XDBI

This repository contains the database interface and backends to store, search and retrieve e.g. XTypes.

XDBI was initiated and is currently developed at the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) in Bremen, together with the Robotics Group of the University of Bremen.

XDBI provides the database interface, for all types generated with the xtypes_generator.

Installation

Dependencies

• xtypes_generator
• CMake >= 3.10
• libspdlog
• cpr >= 1.3.0
• nlohmann_json >= 3.10.5
• pybind11 >=2.9.1
• pybind11_json >=0.2.12

Manual

1. Clone this repository
2. Build and install via:

cd xdbi
mkdir build
cd build
cmake ..
make install

Autoproj

1. Add this repository to you autoproj setup.
2. Then run in your autoproj workspace:

aup xdbi
amake xdbi

Testing

cd build
make cpp_test # for testing the C++ interface
make py_test # for testing the python interface

Tools

XDBI comes with some generic database tools.

jsondb

The most important one is jsondb it is used to start a HTTP/REST server providing access to the local database instance specified via --db_path. By default this server is reachable via "http://0.0.0.0:8183", but of course you can specify your own IP and port.

See also the output of jsondb -h for further information.

Merging JSON databases

If GIT is used to track and publish changes in a common database, the standard line-based merge will create fake conflicts and is not able to correctly merge JSON files. To overcome this issue there is a tool called xdbi-json-merge which can perform a 3-way merge on JSON files.

To use it, you have to edit the .git/config file and add the following section:

[merge "json"]
    name = Merge JSON files
    driver = xdbi-json-merge %O %A %B

Furthermore, you have to create a .git/info/attributes file (if not present) and add

* merge=text
/*/** merge=json

So on the top level (where README.md and stuff like that is) the standard merge will be used, but in the subfolders named by Xtype classnames the JSON merger will be used.

xdbi-clear & xdbi-remove

These tools are used to clear a complete database graph/directory (xdbi-clear) or to remove one specific XType instance specified via the passed URIs from the database.

See also the output of xdbi-clear -h or xdbi-remove -h for further information.

Usage as CPP Library

You can use xdbi in you project by including and linking against the xdbi library.

For CMake use find_package(xdbi REQUIRED) in you CMakeLists.txt and link against xdbi::xdbi_cpp in you target_link_libraries call.

Please see the API documentation on how to use it in your code.

Usage as Python module

XDBI comes with python bindings. Basically, you can use everything you'll find in the CPP-API-documentation in the same way in python. Just import xdbi_py and you are ready to go.

You can have a look into bin/xdbi-clear.py, bin/xdbi-remove.py or into the unit tests in the test directory for examples.