[[TOC]]

Introduction

Libamxj is a extension library for libamxc

The library provides:

json parsing
json generation from variants
json parsing into variants
variant type jstring_t

Is this yet another json parser? No it is not. For parsing json libamxj is using yajl, to generate an json string from an libamxc variant, yajl is used as well.

Building, installing and testing

Docker container

You could install all tools needed for testing and developing on your local machine, but it is easier to just use a pre-configured environment. Such an environment is already prepared for you as a docker container.

Install docker

Docker must be installed on your system.

If you have no clue how to do this here are some links that could help you:
Make sure you user id is added to the docker group:

``` sudo usermod -aG docker $USER ```

Fetch the container image

To get access to the pre-configured environment, all you need to do is pull the image and launch a container.

Pull the image:

```bash docker pull softathome/oss-dbg:latest ```

Before launching the container, you should create a directory which will be shared between your local machine and the container.

```bash mkdir -p ~/amx_project/libraries/ ```

Launch the container:

```bash docker run -ti -d –name oss-dbg –restart always –cap-add=SYS_PTRACE –sysctl net.ipv6.conf.all.disable_ipv6=1 -e "USER=$USER" -e "UID=$(id -u)" -e "GID=$(id -g)" -v ~/amx_project/:/home/$USER/amx_project/ softathome/oss-dbg:latest ```

The -v option bind mounts the local directory for the ambiorix project in the container, at the exact same place. The -e options create environment variables in the container. These variables are used to create a user name with exactly the same user id and group id in the container as on your local host (user mapping).

You can open as many terminals/consoles as you like:

```bash docker exec -ti –user $USER oss-dbg /bin/bash ```

Building

Prerequisites

libamxc - Generic C api for common data containers
libyajl2

Build libamxj

Clone the git repository

To be able to build it, you need the source code. So open the directory just created for the ambiorix project and clone this library in it.

```bash cd ~/amx_project/libraries/ git clone https://gitlab.com/soft.at.home/ambiorix/libraries/libamxj.git ```

Install dependencies

Although the container will contain all tools needed for building, it does not contain the libraries needed for building libamxj. To be able to build libamxj you need libamxc. This library can be installed in the container.

```bash sudo apt update sudo apt install libamxc ```

Note that some of the components are allready preinstalled in the container.

Build it

```bash cd ~/amx_project/libraries/libamxj make ```

Installing

Using make target install

You can install your own compiled version easily in the container by running the install target.

cd ~/amx_project/libraries/libamxj

sudo make install

Using package

From within the container you can create packages.

cd ~/amx_project/libraries/libamxj

make package

The packages generated are:

~/amx_project/libraries/libamxj/libamxj-<VERSION>.tar.gz

~/amx_project/libraries/libamxj/libamxj-<VERSION>.deb

You can copy these packages and extract/install them.

For ubuntu or debian distributions use dpkg:

sudo dpkg -i ~/amx_project/libraries/libamxj/libamxj-<VERSION>.deb

Testing

Prerequisites

No extra components are needed for testing libamxj.

Run tests

You can run the tests by executing the following command.

cd ~/amx_project/libraries/libamxj/tests

make

Or this command if you also want the coverage tests to run:

cd ~/amx_project/libraries/libamxj/tests

make run coverage

Coverage reports

The coverage target will generate coverage reports using gcov and gcovr.

A summary for each file (*.c files) is printed in your console after the tests are run. A HTML version of the coverage reports is also generated. These reports are available in the output directory of the compiler used. Example: using native gcc When the output of gcc -dumpmachine is x86_64-linux-gnu, the HTML coverage reports can be found at ~/amx_project/libraries/libamxj/output/x86_64-linux-gnu/coverage/report.

You can easily access the reports in your browser. In the container start a python3 http server in background.

cd ~/amx_project/

python3 -m http.server 8080 &

Use the following url to access the reports http://<IP ADDRESS OF YOUR CONTAINER>:8080/libraries/libamxj/output/<MACHINE>/coverage/report You can find the ip address of your container by using the ip command in the container.

Example:

USER@<CID>:~/amx_project/libraries/libamxj$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
173: eth0@if174: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:ac:11:00:07 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.7/16 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 2001:db8:1::242:ac11:7/64 scope global nodad 
       valid_lft forever preferred_lft forever
    inet6 fe80::42:acff:fe11:7/64 scope link 
       valid_lft forever preferred_lft forever

in this case the ip address of the container is 172.17.0.7. So the uri you should use is: http://172.17.0.7:8080/libraries/libamxj/output/x86_64-linux-gnu/coverage/report/