edu/java-hdf5-html


Bug Fixes since HDF5-1.4.0 Release
==================================

   * h4toh5 utility: conversion of images is fixed

     Earlier releases of the h4toh5 utility produced images that did not
     correctly conform to the HDF5 Image and Palette Specification.

       http://hdf.ncsa.uiuc.edu/HDF5/doc/ImageSpec.html

     Several required HDF5 attributes are omitted, and the dataspace
     is reversed (i.e., the ht. and width of the image dataset is
     incorrectly described.)  For more information, please see:

       http://hdf.ncsa.uiuc.edu/HDF5/H5Image/ImageDetails.htm

   * Fixed bug with contiguous hyperslabs not being detected, causing
     slower I/O than necessary.
   * Fixed bug where non-aligned hyperslab I/O on chunked datasets was
     causing errors during I/O
   * The RCSID string in H5public.h was causing the C++ compiling problem
     because when it was included multiple times, C++ did not like
     multiple definitions of the same static variable. All occurance of
     RCSID definition are removed since we have not used it consistently
     before.


Documentation
=============

    PDF and Postscript versions of the following documents are available 
    for this release:
        Document                                 Filename
        --------                                 --------
        Introduction to HDF5                     H5-R141-Introduction.pdf
        HDF5 Reference Manual                    H5-R141-RefManual.pdf 
        C++ APIs to HDF5 documents               H5-R141-Cplusplus.pdf
        Fortran90 APIs to HDF5 documents         H5-R141-Fortran90.pdf

        PDF and Postscript files containing      H5-R141-DocSet.pdf
            all of the above                     H5-R141-DocSet.ps

    These files are not included in this distribution, but are available 
    via the Web or FTP at the following locations:
        http://hdf.ncsa.uiuc.edu/HDF5/doc/PSandPDF/
        ftp://ftp.ncsa.uiuc.edu/HDF/HDF5/docs/

    While these documents are labeled Release 1.4.1, they describe 
    Release 1.4.0 as well.  


Platforms Tested
================

Due to the nature of this release only C, C++ libraries and tools were tested.

    AIX 4.3.3.0 (IBM SP powerpc)  xlc 3.6.6
                                  mpcc_r 3.6.6
    Cray T3E sn6711 2.0.5.47      Cray Standard C Version 6.5.0.0
    Cray SV1 10.0.0.8             Cray Standard C Version 6.5.0.0
    FreeBSD 4.3                   gcc 2.95.2
    HP-UX B.10.20                 HP C  HP92453-01 A.10.32.30
    HP-UX B.11.00                 HP C  HP92453-01 A.11.01.20
    IRIX 6.5                      MIPSpro cc 7.30
    IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
    Linux 2.2.18smp               gcc-2.95.2
                                  g++ 2.95.2
    OSF1 V4.0                     DEC-V5.2-040
                                  Digital Fortran 90 V4.1-270
    SunOS 5.6                     WorkShop Compilers 5.0 98/12/15 C 5.0 
     (Solaris 2.6)                

    SunOS 5.7                     WorkShop Compilers 5.0 98/12/15 C 5.0
     (Solaris 2.7)                Workshop Compilers 5.0 98/12/15 C++ 5.0
    TFLOPS r1.0.4 v4.0            mpich-1.2.1 with local changes
    Windows NT4.0, 2000 (NT5.0)   MSVC++ 6.0
    Windows 98                    MSVC++ 6.0


Supported Configuration Features Summary
========================================

    * See "Supported Configuration Features Summary" section for the HDF5
      1.4.0 release in the HISTORY.txt file.

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

    * The h5dump tests may fail to match the expected output in some
      platforms (e.g. SP2 parallel, Windows) where the error messages
      directed to "stderr" do not appear in the "right order" with output
      from stdout.  This is not an error.

    * The --enable-static-exec configure flag fails to compile for HP-UX
      11.00 platforms.

    * The executable are always dynamic on IRIX64 6.5(64 and n32) and 
      IRIX 6.5 even if they are configured with --enable-static-exec.

    * The shared library failed compilation on IRIX 6.5.
    
    * After "make install" or "make install-doc" one may need to reload the source
      from the tar file before doing another build.

    * See "Known problems" section for the HDF5 1.4.0 release in the
      HISTORY.txt file.

%%%%1.4.0%%%%   Release Information for hdf5-1.4.0 (2/22/01)

I. Release Information for hdf5-1.4.0
 
                       HDF5 Release 1.4.0


INTRODUCTION

This document describes the differences between HDF5-1.2.0 and
HDF5-1.4.0, and contains information on the platforms tested and
known problems in HDF5-1.4.0. For more details check the HISTORY.txt
file in the HDF5 source.

The HDF5 documentation can be found on the NCSA ftp server
(ftp.ncsa.uiuc.edu) in the directory:

     /HDF/HDF5/docs/

For more information look at the HDF5 home page at:
   
    http://hdf.ncsa.uiuc.edu/HDF5/

If you have any questions or comments, please send them to:

    hdfhelp@ncsa.uiuc.edu


CONTENTS

- New Features
- h4toh5 Utility 
- F90 Support
- C++ Support
- Pablo Support 
- Bug Fixes since HDF5-1.2.0 
- Bug Fixes since HDF5-1.4.0-beta2
- Bug Fixes since HDF5-1.4.0
- Documentation
- Platforms Tested
- Supported Configuration Features
- Known Problems


New Features
============
   * The Virtual File Layer, VFL, was added to replace the old file
     drivers. It also provides an API for user defined file drivers.
   * New features added to snapshots. Use 'snapshot help' to see a
     complete list of features.
   * Improved configure to detect if MPIO routines are available when
     parallel mode is requested.
   * Added Thread-Safe support. Phase I implemented. See:

        http://hdf.ncsa.uiuc.edu/HDF5/papers/mthdf/MTHDFpaper.htm

     for more details.
   * Added data sieve buffering to raw data I/O path. This is enabled
     for all VFL drivers except the mpio & core drivers. Setting the
     sieve buffer size is controlled with the new API function,
     H5Pset_sieve_buf_size(), and retrieved with H5Pget_sieve_buf_size().
   * Added new Virtual File Driver, Stream VFD, to send/receive entire
     HDF5 files via socket connections.
   * As parts of VFL, HDF-GASS and HDF-SRB are also added to this
     release. To find out details, please read INSTALL_VFL file. 
   * Increased maximum number of dimensions for a dataset (H5S_MAX_RANK)
     from 31 to 32 to align with HDF4 & netCDF.
   * Added 'query' function to VFL drivers.  Also added 'type' parameter to
     VFL 'read' & 'write' calls, so they are aware of the type of data
     being accessed in the file.  Updated the VFL document also.
   * A new h4toh5 utility, to convert HDF4 files to analogous HDF5 files.
   * Added a new array datatype to the datatypes which can be created.  
     Removed "array fields" from compound datatypes (use an array datatype 
     instead).
   * Parallel HDF5 works correctly with mpich-1.2.1 on Solaris, SGI, Linux.
   * You can now install the HDF5 documentation using the
     ``make install-doc'' command. The documentation is installed in the
     $(prefix)/doc directory where $(prefix) is the prefix specified by
     the (optional) ``--prefix'' flag during configuration.
   * HDF5 can operate correctly in the OpenMP environment in a limited way.
     Check doc/html/TechNotes/openmp-hdf5.html for details.


h4toh5 Utility 
==============
    The h4toh5 utility is a new utility that converts an HDF4 file to an 
    HDF5 file.  For details, see the document, "Mapping HDF4 Objects to 
    HDF5 Objects":
       http://hdf.ncsa.uiuc.edu/HDF5/papers/H4-H5MappingGuidelines.pdf

    Known Bugs:

      The h4toh5 utility produces images that do not correctly conform
      to the HDF5 Image and Palette Specification. 

        http://hdf.ncsa.uiuc.edu/HDF5/doc/ImageSpec.html

      Several required HDF5 attributes are omitted, and the dataspace 
      is reversed (i.e., the ht. and width of the image dataset is 
      incorrectly described.)  For more information, please see:

        http://hdf.ncsa.uiuc.edu/HDF5/H5Image/ImageDetails.html
 
      This bug has been fixed for the snapshot of hdf5 1.4 release. March 12th,2001

    Known Limitations of the h4toh5 release
    ---------------------------------------------

    1. Error handlings

       h4toh5 utility will print out an error message when an error occurs.

    2. String Datatype

    HDF4 has no 'string' type. String valued data are usually defined as
    an array of 'char' in HDF4. The h4toh5 utility will generally map
    these to HDF5 'String' types rather than array of char, with the
    following additional rules:

       * For the data of an HDF4 SDS, image, and palette, if the data is
         declared 'DFNT_CHAR8' it will be assumed to be integer and will
         be an H5T_INTEGER type.
       * For attributes of any HDF4 object, data of type 'DFNT_CHAR8'
         will be converted to an HDF5 'H5T_STRING' type.
       * For an HDF4 Vdata, it is difficult to determine whether data 
         of type 'DFNT_CHAR8' is intended to be bytes or characters. The
         h4toh5 utility will consider them to be C characters, and will
         convert them to an HDF5 'H5T_STRING' type.


    3. Compression, Chunking and External Storage

    Chunking is supported, but compression and external storage is not.

    An HDF4 object that uses chunking will be converted to an HDF5 file
    with analogous chunked storage.

    An HDF4 object that uses compression will be converted to an
    uncompressed HDF5 object.  

    An HDF4 object that uses external storage will be converted to an
    HDF5 object without external storage.  

    4. Memory Use

    This version of the h4toh5 utility copies data from HDF4 objects
    in a single read followed by a single write to the HDF5 object. For
    large objects, this requires a very large amount of memory, which may
    be extremely slow or fail on some platforms.

    Note that a dataset that has only been partly written will
    be read completely, including uninitialized data, and all the
    data will be written to the HDF5 object.

    5. Platforms

    The h4toh5 utility requires HDF5-1.4.0 and HDF4r1.4

    h4toh5 utility has been tested on all platforms listed below (see 
    section "Platforms Tested") except TFLOPS.

 
F90 Support
===========
    This is the first release of the HDF5 Library with fully integrated 
    F90 API support.  The Fortran Library is created when the 
    --enable-fortran flag is specified during configuration.

    Not all F90 subroutines are implemented. Please refer to the HDF5 
    Reference Manual for more details.
   
    F90 APIs are available for the Solaris 2.6 and 2.7, Linux, DEC UNIX, 
    T3E, SV1 and O2K (64 bit option only) platforms. The Parallel version of 
    the HDF5 F90 Library is supported on the O2K and T3E platforms.

    Changes since the last prototype release (July 2000)
    ----------------------------------------------------
       * h5open_f and h5close_f must be called instead of h5init_types and 
         h5close_types.

       * The following subroutines are no longer available: 

             h5pset_xfer_f
             h5pget_xfer_f
             h5pset_mpi_f
             h5pget_mpi_f
             h5pset_stdio_f
             h5pget_stdio_f
             h5pset_sec2_f
             h5pget_sec2_f
             h5pset_core_f
             h5pget_core_f
             h5pset_family_f
             h5pget_family_f
             
       * The following functions have been added:

             h5pset_fapl_mpio_f
             h5pget_fapl_mpio_f
             h5pset_dxpl_mpio_f
             h5pget_dxpl_mpio_f
        
       * In the previous HDF5 F90 releases, the implementation of object 
         references and dataset region references was not portable. This 
         release introduces a portable implementation, but it also introduces 
         changes to the read/write APIs that handle references.  If object or 
         dataset region references are written or read to/from an HDF5 file, 
         h5dwrite_f and h5dread_f must use the extra parameter, n, for the 
         buffer size:

            h5dwrite(read)_f(dset_id, mem_type_id, buf, n, hdferr, &
                                                       ^^^ 
                             mem_space_id, file_space_id, xfer_prp)

         For other datatypes the APIs were not changed. 
              
             
C++ Support
===========
    This is the first release of the HDF5 Library with fully integrated 
    C++ API support. The HDF5 C++ library is built when the --enable-cxx
    flag is specified during configuration.

    Check the HDF5 Reference Manual for available C++ documentation.

    C++ APIs are available for Solaris 2.6 and 2.7, Linux, and FreeBSD. 


Pablo Support
=============
    This version does not allow proper building of the Pablo-instrumented
    version of the library.  A version supporting the pablo build is
    available on the Pablo Website at 
    www-pablo.cs.uiuc.edu/pub/Pablo.Release.5/HDFLibrary/hdf5_v1.4.tar.gz


Bug Fixes since HDF5-1.2.0
==========================

Library
-------
   * The function H5Pset_mpi is renamed as H5Pset_fapl_mpio.
   * Corrected a floating point number conversion error for the Cray J90
     platform. The error did not convert the value 0.0 correctly.
   * Error was fixed which was not allowing dataset region references to
     have their regions retrieved correctly.
   * Corrected a bug that caused non-parallel file drivers to fail in
     the parallel version.
   * Added internal free-lists to reduce memory required by the library
     and H5garbage_collect API function
   * Fixed error in H5Giterate which was not updating the "index"
     parameter correctly.
   * Fixed error in hyperslab iteration which was not walking through the
     correct sequence of array elements if hyperslabs were staggered in a
     certain pattern
   * Fixed several other problems in hyperslab iteration code.
   * Fixed another H5Giterate bug which was causes groups with large
     numbers of objects in them to misbehave when the callback function
     returned non-zero values.
   * Changed return type of H5Aiterate and H5A_operator_t typedef to be
     herr_t, to align them with the dataset and group iterator functions.
   * Changed H5Screate_simple and H5Sset_extent_simple to not allow
     dimensions of size 0 with out the same dimension being unlimited.
   * QAK - 4/19/00 - Improved metadata hashing & caching algorithms to
     avoid many hash flushes and also remove some redundant I/O when
     moving metadata blocks in the file.
   * The "struct(opt)" type conversion function which gets invoked for
     certain compound datatype conversions was fixed for nested compound
     types. This required a small change in the datatype conversion
     function API.
   * Re-wrote lots of the hyperslab code to speed it up quite a bit.
   * Added bounded garbage collection for the free lists when they run
     out of memory and also added H5set_free_list_limits API call to
     allow users to put an upper limit on the amount of memory used for
     free lists.
   * Checked for non-existent or deleted objects when dereferencing one
     with object or region references and disallow dereference.
   * "Time" datatypes (H5T_UNIX_D*) were not being stored and retrieved
     from object headers correctly, fixed now.
   * Fixed H5Dread or H5Dwrite calls with H5FD_MPIO_COLLECTIVE requests
     that may hang because not all processes are transfer the same amount
     of data. (A.K.A. prematured collective return when zero amount data
     requested.) Collective calls that may cause hanging is done via the
     corresponding MPI-IO independent calls.
   * If configure with --enable-debug=all, couple functions would issue
     warning messages to "stderr" that the operation is expensive time-wise.
     This messed up applications (like testings) that did not expect the
     extra output. It is changed so that the warning will be printed only
     if the corresponding Debug key is set.

Configuration
-------------
   * The hdf5.h include file was fixed to allow the HDF5 Library to be
     compiled with other libraries/applications that use GNU autoconf. 
   * Configuration for parallel HDF5 was improved. Configure now attempts
     to link with libmpi.a and/or libmpio.a as the MPI libraries by
     default. It also uses "mpirun" to launch MPI tests by default. It
     tests to link MPIO routines during the configuration stage, rather
     than failing later as before. One can just do "./configure
     --enable-parallel" if the MPI library is in the system library.
   * Added support for pthread library and thread-safe option.
   * The libhdf5.settings file shows the correct machine byte-sex.
   * Added option "--enable-stream-vfd" to configure w/o the Stream VFD.
     For Solaris, added -lsocket to the LIBS list of libraries.

Tools
-----
   * h5dump now accepts both short and long command-line parameters:
         -h, --help          Print a usage message and exit
         -B, --bootblock     Print the content of the boot block
         -H, --header        Print the header only; no data is displayed
         -i, --object-ids    Print the object ids
         -V, --version       Print version number and exit
         -a P, --attribute=P Print the specified attribute
         -d P, --dataset=P   Print the specified dataset
         -g P, --group=P     Print the specified group and all members
         -l P, --soft-link=P Print the value(s) of the specified soft link
         -o F, --output=F    Output raw data into file F
         -t T, --datatype=T  Print the specified named data type
         -w #, --width=#     Set the number of columns

     P - is the full path from the root group to the object.
     T - is the name of the data type.
     F - is a filename.
     # - is an integer greater than 1.
   * A change from the old way command line parameters were interpreted
     is that multiple attributes, datasets, groups, soft-links, and
     object-ids cannot be specified with just one flag but you have to
     use a flag with each object. I.e., instead of doing this:

       h5dump -a /attr1 /attr2 foo.h5

     do this:

       h5dump -a /attr1 -a /attr2 foo.h5

     The cases are similar for the other object types.
   * h5dump correctly displays compound datatypes.
   * Corrected an error in h5toh4 which did not convert the 32bits
     int from HDF5 to HDF4 correctly for the T3E platform.
   * h5dump correctly displays the committed copy of predefined types
     correctly.
   * Added an option, -V, to show the version information of h5dump.
   * Fixed a core dumping bug of h5toh4 when executed on platforms like 
     TFLOPS.
   * The test script for h5toh4 used to not able to detect the hdp
     dumper command was not valid.  It now detects and reports the
     failure of hdp execution.
   * Merged the tools with the 1.2.2 branch. Required adding new
     macros, VERSION12 and VERSION13, used in conditional compilation.
     Updated the Windows project files for the tools.            
   * h5dump displays opaque and bitfield data correctly.
   * h5dump and h5ls can browse files created with the Stream VFD
     (eg. "h5ls <hostname>:<port>").
   * h5dump has a new feature "-o <filename>" which outputs the raw data
     of the dataset into ascii text file <filename>.
   * h5toh4 used to converts hdf5 strings type to hdf4 DFNT_INT8 type.
     Corrected to produce hdf4 DFNT_CHAR type instead.
   * h5dump and h5ls displays array data correctly.


Bug Fixes since HDF5-1.4.0-beta2
================================
   * Fixed a bug in the conversion from a little endian double to a big 
     endian float in some special cases.
   * Corrected configuration error which was not including compression 
     support correctly. 
   * Cleaned up lots of warnings.
   * Changed a few h5dump command line switches and added long versions of
     the switches.
   * Changed parameters for H5Tconvert, H5Pset_bufer and H5Pget_buffer from
     size_t to hsize_t
   * Fixed fairly obscure bug in hyperslab I/O which could (in rare cases)
     not copy all the data during a transfer.
   * Removed ragged array code from library.
   * F90 library and module files are installed properly now on all supported 
     platforms.


Bug Fixes since HDF5-1.4.0 Release
==================================

   * Fixed bug with contiguous hyperslabs not being detected, causing
     slower I/O than necessary.
   * Fixed bug where non-aligned hyperslab I/O on chunked datasets was
     causing errors during I/O
   * Implemented XML support in h5dump.


Documentation
=============
   * A new document summarizing the changes in the library leading up to 
     the current release has been added: 
           HDF5 Software Changes from Release to Release
     This document is in the Application Developer's Guide and is of 
     particular interest to developers who must keep an application 
     synchronized with the library.
   * The documentation for the Fortran90 and C++ APIs is linked to the
     opening page of the Reference Manual.  Fortran90 functions are 
     individually referenced from the corresponding C functions through-
     out the Reference Manual.
   * User's Guide and Reference Manual were updated to reflect changed 
     function syntax and to fix reported bugs. 
   * Functions that are new at this release were added to the Reference 
     Manual.  
   * Functions that have been removed from the library were removed from 
     the User's Guide and the Reference Manual.
   * PostScript and PDF versions of the Release 1.4 document set are 
     not available at the time of Release 1.4.0.

   
Platforms Tested
================
    AIX 4.3.3.0 (IBM SP powerpc)  xlc 3.6.6
                                  mpcc_r 3.6.6
    Cray T3E sn6711 2.0.5.45      Cray Standard C Version 6.4.0.0
                                  Cray Fortran Version 3.4.0.2
    Cray SV1 sn9605 10.0.0.7      Cray Standard C Version 6.4.0.0
                                  Cray Fortran Version 3.4.0.2
    FreeBSD 4.2                   gcc 2.95.2
                                  g++ 2.95.2
    HP-UX B.10.20                 HP C  HP92453-01 A.10.32.30
    HP-UX B.11.00                 HP C  HP92453-01 A.11.00.13
    IRIX 6.5                      MIPSpro cc 7.30
                                  mpich-1.2.1
    IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
                                  mpt.1.4.0.2
                                  mpich-1.2.1
    Linux 2.2.16-3smp             gcc-2.95.2
                                  g++ 2.95.2
                                  pgf90 3.1-3
                                  mpich-1.2.1
    OSF1 V4.0                     DEC-V5.2-040
                                  Digital Fortran 90 V4.1-270
    SunOS 5.6                     WorkShop Compilers 5.0 98/12/15 C 5.0 
    (Solaris 2.6)                 WorkShop Compilers 5.0 99/10/25 Fortran 90
                                         2.0 Patch 107356-04
                                  Workshop Compilers 5.0 98/12/15 C++ 5.0
    SunOS 5.7                     WorkShop Compilers 5.0 98/12/15 C 5.0
     (Solaris 2.7)                WorkShop Compilers 5.0 99/10/25 Fortran 90
                                         2.0 Patch 107356-04
                                  Workshop Compilers 5.0 98/12/15 C++ 5.0
                                  mpich-1.2.1
    SunOS 5.5.1                   gcc-2.7.2 
     (Solaris 2.5.1 (x86))
    TFLOPS r1.0.4 v4.0            mpich-1.2.1 with local changes
    Windows NT4.0, 2000 (NT5.0)   MSVC++ 6.0
    Windows 98                    MSVC++ 6.0


Supported Configuration Features Summary
========================================
    In the tables below
          y  = tested and supported
          n  = not supported or not working in this release
         ( ) = footnote appears below table

    Platform       C   C         F90  F90       C++  Shared     zlib   Tools
                       parallel       parallel       libraries
    Solaris2.6     y   n         y    n         y    y          y      y
    Solaris2.7     y   y (1)     y    n         y    y          y      y
    Solarisx86     y   n         n    n         n    y          y      y
    IRIX6.5        y   y (1)     n    n         n    n          y      y
    IRIX64_6.5 64  y   y (2)     y    y         n    y          y      y
    IRIX64_6.5 32  y   y (2)     n    n         n    y          y      y
    HPUX10.20      y   n         n    n         n    y          y      y
    DECOSF         y   n         y    n         n    y          y      y
    T3E            y   y         y    y         n    n          y      y
    SV1            y   n         y    n         n    n          y      y
    TFLOPS         y   y (1)     n    n         n    n          y      y (4)
    AIX-4.3        y   y         n    n         n    n          y      n
    Win2000        y   n         n    n         n    y          y      y
    Win98          y   n         n    n         n    y          y      y
    WinNT          y   n         n    n         n    y          y      y
    FreeBSD        y   n         n    n         y    y          y      y
    Linux          y   y (1)     y    n         y    y          y      y


    Platform       1.2            static-   Thread-  SRB  GASS  STREAM-
                   compatibility  exec      safe                VFD
    Solaris2.6     y              n         n        n    n     y
    Solaris2.7     y              n         y        n    n     y
    Solarisx86     y              n         n        n    n     y
    IRIX6.5        y              n         y        n    n     y
    IRIX64_6.5 64  y              n         n        n    n     y
    IRIX64_6.5 32  y              n         n        n    n     y
    HPUX10.20      y              y         n        n    n     y
    DECOSF         y              y         n        n    n     y
    T3E            y              y         n        n    n     y
    SV1            y              y         n        n    n     y
    TFLOPS         y              y         n        n    n     n
    AIX-4.3        y              y (3)     n        n    n     y
    Win2000        y              y         n        n    n     n
    Win98          y              y         n        n    n     n
    WinNT          y              y         n        n    n     n
    FreeBSD        y              y         n        n    n     y
    Linux          y              n         y        n    n     y

    Footnotes:  (1) Using mpich.
                (2) Using mpt and mpich.
                (3) When configured with static-exec enabled, tests fail 
                    in serial mode.
                (4) No HDF4-related tools.


Known Problems
==============
   * The stream-vfd test uses ip port 10007 for testing.  If another 
     application is already using that port address, the test will hang 
     indefinitely and has to be terminated by the kill command.  To try the 
     test again, change the port address in test/stream_test.c to one not 
     being used in the host.

   * The --enable-static-exec configure flag fails to compile for Solaris
     platforms. This is due to the fact that not all of the system
     libraries on Solaris are available in a static format.

     The --enable-static-exec configure flag also fails to correctly compile
     on Linux platforms using the gcc-2.95.2 compiler.
   
     The --enable-static-exec configure flag also fails to correctly compile
     on IBM SP2 platform for the serial mode.  The parallel mode works fine
     with this option.

     The compilation fails if configured with --enable-static-exec on IRIX 6.5.

     The executable files in hdf5/bin are dynamic-linked for IRIX64 6.5(64 and
     n32 modes) and IRIX 6.5, even though they are compiled with static library.
  
     It is suggested that you don't use this option on these platforms
     during configuration.

   * testhdf5 got bus error with configuration options --prefix and --with-hdf4
     on IRIX 6.5.

   * With the gcc 2.95.2 compiler, HDF 5 uses the `-ansi' flag during
     compilation. The ANSI version of the compiler complains about not being
     able to handle the `long long' datatype with the warning:

           warning: ANSI C does not support `long long'
  
     This warning is innocuous and can be safely ignored.

   * SunOS 5.6 with C WorkShop Compilers 4.2:  Hyperslab selections will 
     fail if library is compiled using optimization of any level.

   * When building hdf5 tools and applications on windows platform, a linking
     warning: defaultlib "LIBC" conflicts with use of other libs will appear
     on debug version when running VC++6.0. This warning doesn't affect building
     and testing hdf5 applications. We will continue investigating this.

   * h5toh4 converter fails two cases(tstr.h5 and tmany.h5) for release dll 
     version on windows 2000 and NT.  The reason is possibly due to Windows NT 
     DLL convention on freeing memory. It seems that memory cannot be freed
     across library or DLL. It is still under investigation.

   * HDF-GASS testings and testhdf5 in the test directory will get bus error if
     the configured with --with-gass.

   * HDF-SRB testing got segmentation error on Solaris 2.7.
    
   * The Stream VFD was not tested yet under Windows.
     It is not supported in the TFLOPS machine.

   * Shared library option is broken for IBM SP and some Origin 2000 platforms.
     One needs to run ./configure with '--disable-shared --enable-static'.

   * The ./dsets tests failed in the TFLOPS machine if the test program,
     dsets.c, is compiled with the -O option.  The hdf5 library still works
     correctly with the -O option.  The test program works fine if it is
     compiled with -O1 or -O0.  Only -O (same as -O2) causes the test
     program to fail.

   * Certain platforms give false negatives when testing h5ls:
       - Solaris x86 2.5.1, Cray T3E and Cray J90 give errors during testing
         when displaying object references in certain files.  These are benign 
         differences due to the difference in sizes of the objects created on
         those platforms.  h5ls appears to be dumping object references
         correctly.
       - Cray J90 give errors during testing when displaying
         some floating-point values.  These are benign differences due to the
         different precision in the values displayed and h5ls appears to be
         dumping floating-point numbers correctly.

   * Before building HDF5 F90 Library from source on Crays (T3E and SV1) 
     replace H5Aff.f90, H5Dff.f90 and H5Pff.f90 files in the fortran/src 
     subdirectory in the top level directory with the Cray-specific files from 
     the ftp://ftp.ncsa.uiuc.edu/HDF/HDF5/hdf5-1.4.0/src/crayf90/  directory.

   * The h4toh5 utility produces images that do not correctly conform
     to the HDF5 Image and Palette Specification. 

         http://hdf.ncsa.uiuc.edu/HDF5/doc/ImageSpec.html

     Several required HDF5 attributes are omitted, and the dataspace 
     is reversed (i.e., the ht. and width of the image dataset is 
     incorrectly described.)  For more information, please see:

         http://hdf.ncsa.uiuc.edu/HDF5/H5Image/ImageDetails.htm

%%%%1.2.2%%%%   Release Information for hdf5-1.2.2 (6/23/00)

II. Release Information for hdf5-1.2.2

INTRODUCTION

This document describes the differences between HDF5-1.2.1 and 
HDF5-1.2.2, and contains information on the platforms where HDF5-1.2.2
was tested and known problems in HDF5-1.2.2. 

The HDF5 documentation can be found on the NCSA ftp server 
(ftp.ncsa.uiuc.edu) in the directory:

     /HDF/HDF5/docs/

For more information look at the HDF5 home page at:
   
    http://hdf.ncsa.uiuc.edu/HDF5/

If you have any questions or comments, please send them to:

    hdfhelp@ncsa.uiuc.edu


CONTENTS

- Features Added since HDF5-1.2.1 
- Bug Fixes since HDF5-1.2.1
- Known Problems
- Platforms Tested


Features Added since HDF5-1.2.1
===============================
   * Added internal free-lists to reduce memory required by the library and
     H5garbage_collect API function.
   * h5dump displays opaque and bitfield types.
   * New features added to snapshots.  Use 'snapshot help' to see a
     complete list of features.
   * Improved configure to detect if MPIO routines are available when
     parallel mode is requested.

Bug Fixes since HDF5-1.2.1
==========================
   * h5dump correctly displays compound datatypes, including simple and
     nested compound types.
   * h5dump correctly displays the committed copy of predefined types.
   * Corrected an error in h5toh4 which did not convert the 32-bit
     int from HDF5 to HDF4 correctly for the T3E platform.
   * Corrected a floating point number conversion error for the
     Cray J90 platform.  The error did not convert the value 0.0
     correctly.
   * Fixed error in H5Giterate which was not updating the "index" parameter
     correctly.
   * Fixed error in hyperslab iteration which was not walking through the
     correct sequence of array elements if hyperslabs were staggered in a
     certain pattern.
   * Fixed several other problems in hyperslab iteration code.
   * Fixed another H5Giterate bug which caused groups with large numbers
     of objects in them to misbehave when the callback function returned
     non-zero values.
   * Changed return type of H5Aiterate and H5A_operator_t typedef to be
     herr_t, to align them with the dataset and group iterator functions.
   * Changed H5Screate_simple and H5Sset_extent_simple to not allow dimensions
     of size 0 without the same dimension being unlimited.
   * Improved metadata hashing & caching algorithms to avoid
     many hash flushes and also removed some redundant I/O when moving metadata
     blocks in the file.
   * The libhdf5.settings file shows the correct machine byte-sex.
   * The "struct(opt)" type conversion function which gets invoked for
     certain compound datatype conversions was fixed for nested compound
     types. This required a small change in the datatype conversion
     function API.

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

o SunOS 5.6 with C WorkShop Compilers 4.2:  hyperslab selections will 
  fail if library is compiled using optimization of any level.
o TFLOPS: dsets test fails if compiled with optimization turned on.
o J90: tools fail to dispay data for the datasets with a compound datatype. 

Platforms Tested
================

  AIX 4.3.3 (IBM SP)            3.6.6                               | binaries
                                mpicc using mpich 1.1.2             | are not
                                mpicc_r using IBM MPI-IO prototype  | available
  AIX 4.3.2.0 (IBM SP)          xlc 5.0.1.0
  Cray J90 10.0.0.7             cc 6.3.0.2
  Cray T3E 2.0.5.29             cc 6.3.0.2
                                mpt.1.3
  FreeBSD 4.0                   gcc 2.95.2
  HP-UX B.10.20                 HP C  HP92453-01 A.10.32
  HP-UX B.11.00                 HP92453-01 A.11.00.13 HP C Compiler 
                                (static library only, h5toh4 tool is not available) 
  IRIX 6.5                      MIPSpro cc 7.30
  IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
                                mpt.1.4

  Linux 2.2.10 SMP              gcc 2.95.1 
                                mpicc(gcc-2.95.1)
                                gcc (egcs-2.91.66)
                                mpicc (egcs-2.91.66)
  Linux 2.2.16 (RedHat 6.2)     gcc 2.95.2

  OSF1 V4.0                     DEC-V5.2-040
  SunOS 5.6                     cc WorkShop Compilers 5.0 no optimization
  SunOS 5.7                     cc WorkShop Compilers 5.0
  SolarisX86 SunOS 5.5.1        gcc version 2.7.2 with --disable-hsizet
  TFLOPS 3.2.1                  pgcc Rel 3.1-3i
                                mpich-1.1.2 with local changes
  Windows NT4.0 sp5             MSVC++ 6.0
  Windows 98                    MSVC++ 6.0
  Windows 2000                  MSVC++ 6.0



%%%%1.2.1%%%%   Release Information for hdf5-1.2.1

III. Release Information for hdf5-1.2.1

Bug fixes since HDF5-1.2.0
==========================

Configuration
-------------

   * The hdf5.h include file was fixed to allow the HDF5 Library to be compiled
     with other libraries/applications that use GNU autoconf. 
   * Configuration for parallel HDF5 was improved. Configure now attempts to
     link with libmpi.a and/or libmpio.a as the MPI libraries by default.
     It also uses "mpirun" to launch MPI tests by default.  It tests to
     link MPIO routines during the configuration stage, rather than failing
     later as before.  One can just do "./configure --enable-parallel"
     if the MPI library is in the system library.

Library
-------

   * Error was fixed which was not allowing dataset region references to have
     their regions retrieved correctly.
   * Added internal free-lists to reduce memory required by the library and
     H5garbage_collect API function
   * Fixed error in H5Giterate which was not updating the "index" parameter
     correctly.
   * Fixed error in hyperslab iteration which was not walking through the
     correct sequence of array elements if hyperslabs were staggered in a
     certain pattern
   * Fixed several other problems in hyperslab iteration code.

Tests
------

   * Added additional tests for group and attribute iteration.
   * Added additional test for staggered hyperslab iteration.
   * Added additional test for random 5-D hyperslab selection.

Tools
------

   * Added an option, -V, to show the version information of h5dump.
   * Fixed a core dumping bug of h5toh4 when executed on platforms like 
     TFLOPS.
   * The test script for h5toh4 used to not able to detect the hdp
     dumper command was not valid.  It now detects and reports the
     failure of hdp execution.

Documentation
-------------

   * User's Guide and Reference Manual were updated. 
     See doc/html/PSandPDF/index.html for more details. 

   
Platforms Tested:
================
Note: Due to the nature of bug fixes, only static versions of the library and tools were tested.


  AIX 4.3.2 (IBM SP)            3.6.6
  Cray T3E 2.0.4.81             cc 6.3.0.1
                                mpt.1.3
  FreeBSD 3.3-STABLE            gcc 2.95.2
  HP-UX B.10.20                 HP C  HP92453-01 A.10.32
  IRIX 6.5                      MIPSpro cc 7.30
  IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
                                mpt.1.3 (SGI MPI 3.2.0.0)

  Linux 2.2.10 SuSE             egcs-2.91.66               configured with
  (i686-pc-linux-gnu)                                      --disable-hsizet
                                mpich-1.2.0 egcs-2.91.66 19990314/Linux 

  OSF1 V4.0                     DEC-V5.2-040
  SunOS 5.6                     cc WorkShop Compilers 4.2  no optimization
  SunOS 5.7                     cc WorkShop Compilers 5.0
  TFLOPS 2.8                    cicc (pgcc Rel 3.0-5i)
                                mpich-1.1.2 with local changes
  Windows NT4.0 sp5             MSVC++ 6.0

Known Problems:
==============

o SunOS 5.6 with C WorkShop Compilers 4.2:  Hyperslab selections will 
  fail if library is compiled using optimization of any level.



%%%%1.2.0%%%%   Release Information for hdf5-1.2.0
         
IV. Release Information for hdf5-1.2.0

A. Platforms Supported
   -------------------

Operating systems listed below with compiler information and MPI library, if
applicable, are systems that HDF5 1.2.0 was tested on.

                           Compiler & libraries
  Platform                      Information              Comment
  --------                      ----------               -------- 
                                
  AIX 4.3.2 (IBM SP)            3.6.6

  Cray J90 10.0.0.6             cc 6.3.0.0

  Cray T3E 2.0.4.61             cc 6.2.1.0 
                                mpt.1.3

  FreeBSD 3.2                   gcc 2.95.1

  HP-UX B.10.20                 HP C  HP92453-01 A.10.32
                                gcc 2.8.1

  IRIX 6.5                      MIPSpro cc 7.30 

  IRIX64 6.5 (64 & n32)         MIPSpro cc 7.3.1m
  			        mpt.1.3 (SGI MPI 3.2.0.0)

  Linux 2.2.10                  egcs-2.91.66               configured with
  						         --disable-hsizet
                                                           lbraries: glibc2

  OSF1 V4.0                     DEC-V5.2-040

  SunOS 5.6                     cc WorkShop Compilers 4.2   
                                                           no optimization
  			        gcc 2.8.1

  SunOS 5.7                     cc WorkShop Compilers 5.0
                                gcc 2.8.1
 
  TFLOPS 2.7.1                  cicc (pgcc Rel 3.0-4i)
  			        mpich-1.1.2 with local changes

  Windows NT4.0 intel           MSVC++ 5.0 and 6.0

  Windows NT alpha 4.0          MSVC++ 5.0 

  Windows 98                    MSVC++ 5.0


B. Known Problems
   --------------

* NT alpha 4.0
  Dumper utiliy h5dump fails if linked with DLL.

* SunOS 5.6 with C WorkShop Compilers 4.2
  Hyperslab selections will fail if library is compiled using optimization
  of any level.

 
C. Changes Since Version 1.0.1
   ---------------------------

1. Documentation
   -------------

* More examples

* Updated user guide, reference manual, and format specification.

* Self-contained documentation for installations isolated from the
  Internet.

* HDF5 Tutorial was added to the documentation  

2. Configuration
   -------------

* Better detection and support for MPI-IO.

* Recognition of compilers with known code generation problems.

* Support for various compilers on a single architecture (e.g., the
  native compiler and the GNU compilers).

* Ability to build from read-only media and with different compilers
  and/or options concurrently.

* Added a libhdf5.settings file which summarizes the configuration
  information and is installed along with the library.

* Builds a shared library on most systems that support it.

* Support for Cray T3E, J90 and Windows/NT.

3. Debugging
   ---------

* Improved control and redirection of debugging and tracing messages.

4. Datatypes
   ---------

* Optimizations to compound datatype conversions and I/O operations.

* Added nearly 100 optimized conversion functions for native datatypes 
  including support for non-aligned data.

* Added support for bitfield, opaque, and enumeration types.

* Added distinctions between signed and unsigned char types to the
  list of predefined native hdf5 datatypes.

* Added HDF5 type definitions for C9x types like int32_t.

* Application-defined type conversion functions can handle non-packed
  data.

* Changed the H5Tunregister() function to use wildcards when matching
  conversion functions.  H5Tregister_hard() and H5Tregister_soft()
  were combined into H5Tregister().

* Support for variable-length datatypes (arrays of varying length per
  dataset element). Variable length strings currently supported only
  as variable length arrays of 1-byte integers.

5. Dataspaces
   ----------

* New query functions for selections.

* I/O operations bypass the stripmining loop and go directly to
  storage for certain contiguous selections in the absense of type
  conversions.  In other cases the stripmining buffers are used more
  effectively.

* Reduced the number of I/O requests under certain circumstances,
  improving performance on systems with high I/O latency.

6. Persistent Pointers
   -------------------

* Object (serial and parallel) and dataset region (serial only)
  references are implemented.

7. Parallel Support
   ----------------

* Improved parallel I/O performance.

* Supported new platforms: Cray T3E, Linux, DEC Cluster.

* Use vendor supported version of MPIO on SGI O2K and Cray platforms.

* Improved the algorithm that translates an HDF5 hyperslab selection
  into an MPI type for better collective I/O performance.

8. New API functions 
   -----------------

  a. Property List Interface:
     ------------------------

  H5Pset_xfer		- set data transfer properties
  H5Pset_preserve      - set dataset transfer property list status 
  H5Pget_preserve      - get dataset transfer property list status
  H5Pset_hyper_cache   - indicates whether to cache hyperslab blocks during I/O
  H5Pget_hyper_cache   - returns information regarding the caching of 
                         hyperslab blocks during I/O
  H5Pget_btree_ratios  - sets B-tree split ratios for a dataset 
                         transfer property list
  H5Pset_btree_ratios  - gets B-tree split ratios for a dataset
                         transfer property list
  H5Pset_vlen_mem_manager - sets the memory manager for variable-length 
                            datatype allocation
  H5Pget_vlen_mem_manager - sets the memory manager for variable-length
                            datatype allocation

  b. Dataset Interface:
     ------------------

  H5Diterate           - iterate over all selected elements in a dataspace
  H5Dget_storage_size  - return the amount of storage required for a dataset
  H5Dvlen_reclaim      - reclaim VL datatype memory buffers

  c. Dataspace Interface:
     --------------------
  H5Sget_select_hyper_nblocks   - get number of hyperslab blocks
  H5Sget_select_hyper_blocklist - get the list of hyperslab blocks 
                                  currently selected
  H5Sget_select_elem_npoints    - get the number of element points 
                                  in the current selection
  H5Sget_select_elem_pointlist  - get the list of element points 
                                  currently selected
  H5Sget_select_bounds          - gets the bounding box containing 
                                  the current selection

  d. Datatype Interface:
     -------------------
  H5Tget_super         - return the base datatype from which a 
                         datatype is derived
  H5Tvlen_create       - creates a new variable-length dataype
  H5Tenum_create       - creates a new enumeration datatype
  H5Tenum_insert       - inserts a new enumeration datatype member
  H5Tenum_nameof       - returns the symbol name corresponding to a 
                         specified member of an enumeration datatype
  H5Tvalueof           - return the value corresponding to a 
                         specified member of an enumeration datatype 
  H5Tget_member_value  - return the value of an enumeration datatype member
  H5Tset_tag           - tags an opaque datatype
  H5Tget_tag           - gets the tag associated with an opaque datatype

  e. Identifier Interface:
     ---------------------
  H5Iget_type          - retrieve the type of an object

  f. Reference Interface:
     --------------------
  H5Rcreate            - creates a reference
  H5Rdereference       - open the HDF5 object referenced
  H5Rget_region        - retrieve a dataspace with the specified region selected
  H5Rget_object_type   - retrieve the type of object that an 
                         object reference points to

  g. Ragged Arrays (alpha) (names of those API functions were changed):
     ------------------------------------------------------------------
   H5RAcreate		- create a new ragged array (old name was H5Rcreate)
   H5RAopen		- open an existing array    (old name was H5Ropen)
   H5RAclose		- close a ragged array      (old name was H5Rclose)
   H5RAwrite		- write to an array         (old name was H5Rwrite)
   H5RAread		- read from an array        (old name was H5Rread)


9. Tools
   -----

* Enhancements to the h5ls tool including the ability to list objects
  from more than one file, to display raw hexadecimal data, to
  show file addresses for raw data, to format output more reasonably,
  to show object attributes, and to perform a recursive listing, 

* Enhancements to h5dump: support new data types added since previous
  versions.

* h5toh4: An hdf5 to hdf4 converter.



%%%%1.0.1%%%%   Release Information for hdf5-1.0.1
         
V. Changes from Release 1.0.0 to Release 1.0.1

* [Improvement]: configure sets up the Makefile in the parallel tests
  suit (testpar/) correctly.

* [Bug-Fix]: Configure failed for all IRIX versions other than 6.3.
  It now configures correctly for all IRIX 6.x version.

* Released Parallel HDF5 

     Supported Features:
     ------------------

     HDF5 files are accessed according to the communicator and INFO
     object defined in the property list set by H5Pset_mpi.

     Independent read and write accesses to fixed and extendable dimension
     datasets.

     Collective read and write accesses to fixed dimension datasets.

     Supported Platforms:
     -------------------

     Intel Red
     IBM SP2
     SGI Origin 2000

     Changes In This Release: 
     -----------------------

   o Support of Access to Extendable Dimension Datasets.
     Extendable dimension datasets must use chunked storage methods.
     A new function, H5Dextend, is created to extend the current
     dimensions of a dataset.  The current release requires the
     MPI application must make a collective call to extend the
     dimensions of an extendable dataset before writing to the
     newly extended area.  (The serial does not require the
     call of H5Dextend.  The dimensions of an extendable
     dataset is increased when data is written to beyond the
     current dimensions but within the maximum dimensions.)
     The required collective call of H5Dextend may be relaxed
     in future release.

     This release only support independent read and write accesses
     to extendable datasets.  Collective accesses to extendable
     datasets will be implemented in future releases.

   o Collective access to fixed dimension datasets.
     Collective access to a dataset can be specified in the transfer
     property list argument in H5Dread and H5Dwrite.  The current
     release supports collective access to fixed dimension datasets.
     Collective access to extendable datasets will be implemented in
     future releases.

   o HDF5 files are opened according to Communicator and INFO object.
     H5Dopen now records the communicator and INFO setup by H5Pset_mmpi
     and pass them to the corresponding MPIO open file calls for
     processing.

   o This release has been tested on IBM SP2, Intel Red and SGI Origin 2000
     systems.  It uses the ROMIO version of MPIO interface for parallel
     I/O supports.



%%%%1.0.0%%%%   Release Information for hdf5-1.0.0

VI. Changes from the Beta 1.0.0 Release to Release 1.0.0

* Added fill values for datasets.  For contiguous datasets fill value
  performance may be quite poor since the fill value is written to the 
  entire dataset when the dataset is created.  This will be remedied
  in a future version.  Chunked datasets using fill values do not
  incur any additional overhead. See H5Pset_fill_value().

* Multiple hdf5 files can be "mounted" on one another to create a
  larger virtual file. See H5Fmount().

* Object names can be removed or changed but objects are never
  actually removed from the file yet. See H5Gunlink() and H5Gmove().

* Added a tuning mechanism for B-trees to insure that sequential
  writes to chunked datasets use less overhead.  See H5Pset_btree_ratios().

* Various optimizations and bug fixes.



%%%%1.0.0 Beta%%%%   Release Information for hdf5-1.0.0 Beta

VII. Changes from the Second Alpha 1.0.0 Release to the Beta 1.0.0 Release

* Strided hyperslab selections in dataspaces now working.

* The compression API has been replaced with a more general filter
  API.  See doc/html/Filters.html for details.

* Alpha-quality 2d ragged arrays are implemented as a layer built on
  top of other hdf5 objects.  The API and storage format will almost
  certainly change.

* More debugging support including API tracing.  See Debugging.html.

* C and Fortran style 8-bit fixed-length character string types are
  supported with space or null padding or null termination and
  translations between them.

* Added function H5Fflush() to write all cached data immediately to
  the file.

* Datasets maintain a modification time which can be retrieved with
  H5Gstat().

* The h5ls tool can display much more information, including all the
  values of a dataset.



%%%%1.0.0 Alpha 2%%%%   Release Information for hdf5-1.0.0 Alpha 2

VIII. Changes from the First Alpha 1.0.0 Release to 
     the Second Alpha 1.0.0 Release

* Two of the packages have been renamed.  The data space API has been
  renamed from `H5P' to `H5S' and the property list (template) API has 
  been renamed from `H5C' to `H5P'.

* The new attribute API `H5A' has been added.  An attribute is a small 
  dataset which can be attached to some other object (for instance, a
  4x4 transformation matrix attached to a 3-dimensional dataset, or an 
  English abstract attached to a group).

* The error handling API `H5E' has been completed.  By default, when an
  API function returns failure an error stack is displayed on the
  standard error stream.  The H5Eset_auto() controls the automatic
  printing and H5E_BEGIN_TRY/H5E_END_TRY macros can temporarily
  disable the automatic error printing.

* Support for large files and datasets (>2GB) has been added.  There
  is an html document that describes how it works.  Some of the types
  for function arguments have changed to support this: all arguments
  pertaining to sizes of memory objects are `size_t' and all arguments 
  pertaining to file sizes are `hsize_t'.

* More data type conversions have been added although none of them are
  fine tuned for performance.  There are new converters from integer
  to integer and float to float, but not between integers and floating
  points.  A bug has been fixed in the converter between compound
  types.

* The numbered types have been removed from the API: int8, uint8,
  int16, uint16, int32, uint32, int64, uint64, float32, and float64.
  Use standard C types instead.  Similarly, the numbered types were
  removed from the H5T_NATIVE_* architecture; use unnumbered types
  which correspond to the standard C types like H5T_NATIVE_INT.

* More debugging support was added.  If tracing is enabled at
  configuration time (the default) and the HDF5_TRACE environment
  variable is set to a file descriptor then all API calls will emit
  the function name, argument names and values, and return value on
  that file number.  There is an html document that describes this.
  If appropriate debugging options are enabled at configuration time,
  some packages will display performance information on stderr.

* Data types can be stored in the file as independent objects and
  multiple datasets can share a data type.

* The raw data I/O stream has been implemented and the application can 
  control meta and raw data caches, so I/O performance should be
  improved from the first alpha release.

* Group and attribute query functions have been implemented so it is
  now possible to find out the contents of a file with no prior
  knowledge.

* External raw data storage allows datasets to be written by other
  applications or I/O libraries and described and accessed through
  HDF5.

* Hard and soft (symbolic) links are implemented which allow groups to 
  share objects. Dangling and recursive symbolic links are supported.

* User-defined data compression is implemented although we may
  generalize the interface to allow arbitrary user-defined filters
  which can be used for compression, checksums, encryption,
  performance monitoring, etc.  The publicly-available `deflate'
  method is predefined if the GNU libz.a can be found at configuration 
  time.

* The configuration scripts have been modified to make it easier to
  build debugging vs. production versions of the library.

* The library automatically checks that the application was compiled
  with the correct version of header files.


		    Parallel HDF5 Changes

* Parallel support for fixed dimension datasets with contiguous or
  chunked storages.  Also, support unlimited dimension datasets which
  must use chunk storage.  No parallel support for compressed datasets.

* Collective data transfer for H5Dread/H5Dwrite.  Collective access
  support for datasets with contiguous storage only, thus only fixed
  dimension datasets for now.

* H5Pset_mpi and H5Pget_mpi no longer have the access_mode
  argument.  It is taken over by the data-transfer property list
  of H5Dread/H5Dwrite.

* New functions H5Pset_xfer and H5Pget_xfer to handle the
  specification of independent or collective data transfer_mode
  in the dataset transfer properties list.  The properties
  list can be used to specify data transfer mode in the H5Dwrite
  and H5Dread function calls.

* Added parallel support for datasets with chunked storage layout.
  When a dataset is extend in a PHDF5 file, all processes that open
  the file must collectively call H5Dextend with identical new dimension
  sizes.


			LIST OF API FUNCTIONS

The following functions are implemented. Errors are returned if an
attempt is made to use some feature which is not implemented and
printing the error stack will show `not implemented yet'.

Library
   H5check		- check that lib version matches header version
   H5open		- initialize library (happens automatically)
   H5close		- shut down the library (happens automatically)
   H5dont_atexit	- don't call H5close on exit
   H5get_libversion	- retrieve library version info
   H5check_version	- check for specific library version

Property Lists
   H5Pclose		- release template resources
   H5Pcopy		- copy a template
   H5Pcreate		- create a new template
   H5Pget_chunk		- get chunked storage properties
   H5Pset_chunk		- set chunked storage properties
   H5Pget_class		- get template class
   H5Pget_istore_k	- get chunked storage properties
   H5Pset_istore_k	- set chunked storage properties
   H5Pget_layout	- get raw data layout class
   H5Pset_layout	- set raw data layout class
   H5Pget_sizes		- get address and size sizes
   H5Pset_sizes		- set address and size sizes
   H5Pget_sym_k		- get symbol table storage properties
   H5Pset_sym_k		- set symbol table storage properties
   H5Pget_userblock	- get user-block size
   H5Pset_userblock	- set user-block size
   H5Pget_version	- get file version numbers
   H5Pget_alignment	- get data alignment properties
   H5Pset_alignment	- set data alignment properties
   H5Pget_external_count- get count of external data files
   H5Pget_external	- get information about an external data file
   H5Pset_external	- add a new external data file to the list
   H5Pget_driver	- get low-level file driver class
   H5Pget_stdio		- get properties for stdio low-level driver
   H5Pset_stdio		- set properties for stdio low-level driver
   H5Pget_sec2		- get properties for sec2 low-level driver
   H5Pset_sec2		- set properties for sec2 low-level driver
   H5Pget_core		- get properties for core low-level driver
   H5Pset_core		- set properties for core low-level driver
   H5Pget_split		- get properties for split low-level driver
   H5Pset_split		- set properties for split low-level driver
   H5P_get_family	- get properties for family low-level driver
   H5P_set_family	- set properties for family low-level driver
   H5Pget_cache		- get meta- and raw-data caching properties
   H5Pset_cache		- set meta- and raw-data caching properties
   H5Pget_buffer	- get raw-data I/O pipe buffer properties
   H5Pset_buffer	- set raw-data I/O pipe buffer properties
   H5Pget_preserve	- get type conversion preservation properties
   H5Pset_preserve	- set type conversion preservation properties
   H5Pget_nfilters	- get number of raw data filters
   H5Pget_filter	- get raw data filter properties
   H5Pset_filter	- set raw data filter properties
   H5Pset_deflate	- set deflate compression filter properties
   H5Pget_mpi		- get MPI-IO properties
   H5Pset_mpi		- set MPI-IO properties
   H5Pget_xfer		- get data transfer properties
 + H5Pset_xfer		- set data transfer properties
 + H5Pset_preserve      - set dataset transfer property list status 
 + H5Pget_preserve      - get dataset transfer property list status
 + H5Pset_hyper_cache   - indicates whether to cache hyperslab blocks during I/O
 + H5Pget_hyper_cache   - returns information regarding the caching of 
                          hyperslab blocks during I/O
 + H5Pget_btree_ratios  - sets B-tree split ratios for a dataset 
                          transfer property list
 + H5Pset_btree_ratios  - gets B-tree split ratios for a dataset
                          transfer property list
 + H5Pset_vlen_mem_manager - sets the memory manager for variable-length 
                             datatype allocation
 + H5Pget_vlen_mem_manager - sets the memory manager for variable-length
                             datatype allocation

Datasets
   H5Dclose		- release dataset resources
   H5Dcreate		- create a new dataset
   H5Dget_space		- get data space
   H5Dget_type		- get data type
   H5Dget_create_plist	- get dataset creation properties
   H5Dopen		- open an existing dataset
   H5Dread		- read raw data
   H5Dwrite		- write raw data
   H5Dextend		- extend a dataset
 + H5Diterate           - iterate over all selected elements in a dataspace
 + H5Dget_storage_size  - return the amount of storage required for a dataset
 + H5Dvlen_reclaim      - reclaim VL datatype memory buffers

Attributes
   H5Acreate		- create a new attribute
   H5Aopen_name		- open an attribute by name
   H5Aopen_idx		- open an attribute by number
   H5Awrite		- write values into an attribute
   H5Aread		- read values from an attribute
   H5Aget_space		- get attribute data space
   H5Aget_type		- get attribute data type
   H5Aget_name		- get attribute name
   H5Anum_attrs		- return the number of attributes for an object
   H5Aiterate		- iterate over an object's attributes
   H5Adelete		- delete an attribute
   H5Aclose		- close an attribute

Errors
   H5Eclear		- clear the error stack
   H5Eprint		- print an error stack
   H5Eget_auto		- get automatic error reporting settings
   H5Eset_auto		- set automatic error reporting
   H5Ewalk		- iterate over the error stack
   H5Ewalk_cb		- the default error stack iterator function
   H5Eget_major		- get the message for the major error number
   H5Eget_minor		- get the message for the minor error number

Files
   H5Fclose		- close a file and release resources
   H5Fcreate		- create a new file
   H5Fget_create_plist	- get file creation property list
   H5Fget_access_plist	- get file access property list
   H5Fis_hdf5		- determine if a file is an hdf5 file
   H5Fopen		- open an existing file
   H5Freopen            - reopen an HDF5 file
   H5Fmount             - mount a file
   H5Funmount           - unmount a file
   H5Fflush             - flush all buffers associated with a file to disk

Groups
   H5Gclose		- close a group and release resources
   H5Gcreate    	- create a new group
   H5Gopen		- open an existing group
   H5Giterate   	- iterate over the contents of a group
   H5Gmove		- change the name of some object
   H5Glink		- create a hard or soft link to an object
   H5Gunlink    	- break the link between a name and an object
   H5Gget_objinfo	- get information about a group entry
   H5Gget_linkval	- get the value of a soft link
   H5Gget_comment	- get the comment string for an object
   H5Gset_comment	- set the comment string for an object

Dataspaces
   H5Screate	        - create a new data space
   H5Scopy		- copy a data space
   H5Sclose		- release data space
   H5Screate_simple	- create a new simple data space
   H5Sset_space		- set simple data space extents
   H5Sis_simple		- determine if data space is simple
   H5Sset_extent_simple	- set simple data space dimensionality and size
   H5Sget_simple_extent_npoints	- get number of points in simple extent
   H5Sget_simple_extent_ndims - get simple data space dimensionality
   H5Sget_simple_extent_dims - get simple data space size
   H5Sget_simple_extent_type - get type of simple extent
   H5Sset_extent_none	- reset extent to be empty
   H5Sextent_copy	- copy the extent from one data space to another
   H5Sget_select_npoints - get number of points selected for I/O
   H5Sselect_hyperslab	- set hyperslab dataspace selection
   H5Sselect_elements   - set element sequence dataspace selection
   H5Sselect_all	- select entire extent for I/O
   H5Sselect_none	- deselect all elements of extent
   H5Soffset_simple	- set selection offset
   H5Sselect_valid	- determine if selection is valid for extent
 + H5Sget_select_hyper_nblocks   - get number of hyperslab blocks
 + H5Sget_select_hyper_blocklist - get the list of hyperslab blocks 
                                   currently selected
 + H5Sget_select_elem_npoints    - get the number of element points 
                                   in the current selection
 + H5Sget_select_elem_pointlist  - get the list of element points 
                                   currently selected
 + H5Sget_select_bounds          - gets the bounding box containing 
                                   the current selection

Datatypes
   H5Tclose		- release data type resources
   H5Topen		- open a named data type
   H5Tcommit		- name a data type
   H5Tcommitted		- determine if a type is named
   H5Tcopy		- copy a data type
   H5Tcreate		- create a new data type
   H5Tequal		- compare two data types
   H5Tlock		- lock type to prevent changes
   H5Tfind		- find a data type conversion function
   H5Tconvert		- convert data from one type to another
   H5Tregister    	- register a conversion function
   H5Tunregister	- remove a conversion function
   H5Tget_overflow	- get function that handles overflow conv. cases
   H5Tset_overflow	- set function to handle overflow conversion cases
   H5Tget_class		- get data type class
   H5Tget_cset		- get character set
   H5Tget_ebias		- get exponent bias
   H5Tget_fields	- get floating point fields
   H5Tget_inpad		- get inter-field padding
   H5Tget_member_dims	- get struct member dimensions
   H5Tget_member_name	- get struct member name
   H5Tget_member_offset	- get struct member byte offset
   H5Tget_member_type	- get struct member type
   H5Tget_nmembers	- get number of struct members
   H5Tget_norm		- get floating point normalization
   H5Tget_offset	- get bit offset within type
   H5Tget_order		- get byte order
   H5Tget_pad		- get padding type
   H5Tget_precision	- get precision in bits
   H5Tget_sign		- get integer sign type
   H5Tget_size		- get size in bytes
   H5Tget_strpad	- get string padding
   H5Tinsert		- insert scalar struct member
   H5Tinsert_array	- insert array struct member
   H5Tpack		- pack struct members
   H5Tset_cset		- set character set
   H5Tset_ebias		- set exponent bias
   H5Tset_fields	- set floating point fields
   H5Tset_inpad		- set inter-field padding
   H5Tset_norm		- set floating point normalization
   H5Tset_offset	- set bit offset within type
   H5Tset_order		- set byte order
   H5Tset_pad		- set padding type
   H5Tset_precision	- set precision in bits
   H5Tset_sign		- set integer sign type
   H5Tset_size		- set size in bytes
   H5Tset_strpad	- set string padding
 + H5Tget_super         - return the base datatype from which a 
                          datatype is derived
 + H5Tvlen_create       - creates a new variable-length dataype
 + H5Tenum_create       - creates a new enumeration datatype
 + H5Tenum_insert       - inserts a new enumeration datatype member
 + H5Tenum_nameof       - returns the symbol name corresponding to a 
                          specified member of an enumeration datatype
 + H5Tvalueof           - return the value corresponding to a 
                          specified member of an enumeration datatype 
 + H5Tget_member_value  - return the value of an enumeration datatype member
 + H5Tset_tag           - tags an opaque datatype
 + H5Tget_tag           - gets the tag associated with an opaque datatype

 - H5Tregister_hard	- register specific type conversion function
 - H5Tregister_soft	- register general type conversion function

Filters
   H5Tregister		- register a conversion function 

Compression
   H5Zregister		- register new compression and uncompression 
                          functions for a method specified by a method number

Identifiers
 + H5Iget_type          - retrieve the type of an object

References
 + H5Rcreate            - creates a reference
 + H5Rdereference       - open the HDF5 object referenced
 + H5Rget_region        - retrieve a dataspace with the specified region selected
 + H5Rget_object_type   - retrieve the type of object that an 
                          object reference points to

Ragged Arrays (alpha)
   H5RAcreate		- create a new ragged array
   H5RAopen		- open an existing array
   H5RAclose		- close a ragged array
   H5RAwrite		- write to an array
   H5RAread		- read from an array