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Elektra 0.11.0
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We are proud to present Elektra 0.8.25.
Elektra serves as a universal and secure framework to access configuration settings in a global, hierarchical key database. For more information, visit https://libelektra.org.
For a small demo see here:
You can also read the news on our website
This release is dedicated to drastically improve the speed of Elektra. Two non-trivial features facilitate most of the improvement:
ksLookup (...)
for very fast access of configurationWe added a new, binary and fast storage plugin called mmapstorage
. It leverages the mmap()
syscall and supports full Elektra semantics. We provide two compile variants: mmapstorage
and mmapstorage_crc
. The mmapstorage_crc
variant enables CRC32 checksums for critical data, while the mmapstorage
variant omits the checksum for maximum performance.
We ran a synthetic benchmark with 257 iterations using 40k keys in a keyset, and compared the performance to the dump
storage plugin.
Median write time in microseconds:
Plugin | Time |
---|---|
dump | 71079 |
mmapstorage | 2964 |
mmapstorage_crc | 7644 |
Median read time in microseconds:
Plugin | Time |
---|---|
dump | 82737 |
mmapstorage | 1145 |
mmapstorage_crc | 5744 |
In our benchmark, the mmapstorage
plugin writes more than 23x faster, and reads more than 72x faster than the dump
storage plugin.
For this release the plugin is marked as experimental, even though it is already used as default storage plugin in a build job on our build server.
Thanks to Mihael Pranjić for this improvement.
The hybrid search algorithm is now implemented, this concludes the extension of the ksLookup (...)
search with the order preserving minimal perfect hash map (OPMPHM). The hybrid search combines the best properties of the binary search and the OPMPHM. The hybrid search decides dynamically which search algorithm to use.
Because of the automatic decision, usually nothing needs to be done by API users to take advantage of this improvement. Advanced API user, however, can overrule the hybrid search by passing KDB_O_OPMPHM
or KDB_O_BINSEARCH
to ksLookup (...)
. The constants are defined in kdbproposal.h. For low-memory systems the building of the hash map can be disabled altogether at build-time by disabling the CMake variable ENABLE_OPTIMIZATIONS
(by default enabled now).
The implemented randomized OPMPHM algorithm is in 99.5% of the measured random cases optimal. However the randomization property of the algorithm leaves an uncertainty.
The results made with random cases had shown that the hybrid search is, except for small keyset sizes, almost always faster compared to the standalone binary search. The performance increase strongly depended on the measured hardware. In the random cases where the hybrid search is faster, on average ~8.53% to ~20.92% of time was saved. The implemented hybrid search works only above a keyset size of 599
to exclude the small keyset sizes.
Thanks to Kurt Micheli for this improvement.
The following section lists news about the plugins we updated in this release.
We improved the performance of the directoryvalue plugin. _(René Schwaiger)_ This plugin is used for configuration file formats that do not support that directories contain values, like it is the case in JSON. A program manipulating a 13 MB JSON file which first did not succeed within 10 hours is now finished in 44 seconds.
There is a new, experimental plugin called process. This plugin utilizes the pluginprocess library in order to execute arbitrary other plugins in an own process, acting as a proxy itself. Therefore it is not required to explicitly change a plugin's implementation if it shall be executed in an own process. This plugin is not completely finished yet, as currently there is no way for it to mimic the proxied plugin's contract in Elektra. It can be used with simple plugins like dump
however, check the limitations in the readme for more details. _(Armin Wurzinger)_
The detection of the mntent
functions now also works correctly, if you use the compiler switch -Werror
. _(René Schwaiger)_
We fixed an issue with the passwd plugin not properly setting compile flags. This resolves a problem with undefined functions when building with musl. _(Lukas Winkler)_
The experimental gpgme plugin was brought into existence to provide cryptographic functions using GnuGP via the libgpgme
library. _(Peter Nirschl)_
The network
plugin now also allows for non-numerical hosts (i.e. "localhost") to be set and tries to resolve it via DNS. _(Michael Zronek)_
This new plugin parses a subset of YAML using a parser generated by Bison. _(René Schwaiger)_
The build system now disables the plugin automatically, if you use a GCC compiler (6.x
or earlier) and enable the option ENABLE_ASAN
. We updated the behavior, since otherwise the plugin will report memory leaks at runtime. _(René Schwaiger)_
now works correctly. _(René Schwaiger)_
antlr
as ANTLR executable, if antlr4
is not available. _(René Schwaiger)_6.x
or earlier) to translate Elektra. We introduced this behavior, since the code generated by ANTLR (YAML.h
) seems to contain a double free that causes a segmentation fault on systems that use the GNU C library. _(René Schwaiger)_6.x
or earlier) and enable the option ENABLE_ASAN
. _(René Schwaiger)_This new plugin parses a subset of YAML using the Earley Parser library YAEP. _(René Schwaiger)_
This new plugin can be used to validate that the value of a key is a reference to another key. _(Klemens Böswirth)_
The text below summarizes updates to the C (and C++)-based libraries of Elektra.
As always, the ABI and API of kdb.h is fully compatible, i.e. programs compiled against an older 0.8 version of Elektra will continue to work (ABI) and you will be able to recompile programs without errors (API).
This is the last release for which we have built Jessie packages:
Obviously, we will continue to update the stretch package:
Following plugins got added:
A new library got added (should be packaged privately for now):
Optimize elektraKsFilter to not duplicate keys _(Markus Raab)_
A new library which can be used to match keys against globbing patterns was introduced. _(Klemens Böswirth)_
The API is still experimental, so it should not be used externally for now.
libease
provides the function elektraArrayValidateBaseNameString
, which can be used to validate that a given string is an Elektra array name. _(Klemens Böswirth)_
Bindings allow you to utilize Elektra using various programming languages. This section keeps you up-to-date with the multi-language support provided by Elektra.
Do not use private Elektra headers for Ruby bindings as preparation for a Ruby libelektra
gem. _(Bernhard Denner)_
dump
and mmapstorage
. _(Mihael Pranjić)_cp
. _(Markus Raab)_mount
. _(Markus Raab)_kdb find-tools
. _(Markus Raab)_clang-format
6.0 for formatting C and C++ code. _(René Schwaiger)_reformat-source
now displays information about the installed version of clang-format
, if it is unable to locate a supported version of the tool. _(René Schwaiger)_shfmt
. _(René Schwaiger)_reformat-shfmt
reformats Shell scripts using the tool shfmt
. _(René Schwaiger)_dbus
plugin does not leak memory anymore, if it fails on macOS. _(Thomas Wahringer)_testkdb_allplugins
and testscr_check_kdb_internal_check
do not test a plugin on an ASAN enabled build anymore, if you specify the status tag memleak
in the plugin contract. _(René Schwaiger)_compare_key
now also checks if the meta values of keys are equal. _(René Schwaiger)_testscr_check_bashisms
does not print warnings about skipped files anymore. _(René Schwaiger)_shell
plugin. _(René Schwaiger)_dump
and mmapstorage
. _(Mihael Pranjić)_testcpp_contextual_basic
now compiles without warnings, if we use Clang 7 as compiler. _(René Schwaiger)_testmod_[plugin]
) now depend on the respective CMake targets for the plugins themselves (elektra-[plugin]
). _(Klemens Böswirth)_BUILD_FULL
but not BUILD_SHARED
is used. _(Klemens Böswirth)_testscr_check_formatting
now also checks the formatting of Shell code. _(René Schwaiger)_kdb run_all
now only prints the output of tests that failed. To print the full output of all test, please use the option -v
. _(René Schwaiger)_--text
any more. _(René Schwaiger)_1.8.1
. _(René Schwaiger)_check_symbol_exists
that handles issues with -Werror -Wpedantic
. _(Lukas Winkler)_INCLUDE_SYSTEM_DIRECTORIES
of the function add_plugin
now supports multiple include directories. _(René Schwaiger)_ENABLE_COVERAGE=ON
) should now also work on macOS. _(René Schwaiger)_run_checkshell
to run all shell checks (testscr_check.*
). _(René Schwaiger)_run_nocheckshell
runs all tests except for shell checks. _(René Schwaiger)_run_all
now runs tests that do not modify the key database in parallel. _(René Schwaiger)_docker run --rm anoxis/registry-cli -r https://hub-public.libelektra.org
. You can search for images using --images-like
, for example: docker run --rm anoxis/registry-cli -r https://hub-public.libelektra.org --images-like alpine
. Afterwards pull your desired image as you would do from any public registry, for example: docker pull hub-public.libelektra.org/build-elektra-alpine:201811-37597a34fed4988639cdaf4d6a2c54754d09918586f53389e4fde5fd3b3a7180
. _(Lukas Winkler)_alpine
. _(René Schwaiger)_-Werror
in debian-stable-full
. _(Lukas Winkler)_-Werror
to the build jobs:alpine
,debian-stable-full-i386
,debian-stable-full-mmap-asan
,debian-stable-full-mmap
,debian-stable-full-optimizations-off
,debian-stable-full-xdg
,debian-stable-minimal
,debian-stable-multiconf
,debian-unstable-clang-asan
,debian-unstable-full-clang
,debian-unstable-full
,ubuntu-xenial
, anddebian-stable-asan
. _(René Schwaiger)_debian-stable-full-mmap
and debian-stable-full-mmap-asan
with mmapstorage
as the default storage. _(Mihael Pranjić)_🍏 Clang ASAN
. _(René Schwaiger)_🍏 Clang ASAN
and 🐧 GCC ASAN
now only translates a minimal set of plugins, since we had various timeout problems with these jobs before. We explicitly excluded plugins, to make sure that the build jobs still test newly added plugins. _(René Schwaiger)_🍏 mmap
on macOS with mmapstorage
as the default storage. _(Mihael Pranjić)_10.0
). _(René Schwaiger)_🍏 Check Shell
, which only runs shell checks such as testscr_check_oclint
. This update allows us to remove the shell checks from the jobs 🍏 MMap
and 🍏 Clang
, which sometimes hit the timeout limit for public repositories before. _(René Schwaiger)_-Werror
. _(René Schwaiger)_🍏 FULL
and the build job 🐧 FULL
build Elektra using the CMake options BUILD_FULL=ON
and BUILD_SHARED=OFF
. _(René Schwaiger)_script
stage of the build jobs print less non-relevant output. Usually the commands in this stage should now only print verbose output if a test fails. _(René Schwaiger)_The website is generated from the repository, so all information about plugins, bindings and tools are always up-to-date.
We are currently working on following topics:
Following authors made this release possible:
Commits | Author |
---|---|
1 | Thomas Wahringer thoma s.wa hring er@l ibele ktra .org |
2 | Bernhard Denner bernh ard. denne r@gm ail.c om |
7 | Kurt Micheli e1026 558@ stude nt.t uwien .ac. at |
12 | Michael Zronek micha el.z ronek @gma il.co m |
33 | Lukas Winkler derwi nlu+ git@g mail .com |
28 | Klemens Böswirth k.boe swir th+gi t@gm ail.c om |
30 | Armin Wurzinger e1528 532@ stude nt.t uwien .ac. at |
38 | Peter Nirschl peter .nir schl@ gmai l.com |
100 | Markus Raab marku s@li belek tra. org |
180 | Mihael Pranjic mpran j@li mun.o rg |
418 | René Schwaiger sanss ecou rs@me .com |
849 commits, 581 files changed, 18503 insertions(+), 3192 deletions(-)
We welcome new contributors!
You can download the release from here or GitHub
The hashsums are:
The release tarball is also available signed by Markus Raab using GnuPG from here or GitHub
Already built API documentation can be found here or GitHub.
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If you also want to participate, or for any questions and comments please contact us via the issue tracker on GitHub.
For more information, see https://libelektra.org
Best regards, Elektra Initiative