statesystem/org.eclipse.tracecompass.statesystem.core/src/org/eclipse/tracecompass/statesystem/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.tracecompass.statesystem.core.statevalue;
  14
  15 import org.eclipse.tracecompass.statesystem.core.exceptions.StateValueTypeException;
  16
  17 /**
  18  * This is the interface for using state values and reading their contents.
  19  *
  20  * @author Alexandre Montplaisir
  21  */
  22 public interface ITmfStateValue extends Comparable<ITmfStateValue> {
  23
  24     /**
  25      * The supported types of state values
  26      */
  27     public enum Type {
  28         /** Null value, for an interval not carrying any information */
  29         NULL,
  30         /** 32-bit integer value */
  31         INTEGER,
  32         /** 64-bit integer value */
  33         LONG,
  34         /** IEEE 754 double precision number */
  35         DOUBLE,
  36         /** Variable-length string value */
  37         STRING,
  38     }
  39
  40     /**
  41      * Each implementation has to define which one (among the supported types)
  42      * they implement. There could be more than one implementation of each type,
  43      * depending on the needs of the different users.
  44      *
  45      * @return The ITmfStateValue.Type enum representing the type of this value
  46      */
  47     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     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     int unboxInt();
  65
  66     /**
  67      * Read the contained value as a 'long' primitive
  68      *
  69      * @return The long contained in the state value
  70      * @throws StateValueTypeException
  71      *             If the contained value cannot be read as a long
  72      */
  73     long unboxLong();
  74
  75     /**
  76      * Read the contained value as a 'double' primitive
  77      *
  78      * @return The double contained in the state value
  79      * @throws StateValueTypeException
  80      *             If the contained value cannot be read as a double
  81      */
  82     double unboxDouble();
  83
  84     /**
  85      * Read the contained value as a String
  86      *
  87      * @return The String contained in the state value
  88      * @throws StateValueTypeException
  89      *             If the contained value cannot be read as a String
  90      */
  91     String unboxStr();
  92
  93 }