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

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2014 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  * This is the interface for using state values and reading their contents.
  19  *
  20  * @version 1.0
  21  * @author Alexandre Montplaisir
  22  */
  23 public interface ITmfStateValue {
  24
  25     /**
  26      * The supported types of state values
  27      * @since 2.0
  28      */
  29     public enum Type {
  30         /** Null value, for an interval not carrying any information */
  31         NULL,
  32         /** 32-bit integer value */
  33         INTEGER,
  34         /** 64-bit integer value */
  35         LONG,
  36         /** IEEE 754 double precision number
  37          * @since 3.0*/
  38         DOUBLE,
  39         /** Variable-length string value */
  40         STRING,
  41     }
  42
  43     /**
  44      * Each implementation has to define which one (among the supported types)
  45      * they implement. There could be more than one implementation of each type,
  46      * depending on the needs of the different users.
  47      *
  48      * @return The ITmfStateValue.Type enum representing the type of this value
  49      * @since 2.0
  50      */
  51     Type getType();
  52
  53     /**
  54      * Only "null values" should return true here
  55      *
  56      * @return True if this type of SV is considered "null", false if it
  57      *         contains a real value.
  58      */
  59     boolean isNull();
  60
  61     /**
  62      * Read the contained value as an 'int' primitive
  63      *
  64      * @return The integer contained in the state value
  65      * @throws StateValueTypeException
  66      *             If the contained value cannot be read as an integer
  67      */
  68     int unboxInt();
  69
  70     /**
  71      * Read the contained value as a 'long' primitive
  72      *
  73      * @return The long contained in the state value
  74      * @throws StateValueTypeException
  75      *             If the contained value cannot be read as a long
  76      * @since 2.0
  77      */
  78     long unboxLong();
  79
  80     /**
  81      * Read the contained value as a 'double' primitive
  82      *
  83      * @return The double contained in the state value
  84      * @throws StateValueTypeException
  85      *             If the contained value cannot be read as a double
  86      * @since 3.0
  87      */
  88     double unboxDouble();
  89
  90     /**
  91      * Read the contained value as a String
  92      *
  93      * @return The String contained in the state value
  94      * @throws StateValueTypeException
  95      *             If the contained value cannot be read as a String
  96      */
  97     String unboxStr();
  98 }