- support for event by event reconstruction added to AliHLTSystem

[u/mrichter/AliRoot.git] / HLT / README

Package: ALICE HLT

This package implements the ALICE High Level Trigger analysis framework
and analysis component libraries. All files are property of and copyright
by the ALICE HLT Project unless stated differently.

All contributions are under the terms of the 
GNU General Public License as published by the Free Software 
Foundation. Also see files AUTHORS and THANKS.

This packages is maintained by Matthias.Richter@ift.uib.no
Comments, bug reports, suggestions welcome! 

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ TOC
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ 1. Overview
+ 2. Requirements
+ 3. Setting up a version retrieved from CVS
+ 4. Modifying a distributed package
+ 5. Installation
+ 6. Documentation
+ 7. Further information
+ 8. Reporting bugs/Asking for support
+ 9. Committing to the AliRoot CVS
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1. Overview
===========
This package provides a compilation of shared libraries of the ALICE
HLT project and is intended for stand-alone compilation, i.e. not as part 
of the AliRoot compilation. 

 - \b BASE: The base library (libHLTbase.so) provides the common interface for
   HLT processing components, the binding into the ALICE offline project
   AliRoot and a pure C interface to the HLT on-line framework 
   (Publisher/Subscriber framework)

 - \b SampleLib: The sample library contains examples for component 
   implementation and a tutorial.

 - \b TPCLib: The HLT code for the TPC
 - \b TPCLib/OnlineDisplay: HLT visualization code for the TPC

 - \b PHOS: The HLT code for PHOS

 - \b TRD: The HLT code for TRD

 - \b MUON: The HLT code for MUON

2. Requirements
===============
The package needs both ROOT and AliRoot. Both must be set up in the
usual way (ROOTSYS, ALICE_ROOT, library locations evtl. specified in
LD_LIBRARY_PATH, ...). Actually, the BASE and SampleLib modules are
not dependend on AliRoot. The TPCLib does.

To set up a version retrieved from CVS, autoconf 2.57, automake 1.6
,and libtool 1.4 or higher versions are required. Thats the versions
which come with the Scientific Linux CERN 3. The same applies if
you want to change the Makefiles.

If your GNU build tools are too old, ask the maintainers for a distributed
package.  

3. Setting up a version retrieved from CVS
==========================================
Skip this section if you have started from the tar ball.

A version checked out from CVS requires a few steps to set up the Makefiles.
Go to the directory and run

  autoreconf -i -f

Then continue with the package configuration described in the 'Installation'
section.

4. Modifying a distributed package
==================================
If you are going the modify a distributed package you might need to re-make 
the GNU build system by running

  autoreconf -f -i

Please notify the authors about bug fixes/corrections/extensions you made if
you consider them worth to be merged into the project.

Then continue with the package configuration described in the 'Installation'
section.

5. Installation
===============
Package build relies on the GNU triplet configure, make and make install.
In order to keep the development directory clean, it is recommended to
use a separate build directory. 

\b NOTE: Autotools creates the Makefiles from templates. All \b changes have to
be done to the \b Makefile.am templates.

It is recommended to read the complete section before the build process.

5.1 For the impatiant user
--------------------------

  mkdir build
  cd build
  ../configure
  make
  make install

5.2 Installation directory
--------------------------
The default install directory is set to the current directory ($PWD). To
override the default directory use the option 
  --prefix=<dir>. 
More information can be obtained from the configure script by running it with
option --help. All binary libraries will be installed under
  <prefix>/lib.

If the directory is equal to $ALICE_ROOT, the libraries will be installed under
  <prefix>/lib/tgt_<arch>
as used for AliRoot. This is a custom extension in
order to adapt to the specific AliRoot installation directories.

5.3 For the AliRoot user
------------------------
To install all libraries in the AliRoot lib dir:

  mkdir build
  cd build
  ../configure --prefix=$ALICE_ROOT
  make
  make install

5.4 Package options
-------------------
Some important options (all options are on by default):

  --disable-sample           # disable compilation the sample library
  --disable-util             # disable compilation the util library
  --disable-tpc              # disable compilation the TPC library
  --disable-phos             # disable compilation the PHOS library
  --disable-trd              # disable compilation the TRD library
  --disable-dimuon           # disable compilation the MUON library
  --disable-aliroot-logging  # disable logging

All detector libraries (including sample and util lib) require AliRoot,
compilation is disabled if no working AliRoot version was found. This can
occur even if an AliRoot version is set up correctly since the configure
script checks for the usability of the AliRoot libraries (mainly STEER and
the ones it depends on). If new dependencies are introduced, the check
might fail.

Compilation of detector libraries can be forced by the switch

  --enable-detector, e.g. --enable-phos
 
Debugging (default disabled)

  --enable-debug             # enable debugging: symbols & messages

Optimization (default -O2)

  --disable-optimization     # disable compiler optimization
  --enable-optimization<=l>  # enable compiler optimization level l

5.5 External packages
---------------------
PubSub framework: the TPC online display needs the HOMER interface, which
is currently part of the PubSub framework. It is planned to integrate it
into AliRoot.<br>
If the TPC online display is not necessary one can skip this option.

  --with-pubsub=<dir>        # the top dir of the HLT PubSub framework

5.6 Final remarks/further information 
-------------------------------------
\b Note: You can have several build directories with different configure
options, but using the same source code. 

If you need further information on the GNU build system, execute from the 
top directory:

  ./configure --help | less


6. Documentation
================
Documentation is build as part of the build process if \b doxygen is installed.
The documentation can be opended from the
  doc/html/
sub-folder of your build directory. E.g with a web browser like firefox
(assuming you are in the build directory):<br>
  firefox file://`pwd`/doc/html/index.html

A special target can be used to make a tar ball out of the documentation (again
provided you are in the build directory):<br>
  (cd doc && make tar-ball)

On-line documentation is available at
  http://web.ift.uib.no/~kjeks/doc/alice-hlt/

7. Further information
======================
A wiki with detailed information is set up at
  http://www.kip.uni-heidelberg.de/wiki/HLT

8. Reporting bugs/Asking for support
====================================
Please include the following information into your request:
 - config.log from your build directory
 - output of the make process. Note: Redirect BOTH the stdout and stderr
   channel to a log file. Redirection depends on the shell you are using:     <br>
    bash: make 2>&1 | tee make.log                                            <br>
    csh: make |& tee make.log                                                 <br>
   The 'tee' command just duplicates the output.
 - history of the commands you are using for compilation
   history > history.log

9. Committing to the AliRoot CVS
================================
For development of HLT analysis code check out a HEAD version from the 
repository and implement your code. 

For committing do:
 - 1. make sure that the code changes are correct                    <br><tt>
      cvs diff | less                                                </tt><br>
      \b Remember to restore all temporary changes you made (e.g. log level)
 - 2. cvs update
 - 3. correct merging conflicts
 - 4. compile and test your code again
 - 5. send the whole HLT module except the build sub-directories to
      Matthias.Richter@ift.uib.no
 - 6. you will get a notification when the code is committed, right after that
      you must either do another cvs update or check out the complete module
      again in order to have the right CVS information.