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