Tracker

Tracker is an efficient search engine and triplestore for desktop, embedded and mobile.

The Tracker project is divided into two main repositories:

• Tracker core contains the database (tracker-store), the database ontologies, the commandline user interface (tracker), and several support libraries.

• Tracker Miners contains the indexer daemon (tracker-miner-fs) and tools to extract metadata from many different filetypes.

More information on Tracker can be found at:

• https://wiki.gnome.org/Projects/Tracker

Source code and issue tracking:

• https://gitlab.gnome.org/GNOME/tracker

All discussion related to Tracker happens on:

• https://mail.gnome.org/mailman/listinfo/tracker-list

IRC channel #tracker on:

• irc.gimp.net

Related projects:

• GNOME Online Miners extends Tracker to allow searching and indexing some kinds of online content.

Developing Tracker

If you want to help develop and improve Tracker, great! Remember that Tracker is a middleware component, designed to be integrated into larger codebases. To fully test a change you may need to build and test Tracker as part of another project.

For the GNOME desktop, consider using the documented Building a System Component workflow.

It's also possible to build Tracker on its own and install it inside your home directory for testing purposes. Read on for instructions on how to do this.

Compilation

Tracker uses the Meson build system, which you must have installed in order to build Tracker.

We recommend that you build tracker core as a subproject of tracker-miners. You can do this by cloning both repos, then creating a symlink in the subprojects/ directory of tracker-miners.git to the tracker.git checkout.

git clone https://gitlab.gnome.org/GNOME/tracker.git
git clone https://gitlab.gnome.org/GNOME/tracker-miners.git

mkdir tracker-miners/subprojects
ln -s ../../tracker tracker-miners/subprojects/

Now you can run the commands below to build Tracker and install it in a new, isolated prefix named opt/tracker inside your home folder.

NOTE: If you see 'dependency not found' errors from Meson, that means there is a package missing on your computer that you need to install so you can compile Tracker. On Ubuntu/Debian, you can run apt build-dep tracker-miners and on Fedora dnf build-dep tracker-miners to install all the necessary packages.

cd tracker-miners
meson ./build --prefix=$HOME/opt/tracker -Dtracker_core=subproject
cd build
ninja install

Running the testsuite

At this point you can run the Tracker test suite from the build directory:

meson test --print-errorlogs

Developing with tracker-sandbox

Tracker normally runs automatically, indexing content in the background so that search results are available quickly when needed.

When developing and testing Tracker you will normally want it to run in the foreground instead. The tracker-sandbox tool exists to help with this.

You can run the tool directly from the tracker.git source tree. Ensure you are in the top of the tracker source tree and type this to see the --help output:

./utils/sandbox/tracker-sandbox.py --help

You should always pass the --prefix option, which should be the same as the --prefix argument you passed to Meson. You also need to use --index which controls where internal state files like the database are kept. You may also want to pass --debug to see detailed log output.

Now you can index some files using --update mode. Here's how to index files in ~/Documents for example:

./utils/sandbox/tracker-sandbox.py  --prefix ~/opt/tracker --index ~/tracker-content \
    --update --content ~/Documents

You can then list the files that have been indexed...

./utils/sandbox/tracker-sandbox.py  --prefix ~/opt/tracker --index ~/tracker-content \
    --list-files

... run a full-text search ...

./utils/sandbox/tracker-sandbox.py  --prefix ~/opt/tracker --index ~/tracker-content \
    --search "bananas"

... or run a SPARQL query on the content:

./utils/sandbox/tracker-sandbox.py  --prefix ~/opt/tracker --index ~/tracker-content \
    --sparql "SELECT ?url { ?resource a nfo:FileDataObject ; nie:url ?url . }"

You can also open a shell inside the sandbox environment. From here you can run the tracker commandline tool, and you can run the Tracker daemons manually under a debugger such as GDB.

For more information about developing Tracker, look at https://wiki.gnome.org/Projects/Tracker.