bt2c::Logger: remove unused cLevel() method

[babeltrace.git] / doc / api / libbabeltrace2 / dox / main-page.dox

/*!
@mainpage Välkommen!

@note
This documentation (text and illustrations) is licensed under a
<a href="https://creativecommons.org/licenses/by-sa/4.0/legalcode">Creative
Commons Attribution-ShareAlike 4.0 International</a> license.

Welcome to the
<strong><em>\bt_api</em></strong> (libbabeltrace2) documentation!

To get an idea of how to use the libbabeltrace2 API, have a look at
the \ref guides "guides" and \ref examples "examples".
That being said, we recommend that you read the \ref api-fund to
understand what the API expects exactly.

If you are developing a \bt_name \bt_plugin or an application which
uses libbabeltrace2, we recommend that you
\ref guide-build-bt2-dev "build the \bt_name library for development".

@section main-bt2-nutshell \bt_name in a nutshell

<a href="https://babeltrace.org/"><strong><em>\bt_name</em></strong></a>
is an open-source software project by
<a href="https://www.efficios.com/">EfficiOS</a>; its purpose is to
process or convert
<a href="https://en.wikipedia.org/wiki/Tracing_(software)">traces</a>.

The \bt_name project contains:

- A library, libbabeltrace2, which all the other parts rely on.

  libbabeltrace2 offers a
  <a href="https://en.wikipedia.org/wiki/C99">C99</a> interface.

  This documentation is about libbabeltrace2's API.

- A command-line program, \bt_cli, which can convert and manipulate
  traces.

- Python&nbsp;3 bindings which offer a Pythonic interface of
  libbabeltrace2.

- "Standard" plugins which ship with the project.

  <a href="https://diamon.org/ctf/">Common Trace Format</a> (CTF) input
  and output, plain text input and output, and various utilities are
  part of those plugins.

With the \bt_name library, you can:

- Write custom \ref api-comp-cls-src "source",
  \ref api-comp-cls-flt "filter", \ref api-comp-cls-sink "sink"
  component classes which you can package as \bt_p_plugin.

  Component classes are instantiated as \bt_p_comp within a trace
  processing \bt_graph and components are assembled to accomplish a
  trace manipulation or conversion job.

- Load \bt_p_plugin, instantiate their component classes within a
  trace processing \bt_graph, connect the components as needed, and
  run the graph to accomplish a trace manipulation or conversion job.

  This is what the \bt_cli CLI tool's
  <a href="https://babeltrace.org/docs/v\bt_version_min_maj/man1/babeltrace2-convert.1"><code>convert</code></a>
  and
  <a href="https://babeltrace.org/docs/v\bt_version_min_maj/man1/babeltrace2-run.1"><code>run</code></a>
  commands do, for example.

A trace processing \bt_graph contains connected components. The specific
component topology determines the trace processing task to realize.

@image html basic-convert-graph.png "A conversion graph, a specific trace processing graph."

Between the components of a trace processing graph, \bt_p_msg flow from
\bt_p_oport to \bt_p_iport following the configured \bt_p_conn through
\bt_p_msg_iter. There are many types of messages, chief amongst which is
the \bt_ev_msg.

With libbabeltrace2, you can also \ref api-qexec "query" some specific
object from a component class (for example, the available LTTng live sessions
of an <a href="https://lttng.org">LTTng</a> relay daemon).
This is what the \bt_cli CLI tool's
<a href="https://babeltrace.org/docs/v\bt_version_min_maj/man1/babeltrace2-query.1"><code>query</code></a>
command does, for example.

Make sure to read \bt_man{babeltrace2-intro,7}
to learn even more about the \bt_name project and its core concepts.

@section main-contents What's in this documentation?

<dl>
  <dt>\ref api-fund</dt>
  <dd>
    Explains the basic principles of the \bt_api.

    Make sure you understand this section as you need this knowledge to
    use the API correctly.
  </dd>

  <dt>\ref guides</dt>
  <dd>
    Shows how to achieve common tasks with libbabeltrace2.

    Guides help you navigate through the most important features of
    the library and its API.
  </dd>

  <dt>\ref examples</dt>
  <dd>
    Contains simple and more complex examples which apply the different
    parts of the API to accomplish real tasks.
  </dd>

  <dt><a class="el" href="modules.html">API reference</a></dt>
  <dd>
    Documents all the \bt_name C functions, definitions, macros,
    enumerators, and types.

    Each documentation module describes its API thoroughly and how it's
    related to other modules.
  </dd>
</dl>
*/