Learning POOL by examples: Simple I/O

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Learning POOL by examples: Simple I/O

Description

The aim of this example is to demonstrate the basic I/O operations of simple objects using ROOT Tree technology as the storage backend, XML for the file catalog, the POOL Ref/DataSvc for caching, and the Implicit Collections for reading back the objects.

The user creates a class library which contains the implementation of a simple Hit class, runs the LCG dictionary for this class and builds the corresponding dictionary run time library.
A simple writer application writes the objects in a container of a database file which are specified in the program. The reader starts an iteration in the implicit collection of objects defined by the database/container specified in the writer and prints the contents of the objects.
The writer and reader applications are linked against the user class library. The dictionary library is explicitly loaded during run time.

Files

Hit.h, Hit.cpp : The simple object which is persistified.
SimpleWriter.cpp : The application which stores the objects.
SimpleReader.cpp : The application which reads back the objects.
classes.xml : The selection file specifying the classes whose dictionary should be generated.
buildAndRunAll.sh : The shell script which builds and runs all the applications.

Building and running

Please copy above files to your workspace and simply execute the shell script:

./buildAndRunAll.sh

Extend this example

Alter the Hit class to contain more data members or different types.
Change the names of the database and the container, where the objects are stored.

Contact : Zhang Yiheng, ATLAS, LNF-INFN.