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  * @author alexmont
  22  *
  23  */
  24 public interface ITmfStateValue {
  25
  26     /** The 'byte' value associated to null state values (-1) */
  27     public static final byte TYPE_NULL = -1;
  28
  29     /** The 'byte' value associated to integer state values (0) */
  30     public static final byte TYPE_INTEGER = 0;
  31
  32     /** The 'byte' value associated to null state values (1) */
  33     public static final byte TYPE_STRING = 1;
  34
  35     /**
  36      * Each implementation has to supply a "type" number. This will get written
  37      * as-is in the History file to recognize the type, so it needs to be unique
  38      *
  39      * @return The unique "int8" assigned to this state value type
  40      */
  41     public byte getType();
  42
  43     /**
  44      * Only "null values" should return true here
  45      *
  46      * @return True if this type of SV is considered "null", false if it
  47      *         contains a real value.
  48      */
  49     public boolean isNull();
  50
  51     /**
  52      * Read the contained value as an 'int' primitive
  53      *
  54      * @return The integer contained in the state value
  55      * @throws StateValueTypeException
  56      *             If the contained value cannot be read as an integer
  57      */
  58     public int unboxInt() throws StateValueTypeException;
  59
  60     /**
  61      * Read the contained value as a String
  62      *
  63      * @return The String contained in the state value
  64      * @throws StateValueTypeException
  65      *             If the contained value cannot be read as a String
  66      */
  67     public String unboxStr() throws StateValueTypeException;
  68 }