HDF5 Tools Update

02/18/14 HDF and HDF-EOS Workshop X, Landover, MD 1

HDF5 Tools Update

Peter CaoThe HDF Group

[email protected]

November 28, 2006

This report is based upon work supported in part by a Cooperative Agreement with NASA under NASA NNG05GC60A. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration.

mailto:[email protected]

02/18/14 HDF and HDF-EOS Workshop X, Landover, MD2

Outline

• Overview of current tools• New tools with HDF5 1.8 release• A future tool: h5ub


HDF5 Command Line Tools

• Readers • h5dump, h5diff, h5ls• new tools: h5check, h5stat

• Writers• h5repack, h5repart, h5import, h5jam/h5unjam• new tool: h5copy

• Converters• h4toh5, h5toh4, gif2h5, h52gif


Help Information

• Located at bin/ with binary release• Use “-h” option for help• Online help at

http://www.hdfgroup.org/hdf5tools.html• For further help, bug report and feature request, send to

[email protected]

http://www.hdfgroup.org/hdf5tools.html

mailto:[email protected]


h5dump

Dumps the content of an HDF5 file to stdout and optionally to following types of files

• ASCII text file• XML file• Binary file (new feature)


h5dump -H SDS.h5

HDF5 "SDS.h5" {

GROUP "/" {

GROUP "Floats" {

DATASET "FloatArray" {

DATATYPE H5T_IEEE_F32LE

DATASPACE SIMPLE { ( 4, 3 ) / ( 4, 3 ) }

}

}

DATASET "IntArray" {

DATATYPE H5T_STD_I32LE


}

}

}


h5dump -d /Floats/FloatArray SDS.h5

HDF5 "SDS.h5" {

DATASET "/Floats/FloatArray" {

DATATYPE H5T_IEEE_F32LE


DATA {

(0,0): 0.01, 0.02, 0.03,

(1,0): 0.1, 0.2, 0.3,

(2,0): 1, 2, 3,

(3,0): 10, 20, 30

}

}

}


h5dump -x SDS.h5


h5dump Binary Output

-b F, --binary=F

The form of the binary output (F):• MEMORY -- for memory type• FILE -- for the disk file type • LE -- for pre-defined little endian type• BE -- for pre-defined big endian type


h5dump -d /IntArray -o out_le.bin -b LE SDS.h5

od --width=24 -t x4 out_le.bin0000000 00000000 00000001 00000002 00000003 00000004 00000005

0000030 0000000a 0000000b 0000000c 0000000d 0000000e 0000000f

0000060 00000014 00000015 00000016 00000017 00000018 00000019

0000110 0000001e 0000001f 00000020 00000021 00000022 00000023

0000140 00000028 00000029 0000002a 0000002b 0000002c 0000002d

Dumps a 32-bit integer dataset, IntArray, from SDS.h5 to a little endian binary file out_le.bin


h5diff

Using h5diff, you can • compares two objects in the same file• compares two objects between two files• compares all objects between two files


h5diff SDS.h5 SDS2.h5

• Dataset: </IntArray> and </IntArray>• 5 differences found


h5diff SDS.h5 SDS2.h5 -r /IntArray

• Dataset: </IntArray> and </IntArray>• position IntArray IntArray difference • ------------------------------------------------------------• [ 0 0 ] 0 10 10 • [ 1 0 ] 10 100 90 • [ 2 0 ] 20 200 180 • [ 3 0 ] 30 300 270 • [ 4 0 ] 40 400 360 • 5 differences found


h5repack

Copies an HDF5 file to a new file with/without compression/chunking• Remove un-used space• Apply compression filter• Apply layout


h5repack: new filters

-f FILTER• GZIP, to apply GZIP compression• SZIP, to apply SZIP compression• SHUF, to apply the HDF5 shuffle filter• FLET, to apply the HDF5 checksum filter• NBIT, to apply NBIT compression• SOFF, to apply the HDF5 Scale/Offset filter• NONE, to remove all filters

For exampleh5repack -i SDS2.h5 -o SDS2_compressed.h5 /IntArray:GZIP=9


h5repack: data layout

-l LAYOUT• CHUNK, to apply chunking layout• COMPA, to apply compact layout• CONTI, to apply continuous layout

For exampleh5repack -i SDS.h5 -o SDS_chunk.h5

-l /Floats/FloatArray,/IntArray:CHUNK=2x3


new h5repack: using H5Ocopy()

0.27

13.52

0.03

8.32

17.30 18.83

80.97

15.34

30.18

41.6248.39

32.06

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

attrs20k.h5

dataset_comp_80000k.h5

float16kx16k_chunk512x512_deflate9.h5

float16kx16k_chunk512x512.h5

groups10k.h5 int16kx16k.h5

New h5repack Old h5repack


h5repart

Repartitions a file or family of files

For exampleh5repart -m 200m int16kx16k.h5 part200m%d.h5

977 MB

200 MB part200m0.h5

200 MB part200m1.h5

200 MB part200m2.h5

200 MB part200m3.h5

177 MB part200m1.h5


h5import

Imports binary/ASCII data into an HDF5 file• h5import infile -c config_file [infile -c config_file2 ...] -outfile outfile

For eaxmpleh5import float5x4x2.txt -c First_set.conf -o First_set.h5

PATH work/First-set INPUT-CLASS TEXTFP RANK 3 DIMENSION-SIZES 5 2 4 OUTPUT-CLASS FP OUTPUT-SIZE 64 OUTPUT-ARCHITECTURE IEEE OUTPUT-BYTE-ORDER LE CHUNKED-DIMENSION-SIZES 2 2 2 MAXIMUM-DIMENSIONS 8 8 -1

GROUP "/" { GROUP "work" { DATASET "First-set" { DATATYPE H5T_IEEE_F64LE DATASPACE SIMPLE { ( 5, 2, 4 ) / ( 8, 8, H5S_UNLIMITED ) } DATA { (0,0,0): 1.01, 1.02, 1.03, 1.04, (0,1,0): 1.11, 1.12, 1.13, 1.14, (1,0,0): 1.21, 1.22, 1.23, 1.24, (1,1,0): 1.31, 1.32, 1.33, 1.34, (2,0,0): 1.41, 1.42, 1.43, 1.44, (2,1,0): 1.51, 1.52, 1.53, 1.54, (3,0,0): 2.01, 2.02, 2.03, 2.04, (3,1,0): 2.11, 2.12, 2.13, 2.14, (4,0,0): 2.21, 2.22, 2.23, 2.24, (4,1,0): 2.31, 2.32, 2.33, 2.34 } } }}}


h5jam/h5unjam

• h5jam -- add text to User Blockh5jam -u test_ub.txt -i test_ub.h5

• h5unjam -- remove text from User Blockh5unjam -i test_ub.h5 -o out_ub.txt -o out_ub.h5


h5ls

• Lists selected information about file objects in the specified format

For Example, h5ls -r SDS2.h5

/Floats Group/Floats/DoubleArray Dataset {10, 5}/Floats/FloatArray Dataset {4, 3}/Floats/subs Group/IntArray Dataset {5, 6}


gif2h5 / h52gif

• gif2h5 – converts a GIF file into HDF5gif2h5 apollo17_earth.gif apollo17_earth.h5

• h52gif – converts an HDF5 file into GIFh52gif apollo17_earth.h5 apollo17_earth2.gif -i /apollo17_earth.gif/Image0 -p "/apollo17_earth.gif/Global Palette"


h5toh4 / h4toh5

• h5toh4 -- Converts an HDF5 file to an HDF4 file • h4toh5 -- Converts an HDF4 file to an HDF5 file


New tools

• h5copy• h5check• h5stat


h5copy

• Copies an object from one location to another location within a file or across files

• http://hdfgroup.com/RFC/h5copy/h5copy.htm

/

FloatArray

FloatsIntArray

/

FloatArray

http://hdfgroup.com/RFC/h5copy/h5copy.htm


h5copy

usage: h5copy [OPTIONS] [OBJECTS...] -i, --input input file name -o, --output output file name -s, --source source object name -d, --destination destination object name

-f, --flagshallow Copy only immediate members for groupssoft Expand soft links into new objectsext Expand external links into new objectsref Copy objects that are pointed by referencesnoattr Copy object without copying attributes


h5copy

For exampleh5copy -i SDS.h5 -o SDS_cp.h5 -s /Floats/FloatArray -d /FloatArray

/

FloatArray

FloatsIntArray

/

FloatArray

SDS.h5

SDS_cp.h5


h5copy -f shallow

/

i1

floatsintegers

64-bit

i2

f32 f2f1

/

floats

64-bitf32

f2f1

/

floats

64-bitf32

-f shallow


h5copy -f soft

/

-f soft

dset_SL

/f1/f1

f1

/

dset_SL

/f1/f1

f1

/

dset_SL

/f1/f1


h5copy -f ref

/

-f ref

d1

dset_ref

d2

1895

763

/

d1

dset_ref

d2

679

1287

/

dset_ref

0

0


h5copy todo

• Fix references embedded in compound datatype• Follow external links• Test functionalities• Test performance


h5stat

• Prints different statistics about HDF5 file• Helps

• To troubleshoot size overhead in HDF5 files• To choose specific object’s properties and storage

strategies


h5check

A validation tool that verifies if an HDF5 file is encoded according to the HDF5 File Format Specification


Why is it needed?

• Verify if the file is compliant with the File Format to ensure the data model integrity and long term compatibility between evolving versions of the HDF5 library

• As a verification tool required by the application of HDF5 File Format to be an ANSI standard

• Serves as a watch dog that the HDF5 library implementation is compliant with the File Format


What does it do?

Given a file, it scans through the encoded content against the defined File Format• If it finds any non-compliance, it prints out the error

and reason of non-compliance.• After finding any non-compliance, it tries to continue

scanning the file if possible.• Eventually, it exits with non-zero.• If it does not find any non-compliance, it prints out an

approval statement at the end and exits with zero.


How is it implemented? (1/2)

• The tool is coded from scratch and does not use the formal HDF5 library API calls

• It does not link with the HDF5 library at all• It may borrow coding, including algorithms or data

structure from the HDF5 library source code but after close verification that they are in compliance with the File Format.


How is it implement? (2/2)

• It links external libraries that HDF5 library uses. E.g.,• Zlib• szlib


How to use it?

• H5check [-vn] <filename>-vn verboseness mode

n=0 Terse—only prints if the file is compliant or not

n=1 Default—prints its progress and all errors found

n=2 Verbose—prints everything it knows, usually for debugging


Example: a compliant file

• % h5check example1.h5• VALIDATING example1.h5• FOUND super block signature• VALIDATING the super block at 0...• VALIDATING the object header at 928...• VALIDATING the btree at 384...• FOUND btree signature.• VALIDATING the local heap at 96...• FOUND local heap signature.• …• Result: File is in compliance.


Example: a non-compliant file

h5check invalid2.h5• FOUND super block signature• VALIDATING the super block at 0...• VALIDATING the object header at 928...• VALIDATING the btree at 384...• FOUND btree signature.• VALIDATING the SNOD at 1248...• FOUND SNOD signature.• VALIDATING the object header at 976...• check_sym(at 1248): Errors from check_obj_header()• decode_validate_messages(): Failure in type->decode().• H5O_sdspace_decode(): Bad version number in simple dataspace message.• VALIDATING the local heap at 96...• FOUND local heap signature.• Main(): Errors from check_obj_header().• decode_validate_messages(): Failure in type->decode().• H5O_attr_decode(): Can't decode attribute dataspace.• H5O_sdspace_decode(): Bad version number in simple dataspace message.• …• Result: File is not in compliance.


Implementation Status

• All basic File Format components are implemented• Coding recognition of HDF5 files created by non-

default Virtual File Driver such as the Multi-File format

• Alpha release planned in December 2006


h5ub

• Combine nub, h5jam and h5unjam• nub -- NPOESS user block tool for HDF5 files

(Richard)• Plan for h5ub development

3/5/07

3/22/0

7

3/25/0

7

4/2/07

2/23/0

7

Design Implementation Testing Release

HDF5 Tools Update

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