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

   1 /*******************************************************************************
   2  * Copyright (c) 2012, 2013 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         DOUBLE,
  38         /** Variable-length string value */
  39         STRING,
  40     }
  41
  42     /**
  43      * Each implementation has to define which one (among the supported types)
  44      * they implement. There could be more than one implementation of each type,
  45      * depending on the needs of the different users.
  46      *
  47      * @return The ITmfStateValue.Type enum representing the type of this value
  48      * @since 2.0
  49      */
  50     Type getType();
  51
  52     /**
  53      * Only "null values" should return true here
  54      *
  55      * @return True if this type of SV is considered "null", false if it
  56      *         contains a real value.
  57      */
  58     boolean isNull();
  59
  60     /**
  61      * Read the contained value as an 'int' primitive
  62      *
  63      * @return The integer contained in the state value
  64      * @throws StateValueTypeException
  65      *             If the contained value cannot be read as an integer
  66      */
  67     int unboxInt() throws StateValueTypeException;
  68
  69     /**
  70      * Read the contained value as a 'long' primitive
  71      *
  72      * @return The long contained in the state value
  73      * @throws StateValueTypeException
  74      *             If the contained value cannot be read as a long
  75      * @since 2.0
  76      */
  77     long unboxLong() throws StateValueTypeException;
  78
  79     /**
  80      * Read the contained value as a 'double' primitive
  81      *
  82      * @return The double contained in the state value
  83      * @throws StateValueTypeException
  84      *             If the contained value cannot be read as a double
  85      */
  86     double unboxDouble() throws StateValueTypeException;
  87
  88     /**
  89      * Read the contained value as a String
  90      *
  91      * @return The String contained in the state value
  92      * @throws StateValueTypeException
  93      *             If the contained value cannot be read as a String
  94      */
  95     String unboxStr() throws StateValueTypeException;
  96 }