libhdf5-wasm

A precompiled static hdf5 library in webassembly (Emscripten)

Support for GZIP and SZIP compression (through libz and libsz) are included.

Building

Prerequisites

• Emscripten
• CMake >= 3.10
• make

Build

• clone this repository
• activate emscripten (emcc and emcmake)
• alter CMakeLists.txt with whatever flags and options you want
• run make all to build all supported versions of hdf5, currently:
  • 1.10.10
  • 1.12.2
  • 1.14.2
• this will create gzipped tarballs of all chosen versions e.g. HDF5-1.12.2-Emscripten.tar.gz

Using prebuilt artifacts

Prebuilt CMake TGZ packages are attached to the releases of this repository. In e.g. HDF5-1.12.1-Emscripten.tar.gz you will find:

• share/COPYING license for HDF5
• the include folder for building against these libraries
• lib/libhdf5.a
• lib/libhdf5_hl.a
• lib/libhdf5_cpp.a
• lib/libhdf5_hl_cpp.a
• cmake/hdf5-config.txt (enables FetchContent, see below)

Tools:

You'll also find in the same directory as lib and include above, some tools that use the webassembly library, e.g.

• bin/h5dump
• bin/h5repack

These require that you have nodejs >= 16 installed and on your path (they use #!/usr/bin/env -S node shebang to invoke nodejs). They do not depend on any installed HDF5 libraries, and are statically linked

Using CMake FetchContent

To pull in automatically for use with CMake, see example below. This functionality is provided based on contributions from @LTLA (thanks!)

Defined CMake IMPORTED targets:

• hdf5-static
• hdf5_hl-static
• hdf5_cpp-static
• hdf5_hl_cpp-static

# CMakeLists.txt:
cmake_minimum_required(VERSION 3.10)
include(FetchContent)

project(libhdf5-test
    VERSION 1.0.0
    DESCRIPTION "test the availability of libhdf5"
    LANGUAGES CXX C
)

FetchContent_Declare(
  libhdf5-wasm
  URL https://github.com/usnistgov/libhdf5-wasm/releases/download/v0.4.0_3.1.43/HDF5-1.12.2-Emscripten.tar.gz
  # URL_HASH SHA256=7089f9bf29dc3759d7aa77848cfa12d546eabd152d40dd00a90aace99c056600
)
FetchContent_MakeAvailable(libhdf5-wasm)
set(HDF5_DIR ${libhdf5-wasm_SOURCE_DIR}/cmake)
find_package(HDF5 REQUIRED CONFIG)

# build a project using only C headers (libhdf5.a, libhdf5_hl.a):
# add_executable(test test.cpp)
# target_link_libraries(test hdf5-static hdf5_hl-static)

# build a project using C++ headers 
# (C headers + libhdf5_cpp.a, libhdf5_hl_cpp.a):
add_executable(test_cpp test_cpp.cpp)
target_link_libraries(test_cpp hdf5_hl_cpp-static hdf5_cpp-static)

# Optional flags to set when building your project
set_target_properties(test_cpp PROPERTIES
    LINK_FLAGS "--bind -s ALLOW_MEMORY_GROWTH=1 -s USE_ZLIB=1 -s FORCE_FILESYSTEM=1 -s 'EXPORTED_RUNTIME_METHODS=[\"FS\"]'"
)