org.eclipse.linuxtools.tmf.core/src/org/eclipse/linuxtools/tmf/core/statevalue/ITmfStateValue.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are
   5  * made available under the terms of the Eclipse Public License v1.0 which
   6  * accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *   Alexandre Montplaisir - Initial API
  11  ******************************************************************************/
  12
  13 package org.eclipse.linuxtools.tmf.core.statevalue;
  14
  15 import org.eclipse.linuxtools.tmf.core.exceptions.StateValueTypeException;
  16
  17
  18 /**
  19  * This is the interface for using state values and reading their contents.
  20  *
  21  * @version 1.0
  22  * @author Alexandre Montplaisir
  23  */
  24 public interface ITmfStateValue {
  25
  26     /**
  27      * The supported types of state values
  28      * @since 2.0
  29      */
  30     public enum Type {
  31         /** Null value, for an interval not carrying any information */
  32         NULL,
  33         /** 32-bit integer value */
  34         INTEGER,
  35         /** Variable-length string value */
  36         STRING
  37     }
  38
  39     /**
  40      * Each implementation has to define which one (among the supported types)
  41      * they implement. There could be more than one implementation of each type,
  42      * depending on the needs of the different users.
  43      *
  44      * @return The ITmfStateValue.Type enum representing the type of this value
  45      * @since 2.0
  46      */
  47     public Type getType();
  48
  49     /**
  50      * Only "null values" should return true here
  51      *
  52      * @return True if this type of SV is considered "null", false if it
  53      *         contains a real value.
  54      */
  55     public boolean isNull();
  56
  57     /**
  58      * Read the contained value as an 'int' primitive
  59      *
  60      * @return The integer contained in the state value
  61      * @throws StateValueTypeException
  62      *             If the contained value cannot be read as an integer
  63      */
  64     public int unboxInt() throws StateValueTypeException;
  65
  66     /**
  67      * Read the contained value as a String
  68      *
  69      * @return The String contained in the state value
  70      * @throws StateValueTypeException
  71      *             If the contained value cannot be read as a String
  72      */
  73     public String unboxStr() throws StateValueTypeException;
  74 }