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HDF5 Software Changes from Release to Release
for HDF5 Releases 1.8.x


This document covers HDF5 releases in the HDF5 Release 1.8.x series prior to the current release. For each release, we list new features and changes in the existing HDF5 feature set, the HDF5 application programming interface (API), and the command-line tools distributed with the HDF5 Library. The intent is to note changes that application developers must be aware of when maintaining applications or libraries that must work with progressively newer versions of HDF5.

See “HDF5 Software Changes from Release to Release” for:

See “HDF5 Software Changes from Release to Release for HDF5 Releases 1.4.0 through 1.6.10” for:


Release 1.8.16 of November 2015 versus Release 1.8.15

This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.15 to Release 1.8.16.

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

In the C Interface (main library)
New HDF5 Plugin Interface (H5PL)
A new HDF5 Plugin Interface (H5PL), enabling programmatic control of dynamically loaded plugins, was introduced at HDF5 Release 1.8.15. This interface was only partially documented at that time, but more complete documentation is now available:

The following new C function has been added:
This function reports whether the linked version of the HDF5 Library was built with the thread-safety feature enabled.

The following flag has been removed:
H5F_ACC_DEBUG flag for H5Fopen/create
 
The flag H5F_ACC_DEBUG was used to provide extra debugging information for HDF Library developers. This flag and the underlying functionality have been removed from the library due to disuse. The symbol remains defined since it was visible in H5Fpublic.h, but it has been set to zero (0) and has no effect anywhere in the library.

In the C++ Interface
The following features have been added:
  • New class H5::ObjCreatPropList for the object creation property list class

    The new class H5::ObjCreatPropList is derived from H5::PropList and is a baseclass of H5::DSetCreatPropList. Additional property list classes will be added to the library in future releases and some of those will be derived from H5::ObjCreatPropList.

  • New wrappers for the C functions H5P[s/g]et_attr_phase_change and H5P[s/g]et_attr_creation_order

    The following wrappers were added to the class H5::ObjCreatPropList for the respective C functions:
    C Function C++ Wrapper
    H5Pset_attr_phase_change H5::ObjCreatPropList::setAttrPhaseChange
    H5Pget_attr_phase_change H5::ObjCreatPropList::getAttrPhaseChange
    H5Pset_attr_creation_order H5::ObjCreatPropList::setAttrCrtOrder
    H5Pget_attr_creation_order   H5::ObjCreatPropList::getAttrCrtOrder

  • Library Configuration

    Use of thread-safety with the HDF5 High-level Library has been declared unsupported in the build tools: Autotools and CMake.
     
    The global lock used by the thread-safety mechanism is not raised to the high-level library level, making it possible that the library state could change if a context switch were to occur in a high-level library call. Because of this, the combination of thread-safety and the high-level library is officially unsupported by The HDF Group.

    Though this combination has never been supported in HDF5, this was not enforced by the build systems. With this release, the combination has been explicitly flagged as unsupported in Autotools and CMake, the build systems used with HDF5.

    The new unsupported declaration will cause an Autotools configure step to fail if --enable-threadsafe and --enable-hl are combined unless additional options are specified (see below). Since the high-level library is built by default, this means that these extra configuration options will need to be used any time --enable-threadsafe is selected.

    To use Autotools to build an application with --enable-threadsafe, use one of the following approaches:

    • Use --disable-hl to disable the high-level library. (Recommended)
    • Use --enable-unsupported to build the high-level library with the thread-safety feature.

    To use CMake to build an application with HDF5_ENABLE_THREADSAFE=ON, use one of the following approaches:

    • Use HDF5_BUILD_HL_LIB=OFF to disable the high-level library. (Recommended)
    • Use HDF5_ALLOW_UNSUPPORTED=ON to build the high-level library with the thread-safety feature.

    Since this combination is unsupported, applications using it must be carefully tested for potential thread-safety failures.

    Compatibility Notes and Report

    Decoupled shared object version numbers (soname)
    Shared object version numbers, soname, for HDF5 wrapper libraries, such as the C++ and Fortran libraries, have been decoupled from the shared object version number for the HDF5 library. In this and future releases, each library’s soname will be maintained on an individual basis according to the interface changes specific to each wrapper library.

    Changed shared library interface version numbers (soname)
    For HDF5 Release 1.8.16, the shared object version numbers have changed as follows.
    Library Release 1.8.15   Release 1.8.16   Reason for Change
    HDF5 Library   10.0.1 10.1.0 Added APIs
    C++ Library 10.0.1 11.0.0 Changes in existing APIs
    High‐level C++ Library 10.0.1 11.0.0 Changes in existing APIs
    All others 10.0.1 10.0.2 Code changes that did not result in interface changes

    Compatibility report for Release 1.8.16 versus Release 1.8.15
    The following interface compatibility report provides a full list of the changed symbols:

    API compatibility report for the HDF5 Library between 1.8.15 and 1.8.16 versions on x86


    Release 1.8.15 of May 2015 versus Release 1.8.14

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.14 to Release 1.8.15.

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

    In the C Interface (main library)
    The following new C functions have been added:
    Memory allocation functions that use the library’s allocator.

    The following functions enable programmatic control of the loading of dynamic plugin filters in user applications:

    In the C++ Interface
    The following features have been added:
  • New wrappers for the C functions H5Pset_libver_bounds and H5Pget_libver_bounds

    The following wrappers have been added to class H5::FileAccPropList. The first sets the bounds on versions of the HDF5 Library format to be used when creating or writing objects; the second retrieves the current settings:

        void setLibverBounds(H5F_libver_t libver_low, H5F_libver_t libver_high) const;
    
        void getLibverBounds(H5F_libver_t& libver_low, H5F_libver_t& libver_high) const;
                        
  • New wrappers to retrieve the version of an object header

    The following wrappers have been added to class H5::CommonFG to retrieve the object header version of an object in a file or group, given the object’s name.

        unsigned childObjVersion(const char* objname) const;
    
        unsigned childObjVersion(const H5std_string& objname) const;
                        
  • A new DataType constructor

    A new DataType constructor takes a PredType object and invokes H5Tcopy to generate another datatype identifier from a predefined datatype.

  • The following features have been changed:
  • Combined H5File::getObjCount overloaded methods

    The following methods:

        ssize_t getObjCount(unsigned types) const;
    
        ssize_t getObjCount() const;
                       
    have been combined into the following:
        ssize_t getObjCount(unsigned types = H5F_OBJ_ALL) const;
                       
  • Deprecated constructors

    The following two constructors of the classes AbstractDs, IdComponent, H5Location, and H5Object are no longer appropriate after the data member id was moved from IdComponent to the sub-classes in previous releases:

        <Classname>(const hid_t h5_id);
    
        <Classname>(const <Classname>& original);
                        
    The copy constructors have been no-ops and are removed in this HDF5 Release 1.8.15. The other constructors will be removed in HDF5 Release 1.10 and are expected to be removed from HDF5 Release 1.8.17 if their removal causes no problems.
  • In the Fortran Interface
    The following Fortran 2003 API has been added:
    h5tenum_insert_f

    Operation of the new Fortran 2003 version of this API is more consistent with the operation of the C API than was the Fortran 90 version.
    Users are strongly encouraged to use the Fortran 2003 API.

    Several global variables have been added in the Fortran API. These global variables are equivalent in definition to the comparable C definitions:
    H5G_UDLINK_F
    H5G_SAME_LOC_F
    H5O_TYPE_UNKNOWN_F
    H5O_TYPE_GROUP_F
    H5O_TYPE_DATASET_F
    H5O_NAMED_DATATYPE_F
    H5O_TYPE_NTYPES_F   

    For parallel applications
    A fix for issues encountered upon calling MPI_Finalize without having closed everything in an HDF5 file

    An attribute destroy callback has been attached to MPI_COMM_SELF that shuts down the HDF5 Library when MPI_COMM_SELF is destroyed, that is, on MPI_Finalize. This should fix several issues that users see when they forget to close HDF5 objects before calling MPI_Finalize().

    Compatibility Report and Comments

    Compatibility report for Release 1.8.15 versus Release 1.8.14
    API compatibility report for the HDF5 Library between 1.8.14 and 1.8.15 versions on x86

    Changed shared library interface version number (soname)
    In the C++ interface, two overloaded methods have been combined into a single method and one constructor has been deprecated.

    Due to these changes, the shared library interface version number (soname) has been increased. For a full list of the changed symbols, see the interface compatibility report linked immediately above.

    Release 1.8.14 of November 2014 versus Release 1.8.13

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.13 to Release 1.8.14.

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

    In the main library C Interface
    No new C functions have been added.

    The behavior of the following C function has been changed:
    The function H5Pset_core_write_tracking has been modified to enforce the limitation that the value of the page_size parameter cannot equal 0 (zero):

    The following performance optimization has been implemented in the Parallel HDF5 library:
    The algoritm for writing chunk fill values for new datasets has been optimized to write out all chunk fill values collectively in a single MPI-IO call. This was previously done independently by rank 0 (zero) one block at a time. This optimization should produce a significant performance improvement when creating chunked datasets in parallel, most notably when chunk dimensions are relatively small. This optimization will be evident in use of the following function:

    In the high-level library C Interface
    High-level HDF5 interfaces now ensure that strings are null-terminated and will not overflow a buffer.
    In several high-level functions, the type from the file was previously re-used as the memory type and no check is made to ensure that a string was actually null-terminated.

    All high-level functions now check for NULL pointers; verify that a received a string is null-terminated; and verify that the string will not overflow the buffer. The minimum length of the buffers is now used in strncmp to avoid overflow.

    In the main library C++ Interface
    No new C++ methods have been added.

    The following changes have been made in the C++ interface:
    Changed defaults
    • Default value of class member id:
      The data member id in several classes that represent HDF5 objects are now initialized to H5I_INVALID_ID.
    • Default value of a PropList member id:
      The data member id in class PropList is now initialized to H5P_DEFAULT.
    • In HDF5 Release 1.8.13 and earlier, the above were initialized to 0 (zero).

    Changed file access flags
    • The flag H5F_ACC_CREAT has been removed from the C++ interface.

    In the main library Fortran Interface
    No new Fortran subroutines have been added.

    Changed Fortran INTEGER parameter types:
    Types of the following Fortran parameter constants have been changed from INTEGER to INTEGER(HID_T):
        H5FD_CORE            H5FD_MULTI
        H5FD_FAMILY          H5FD_SEC2
        H5FD_LOG             H5FD_STDIO
        H5FD_MPIO       
    Other internal int types have been changed to hid_t, but this change is expected to be transparent to the user.

    Compatibility Report and Comments

    Compatibility report for Release 1.8.14 versus Release 1.8.13
    API compatibility report for the HDF5 Library between 1.8.13 and 1.8.14 versions on x86

    Changed shared library interface version number (soname)
    To increase the maintainability of HDF5, an architectural change has been made that required renaming several public symbols in H5Ppublic.h.

    Due to these changes, the shared library interface version number (soname) has been increased. For a full list of the changed symbols, see the interface compatibility report linked immediately above.


    Release 1.8.13 of May 2014 versus Release 1.8.12

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.12 to Release 1.8.13.

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

    In the C Interface (main library)

    The following new C functions have been added:
    To free memory allocated by HDF5 function calls:
    • H5free_memory
      This function should be used to free memory that has been allocated by HDF5 API calls such as H5Tget_member_name and H5Pget_class_name.

      The primary value for this call is on Windows systems, where it is common for application code and the HDF5 Library to be using different C run-time libraries (CRT). Using this new call ensures that the same CRT handles both the allocation and free.

      This function can also be useful in any case where the library uses a different memory manager than the application, such as when a debug memory manager is in use or when the HDF5 Library is wrapped for use in a managed language like Python or Java.

    New configuration property for the CORE driver:
    • H5Pset_core_write_tracking
      H5Pget_core_write_tracking
      With this property, the CORE driver, H5Pset_fapl_core, can be configured to track dirty regions in the file and write out only the changed regions on flush or close operations. Additionally, a page aggregation size can be set that will aggregate small writes into larger writes. For example, setting a 1 mebibyte (1 MiB) page aggregation size will logically partition the the in-memory file into 1 MiB pages that will be written out in their entirety if even a single byte is dirtied.

    The following C functions have been modified:
    • H5Rget_name
      If the name parameter is passed as NULL, then the size parameter is ignored and the function returns the size of the buffer required to read the name (not including the NULL terminator).
    • H5Zfilter_avail
      This function has been updated to correctly identify dynamically loaded filters. If a filter is not found among registered filters, the function now checks for dynamically loaded filters.

    In the C++ Interface
    The following new features have been added:
    Wrappers to the class H5Object to get an object’s name:
        ssize_t getObjName(char *obj_name, size_t buf_size = 0)
        ssize_t getObjName(H5std_string& obj_name, size_t len = 0)
        H5std_string getObjName()
    
    Wrappers to the class H5CommonFG to get a child object’s type from a group or file:
        H5O_type_t childObjType(const H5std_string& objname)
        H5O_type_t childObjType(const char* objname)
        H5O_type_t childObjType(hsize_t index,
            H5_index_t index_type=H5_INDEX_NAME,
            H5_iter_order_t order=H5_ITER_INC, const char* objname=".")
    
    Wrappers to the class DSetMemXferPropList for setting or getting a transform property list:
        DSetMemXferPropList(const char* expression);
        void setDataTransform(const char* expression)
        void setDataTransform(const H5std_string& expression)
        ssize_t getDataTransform(char* exp, size_t buf_size=0)
        H5std_string getDataTransform()
    
    Wrapper to CompType for setting the size of a compound datatype:
        void setSize(size_t size)
    
    Overloaded functions to provide prototypes that declare constant arguments const:
        DataSet::fillMemBuf
        DataSet::getVlenBufSize
        DataSpace::extentCopy
        DataType::commit
        FileAccPropList::setSplit
        H5File::getVFDHandle
    
    Additional overload to the class H5Location to get a comment as a char*:
        ssize_t getComment(const char* name, size_t buf_size, char* comment) 
    
    Additional overloads to the class Attribute to get an attribute’s name for convenience:
        ssize_t getName(char* attr_name, size_t buf_size=0)
        ssize_t getName(H5std_string& attr_name, size_t buf_size=0)
    

    In the Fortran Interface
    The following new Fortran subroutines have been added:
    Fortran2003 subroutines:
    h5pset_file_image_f
    h5pget_file_image_f
     
    h5fget_file_image_f (Added in Release 1.8.11, but not documented at that time.)

    The following Fortran subroutine has been changed:
    • h5pset_chunk_cache_f
      The values of the constants H5D_CHUNK_CACHE_NSLOTS_DFLT_F and H5D_CHUNK_CACHE_NBYTES_DFLT_F have been changed to INTEGER(KIND=size_t).

    Other New Features

    Parallel I/O support:
    Parallel I/O support has been enhanced to allow collective I/O on point selections.

    Thread safety (Windows only)
    The thread-safe HDF5 library no longer leaks thread-local storage resources on Windows with Win32 threads. This cleanup can only be performed when the library is built as a shared library, so a thread-safe HDF5 static library with Win32 threads is no longer supported.

    This change affects only Windows environments.

    Also see “Build and Configuration” below.

    Command-line Tools with Changed Behavior

    h5repack
    h5repack has been updated to correctly handle dynamically loaded filters.

    Build and Configuration

    Thread safety
    When configuring a thread-safe HDF5 Library with --enable-threadsafe, it is no longer necessary to specify --with-pthreads if the Pthreads library is in a standard location.

    Removed Functions and Wrappers

    The MPI-POSIX driver has been removed. The following C functions and the corresponding Fortran subroutines and C++ wrappers therefore are no longer included in the HDF5 distribution:
    • H5Pset_fapl_mpiposix
    • H5Pget_fapl_mpiposix
    Applications performing parallel I/O should use the MPI-IO driver, H5Pset_fapl_mpio.

    Release 1.8.12 of November 2013 versus Release 1.8.11

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.11 to Release 1.8.12.

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

    In the C Interface (main library)
    The following C functions have been modified:
    • H5Zunregister now checks for open objects using a filter before allowing the filter to be unregistered.
    • H5Dscatter and H5Dgather signatures have changed slightly.
      The src_buff parameter type is now 'const void *'  (previously: 'void *').

    In the C++ Interface
    The following new C++ class has been added:
    H5::H5Location
    The class H5::H5Location has been added as a base class of H5File and H5Object. It represents the location concept in the C library, where an identifier of an HDF5 object or an HDF5 file being passed in as a loc_id parameter.

    The following member functions and their overloaded versions have been moved from various subclasses into the base class H5Location:
    createAttribute()
    openAttribute()
    attrExists()
    renameAttr()
    removeAttr()
    flush()
    getFileName()
    getNumAttrs()
             getObjType()
    iterateAttrs()
    setComment()
    getComment()
    removeComment()
    reference()
    dereference()
    getRegion()

    The following wrappers for C functions have been added:
    H5Location::getRefObjType
    Corresponding C function: H5Rget_obj_type2
    Retrieves the type of the object that an object reference points to.
    H5Location::attrExists
    Corresponding C function: H5Aexist
    Determines whether a given attribute exists.
    H5Location::setComment
    Two overloaded versions of H5Location::setComment have been added to take "." in lieue of the name of the object.

    In the classes DataSet, DataType, and Group, the following constructors have changed as follows:
  • These constructors
        DataSet(H5Object& obj, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        DataSet(H5File& h5file, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        DataSet(Attribute& attr, const void* ref, H5R_type_t ref_type = H5R_OBJECT);

    have changed to
        DataSet(const H5Location& loc, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        DataSet(const Attribute& attr, const void* ref, H5R_type_t ref_type = H5R_OBJECT);

  • These constructors
        DataType(H5Object& obj, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        DataType(H5File& h5file, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        DataType(Attribute& attr, const void* ref, H5R_type_t ref_type = H5R_OBJECT);

    have changed to
        DataType(const H5Location& loc, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        DataType(const Attribute& attr, const void* ref, H5R_type_t ref_type = H5R_OBJECT);

                                                                                            
  • These constructors
        Group(H5Object& obj, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        Group(H5File& h5file, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        Group(Attribute& attr, const void* ref, H5R_type_t ref_type = H5R_OBJECT);

    have changed to
        Group(const H5Location& loc, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
        Group(const Attribute& attr, const void* ref, H5R_type_t ref_type = H5R_OBJECT);
  • New Command-line Tool Options and Option Parameters

    h5dump
    h5dump has a new option for identifying objects by a full or partial path:
       -NP
       --any-path=P
     
    The h5dump attributes-only option, -A or --only-attr, now accepts an optional parameter value of 0 (zero):
       -A 0
       --only-attr=0
    Specifying this value has the effect of reversing the role of the option to display everything except attributes.
     
    h5repack
    The h5repack option -f, --filter has a new parameter, UD, to enable the use of user-defined filters:
       -f UD=<filter_parameters>
       --filter=UD=<filter_parameters>
     
    h5stat
    h5stat has three new options for setting print thresholds:
       For attributes:
          -aN
          --attribute=N
     
       For links in a group:
          -lN
          --links=N
     
       For dimension sizes:
          -mN
          --dims=N

    Build and Configuration

    CMake and Autotools configuration
    A new configuration option can be used to change the default plugin path:
        Autotools configure option      --with-default-plugindir=location
      cmake option      -DH5_DEFAULT_PLUGINDIR:PATH=location

    CMake configuration
    CMake builds of HDF5 now create *.so.{lt_version} files with the same version as configure.

    Autotools configure flag
    The configure flag FFLAGS has been renamed to FCFLAGS.

    Compile Scripts with Changed Behavior

    h5cc and h5pcc
    h5c++
    h5fc and h5pfc
    These compile scripts have been modified to change the default behavior to link to shared libraries in environments where HDF5 has been configured with --disable-static.

    Command-line Tools with Changed Behavior

    h5dump
    h5dump output now displays
        USER_DEFINED_FILTER
    where it previously displayed UNKNOWN_FILTER.
     
    h5dump now correctly exports subsetted data to a file using the -o, --output option.

    Release 1.8.11 of May 2013 versus Release 1.8.10

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.10 to Release 1.8.11.

    New and Changed Functions and Subroutines

    The following new high-level C function has been added:
    This function writes a data chunk directly into a file, bypassing hyperslab selection, data conversion, and the filter pipeline. The user must be careful with the function and clearly understand the I/O process of the library. See “Direct Chunk Write” for additional information.

    H5DOwrite_chunk is the first function in HDF5’s new high-level “HDF5 Optimized Functions” library.

    The following new C functions have been added:
    These functions scatter data to and gather data from a selection within a memory buffer.

    The following new Fortran subroutines have been added:
    Fortran90 subroutines:
    • h5odecr_refcount_f
    • h5oexists_by_name_f
    • h5oget_comment_f
    • h5oget_comment_by_name_f
    • h5oincr_refcount_f
    • h5oopen_by_idx_f
    • h5oset_comment_f
    • h5oset_comment_by_name_f
     
    • h5oclose_f was introduced in HDF5 Release 1.8.8 but remained undocumented until this release.
     
    Fortran2003 subroutines:
    • h5oget_info_f
    • h5oget_info_by_idx_f
    • h5ovisit_by_name_f

    New Feature: Dynamically Loaded Filters

    HDF5 now detects and dynamically loads external filters, reducing the need for an application to register custom filters or for a developer building on HDF5 to compile a custom filter into a customized HDF5 distribution.

    See “HDF5 Dynamically Loaded Filters” (PDF only) for further information.

    New Command-line Tool Option

    h5dump and h5import
    h5dump has a new option to output the DDL structure of a file or object:
       -O<file_name>
       --ddl=<file_name>
    [‘-O’ above is ‘dash-uppercase-o’.]

    h5import can now take the output of
       h5dump -O<ddl_file_name> -o<data_file_name>
    directly as input files.
    See “Using h5dump to create input for h5import” in the h5import reference manual entry.

    New Configuration and Build Tool

    cmakehdf5
    This new build command script is similar to buildhdf5 and is available in the bin/ directory of the distributed source code.

    For HDF5, the CMake minimum is now 2.8.10.

    Function, Subroutines, and Feature with Changed Syntax or Behavior

    The return value of the following high-level C function has changed:
    This function has been changed to not include the NULL terminator in the returned size of of the dimension scale name (bug fix).

    In the Fortran subroutines
    • h5pset_external_f and
    • h5pget_external_f
    the type of the offset parameter has changed to INTEGER(KIND=OFF_T) to support 8-byte integers, matching the C type definition of off_t.

    The HDF5 Library now supports data conversion from enumeration to integer and floating-point numeric datatypes.

    Command-line Tools with Changed Behavior

    h5diff
    When comparing two files or objects, h5diff now recognizes a unique extra attribute attached to an object as a difference and returns with an exit code of 1.

    Previously, h5diff did not recognize the extra attribute as a difference.

    h5ls
    The content of the h5ls --help output has been revised.

    h5dump
    h5dump has been updated to display the compression ratio for user-defined filters.
    In h5dump output, UNKNOWN_FILTER has been changed to USER_DEFINED_FILTER.

    Removed Functions and Wrappers

    The following C functions and the corresponding C++ wrappers have been removed:
    • H5Pset_dxpl_multi
    • H5Pget_dxpl_multi
       
    • H5::DSetMemXferPropList:setMulti
    • H5::DSetMemXferPropList:getMulti

    Release 1.8.10 of November 2012 versus Release 1.8.9

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.9 to Release 1.8.10.

    New and Changed Functions and Subroutines

    The following new C function has been added:
  • H5Pget_mpio_no_collective_cause
  • The following new Fortran subroutine has been added:
  • h5pget_mpio_actual_io_mode_f
  • The syntax of the following high-level C function has changed:
  • H5TBAget_fill
    This function’s return type has been changed to h5tri_t. A return value of 1 indicates that a fill value is present, 0 indicates that no fill value is present, and a negative value indicates an error. (The former return type was herr_t.)

    Note that H5TBAget_fill and a companion function H5TBAget_title, both in the HDF5 Table (H5TB) high-level API, are undocumented. These functions will be added to the HDF5 Reference Manual shortly after HDF5 Release 1.8.10.

  • Changed Command-line Tool

    h5import has been updated to accept an input file created by h5dump.

    Release 1.8.9 of May 2012 versus Release 1.8.8

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.8 to Release 1.8.9.

    New and Changed Functions

    A new high level C function and Fortran subroutine were added to HDF5 Lite (H5LT) to determine whether an HDF5 path is correct and resolves to a valid HDF5 object:

    The new file image operations feature consists of the following functions and their associated callbacks, struct, and ENUM. This feature enables an application to load a file into memory (as a file image) and to operate on that file image without the overhead of disk I/O. This feature provides the following functions:
      
     
    For the callbacks, struct, and ENUM, see H5Pset_file_image_callbacks.
    Use of this feature is described in “HDF5 File Image Operations” (PDF).
     

    The following functions were modified or added to the HDF5 Library to allow an application to control the operation of copying committed datatypes with H5Ocopy:
    Function with changed interface:
    New flag for use with H5Pset_copy_object:
    Function with changed behavior:
    • H5Ocopy
      This function’s behavior is changed, but only with the use of the new flag, H5O_COPY_MERGE_COMMITTED_DTYPE_FLAG.
    New functions and callback function:
     
    Use of this capability is described in “Copying Committed Datatypes with H5Ocopy” (PDF).
     

    The following C functions and Fortran subroutines were added to provide a mechanism to ensure sequential consistency in parallel environments using MPI I/O:
     
    Use of this capability is described in “Enabling a Strict Consistency Semantics Model in Parallel HDF5” (PDF).
     

    The following function was added at Release 1.8.5 but was not documented at that time. It is mentioned here for those who may have missed its introduction:

    New Fortran Subroutines

    The following Fortran subroutines have been added in this release: Where a subroutine is part of a new HDF5 feature, that feature is described above.

    Fortran Subroutine with Changed Behavior

    The content of the buffer returned by the following Fortran subroutine has changed as noted:
    • h5ltget_attribute_string_f
      If the returned buffer requires padding, h5ltget_attribute_string_f now employs space padding; this buffer was previously returned with a C NULL terminator.

    Command-line Utilities with New Options and/or Changed Behavior

    h5repack has one new option and improved performance under certain circumstances:
    • ‐Mn, ‐‐metadata_block_size=n
      Sets the metadata block size in the output file.
       
    • Performance is improved when repacking large chunked datasets (for example, when dataset size exceeds 128 MB).
     
    h5stat has one new option:
    • ‐S, ‐‐summary
      Displays a summary of file space usage for a file.
     
    h5dump has one new option, a new capability, and updated output:
    • ‐‐no-compact-subset
      Disables compact subsetting to allow the left-hand square bracket character ( [ ) in a dataset name.
       
    • The files parameter now accommodates wildcards. With this change, h5dump command-line options can be applied across multiple files without listing the files individually.
       
    • h5dump output has been updated for this release to improve compliance with the HDF5 DDL specification and to improve readablilty. This output is now fully compliant with the HDF5 DDL specification, but these changes may affect some user scripts:
      • Whitespace has been modified.
      • Display errors, such as misplaced brackets, have been fixed.
      • When printing superblock content, user block content is now properly displayed within the superblock.

    Release 1.8.8 of November 2011 versus Release 1.8.7

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.7 to Release 1.8.8.

    New C Functions

    Two new parallel I/O functions enable an application to query whether or how a collective I/O operation actually completed:

    Updated Fortran Interface, including Fortran 2003 Features

    The HDF5 Fortran interface has been extended and upgraded to Fortran 2003 for this release.

    See “Configure and Build Changes” below for the configure options to use when building HDF5 with Fortran 2003 enabled.

    Features enabled in this upgrade are described in New Features in the HDF5 Fortran Library: Adding Support for the Fortran 2003 Standard (PDF only). In general, the links below are to technical descriptions (reference manual entries, for example) of specific interfaces.

    Terminology: If the Fortran compiler in use is Fortran 2003 compliant and the installed HDF5 Library was configured using both the --enable-fortran and --enable-fortran2003 flags, the resulting HDF5 Fortran Library is referred to below as a Fortran 2003 environment. Without either of the Fortran 2003 compliant compiler or the --enable-fortran2003 flag, the resulting HDF5 Fortran Library is referred to below as a Fortran 90 environment.

    New Fortran 2003-only subroutines
    New subroutines available only in Fortran 2003 environments:

    Subroutines with Fortran 90 versions and extended features in Fortran 2003 environments
    Subroutines in this section have extended support in Fortran 2003 environments, but are new or unchanged in Fortran 90 environments.

    All existing Fortran 90 subroutines, including those not mentioned below, are available in both Fortran 90 and Fortran 2003 environments.

    Subroutines with support for the derived type C_PTR in Fortran 2003 environments:

    Subroutines with support for the derived type C_PTR and a changed signature in Fortran 2003 environments:

    Subroutine with additional optional parameters in Fortran 2003 environments:

    New and updated Fortran 90 subroutines
    New Fortran 90 subroutines:

    Updated Fortran 90 subroutines:

    * h5close_f has been modified in this release to close only the HDF5 Fortran Library interface; it no longer closes the underlying HDF5 Library.

    New Fortran utility functions and derived types
    New Fortran utility functions:

    • h5offsetof         Available only in Fortran 2003 environments.
    • h5kind_to_type     Available in either Fortran environment.

    New Fortran derived types in Fortran 2003 environments:

    New high level Fortran interface
    New Fortran subroutines in the HDF5 Dimension Scale high-level interface, H5DS:

    • h5dsset_scale_f
    • h5dsattach_scale_f
    • h5dsdetach_scale_f
    • h5dsis_attached_f
    • h5dsis_scale_f
    • h5dsset_label_f
    • h5dsget_label_f
    • h5dsget_scale_name_f
    • h5dsget_num_scales_f

    These subtroutines are available in both Fortran 90 and Fortran 2003 environments.

    C Functions with Changed Capability

    H5Tcreate now supports fixed-length and variable-length string types.

    Driver Changes on Windows Systems

    Changed behavior:
    HDF5’s Windows driver has been modified in this release to be a wrapper of the POSIX-compliant SEC2 driver. This change should be transparent to all user applications.

    New default driver:
    As of this release, the default driver on Windows systems is changed to SEC2; it had previously been the Windows driver.

    If you wish to use the Windows driver in an application, it remains fully available. In such cases, the driver must be set explicitly with a H5Pset_fapl_windows call.

    Command-line Utilities with Changed Behavior

    h5jam now checks the file that is to be inserted into the user block and does not allow the insertion if it is an HDF5 file. This is necessary because an HDF5 file in the user block will make the original HDF5 portion of the file inaccessable.

    h5diff with the --delta option reports two NaN values as equal regardless of the type of NaN (as described in the reference manual entry).

    h5diff, when comparing a file to itself, now reports no differences.

    Configure and Build Changes

    configure now uses the same flags and symbols in its tests as are used to build the library.

    To build HDF5 with the Fortran 2003 interfaces requires the use of two configure options:
        --enable-fortran  
        --enable-fortran2003  
    Note that building the Fortran 2003 interfaces requires a Fortran 2003-capable compiler and that --enable-fortran2003 cannot be used alone.

    The --enable-h5dump-packed-bits configure option has been removed. The code that this option enabled is now always compiled into h5dump.

    When building on Linux systems, the HDF5 Library now links with the bsd_compat library.

    Parallel Library and Configuration Changes

    The parallel HDF5 library now always compiles code to take advantage of MPI functionalities that allow for the use of complex derived datatypes during IO and that allow for collective IO when one or more processes do not contribute to the operation.

    This was previously conditionally compiled into the library and controlled by configure via the hdf5_cv_mpi_special_collective_io_works and hdf5_cv_mpi_complex_derived_datatype_works cache values. These values were preset in the config/* files based on the compiler and/or system or could be set on the configure line. Support for these cache values has been removed and they no longer have an effect on the compilation of the use of these MPI functionalities.


     
     

    Release 1.8.7 of May 2011 versus Release 1.8.6

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.6 to Release 1.8.7.

    New C Functions and Macros

    Three new functions enable the caching of files opened through external links. This cache can improve the performance of external links in heavy use cases:  
    Two new macros enable compile-time inclusion or exclusion of code depending on the version of the HDF5 Library against which an application is to be linked:

    C Functions with Changed Capability

    HDF5 now allows the size of any dataspace dimension to be 0 (zero). This was previously allowed only if the maximum size of the dimension was unlimited. Though their signatures have not changed, the range of valid parameter values is affected for the following functions: Note that no data can be written to a dataset in which the size of any dimension is set to zero.
     
    In the logging file driver, implementation of the following flags has been completed: H5FD_LOG_TIME_OPEN, H5FD_LOG_TIME_READ, H5FD_LOG_TIME_WRITE, and H5FD_LOG_TIME_SEEK
    Two new flags have been added: H5FD_LOG_NUM_TRUNCATE and H5FD_LOG_TIME_STAT.
     
    HDF5 now blocks committing a datatype that cannot hold any data. This currently includes compound datatypes with no fields and enumerated datatypes with no members. HDF5 has long blocked creating a dataset or attribute with such a datatype.

    Fortran Subroutines with Changed Capability

    Several h5ltmake_dataset*_f and h5ltread_dataset*_f subroutines have been modified to allow them to create or read arrays of up to seven dimensions. They had previously been limited to three dimensions.
        
  • h5ltmake_dataset_f
  • h5ltmake_dataset_int_f
  • h5ltmake_dataset_float_f
  • h5ltmake_dataset_double_f
  •     
  • h5ltread_dataset_f
  • h5ltread_dataset_int_f
  • h5ltread_dataset_float_f
  • h5ltread_dataset_double_f
  •  
    h5tbget_field_info_f has a new maxlen_out parameter. This parameter is optional.

    Command-line Utilities with New Options

    h5diff has a new verbose with levels option to display additional attribute information:
    • -vn, --verbose=n
     
    h5dump has one new option to enable reporting of the HDF5 Library’s error stack:
    • --enable-error-stack

    Command-line Utility with Changed Option Name

    h5ls has one changed option name:
    • --enable-error-stack replaces --error.
    The --error option is deprecated but remains available.

    Command-line Utilities with Changed Behavior

    Attribute comparison with h5diff has been corrected to compare all attributes with common names when comparing objects. Previously, h5diff compared attributes correctly only when two objects had the same number of attributes and all attribute names were identical; if there was either a value or name difference between two attributes, subsequent attributes were not compared.

    h5diff --use-system-epsilon now employs the formula '|a - b|' instead of '|a - b| / b'.

    h5copy now accepts the same file as the source and target file; this enables object copying within a file.

    h5dump now displays reference types as described in DDL in BNF for HDF5:
         H5T_REFERENCE {H5T_STD_REF_OBJ} Object reference
      H5T_REFERENCE {H5T_STD_REF_DSETREG}   Dataset region reference

    Configure and Build Changes

    Configure now generates Makefiles that build in silent make mode by default. In this mode, compile and link lines are significantly simplified for clarity. You can opt out of this default with either of the following approaches:

    The new configure option --enable-unsupported can be used to stop configure from preventing the use of unsupported configure option combinations. For example, use of this option enables building HDF5 with the unsupported and untested configurations of C++ in a parallel environment or Fortran with a threadsafe library.

    Parallel HDF5

    mpicc and mpif90 are now the default C and Fortran compilers on Linux systems when --enable-parallel is specified but no $CC or $FC is defined.

    Release 1.8.6 versus Release 1.8.5, February 2011

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.5 to Release 1.8.6.

    C Functions with Additional Capability

    H5Tset_order and H5Tget_order can now be used with all datatypes. See the related note regarding H5T_ORDER_MIXED immediately below.

    ENUM with New Member

    H5T_order_t, an ENUM used to set or indicate datatype endianness, includes a new member:

         H5T_ORDER_MIXED

    The function H5Tget_order returns this value when called on a compound datatype whose members are not all of the same endianness.

    Command-line Utilities with New Options

    h5diff has one new option:
    • --exclude-path

    h5ls and h5diff have two new options:
    • --follow-symlinks
    • --no-dangling-links

    Command-line Utilities with Changed Behavior

    h5diff now compares member objects and groups recursively when two files or groups are specified to be compared.

    h5ls now displays object and attribute names exactly as stored in the file rather than interpreting them for output. For example, if an attribute is named \ttemp in the file, h5ls will output that name as \ttemp rather than converting the leading \t to a tab.

    h5repack can now convert a dataset to compact layout.

    Compiler Script Arguments and Environment Variables

    h5cc, h5fc, h5c++, h5pcc, and h5pfc arguments have been expanded to enable the user to add compiler and linker flags that will take precedence over the flags from the HDF5 build.

    The arguments CPPFLAGS, CFLAGS, LDFLAGS, and LIBS have been duplicated with the prefix H5BLD_ to put the flags and paths from the HDF5 build in the correct places and to allow the script user to add entries in CPPFLAGS, CFLAGS, LDFLAGS, and LIBS that will take precedence over those from the HDF5 build. Changes to these entries can be made persistent by editing CFLAGSBASE, CPPFLAGSBASE, LDFLAGSBASE, and LIBSBASE near the top of the script. If the change is to be temporary, the user can set HDF5_CFLAGS, HDF5_CPPFLAGS, HDF5_LDFLAGS, or HDF5_LIBS in the environment.

    The new order of arguments for these scripts is as follows:

            $CLINKER 
            $H5BLD_CPPFLAGS 
            $CPPFLAGS 
            $H5BLD_CFLAGS 
            $CFLAGS 
            $LDFLAGS 
            $clibpath 
            $link_objs 
            $LIBS 
            $link_args 
            $shared_link
                

    Thread Safety on Windows

    This release adds support for thread safety on Windows using the Windows threads library. See the file RELEASE.txt in the distributed HDF5 source code (hdf5/release_docs/RELEASE.txt) for details.

    Parallel HDF5

    The Parallel HDF5 build process has changed to use mpiexec instead of mpirun.

    Release 1.8.5 versus Release 1.8.4, June 2010

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.4 to Release 1.8.5.

    New C Function

    The following function was added to the HDF5 Library at this release, but was not documented at that time: (This note added in November 2011, shortly following Release 1.8.8.)

    C Functions with Additional Capability

    The following functions have been modified to accommodate filters set on a group creation property list:
    H5Pall_filters_avail
    H5Pget_filter1
    H5Pget_filter2
    H5Pget_filter_by_id1
    H5Pget_filter_by_id2
    H5Pget_nfilters
         H5Pmodify_filter
    H5Premove_filter
    H5Pset_deflate
    H5Pset_filter
    H5Pset_fletcher32

    Related to H5Zregister, the calling protocol for the can_apply and set_local callback functions has been extended to accommodate the use of filters on group creation property lists.

    New C++ Member Function and Overloaded Member Functions

    The following C++ member function is new in this release:
    DataSet::getInMemDataSize    To simplify getting a dataset’s data size in memory.

    The overloaded forms of the following C++ member functions are new in this release:
    CommonFG::getObjnameByIdx    Overloaded to take char* for name.
    CommonFG::getObjTypeByIdx    Overloaded to return type name as a char*.

    Command-line Utility with New Options

    h5diff has two new options:
    • --follow-links
    • --no-dangling-links

    Fortran Subroutines with Changed Interface

    The link type parameter values associated with the following Fortran subroutines have changed in this release:
    • h5lget_info_f
    • h5lget_info_by_idx_f

    • Valid values for the parameter link_type have changed to the following:
           H5L_TYPE_HARD_F
           H5L_TYPE_SOFT_F
           H5L_TYPE_EXTERNAL_F
           H5L_TYPE_ERROR_F
      These values previously began with the string 'H5L_LINK_'.

    CMake

    This release includes an adaptation enabling HDF5 builds with CMake. This early-stage adaptation is distributed to provide an opportunity for early access and experimentation; the CMake-related files should not be viewed as final and may change before the next release.

    While the initial development effort has been focussed on Microsoft Windows platforms, the HDF5 Library has been successfully built with CMake on Linux and Mac OS X.

    See the file CMake.txt in the distributed HDF5 source code (hdf5/release_docs/CMake.txt) for details.

    Release 1.8.4 versus Release 1.8.3, November 2009

    This section lists interface-level changes and other user-visible changes in behavior in the transition from HDF5 Release 1.8.3 to Release 1.8.4.

    Embedded HDF5 Library Settings Information

    Library settings are now embedded in an HDF5 executable so that an “orphaned” executable can be queried (via the Unix strings command, for example) to display the library settings used to build it. The embedded settings information is the same as that normally found in the libhdf5.settings file.

    This capability may be disabled with the use of the --disable-embedded-libinfo flag during configure.

    New Fortran Subroutine and Constant

    The following Fortran subroutine is new in this release: h5oopen_by_addr_f
    The following Fortran constant, corresponding to the C constant H5T_ORDER_NONE, has been added in this release: H5T_ORDER_NONE_F

    New C++ Member Functions

    New C++ member functions are provided to determine a dataset’s or attribute’s data size in memory: size_t DataSet::getInMemDataSize() const
    size_t Attribute::getInMemDataSize() const
    The size in each case is in bytes.

    Function with Changed Interface or Behavior

    H5check_version now displays embedded library information (see above) if a version mismatch is detected.

    The function has also been changed to suppress the warning message entirely if $HDF5_DISABLE_VERSION_CHECK is set to 2 or higher.

    Fortran Subroutines with Changed Syntax

    The following Fortran subroutines have changed syntax in this release:
    • h5lget_info_f
    • The type of the parameter address has changed from INTEGER to INTEGER(HADDR_T).
      (This note added on 13 January 2010.)

    • h5lget_info_by_idx_f
    • h5lget_info_by_idx_f (loc_id, group_name, index_field, order, n, &
           link_type, f_corder_valid, corder, cset, address, val_size, &
           hdferr, lapl_id)

      The parameters link_type, address, and val_size have been added; the parameter data_size has been removed.

    Tools with Changed Interface or Behavior

    h5diff has one new option: --use-system-epsilon

    With this option, h5diff returns a difference if and only if the difference between two data values exceeds the system value for epsilon (that is, if |a-b| > epsilon).

    The tool’s default behavior has also changed; without this option, the tool now checks for strict equality. Prior default behavior was to use an epsilon internally defined in HDF5.

    This option has no short form.

    h5dump has one new option and the behavior of another set of options has changed: -R or --region

    With this option, h5dump prints the data pointed to by a region reference. Without this option, h5dump prints only the reference.

    Usage of the subsetting parameters has changed. All of START, STRIDE, COUNT, and BLOCK now have default values. If those defaults are satisfactory, h5dump no longer requires that all four be specifiespecified when subsetting a dataset.

    Changed Library Configuration

    The following configuration flag is new with this release: --disable-embedded-libinfo This flag disables the embedding of HDF5 Library settings in an HDF5 executable.

    Release 1.8.3 versus Release 1.8.2, May 2009

    This section lists API-level changes and changes in behavior in the transition from HDF5 Release 1.8.2 to Release 1.8.3.

    New Functions

    C functions:
    The following C functions are new for this release and are documented in the HDF5 Reference Manual.
         H5Pset_elink_cb           herr_t H5Pset_elink_cb( hid_t lapl_id, H5L_elink_traverse_t func, void *op_data )
    See entry.
         H5Pget_elink_cb           herr_t H5Pget_elink_cb( hid_t lapl_id, H5L_elink_traverse_t *func, void **op_data )
    See entry.
         H5Pset_elink_acc_flags           herr_t H5Pset_elink_acc_flags( hid_t lapl_id, unsigned flags )
    See entry.
         H5Pget_elink_acc_flags           herr_t H5Pget_elink_acc_flags( hid_t lapl_id, unsigned *flags )
    See entry.
         H5Pset_chunk_cache           herr_t H5Pset_chunk_cache( hid_t dapl_id, size_t rdcc_nslots, size_t rdcc_nbytes, double rdcc_w0 )
    See entry.
         H5Pget_chunk_cache           herr_t H5Pget_chunk_cache( hid_t dapl_id, size_t *rdcc_nslots, size_t *rdcc_nbytes, double *rdcc_w0 )
    See entry.
         H5Dget_access_plist           hid_t H5Dget_access_plist( hid_t dset_id )
    See entry.
         H5Iis_valid           htri_t H5Iis_valid( hid_t id )
    See entry.

    Fortran Subroutines:
    The following subroutines are new in this release: h5dget_access_plist_f  
    h5iis_valid_f  
    h5pset_chunk_cache  
    h5pget_chunk_cache  

    Function with Changed Behavior

    H5set_free_list_limits
    The HDF5 Library now dynamically creates separate factory free lists to manage blocks of a fixed size; these blocks were previously managed within the blockfree lists. Factory free lists use the same settings as specified in H5set_free_list_limits for block free lists.

    While the API has not changed, users may see both a performance boost and increased memory usage.

    Tools with Changed Interface or Behavior

    h5diff
    The default behavior of h5diff is now to detect and compare NaNs. Use the -N or --nan option (below) to turn this behavior off and avoid the performance penalty that NaN detection and comparison entalis. (NaN detection and comparison became the default in in HDF5 Release 1.6.8.)

    This tool has two new options:

         -c, --compare      Lists objects that are not comparable.

         -N, --nan          Avoids NaNs detection.

    h5dump
    h5dump now correctly specifies an XML DTD or a schema URL.

    h5dump binary output now defaults to NATIVE.

    The new -b, --binary option can be used to specify alternate binary formats.

    h5repack
    When a user does not specify a chunk size, h5repack now defines the default chunk size to be the same same as the size of the hyperslab used to read the chunks.

    Release 1.8.2 versus Release 1.8.1, November 2008

    This section lists API-level changes and changes in behavior in the transition from HDF5 Release 1.8.1 to Release 1.8.2.

    New Functions

    C functions:
    The following C functions are new for this release and are documented in the HDF5 Reference Manual.
         H5Pset_elink_fapl           herr_t H5Pset_elink_fapl( hid_t lapl_id, hid_tfapl_id )
    See entry.
      H5Pget_elink_fapl        hid_t H5Pget_elink_fapl( hid_t lapl_id )
    See entry.

    Fortran Subroutine:
    The following subroutine is new in this release:
         H5Tget_native_type_f

    New C++ Wrappers

    The following functions were added as wrappers for the C function H5Rdereference to replace the incorrect IdComponent::dereference():
            void H5Object::dereference(H5Object& obj, void* ref, 
                                       H5R_type_t ref_type=H5R_OBJECT)
            void H5Object::dereference(H5File& h5file, void* ref, 
                                       H5R_type_t ref_type=H5R_OBJECT)
            void H5Object::dereference(Attribute& obj, void* ref, 
                                       H5R_type_t ref_type=H5R_OBJECT)
                    

    The following constructors were added to create the associated objects by way of dereference:

            DataSet(H5Object& obj, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            DataSet(H5File& file, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            DataSet(Attribute& attr, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            Group(H5Object& obj, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            Group(H5File& obj, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            Group(Attribute& attr, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            DataType(H5Object& obj, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            DataType(H5File& file, void* ref, H5R_type_t ref_type=H5R_OBJECT)
            DataType(Attribute& attr, void* ref, H5R_type_t ref_type=H5R_OBJECT)
                    

    Functions with Changed Syntax

    The following function syntaxes have changed; the affected return values and parameter are noted as underscored red text.

    C functions:
    H5Fget_obj_count
    ssize_t H5Fget_obj_count( hid_t file_id, unsigned int types )

    H5Fget_obj_ids
    ssize_t H5Fget_obj_ids( hid_t file_id, unsigned int types,
            size_t max_objs, hid_t *obj_id_list )

    Changed Fortran Subroutines

    The optional parameter mounted has been added to the following subroutines:
    h5gget_info_f
    h5gget_info_by_idx_f
    h5gget_info_by_name_f     

    Changed Data Structure

    H5G_info_t
    A mounted filed has been added to the H5G_info_t struct.

    Tools with Changed Interface or Behavior

    h5diff
    h5diff now returns 1 if the files differ in structure, i.e., if the file graphs differ by any object.

    The tool’s error return code has been changed to 2.

    h5repack and h5diff
    The standard command-line syntax of both tools has been changed to parallel that of h5dump. The new syntax of each is as follows:

         h5repack [OPTIONS] file1 file2

         h5diff [OPTIONS] file1 file2 [object1 [object2]]

    In each case, the old syntax remains available (though undocumented) to avoid breaking existing scripts.

    h5repack
    The following new options control the addition of user block data to an existing HDF5 file:
    -u U
    --ublock=U
         Specifies the name of the file containing the user block data to be added.

    -b B
    --block=B
        
    Specifies the size of the block to be added.

    The following new options set parameters governing the tool’s use of H5Pset_alignment:
    -t T
    --threshold=T
         Specifies the threshold value for H5Pset_alignment.

    -a A
    --alignment=A
        
    Specifies the alignment value for H5Pset_alignment.

    h5repack now supports multiple instances of the '-f' or '--filter' option, allowing the use of multiple I/O filters with an object.

    With no change in the command-line syntax, h5repack now retains an existing userblock when repacking an HDF5 file.

    h5import
    The floating point format flag TEXTFPE, for scientific notation, has been deprecated. The flag TEXTFP, which accepts scientific notation, should be used instead.

    h5import now imports string data with the STR keyword in the INPUT-CLASS configuration field.

    h5dump and h5ls
    These tools now traverse external links when performing recursive traversals.

    h5dump
    Binary output now defaults to NATIVE with the '-b' option, optionally accepting NATIVE, FILE, BE, and LE.

    The new '-m T' or '--format T' option enables a user-defined formatting string for printing floating-point numbers.

    With no change in the command-line syntax, h5dump now prints a compression ratio when compression filters are in use.

    Deprecated Functions

    The following functions are deprecated as of this release:
            H5Pset_preserve
            H5Pget_preserve 

    The original role of these functions is now part of the core HDF5 Library functionality.

    Changed File Installation

    The file libhdf5_fortran.settings is no longer installed with the HDF5 Library; the original content of that file is now included in libhdf5.settings.

    Changed Library Configuration

    It is no longer necessary to manually set an SZIP library path in LD_LIBRARY_PATH when building HDF5 with shared SZIP libraries; configure will determine the correct path from the --with-szlib flag, prepending it to and exporting LD_LIBRARY_PATH.

    Note that if an SZIP library path is set in a user-supplied LD_LIBRARY_PATH, in an existing script, for example, that does not necessarily need to be changed; configure will prepend the SZIP library path extracted from --with-szlib to the user-supplied LD_LIBRARY_PATH.


    Release 1.8.1 versus Release 1.8.0

    HDF5 Release 1.8.1 is a minor release with several bugfixes and optimizations and limited new features.

    The most significant new feature is an expanded set of Fortran90 APIs, enabling essentially all new C library features of Release 1.8.0.

    New Functions and Tools

    C functions:
    There are no new C functions for Release 1.8.1.

    Fortran subroutines:
    The following Fortran subroutines are new for Release 1.8.1 and are documented in the HDF5 Reference Manual.

    H5A
    h5acreate_f
    h5acreate_by_name_f
    h5adelete_by_idx_f
    h5adelete_by_name_f
    h5aexists_f
    h5aexists_by_name_f
    h5aget_create_plist_f
    h5aget_info_f
    h5aget_info_by_idx_f
                      
     
    h5aget_info_by_name_f
    h5aget_name_by_idx_f
    h5aget_storage_size_f
    h5aopen_f
    h5aopen_by_idx_f
    h5aopen_by_name_f
    h5arename_f
    h5arename_by_name_f
                      
    H5D
    h5dcreate_anon_f
    h5dcreate_f
                      
     
    h5dopen_f
    h5dset_extent_f
                      
    H5G
    h5gcreate_anon_f
    h5gcreate_f
    h5gget_create_plist_f
    h5gget_info_f
                      
     
    h5gget_info_by_idx_f
    h5gget_info_by_name_f
    h5gopen_f
                      
    H5L
    h5lcopy_f
    h5lcreate_external_f
    h5lcreate_hard_f
    h5lcreate_soft_f
    h5ldelete_f
    h5ldelete_by_idx_f
                      
     
    h5lexists_f
    h5lget_info_f
    h5lget_info_by_idx_f
    h5lget_name_by_idx_f
    h5lmove_f
                      
    H5O
    h5olink_f
                      
     
    h5oopen_f
                      
    H5P
    h5pget_attr_creation_order_f
    h5pget_attr_phase_change_f
    h5pget_char_encoding_f
    h5pget_copy_object_f
    h5pget_create_inter_group_f
    h5pget_data_transform_f
    h5pget_elink_prefix_f
    h5pget_est_link_info_f
    h5pget_fapl_direct_f
    h5pget_link_creation_order_f
    h5pget_link_phase_change_f
    h5pget_local_heap_size_hint_f
    h5pget_nlinks_f
    h5pget_obj_track_times_f
    h5pget_shared_mesg_index_f
    h5pget_shared_mesg_nindexes_f
                      
     
    h5pset_attr_creation_order_f
    h5pset_attr_phase_change_f
    h5pset_char_encoding_f
    h5pset_copy_object_f
    h5pset_create_inter_group_f
    h5pset_data_transform_f
    h5pset_elink_prefix_f
    h5pset_est_link_info_f
    h5pset_fapl_direct_f
    h5pset_libver_bounds_f
    h5pset_link_creation_order_f
    h5pset_link_phase_change_f
    h5pset_local_heap_size_hint_f
    h5pset_obj_track_times_f
    h5pset_nbit_f
    h5pset_nlinks_f
    h5pset_scaleoffset_f
                      
    H5R
    h5rget_name_f
                      
     
                      
    H5S
    h5sdecode_f
    h5sencode_f
                      
     
    h5sextent_equal_f
                      
    H5T
    h5tcommit_anon_f
    h5tcommit_f
    h5tcommitted_f
    h5tcompiler_conv_f
                      
     
    h5tdecode_f
    h5tencode_f
    h5tget_create_plist_f
    h5topen_f
                      

    C++ wrappers:
    There are no new C++ wrappers for Release 1.8.1.

    Functions and Tools with Changed Syntax

    C functions with changed syntax:
    There are no C functions with changed syntax in Release 1.8.1.

    Fortran subroutines with changed syntax:
    In the following Fortran subroutines, spos is a new parameter indicating the position of the sign bit:
         h5tset_fields_f(type_id, spos, epos, esize, mpos, msize, hdferr)
         h5tget_fields_f(type_id, spos, epos, esize, mpos, msize, hdferr)

    Changed C++ wrappers:
    • The class AbstractDS was moved out of H5Object.

      The class Attribute now multiply inherits from IdComponent and AbstractDs; the class DataSet now multiply inherits from H5Object and AbstractDs.

      In addition, data member IdComponent::id was moved into subclasses: Attribute, DataSet, DataSpace, DataType, H5File, Group, and PropList.

    • IdComponent::dereference was incorrect; it was changed from:
           void IdComponent::dereference(IdComponent& obj, void* ref)
      to:
           void H5Object::dereference(H5File& h5file, void* ref)
           void H5Object::dereference(H5Object& obj, void* ref)

    Tools with changed syntax:
    • The command-line syntax of h5repack was changed in Release 1.8.0 to the following:
           h5repack [OPTIONS] in_file out_file

      Since this would be imcompatible with existing user scripts, the original syntax has be re-enabled in this release:
           h5repack -i in_file -o out_file [OPTIONS]

      h5repack now understands either syntax.

    • An h5repack option to set the minimum number of links in indexed format was introduced in Release 1.8.0 as '-d min_indexed_links' or '--indexed=min_indexed_links'. In Release 1.8.1, the '-i' form has been changed to '-d' as follows:
           -d min_indexed_links
      or
           --indexed=min_indexed_links

    • The command-line syntax of h5diff was changed in Release 1.8.0 to the following:
           h5diff [OPTIONS] file1 file2 [object1 [object2 ] ]

    Tools with new options:
    • h5dump -m T  or  --format T   Sets format of floating point output

    Changed Behavior or Output

    Changed library behavior:
    A 4GB limit on the size of dataset chunks is now properly enforced when a dataset is created.

    The HDF5 Library now works more effectively with external links. Some valid external links that previously failed will now be properly recognized. See H5Lcreate_external.

    C functions with changed behavior:
    The behavior of H5Lcreate_external has changed as described immediately above.

    Tools with changed behavior and changed output:
    The h5dump -p option now prints the compression ratio if a compression filter is associated with a dataset.

    h5dump now supports external links, displaying the target objects (datasets, groups, and named datatypes).

    Tools with changed output:

    Changed Library Configuration

    The following configuration flag is new with this release:
    --disable-sharedlib-rpath

    Removed Patch Requirement

    The patch that was required for Cygwin with HDF5 Release 1.8.0 has been rolled into this release and no longer needs to be applied by the user.

    Release 1.8.0 versus Release 1.6.x

    HDF5 Release 1.8.0 is a major release with several new features and a variety of bugfixes, optimizations, and portability enhancements.

    See the document “What’s New in HDF5 1.8.0” for a high-level overview of the new functionality in this release. The following pages assume a familiarity with that overview.

    This section provides details of the API-level changes that have been made in the transition to HDF5 Release 1.8.0 from the Release 1.6.x series.

    API Compatibility Macros with Associated Renamed and New Functions

    Release 1.8.0 introduces API compatibility macros designed to facilitate application migration. These macros are intended to facilitate developer management of a clean, step-by-step migration from an older HDF5 Library to the new release; they can also be used to enable older applications to use the new library without requiring that the application be rewritten. See API Compatibility Macros in HDF5 for a full description.

    Macros are identified in reference manual function indexes by an italic typeface.

    The new macros and the new and old functions to which they may be mapped are as follows:

    H5Acreate      H5Acreate1 
    H5Acreate2 
    Renamed from H5Acreate
    New
    H5Aiterate      H5Aiterate1 
    H5Aiterate2 
    Renamed from H5Aiterate
    New
    H5Dcreate      H5Dcreate1 
    H5Dcreate2 
    Renamed from H5Dcreate
    New
    H5Dopen      H5Dopen1 
    H5Dopen2 
    Renamed from H5Dopen
    New
    H5Eclear      H5Eclear1 
    H5Eclear2 
    Renamed from H5Eclear
    New
    H5Eget_auto      H5Eget_auto1 
    H5Eget_auto2 
    Renamed from H5Eget_auto
    New
    H5Eprint      H5Eprint1 
    H5Eprint2 
    Renamed from H5Eprint
    New
    H5Epush      H5Epush1 
    H5Epush2 
    Renamed from H5Epush
    New
    H5Eset_auto      H5Eset_auto1 
    H5Eset_auto2 
    Renamed from H5Eset_auto
    New
    H5Ewalk      H5Ewalk1 
    H5Ewalk2 
    Renamed from H5Ewalk
    New
    H5Gcreate      H5Gcreate1 
    H5Gcreate2 
    Renamed from H5Gcreate
    New
    H5Gopen      H5Gopen1 
    H5Gopen2 
    Renamed from H5Gopen
    New
    H5Pget_filter      H5Pget_filter1 
    H5Pget_filter2 
    Renamed from H5Pget_filter
    New
    H5Pget_filter_by_id      H5Pget_filter_by_id1    
    H5Pget_filter_by_id2 
    Renamed from H5Pget_filter_by_id
    New
    H5Pinsert      H5Pinsert1 
    H5Pinsert2 
    Renamed from H5Pinsert
    New
    H5Pregister      H5Pregister1 
    H5Pregister2 
    Renamed from H5Pregister
    New
    H5Rget_obj_type      H5Rget_obj_type1 
    H5Rget_obj_type2 
    Renamed from H5Rget_obj_type
    New
    H5Tarray_create      H5Tarray_create1 
    H5Tarray_create2 
    Renamed from H5Tarray_create
    New
    H5Tcommit      H5Tcommit1 
    H5Tcommit2 
    Renamed from H5Tcommit
    New
    H5Tget_array_dims      H5Tget_array_dims1 
    H5Tget_array_dims2 
    Renamed from H5Tget_array_dims
    New
    H5Topen      H5Topen1 
    H5Topen2 
    Renamed from H5Topen
    New

    (H5Dcreate and H5Dopen added to the above list in November 2010, prior to Release 1.8.6.)

    New Functions and Tools

    C functions:
    The following C functions are new for Release 1.8.0 and, unless otherwise noted, are documented in the HDF5 Reference Manual.

    Recursive iteration
     
    H5Lvisit      herr_t H5Lvisit( hid_t group_id, H5_index_t index_type, H5_iter_order_t order, H5L_iterate_t op, void *op_data )
    See entry.
    H5Lvisit_by_name      herr_t H5Lvisit_by_name( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, H5L_iterate_t op, void *op_data, hid_t lapl_id )
    See entry.
    H5Ovisit      herr_t H5Ovisit( hid_t group_id, H5_index_t index_type, H5_iter_order_t order, H5O_iterate_t op, void *op_data )
    See entry.
    H5Ovisit_by_name      herr_t H5Ovisit_by_name( hid_t loc_id, const char *object_name, H5_index_t index_type, H5_iter_order_t order, H5O_iterate_t op, void *op_data, hid_t lapl_id )
    See entry.

    “Format bounds” property
    Release-to-release format compatibility
     
    H5Pset_libver_bounds      herr_t H5Pset_libver_bounds( hid_t fapl_id, H5F_libver_t low, H5F_libver_t high )
    See entry.
    H5Pget_libver_bounds      herr_t H5Pget_libver_bounds( hid_t fapl_id, H5F_libver_t *low, H5F_libver_t *high )
    See entry.

    Configurable compact-or-indexed
    groups (compact and large groups)
     
    H5Pset_link_phase_change      herr_t H5Pset_link_phase_change( hid_t gcpl_id, unsigned max_compact, unsigned min_dense )
    See entry.
    H5Pget_link_phase_change      herr_t H5Pget_link_phase_change( hid_t gcpl_id, unsigned *max_compact, unsigned *min_dense )
    See entry.
    H5Pset_est_link_info      herr_t H5Pset_est_link_info( hid_t gcpl_id, unsigned est_num_entries, unsigned est_name_len )
    See entry.
    H5Pget_est_link_info      herr_t H5Pget_est_link_info( hid_t gcpl_id, unsigned *est_num_entries, unsigned *est_name_len )
    See entry.
    H5Pset_nlinks      herr_t H5Pset_nlinks( hid_t lapl_id, size_t nlinks )
    See entry.
    H5Pget_nlinks      herr_t H5Pget_nlinks( hid_t lapl_id, size_t *nlinks )
    See entry.

    User-defined links
     
    H5Lcreate_ud      herr_t H5Lcreate_ud( hid_t link_loc_id, const char *link_name, H5L_type_t link_type, const char *udata, size_t udata_size, hid_t lcpl_id, hid_t lapl_id )
    See entry.
    H5Lregister      herr_t H5Lregister( const H5L_class_t * link_class )
    See entry.
    H5Lunregister      herr_t H5Lunregister( H5L_type_t link_cls_id )
    See entry.
    H5Oincr_refcount      herr_t H5Oincr_refcount( hid_t object_id )
    See entry.
    H5Odecr_refcount      herr_t H5Odecr_refcount( hid_t object_id )
    See entry.

    External links
     
    H5Lcreate_external      herr_t H5Lcreate_external( const char *file_name, const char *object_name, hid_t link_loc_id, const char *link_name, hid_t lcpl_id, hid_t lapl_id )
    See entry.
    H5Lunpack_elink_val      herr_t H5Lunpack_elink_val( char *ext_linkval, size_t link_size, const char **filename, const char **obj_path )
    See entry.
    H5Pset_elink_prefix      herr_t H5Pset_elink_prefix( hid_t lapl_id, const char *prefix )
    See entry.
    H5Pget_elink_prefix      herr_t H5Pget_elink_prefix( hid_t lapl_id, const char **prefix )
    See entry.

    Link creation order
    tracking and indexing
     
    H5Pset_link_creation_order      herr_t H5Pset_link_creation_order( hid_t ocpl_id, unsigned *crt_order_flags )
    See entry.
    H5Pget_link_creation_order      herr_t H5Pget_link_creation_order( hid_t ocpl_id, unsigned *crt_order_flags )
    See entry.
    H5Gget_create_plist      hid_t H5Gget_create_plist( hid_t group_id )
    See entry.
    H5Gget_info_by_idx      herr_t H5Gget_info_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, hsize_t n, H5G_info_t *group_info, hid_t lapl_id )
    See entry.
    H5Tget_create_plist      hid_t H5Tget_create_plist( hid_t dtype_id )
    See entry.

    Link API (H5L), an all-new interface
    (includes user-defined and external links)
     
    H5Lcopy      herr_t H5Lcopy( hid_t src_loc_id, const char *src_name, hid_t dest_loc_id, const char *dest_name, hid_t lcpl_id hid_t lapl_id )
    See entry.
    H5Lcreate_external      herr_t H5Lcreate_external( const char *file_name, const char *object_name, hid_t link_loc_id, const char *link_name, hid_t lcpl_id, hid_t lapl_id )
    See entry.
    H5Lcreate_hard      herr_t H5Lcreate_hard( hid_t obj_loc_id, const char *obj_name, hid_t link_loc_id, const char *link_name, hid_t lcpl_id, hid_t lapl_id )
    See entry.
    H5Lcreate_soft      herr_t H5Lcreate_soft( const char *target_path, hid_t link_loc_id, const char *link_name, hid_t lcpl_id, hid_t lapl_id )
    See entry.
    H5Lcreate_ud      herr_t H5Lcreate_ud( hid_t link_loc_id, const char *link_name, H5L_type_t link_type, const char *udata, size_t udata_size, hid_t lcpl_id, hid_t lapl_id )
    See entry.
    H5Ldelete      herr_t H5Ldelete( hid_t loc_id, const char *name, hid_t lapl_id )
    See entry.
    H5Ldelete_by_idx      herr_t H5Ldelete_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, hid_t lapl_id )
    See entry.
    H5Lexists      htri_t H5Lexists( hid_t loc_id, const char *name, hid_t lapl_id )
    See entry.
    H5Lget_info      herr_t H5Lget_info( hid_t link_loc_id, const char *link_name, H5L_info_t *link_buff, hid_t lapl_id )
    See entry.
    H5Lget_info_by_idx      herr_t H5Lget_info_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, H5L_info_t *link_val, hid_t lapl_id )
    See entry.
    H5Lget_name_by_idx      ssize_t H5Lget_name_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, char *name, size_t size, hid_t lapl_id )
    See entry.
    H5Lget_val      herr_t H5Lget_val( hid_t link_loc_id, const char *link_name, void *linkval_buff, size_t size, hid_t lapl_id )
    See entry.
    H5Lget_val_by_idx      ssize_t H5Lget_val_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, char *value_buf, size_t size, hid_t lapl_id )
    See entry.
    H5Lis_registered      htri_t H5Lis_registered( H5L_type_t link_cls_id )
    See entry.
    H5Literate      herr_t H5Literate( hid_t loc_id, H5_index_t index_type, H5_iter_order_t order, hsize_t *idx, H5L_iterate_t op, void *op_data )
    See entry.
    H5Literate_by_name      herr_t H5Literate( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, hsize_t *idx, H5L_iterate_t op, void *op_data, hid_t *lapl_id )
    See entry.
    H5Lmove      herr_t H5Lmove( hid_t src_loc_id, const char *src_name, hid_t dest_loc_id, const char *dest_name, hid_t lcpl, hid_t lapl )
    See entry.
    H5Lregister      herr_t H5Lregister( const H5L_class_t * link_class )
    See entry.
    H5Lunpack_elink_val      herr_t H5Lunpack_elink_val( char *ext_linkval, size_t link_size, const char **filename, const char **obj_path )
    See entry.
    H5Lunregister      herr_t H5Lunregister( H5L_type_t link_cls_id )
    See entry.
    H5Lvisit      herr_t H5Lvisit( hid_t group_id, H5_index_t index_type, H5_iter_order_t order, H5L_iterate_t op, void *op_data )
    See entry.
    H5Lvisit_by_name      herr_t H5Lvisit_by_name( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, H5L_iterate_t op, void *op_data, hid_t lapl_id )
    See entry.

    Enhanced attribute handling
     
    H5Acreate2      hid_t H5Acreate2( hid_t loc_id, const char *obj_name, const char *attr_name, hid_t type_id, hid_t space_id, hid_t acpl_id, hid_t aapl_id, hid_t lapl_id )
    See entry.
    H5Adelete_by_idx      herr_t H5Adelete_by_idx( hid_t loc_id, const char *obj_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t n, hid_t lapl_id )
    See entry.
    H5Adelete_by_name      herr_t H5Adelete_by_name( hid_t loc_id, const char *obj_name, const char *attr_name, hid_t lapl_id )
    See entry.
    H5Aget_info      herr_t H5Aget_info( hid_t attr_id, H5A_info_t *ainfo )
    See entry.
    H5Aget_info_by_idx      herr_t H5Aget_info_by_idx( hid_t loc_id, const char *obj_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t n, H5A_info_t *ainfo, hid_t lapl_id )
    See entry.
    H5Aget_info_by_name      herr_t H5Aget_info_by_name( hid_t loc_id, const char *obj_name, const char *attr_name, H5A_info_t *ainfo, hid_t lapl_id )
    See entry.
    H5Aget_name_by_idx      ssize_t H5Aget_name_by_idx( hid_t loc_id, const char *obj_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t n, char *name, size_t size, hid_t lapl_id )
    See entry.
    H5Aget_storage_size      hsize_t H5Aget_storage_size( hid_t attr_id )
    See entry.
    H5Aiterate2      herr_t H5Aiterate2( hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order, hsize_t *n, H5A_operator2_t op, void *op_data )
    See entry.
    H5Aiterate_by_name      herr_t H5Aiterate_by_name( hid_t loc_id, const char *obj_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t *n, H5A_operator2_t op, void *op_data, hid_t lapd_id )
    See entry.
    H5Aopen      herr_t H5Aopen( hid_t loc_id, const char *obj_name, const char *attr_name, hid_t aapl_id, hid_t lapl_id )
    See entry.
    H5Aopen_by_idx      herr_t H5Aopen_by_idx( hid_t loc_id, const char *obj_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t n, hid_t aapl_id, hid_t lapl_id )
    See entry.
    H5Arename_by_name      herr_t H5Arename_by_name( hid_t loc_id, const char *obj_name, const char *old_attr_name, const char *new_attr_name, hid_t lapl_id )
    See entry.

    Managing large numbers of attributes
     
    H5Pset_attr_phase_change      herr_t H5Pset_attr_phase_change( hid_t ocpl_id, unsigned max_compact, unsigned min_dense )
    See entry.
    H5Pget_attr_phase_change      herr_t H5Pget_attr_phase_change( hid_t ocpl_id, unsigned *max_compact, unsigned *min_dense )
    See entry.

    Attribute creation order
    tracking and indexing
     
    H5Pset_attr_creation_order      herr_t H5Pset_attr_creation_order( hid_t ocpl_id, unsigned crt_order_flags )
    See entry.
    H5Pget_attr_creation_order      herr_t H5Pget_attr_creation_order( hid_t ocpl_id, unsigned *crt_order_flags )
    See entry.
    H5Aget_create_plist      hid_t H5Aget_create_plist( hid_t attr_id )
    See entry.

    Shared object header messages (SOHM)
     
    H5Pset_shared_mesg_index      herr_t H5Pset_shared_mesg_index( hid_t fcpl_id, unsigned index_num, unsigned mesg_type_flags, unsigned min_mesg_size )
    See entry.
    H5Pset_shared_mesg_nindexes      herr_t H5Pset_shared_mesg_nindexes( hid_t plist_id, unsigned nindexes )
    See entry.
    H5Pset_shared_mesg_phase_change      herr_t H5Pset_shared_mesg_phase_change( hid_t fcpl_id, unsigned max_list, unsigned min_btree )
    See entry.
    H5Pget_shared_mesg_index      herr_t H5Pget_shared_mesg_index( hid_t fcpl_id, unsigned index_num, unsigned *mesg_type_flags, unsigned *min_mesg_size )
    See entry.
    H5Pget_shared_mesg_nindexes      herr_t H5Pget_shared_mesg_nindexes( hid_t fcpl_id, unsigned *nindexes )
    See entry.
    H5Pget_shared_mesg_phase_change      herr_t H5Pget_shared_mesg_phase_change( hid_t fcpl_id, unsigned *max_list, unsigned *min_btree )
    See entry.

    Enhanced local heap size
    management   (group meta data)
     
    H5Pset_local_heap_size_hint      herr_t H5Pset_local_heap_size_hint( hid_t gcpl_id, size_t *size_hint )
    See entry.
    H5Pget_local_heap_size_hint      herr_t H5Pget_local_heap_size_hint( hid_t gcpl_id, size_t size_hint )
    See entry.

    UNICODE support
     
    H5Pset_char_encoding      herr_t H5Pset_char_encoding( hid_t plist_id, H5T_cset_t encoding )
    See entry.
    H5Pget_char_encoding      herr_t H5Pget_char_encoding( hid_t plist_id, H5T_cset_t encoding )
    See entry.

    Object API (H5O), all new
     
    H5Oclose      herr_t H5Oclose( hid_t object_id )
    See entry.
    H5Ocopy      herr_t H5Ocopy( hid_t src_loc_id, const char *src_name, hid_t dst_loc_id, const char *dst_name, hid_t ocp_plist_id, hid_t lcpl_id )
    See entry.
    H5Odecr_refcount      herr_t H5Odecr_refcount( hid_t object_id )
    See entry.
    H5Oget_comment      ssize_t H5Oget_comment( hid_t object_id, char *comment, size_t bufsize )
    See entry.
    H5Oget_comment_by_name      ssize_t H5Oget_comment_by_name( hid_t loc_id, const char *name, char *comment, size_t bufsize, hid_t lapl_id )
    See entry.
    H5Oget_info      herr_t H5Oget_info( hid_t object_id, H5O_info_t *obj_info )
    See entry.
    H5Oget_info_by_idx      herr_t H5Oget_info_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, H5O_info_t *obj_info, hid_t lapl_id )
    See entry.
    H5Oget_info_by_name      herr_t H5Oget_info_by_name( hid_t loc_id, const char *object_name, H5O_info_t *object_info, hid_t lapl_id )
    See entry.
    H5Oincr_refcount      herr_t H5Oincr_refcount( hid_t object_id )
    See entry.
    H5Olink      herr_t H5Olink( hid_t obj_id, hid_t new_loc_id, const char *new_link_name, hid_t lcpl, hid_t lapl )
    See entry.
    H5Oopen      hid_t H5Oopen( hid_t loc_id, const char *name, hid_t lapl_id )
    See entry.
    H5Oopen_by_addr      hid_t H5Oopen_by_addr( hid_t loc_id, haddr_t addr )
    See entry.
    H5Oopen_by_idx      herr_t H5Oopen_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, hid_t lapl_id )
    See entry.
    H5Oset_comment      herr_t H5Oset_comment( hid_t object_id, const char *comment )
    See entry.
    H5Oset_comment_by_name      herr_t H5Oset_comment_by_name( hid_t loc_id, const char *name, const char *comment, hid_t lapl_id )
    See entry.
    H5Ovisit      herr_t H5Ovisit( hid_t group_id, H5_index_t index_type, H5_iter_order_t order, H5O_iterate_t op, void *op_data )
    See entry.
    H5Ovisit_by_name      herr_t H5Ovisit_by_name( hid_t loc_id, const char *object_name, H5_index_t index_type, H5_iter_order_t order, H5O_iterate_t op, void *op_data, hid_t lapl_id )
    See entry.

    Object creation or copying with
    “create intermediate groups” property
     
    H5Pset_create_intermediate_group   herr_t H5Pset_create_intermediate_group( hid_t gcpl_id, unsigned crt_intermed_group )
    See entry.
    H5Pget_create_intermediate_group herr_t H5Pget_create_intermediate_group( hid_t gcpl_id, unsigned *crt_intermed_group )
    See entry.

    Object copy properties
     
    H5Ocopy      herr_t H5Ocopy( hid_t src_loc_id, const char *src_name, hid_t dst_loc_id, const char *dst_name, hid_t ocp_plist_id, hid_t lcpl_id )
    See entry.
    H5Pset_copy_object      herr_t H5Pset_copy_object( hid_t cplist_id, unsigned copy_options )
    See entry.
    H5Pget_copy_object      herr_t H5Pget_copy_object( hid_t cplist_id, unsigned *copy_options )
    See entry.

    Improved object and file
    information retrieval
     
    H5Aget_info      herr_t H5Aget_info( hid_t attr_id, H5A_info_t *ainfo )
    See entry.
    H5Aget_info_by_name      herr_t H5Aget_info_by_name( hid_t loc_id, const char *obj_name, const char *attr_name, H5A_info_t *ainfo, hid_t lapl_id )
    See entry.
    H5Aget_info_by_idx      herr_t H5Aget_info_by_idx( hid_t loc_id, const char *obj_name, H5_index_t idx_type, H5_iter_order_t order, hsize_t n, H5A_info_t *ainfo, hid_t lapl_id )
    See entry.
    H5Fget_info      herr_t H5Fget_info( hid_t obj_id, H5F_info_t *bh_info )
    See entry.
    H5Gget_info      herr_t H5Gget_info( hid_t group_id, H5G_info_t group_info )
    See entry.
    H5Gget_info_by_name      herr_t H5Gget_info_by_name( hid_t loc_id, const char *group_name, H5G_info_t group_info, hid_t lapl_id )
    See entry.
    H5Gget_info_by_idx      herr_t H5Gget_info_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_type, H5_iter_order_t order, hsize_t n, H5G_info_t group_info, hid_t lapl_id )
    See entry.
    H5Lget_info      herr_t H5Lget_info( hid_t link_loc_id, const char *link_name, H5L_info_t *link_buff, hid_t lapl_id )
    See entry.
    H5Lget_info_by_idx      herr_t H5Lget_info_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, H5L_info_t *link_val, hid_t lapl_id )
    See entry.
    H5Oget_info      herr_t H5Oget_info( hid_t object_id, H5O_info_t *obj_info )
    See entry.
    H5Oget_info_by_name      herr_t H5Oget_info_by_name( hid_t loc_id, const char *object_name, H5O_info_t *object_info, hid_t lapl_id )
    See entry.
    H5Oget_info_by_idx      herr_t H5Oget_info_by_idx( hid_t loc_id, const char *group_name, H5_index_t index_field, H5_iter_order_t order, hsize_t n, H5O_info_t *obj_info, hid_t lapl_id )
    See entry.

    Name of referenced object
     
    H5Rget_name      ssize_t H5Rget_name( hid_t loc_id, H5R_type_t ref_type, void *ref, char *name, size_t size )
    See entry.

    Anonymous object creation
     
    H5Dcreate_anon      hid_t H5Dcreate_anon( hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id, hid_t dapl_id )
    See entry.
    H5Gcreate_anon      hid_t H5Gcreate_anon(hid_t loc_id, const char * name, hid_t gcpl_id, hid_t gapl_id)
    See entry.
    H5Tcommit_anon      herr_t H5Tcommit_anon( hid_t loc_id, hid_t type_id, hid_t tcpl_id, hid_t tapl_id )
    See entry.
    H5Lcreate_hard      herr_t H5Lcreate_hard( hid_t obj_loc_id, const char *obj_name, hid_t link_loc_id, const char *link_name, hid_t lcpl, hid_t lapl )
    See entry.

    New-style object creation and open
    functions  (includes anonymous
    object creation)
     
    H5Dcreate_anon      hid_t H5Dcreate_anon( hid_t loc_id, hid_t type_id, hid_t space_id, hid_t dcpl_id, hid_t dapl_id )
    See entry.
    H5Dcreate2      hid_t H5Dcreate2( hid_t loc_id, const char *name, hid_t type_id, hid_t space_id, hid_t lcpl_id, hid_t dcpl_id, hid_t dapl_id )
    See entry.
    H5Dopen2      hid_t H5Dopen2( hid_t loc_id, const char *name, hid_t dapl_id )
    See entry.
    H5Gcreate_anon      hid_t H5Gcreate_anon(hid_t loc_id, const char * name, hid_t gcpl_id, hid_t gapl_id)
    See entry.
    H5Gcreate2      hid_t H5Gcreate2( hid_t loc_id, const char *name, hid_t lcpl_id, hid_t gcpl_id, hid_t gapl_id )
    See entry.
    H5Gopen2      hid_t H5Gopen2( hid_t loc_id, const char * name, hid_t gapl_id )
    See entry.
    H5Tcommit_anon      herr_t H5Tcommit_anon( hid_t loc_id, hid_t type_id, hid_t tcpl_id, hid_t tapl_id )
    See entry.
    H5Tcommit2      herr_t H5Tcommit2( hid_t loc_id, const char *name, hid_t type_id, hid_t lcpl_id, hid_t tcpl_id, hid_t tapl_id )
    See entry.
    H5Topen2      hid_t H5Topen2( hid_t loc_id, const char * name, hid_t tapl_id )
    See entry.

    User-defined identifiers
     
    H5Iregister      hid_t H5Iregister(H5I_type_t type, void *object)
    See entry.
    H5Iregister_type      H5I_type_t H5Iregister_type(size_t hash_size, unsigned reserved, H5I_free_t free_func)
    See entry.
    H5Idestroy_type      herr_t H5Idestroy_type(H5I_type_t type)
    See entry.
    H5Iinc_type_ref      int H5Iinc_type_ref(H5I_type_t type)
    See entry.
    H5Idec_type_ref      int H5Idec_type_ref(H5I_type_t type)
    See entry.
    H5Iget_type_ref      int H5Iget_type_ref(H5I_type_t type)
    See entry.

    Other identifier API (H5I) enhancements
     
    H5Iclear_type      herr_t H5Iclear_type(H5I_type_t type, hbool_t force)
    See entry.
    H5Inmembers      int H5Inmembers(H5I_type_t type, hsize_t *num_members)
    See entry.
    H5Iobject_verify      void * H5Iobject_verify(hid_t id, H5I_type_t id_type)
    See entry.
    H5Iremove_verify      void * H5Iremove_verify(hid_t id, H5I_type_t id_type)
    See entry.
    H5Isearch      void * H5Isearch(H5I_type_t type, H5I_search_func_t func, void *key)
    See entry.
    H5Itype_exists      htri_t H5Itype_exists(H5I_type_t type)
    See entry.

    Compression filters: N-bit
    and scale-offset
     
    H5Pset_nbit      herr_t H5Pset_nbit( hid_t plist_id )
    See entry.
    H5Pset_scaleoffset      herr_t H5Pset_scaleoffset( hid_t plist_id, H5Z_SO_scale_type_t scale_type, int scale_factor )
    See entry.

    User-defined datatype conversion
    callback functions
     
    H5Pget_type_conv_cb      herr_t H5Pget_type_conv_cb( hid_t plist, H5T_conv_except_func_t *func, void **op_data )
    See entry.
    H5Pset_type_conv_cb      herr_t H5Pset_type_conv_cb( hid_t plist, H5T_conv_except_func_t func, void *op_data )
    See entry.

    Datatype compiler conversion check
     
    H5Tcompiler_conv      htri_t H5Tcompiler_conv( hid_t src_id, hid_t dst_id )
    See entry.

    Dataset array size reduction
     
    H5Dset_extent      herr_t H5Dset_extent( hid_t dset_id, const hsize_t *size )
    See entry.

    Dataspace equivalence
     
    H5Sextent_equal      herr_t H5Sextent_equal( hid_t sid1, hid_t sid2 )
    See entry.

    Direct I/O, bypassing system cache
     
    H5Pset_fapl_direct      herr_t H5Pset_fapl_direct( hid_t fapl_id, size_t alignment, size_t block_size, size_t cbuf_size )
    See entry.
    H5Pget_fapl_direct      herr_t H5Pget_fapl_direct( hid_t fapl_id, size_t *alignment, size_t *block_size, size_t *cbuf_size )
    See entry.

    Parallel I/O optimization
    (collective chunk I/O)
     
    H5Pset_dxpl_mpio_chunk_opt      herr_t H5Pset_dxpl_mpio_chunk_opt(hid_t dxpl_id, H5FD_mpio_chunk_opt_t opt_mode)
    See entry.
    H5Pset_dxpl_mpio_chunk_opt_num      herr_t H5Pset_dxpl_mpio_chunk_opt_num(hid_t dxpl_id, unsigned num_chunk_per_proc)
    See entry.
    H5Pset_dxpl_mpio_chunk_opt_ratio      herr_t H5Pset_dxpl_mpio_chunk_opt_ratio(hid_t dxpl_id, unsigned percent_num_proc_per_chunk)
    See entry.
    H5Pset_dxpl_mpio_collective_opt      herr_t H5Pset_dxpl_mpio_collective_opt( hid_t dxpl_id, H5FD_mpio_collective_opt_t opt_mode )
    See entry.

    Enhanced error handling (H5E)
     
    H5Eauto_is_v2      herr_t H5Eauto_is_v2( hid_t estack_id, unsigned *is_stack )
    See entry.
    H5Eclear2      herr_t H5Eclear2( hid_t estack_id )
    See entry.
    H5Eclose_msg      herr_t H5Eclose_msg (hid_t mesg_id)
    See entry.
    H5Eclose_stack      herr_t H5Eclose_stack(hid_t estack_id)
    See entry.
    H5Ecreate_msg      hid_t H5Ecreate_msg(hid_t class, H5E_type_t msg_type, const char* mesg)
    See entry.
    H5Eget_auto2      herr_t H5Eget_auto2(hid_t estack_id, H5E_auto2_t * func, void **client_data)
    See entry.
    H5Eget_class_name      ssize_t H5Eget_class_name(hid_t class_id, char* name, size_t size)
    See entry.
    H5Eget_current_stack      hid_t H5Eget_current_stack(void)
    See entry.
    H5Eget_msg      ssize_t H5Eget_msg(hid_t mesg_id, H5E_type_t* mesg_type, char* mesg, size_t size)
    See entry.
    H5Eget_num      ssize_t H5Eget_num(hid_t estack_id)
    See entry.
    H5Epop      herr_t H5Epop(hid_t estack_id, size_t count)
    See entry.
    H5Eprint2      herr_t H5Eprint2(hid_t estack_id, FILE * stream)
    See entry.
    H5Epush2      herr_t H5Epush2(hid_t estack_id, const char *file, const char *func, unsigned line, hid_t class_id, hid_t major_id, hid_t minor_id, const char *msg, ...)
    See entry.
    H5Eregister_class      hid_t H5Eregister_class(const char* cls_name, const char* lib_name, const char* version)
    See entry.
    H5Eset_auto2      herr_t H5Eset_auto2(hid_t estack_id, H5E_auto2_t func, void *client_data)
    See entry.
    H5Eset_current_stack      herr_t H5Eset_current_stack(hid_t estack_id)
    See entry.
    H5Eunregister_class      herr_t H5Eunregister_class(hid_t class_id)
    See entry.
    H5Ewalk2      herr_t H5Ewalk2(hid_t estack_id, H5E_direction_t direction, H5E_walk2_t func, void * client_data)
    See entry.

    Meta data cache management
     
    H5Fget_mdc_config      herr_t H5Fget_mdc_config(hid_t file_id, H5AC_cache_config_t *config_ptr)
    See entry.
    H5Fget_mdc_hit_rate      herr_t H5Fget_mdc_hit_rate(hid_t file_id, double *hit_rate_ptr)
    See entry.
    H5Fget_mdc_size      herr_t H5Fget_mdc_size(hid_t file_id, size_t *max_size_ptr, size_t *min_clean_size_ptr, size_t *cur_size_ptr, int *cur_num_entries_ptr)
    See entry.
    H5Freset_mdc_hit_rate_stats      herr_t H5Freset_mdc_hit_rate_stats(hid_t file_id)
    See entry.
    H5Fset_mdc_config      herr_t H5Fset_mdc_config(hid_t file_id, H5AC_cache_config_t *config_ptr)
    See entry.
    H5Pset_mdc_config      herr_t H5Pset_mdc_config(hid_t plist_id, H5AC_cache_config_t * config_ptr)
    See entry.
    H5Pget_mdc_config      herr_t H5Pget_mdc_config(hid_t plist_id, H5AC_cache_config_t * config_ptr)
    See entry.

    File read/write status
     
    H5Fget_intent      herr_t H5Fget_intent( hid_t file_id, unsigned *intent )
    See entry.

    Arithmetic data transform on I/O
     
    H5Pget_data_transform      herr_t H5Pget_data_transform( hid_t plist_id, char* expression, size_t size)
    See entry.
    H5Pset_data_transform      herr_t H5Pset_data_transform( hid_t plist, const char* expression )
    See entry.

    Dataspace and datatype serial conversion
     
    H5Sdecode      hid_t H5Sdecode( const void *buf )
    See entry.
    H5Sencode      herr_t H5Sencode( hid_t obj_id, void *buf, size_t *nalloc )
    See entry.
    H5Tdecode      hid_t H5Tdecode( const void *buf )
    See entry.
    H5Tencode      herr_t H5Tencode( hid_t obj_id, void *buf, size_t *nalloc )
    See entry.

    Enhanced filter management
     
    H5Pget_filter2 herr_t H5Pget_filter2( hid_t plist_id, unsigned idx, unsigned int *flags, size_t *cd_nelmts, unsigned cd_values[], size_t namelen, char name[], unsigned *filter_config)
    See entry.
    H5Pget_filter_by_id2 hid_t H5Pget_filter_by_id2( hid_t plist_id, H5Z_filter_t filter_id, unsigned int *flags, size_t *cd_nelmts, unsigned int cd_values[], size_t namelen, char name[], unsigned int *filter_config)
    See entry.

    Comparison of properties
     
    H5Pinsert2 hid_t H5Pinsert2( hid_t plid, const char *name, size_t size, void *value, H5P_prp_set_func_t set, H5P_prp_get_func_t get, H5P_prp_delete_func_t delete, H5P_prp_copy_func_t copy, H5P_prp_compare_func_t compare, H5P_prp_close_func_t close)
    See entry.
    H5Pregister2 herr_t H5Pregister2( hid_t class, const char * name, size_t size, void * default, H5P_prp_create_func_t create, H5P_prp_set_func_t set, H5P_prp_get_func_t get, H5P_prp_delete_func_t delete, H5P_prp_copy_func_t copy, H5P_prp_compare_func_t compare, H5P_prp_close_func_t close)
    See entry.

    Two-way conversion between datatype
    and text description of datatype
     
    H5LTtext_to_dtype hid_t H5LTtext_to_datatype( const char *text, H5LT_lang_t lang_type)
    See entry.
    H5LTdtype_to_text herr_t H5LTdtype_to_text( hid_t datatype, char *str, H5LT_lang_t lang_type, size_t *len)
    See entry.

    Fortran subroutines:
    New Fortran subroutines in the main library are not yet included for Release 1.8.0-beta.

    See below for Fortran routines for High-Level HDF5 APIs.

    C++ wrappers:
    There no new C++ wrappers for Release 1.8.0-beta.

    High Level C APIs:

    H5LT: The following functions have been added to the HDF5 Lite (H5LT) API:
    H5LTtext_to_dtype hid_t H5LTtext_to_datatype( const char *text, H5LT_lang_t lang_type)
    See entry.
    H5LTdtype_to_text herr_t H5LTdtype_to_text( hid_t datatype, char *str, H5LT_lang_t lang_type, size_t *len)
    See entry.
    H5LTset_attribute_long_long herr_t H5LTset_attribute_long_long( hid_t loc_id, const char *obj_name, const char *attr_name, const long_long *data, size_t *size)
    See entry.
    H5LTget_attribute_long_long     herr_t H5LTget_attribute_long_long( hid_t loc_id, const char *obj_name, const char *attr_name, long_long *data)
    See entry.

    Two high-level C APIs are distributed for the first time with this release:
     
    • H5PT, the HDF5 Packet Table interface
    • H5DS, the HDF5 Dimension Scale interface

    Full documentation for these interfaces can be accessed directly from the High Level APIs overview page.

    The new functions included in the packet table (H5PT) high-level APIs are as follows:
    H5PTcreate_fl hid_t H5PTcreate_fl( hid_t loc_id, const char * dset_name, hid_t dtype_id, hsize_t chunk_size )
    H5PTcreate_vl hid_t H5PTcreate_vl( hid_t loc_id, const char *dset_name, hsize_t chunk_size )
    H5PTopen hid_t H5PTopen( hid_t loc_id, const char *dset_name )
    H5PTclose herr_t H5PTclose( hid_t table_id )
    H5PTappend herr_t H5PTappend( hid_t table_id, hsize_t nrecords, const void *data)
    H5PTcreate_index herr_t H5PTcreate_index( hid_t table_id)
    H5PTset_index herr_t H5PTset_index( hid_t table_id, hsize_t pt_index)
    H5PTread_packets herr_t H5PTread_packets( hid_t table_id, hsize_t start, hsize_t nrecords, void *data)
    H5PTget_next herr_t H5PTget_next( hid_t table_id, hsize_t nrecords, void *data)
    H5PTget_num_packets herr_t H5PTget_num_packets( hid_t table_id, hsize_t * nrecords)
    H5PTis_valid herr_t H5PTis_valid( hid_t table_id)
    H5PTis_varlen herr_t H5PTis_varlen( hid_t table_id)
    H5PTfree_vlen_readbuff     herr_t H5PTfree_vlen_readbuff( hid_t table_id, hsize_t bufflen, void * buff)
     

    The new functions included in the dimension scale (H5DS) high-level APIs are as follows:
    H5DSset_scale herr_t H5DSmake_scale(hid_t dsid, char *dimname)
    H5DSattach_scale herr_t H5DSattach_scale(hid_t did, hid_t dsid, unsigned int idx)
    H5DSdetach_scale herr_t H5DSdetach_scale(hid_t did, hid_t dsid, unsigned int idx)
    H5DSis_attached htri_t H5DSis_attached(hid_t did, hid_t dsid, unsigned int idx)
    H5DSis_scale htri_t H5DSis_scale(hid_t did)
    H5DSiterate_scales herr_t H5DSiterate_scales(hid_t did, unsigned dim, int *idx, H5DS_iterate_t visitor, void *visitor_data)
    H5DSset_label herr_t H5DSset_label(hid_t did, unsigned int idx, const char *label)
    H5DSget_label ssize_t H5DSget_label(hid_t did, unsigned int idx, char *label, size_t size)
    H5DSget_scale_name     hssize_t H5DSget_scale_name(hid_t did, char name, size_t *size)
    H5DSget_num_scales int H5DSget_num_scales(hid_t did, unsigned int idx)

    High Level Fortan90 APIs:
    Fortran90 subroutines are now available for the following high-level APIs:
         H5LT: HDF5 Lite
         H5IM: HDF5 Image
         H5TB: HDF5 Table

    Tools:
    h5stat

    Deprecated and Deleted Functions

    The following functions, subroutines and wrappers have been removed in this release:
    C functions:
     
    H5Pset_fapl_gass
    H5Pget_fapl_gass
     
           HDF5 no longer provides GASS support.
    H5Pset_fapl_srb
    H5Pget_fapl_srb
     
     
           HDF5 no longer provides SRB support.
    SRB functionality is now supported through the mechanism described in SRB — The DICE Storage Resource Broker.
    H5Pset_fapl_stream
    H5Pget_fapl_stream
     
           The stream virtual file driver (H5FD_STREAM) has been removed from the HDF5 distribution. The functionality was last available from http://hdf5-addons.origo.ethz.ch/.
    H5Tset_overflow
    H5Tget_overflow
           These two functions are replaced by H5Pget_type_conv_cb and H5Pset_type_conv_cb.

    Several functions, subroutines, and wrappers are deprecated in this HDF5 release and may eventually be removed from the HDF5 distribution and from the HDF5 Reference Manual. A Release 1.6.x compatibility mode is provided enabling these and other Release 1.6.x compatibility features, but is available only if the HDF5 Library is configured with the default settings or with the flag --with-default-api-version=v16. Release 1.8.0 also provides macros that can be mapped selectively to 1.6.x and 1.8.0 function versions according to the needs of a user application. The backward compatibility mode is enabled in the Release 1.8.0 binaries distributed by NCSA. See API Compatibility Macros in HDF5 for full details.
     
    Deprecated functions are marked in the function index at the beginning of each API section in the HDF5 Reference Manual.

    Virtual File Driver Removed

    The stream virtual file driver (H5FD_STREAM) have been removed in this release. This affects the functions H5Pset_fapl_stream and H5Pget_fapl_stream and the constant H5FD_STREAM.

    This virtual file driver will remain available at http://hdf5-addons.origo.ethz.ch/. Note that as of this writing, this transition is still in progress; the necessary integration tools may not be available when HDF5 Release 1.8.0 first comes out.

    Functions with New or Changed Symbols or Fixed Values

    Symbols and preset values associated with the following functions, subroutines or wrappers have changed as noted.

    C functions:

    H5Tregister
    Null is no longer a valid value for the parameter func.
     
    H5Pget_filter_by_id
    H5Pmodify_filter
    H5Premove_filter
    H5Pset_filter
    H5Zfilter_avail
    H5Zget_filter_info
    Two new filter identifiers are available for the filter parameter:
        H5Z_FILTER_NBIT
        H5Z_FILTER_SCALEOFFSET
     
    H5Pget_filter
    Two new filter identifiers are available as the return value:
        H5Z_FILTER_NBIT
        H5Z_FILTER_SCALEOFFSET
     

    Fortran90 subroutines:

    h5pget_filter_f
    h5pget_filter_by_id_f
    h5pmodify_filter_f
    h5premove_filter_f
    h5pset_filter_f
    h5zfilter_avail_f
    h5zget_filter_info_f
    Two new filter identifiers are available for the filter or filter_id parameters:
        H5Z_FILTER_NBIT_F
        H5Z_FILTER_SCALEOFFSET_F
     

    Functions with Changed Syntax

    Function syntax changes in this release are handled through the mechanism described in API Compatibility Macros in HDF5.

    Exceptions:
    • The function H5Eget_minor is not governed by the above-mentioned macros and its return type has changed:
      H5Eget_minor
      char *H5Eget_minor (H5E_minor_t n)
      See entry.
      An application calling H5Eget_minor from an HDF5 Library of Release 1.8.0 or later will have to free the memory associated with the return value to prevent a memory leak.
      (This note added at Release 1.8.4, November 2009.)

       

    • In the function H5Dextend, the size parameter signature was changed.
      H5Dextend
      herr_t *H5Dextend( hid_t dataset_id, const hsize_t size[] )
      See entry for current information; see the Release 1.6 entry for the old signature.
      The new function signature is generally considered equivalent to the old signature, but some compilers require an exact match.
      (This note added in February 2010, following Release 1.8.4.)

    Renamed Functions

    The following C functions have been renamed. The original function names remain available under certain circumstances; see API Compatibility Macros in HDF5 for full details.

    Original name New name
    H5Acreate H5Acreate1
    H5Aiterate
     
    H5Aiterate1
     
    H5Eclear H5Eclear1
    H5Eget_auto H5Eget_auto1
    H5Eprint H5Eprint1
    H5Epush H5Epush1
    H5Eset_auto H5Eset_auto1
    H5Ewalk
     
    H5Ewalk1
     
    H5Gcreate H5Gcreate1
    H5Gopen
     
    H5Gopen1
     
    H5Pget_filter H5Pget_filter1
    H5Pget_filter_by_id     H5Pget_filter_by_id1
    H5Pinsert H5Pinsert1
    H5Pregister
     
    H5Pregister1
     
    H5Rget_obj_type
     
    H5Rget_obj_type1
     
    H5Tarray_create H5Tarray_create1
    H5Tcommit H5Tcommit1
    H5Tget_array_ndims H5Tget_array_ndims1
    H5Topen H5Topen1

    Changed Library Structures

    The following library structures have changed as follows:

    C API:

    H5FD_t
    In this struct, the field fileno[2] has changed to fileno.
    The struct is otherwise unchanged.
     
    H5Z_class_t
    This struct contains three new fields:
        version
        encoder_present
        decoder_present
    The struct is now defined as follows:
        typedef struct H5Z_class_t {
            int version; 
            H5Z_filter_t filter_id;
            unsigned encoder_present
            unsigned decoder_present
            const char  *comment;
            H5Z_can_apply_func_t can_apply_func;
            H5Z_set_local_func_t set_local_func;
            H5Z_func_t filter_func;            
        } H5Z_class_t;
    

    Changed ENUMs

    The following enumerated datatypes used by the library are discontinued in this release:

    H5E_major_t — Major error numbers
    H5E_minor_t — Minor error numbers
    HDF5 error codes have changed from the ENUM format used in earlier releases to an identifier format. As ENUMs, error codes were constants defined at compile time; as identifiers, error codes are defined at runtime, in the same manner as HDF5 object identifiers (file, dataset, group, etc.).

    Under normal circumstances, this change should be transparent to user applications.

    The following enumerated datatypes used by the library have changed in the C and Fortran APIs as follows:

    H5G_obj_t — Object types
    This ENUM has reordered as follows:
        H5G_GROUP
        H5G_DATASET
        H5G_TYPE
        H5G_LINK
     
    H5I_type_t — Identifier types
    The following symbols have been added to this ENUM:
        H5I_UNINT
        H5I_ERROR_CLASS
        H5I_ERROR_MSG
        H5I_ERROR_STACK
     
    Another new symbol
        H5I_NTYPES
    replaces the old symbol
        H5I_NGROUPS
    While visible in the public API, H5I_NTYPES functions as a limit value for the HDF5 Library and is not generally used at the application level. The same was true of H5I_NGROUPS.
     
    H5S_class_t — Dataspace type identifiers
    The following symbol has been added:
        H5S_NULL
     
    H5T_cset_t — Character set encoding identifiers
    The following symbol has been added:
        H5T_CSET_UTF8
     
    H5Z_filter_t — Filters identifiers
    The following symbols have been added:
        H5Z_FILTER_NBIT
        H5Z_FILTER_SCALEOFFSET
     

    New Datatypes

    The following OpenVMS-specific floating point datatypes are new with this release:
    H5T_VAX_F32
    H5T_VAX_F64

    New Property Lists

    The following property lists are new with this release:
    H5P_DATASET_ACCESS
    H5P_GROUP_CREATE
    H5P_GROUP_ACCESS
    H5P_DATATYPE_CREATE
    H5P_DATATYPE_ACCESS
    H5P_ATTRIBUTE_CREATE

    Changed Library Configuration

    The following configuration features have changed as follows.
    • New with this release:
          --disable-dependency-tracking
          
          --enable-hdf5v1_6
          
          --enable-dconv-exception
          --disable-dconv-exception
          --enable-dconv-accuracy
          --disable-dconv-accuracy
          
          --program-prefix=PREFIX
          --program-prefix=SUFFIX
          --program-transform-name=PROGRAM
          
          --enable-maintainer-mode
          
          --disable-dependency-tracking
          --enable-dependency-tracking
          
          --enable-codestack
          
          --enable-direct-vfd
          
          --with-tags[=TAGS]
          
    • New with this release, but expected to be useful only to those working inside the HDF5 Library or working very closely with HDF5 developers:
          --enable-build-all
          --enable-metadata-trace-file
          
    • New with this release, but not actively supported:
          --enable-fphdf5
          
    • Changed in this release:
          --enable-shared[=PKGS]
          --enable-static[=PKGS]
          --enable-fast-install[=PKGS]
          
    • Removed in this release:
          --enable-hdf5v1_4
          --enable-funcstack
          --with-ssl=LIB
          --with-gass=DIR
          --with-srb=DIR

    The environment variables FC and FCFLAGS replace F9X and F9XFLAGS, respectively, which are deprecated in this release.

    Additional new “influential environment variables” in this release include the following:
        CXX
        CXXFLAGS
        CXXCPP
        F77
        FFLAGS

     

    Current Release of HDF5

    Change notes for the current release of HDF5 are published in “HDF5 Software Changes from Release to Release”.

    Releases 1.6.10 and Earlier

    Change notes for HDF5 Release 1.6.10 and earlier releases are published in “HDF5 Software Changes from Release to Release for HDF5 Releases 1.4.0 through 1.6.10”.

    HDF5 documents and links 
    Introduction to HDF5 
    HDF5 User's Guide 
    HDF5 Reference Manual 
    HDF5 Application Developer's Guide 

    The HDF Group Help Desk:
    Describes HDF5 Release 1.8.18, November 2016.
      Copyright by The HDF Group
    and the Board of Trustees of the University of Illinois

    Last modified: 29 April 2016