- guid: 55950e64-fa4e-4eb9-9a3a-2c73d9cd6478
- author: Markus Raab
- pubDate: Tue, 26 Feb 2019 15:31:09 +0100
- shortDesc: high-level API
We are proud to release Elektra 0.8.26 with the new high-level API.
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.
You can also read the news on our website
The new high-level API provides an easier way for applications to get started with Elektra.
To use Elektra in an application (including proper error handling) you now only need a few self-explanatory lines of code:
ElektraError * error = NULL;
Elektra * elektra = elektraOpen ("/sw/org/myapp/#0/current", NULL, &error);
if (elektra == NULL)
{
printf ("An error occurred: %s", elektraErrorDescription (error));
elektraErrorReset (&error);
return -1;
}
// Once you have an instance of `Elektra` you simply call one of the typed `elektraGet*` functions to read a value:
kdb_long_t mylong = elektraGetLong (elektra, "mylong");
printf ("got long " ELEKTRA_LONG_F "\n", mylong);
const char * mystring = elektraGetString (elektra, "mystring");
printf ("got string %s\n", mystring);
elektraClose (elektra);
To run the application, the configuration should be specified, e.g., for mylong:
sudo kdb setmeta /sw/org/myapp/#0/current/mylong type long
sudo kdb setmeta /sw/org/myapp/#0/current/mylong default 5
In the getters/setters there is no need to convert types or to specify the base path
/sw/org/myapp/#0/current
, as the high-level API does that for you.
The API supports the CORBA types already used by the plugins.
The high-level API should also be used in combination with a specification (spec-mount
).
When used this way, the API is designed to be error and crash free while reading values.
Writing values, can of course still produce errors.
Another advantage of the new API is, that it will be much easier to write bindings for other languages now, because only a few simple types and functions have to be mapped to provide the full functionality.
Take a look at the README for more information.
Because of the high-level API, we now have the new header files elektra.h
and a folder elektra
in Elektra's include directory.
Furthermore, we install the library libelektra-highlevel.so
and the pkgconfig file elektra-highlevel.pc
for easier detection.
For an example on how to build an application using this API take a look at this.
A big thanks to Klemens Böswirth for making this possible. Also big thanks to Dominik Hofer, who did all the foundation work for this API.
The following section lists news about the plugins we updated in this release.
- We changed the default Augeas directory prefix for the lenses directory on macOS to the one used by
Homebrew:
/usr/local
. (René Schwaiger)
- The
network
plugin also supports port declarations to check if a port number is valid or if the port is available to use. (Michael Zronek) - We added a Markdown Shell Recorder test to the ReadMe of the plugin. (René Schwaiger)
- The build system does not print a warning about a deprecated directive any more, if you build the plugin with Bison
3.3
or later. (René Schwaiger) - YAMBi now handles comments at the end of input properly. (René Schwaiger)
-
We improved the error reporting capabilities of the plugin. It now stores all of the error message reported by ANTLR and also specifies the line and column number of syntax errors. We also visualize these error messages in a similar way as modern compilers like Clang or GCC. For example, for the following erroneous input:
key: - element 1 - element 2 # Incorrect Indentation!
the plugin currently prints an error message that looks like this:
config.yaml:2:1: mismatched input '- ' expecting end of map - element 2 # Incorrect Indentation! ^^ config.yaml:2:37: extraneous input 'end of map' expecting end of document - element 2 # Incorrect Indentation! ^
. The inspiration for this feature was taken from the book “The Definitive ANTLR 4 Reference” by Terence Parr. (René Schwaiger)
-
Yan LR’s lexer now
- handles comment at the end of a YAML document correctly,
- stores a more human readable description in tokens (e.g.
end of map
instead ofMAP END
)
. (René Schwaiger)
Enhanced the plugin to also check for concrete file or directory permissions such as rwx
.
For example, you can specify that a user can write to a certain directory or file which prevents applications of runtime failures
once they try to access the given path (such as a log directory or file).
Simply add check/path/user <user>
and check/path/mode <modes>
as specification (metadata)
and be assured that you can safely set a path value to the key. A more detailed explanation can be found
here (Michael Zronek)
- The plugin now handles comments at the end of a file properly. (René Schwaiger)
- We improved the syntax error messages of the plugin. (René Schwaiger)
- We fixed a memory leak that occurred, if a YAML file contained syntax errors. (René Schwaiger)
- The new plugin YAy PEG parses a subset of YAML using a parser based on PEGTL. (René Schwaiger)
- Added some basic unit tests (Bernhard Denner)
-
We fixed some compiler warnings for the plugins
reported on FreeBSD. (René Schwaiger)
-
The
resolver
plugin and its tests now better supportKDB_DB_SYSTEM
andKDB_DB_SPEC
paths using~
to refer to a home directory. (Klemens Böswirth) -
If
KDB_DB_SYSTEM
is set to a relative path, it is now treated as relative toCMAKE_INSTALL_PREFIX
. This ensures thatKDB_DB_SYSTEM
actually points to the same location no matter the current working directory. (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).
We have two minor incompatible changes:
- we now support larger array numbers (i.e. the larger numbers are not an error anymore)
elektraArrayValidateBaseNameString
returns the offset to the first digit of the array index instead of1
For details of the changes see below Core
and Libease
.
- All plugins in the KDB now get a handle to a global keyset via
elektraPluginGetGlobalKeySet()
, for communication between plugins. See Global KeySet Handle for details. (Mihael Pranjić) elektraWriteArrayNumber
now useskdb_long_long_t
for array indices to be compatible with the high level API. Similarly the value ofELEKTRA_MAX_ARRAY_SIZE
was changed to match this. (Klemens Böswirth)
-
The function
elektraArrayValidateBaseNameString
now returns the offset to the first digit of the array index, if the given string represents an array element containing an index. This update enhances the behavior of the function. Now it not only tells you if a name represents a valid array element, but also the start position of the array index.elektraArrayValidateBaseNameString ("#_10"); // ~~^ Returns `2` (instead of `1`) elektraArrayValidateBaseNameString ("#___1337"); // ~~~~^ Returns `4` (instead of `1`)
If your program already used
elektraArrayValidateBaseNameString
and you check for a valid array element using the equality operator (== 1
), then please use (>= 1
) instead. For example, if you code that looks like this:if (elektraArrayValidateBaseNameString(baseName) == 1) …;
, please update your code to check for a valid array element name like this:
if (elektraArrayValidateBaseNameString(baseName) >= 1) …;
. (René Schwaiger)
-
This is a new library containing only the function
elektraGetOpts
. This function can be used to parse command line arguments and environment variables and add their values to keys in the proc namespace.You can use
opt
,opt/long
andenv
to specify a short, a long option and an environment variable. For more information take a look at the tutorial and the code documentation ofelektraGetOpts
. (Klemens Böswirth)
kdb spec-mount
correctly includes type plugin to validatetype
. (Markus Raab)kdb setmeta
reports if it removed a metakey. (Markus Raab)system/elektra/version
now has metadata to indicate that it cannot be edited or removed. (Dominic Jäger)
- The script
reformat-source
now also handles filenames containing spaces correctly. (René Schwaiger) - The script
reformat-markdown
formats Markdown files in the repository withprettier
. (René Schwaiger) - The scripts
reformat-source
,reformat-cmake
,reformat-shfmt
andreformat-markdown
don't format files that are ignored by git anymore. (Klemens Böswirth)
- We fixed various spelling mistakes. (René Schwaiger)
- The documentation for
elektraMetaArrayToKS
was fixed. It now reflects the fact that the parent key is returned as well. (Klemens Böswirth)
- The tests for the IO bindings and notification plugins now use increased timeout values so that the test suite fails less often on machines with high load. (René Schwaiger)
- We update most of the Markdown Shell Recorder tests so they use an explicit namespace (like
system
oruser
). This has the advantage that the output of these tests does not change depending on the user that executes them. Before the update these tests used cascading keys. (René Schwaiger) - The Shell Recorder now also works correctly on FreeBSD. (René Schwaiger)
- Fix memcheck target to detect memory problems again and enabled parallel testing to speed it up. (Mihael Pranjić)
- Fix memleak in pluginprocess tests. (Mihael Pranjić)
- The test
check-env-dep
does not require Bash anymore. (René Schwaiger) - We fixed an incorrect directive in the Markdown Shell Recorder test of the Type Checker plugin. (René Schwaiger)
- We added a test that invokes the script
fix-spelling
to check the documentation for common spelling mistakes. (René Schwaiger) - We added a test that checks the formatting of Markdown files with
prettier
. (René Schwaiger) - The test
testscr_check_formatting
now prints instructions that show you how to fix formatting problems. (René Schwaiger)
- The plugin name is now provided as compiler definition
ELEKTRA_PLUGIN_NAME
via CMake. See #1042. (Peter Nirschl) ELEKTRA_PLUGIN_FUNCTION
does not require the module name as parameter any more, instead theELEKTRA_PLUGIN_NAME
compiler definition is being used. See #1042. (Peter Nirschl)ELEKTRA_README
, andELEKTRA_PLUGIN_EXPORT
do not require the module name as parameter any more, instead theELEKTRA_PLUGIN_NAME
compiler definition is being used. See #1042. (Peter Nirschl)- We now specify
- version number,
- project description, and
- homepage URL
in the CMake
project
command. (René Schwaiger)
- We fixed the detection of Python for the Python 2 binding on macOS. (René Schwaiger)
- You can now use the Ruby binding and plugin without any manual configuration, if you installed Ruby (version
2.5
or later) via Homebrew. (René Schwaiger)
- The CMake find module
FindAugeas.cmake
does not print an error message anymore, if it is unable to locate Augeas in thepkg-config
search path. (René Schwaiger) - The CMake find module
FindLua.cmake
does not print an error message anymore, if it is unable to locate a Lua executable. (René Schwaiger) - We added code that makes sure you can compile IO GLIB on macOS, even if
pkg-config
erroneously reports that GLIB requires linking to the libraryintl
(part of GNU gettext). (René Schwaiger) - We added a CMake find module for GLib. The module makes sure you can compile and link IO GLib on macOS. (René Schwaiger)
- The CMake find module
FindLibOpenSSL.cmake
does not requirepkg-config
anymore. The updated code also fixes some linker problems on macOS (and probably other operating systems too), where the build system is not able to link to OpenSSL using only the name of the OpenSSL libraries. (René Schwaiger) - We simplified the CMake find module
FindLibgcrypt.cmake
.The update fixes problems on macOS, where the build system excluded the plugincrypto_gcrypt
, although Libgcrypt was installed on the system. (René Schwaiger) - We now use the official CMake find module for
iconv
. This update fixes linker problems with theiconv
andfilecheck
plugin on FreeBSD 12. (René Schwaiger) - The CMake find module for Botan does not require
pkg-config
anymore. (René Schwaiger) - The CMake find module for libgit2 now also exports the version number of libgit2. (René Schwaiger)
- We added a CMake find module for libuv and fixed a problem on macOS, where the build system was unable to locate the header file of libuv. (René Schwaiger)
- We added a CMake find module for ZeroMQ to fix build problems on macOS. (René Schwaiger)
-
We added
- ANTLR,
- ANTLR’s C++ runtime,
- Ninja, and
shfmt
, to the Dockerfile for Debian sid
. (René Schwaiger)
- We removed the
configure
script from the top-level directory. CMake is now popular enough so that this helper-script is not needed. (René Schwaiger)
-
We now use Cirrus CI to build and test Elektra on
. Both of these build jobs use
-Werror
to make sure we do not introduce any code that produces compiler warnings. (René Schwaiger) -
The new build job
🍎 Clang
tests Elektra on macOS. (René Schwaiger) -
We added the build job
🍎 Clang ASAN
, which uses Clang with enabled AddressSanitizer to test Elektra on macOS. (René Schwaiger) -
The new build job
🍎 FULL
compiles and test Elektra using the CMake optionsBUILD_SHARED=OFF
anBUILD_FULL=ON
. (René Schwaiger) -
We added
🍎 MMap
, which tests Elektra usingmmapstorage
as default storage module. (René Schwaiger) -
We install and uninstall Elektra in all of the macOS build jobs to make sure that
ElektraUninstall.cmake
removes all of the installed files. (René Schwaiger)
- We added a badge displaying the current build status to the main ReadMe. (René Schwaiger)
- The build job
formatting-check
now also checks the formatting of Shell scripts. (René Schwaiger)
- We now test Elektra on Ubuntu Xenial Xerus. (René Schwaiger)
- We removed the build jobs
🍏 Clang
and🍏 Check Shell
in favor of the Cirrus build job🍎 Clang
. (René Schwaiger) - We removed the build jobs
🍏 Clang ASAN
in favor of the Cirrus build job🍎 Clang ASAN
. (René Schwaiger) - We removed the build jobs
🍏 FULL
in favor of the Cirrus build job🍎 FULL
. (René Schwaiger) - We removed the build jobs
🍏 MMap
in favor of the Cirrus build job🍎 MMap
. (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:
- infallible high-level API: creating an API that guarantees you to return configuration values (Klemens Böswirth)
- error handling (Michael Zronek)
- elektrify LCDproc (Klemens Böswirth) and (Michael Zronek)
- YAML as default storage (René Schwaiger)
- misconfiguration tracker (Vanessa Kos)
- global mmap cache: This feature will enable Elektra to return configuration without parsing configuration files or executing other plugins as long as the configuration files are not changed. (Mihael Pranjić)
and since recently:
- automatic shell completion (Ulrike Schaefer)
- plugin framework improvements (Vid Leskovar)
- 3-way merge (Dominic Jäger)
- reducing entry barriers for newcomers (Hani Torabi Makhsos)
- bug fixing (Usama Morad) and (Kurt Micheli)
In this release we created 986 commits in which 802 files were changed, with 21687 insertions(+) and 6912 deletions(-).
Following authors made this release possible:
Commits | Author |
---|---|
1 | Aybuke Ozdemir [email protected] |
2 | Gabriel Rauter [email protected] |
6 | Bernhard Denner [email protected] |
6 | Dominic Jäger [email protected] |
25 | Peter Nirschl [email protected] |
32 | Mihael Pranjic [email protected] |
66 | Michael Zronek [email protected] |
112 | Markus Raab [email protected] |
131 | Klemens Böswirth [email protected] |
141 | Dominik Hofer [email protected] |
464 | René Schwaiger [email protected] |
We welcome new contributors! Read here about how to get started.
As first step, you could give us feedback about these release notes. Contact us via our issue tracker.
You can download the release from here or GitHub
The hashsums are:
- name: elektra-0.8.26.tar.gz
- size: 6395865
- md5sum: 4ef202b5d421cc497ef05221e5309ebc
- sha1: 94f654764bcf49d0ebc7e636f444e24ca6cfeb19
- sha256: 5806cd0b2b1075fe0d5a303649d0bd9365752053e86c684ab7c06e7f369155d3
The release tarball is also available signed by Markus Raab using GnuPG from here or on GitHub
Already built API-Docu can be found here or on GitHub.
Subscribe to the RSS feed to always get the release notifications.
If you also want to participate, or for any questions and comments please contact us via our issue tracker on GitHub.
For more information, see https://libelektra.org
Best regards, Elektra Initiative