org.eclipse.tracecompass.ctf.core/src/org/eclipse/tracecompass/ctf/core/event/types/CompoundDeclaration.java

   1 /*******************************************************************************
   2  * Copyright (c) 2014 Ericsson
   3  *
   4  * All rights reserved. This program and the accompanying materials are made
   5  * 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  *   Matthew Khouzam - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.tracecompass.ctf.core.event.types;
  14
  15 /**
  16  * Parent of sequences and arrays
  17  *
  18  * @author Matthew Khouzam
  19  */
  20 public abstract class CompoundDeclaration extends Declaration {
  21
  22     private static final int BIT_MASK = 0x03;
  23     private static final int BITS_PER_BYTE = 8;
  24
  25     /**
  26      * Get the element type
  27      *
  28      * @return the type of element in the array
  29      */
  30     public abstract IDeclaration getElementType();
  31
  32     @Override
  33     public long getAlignment() {
  34         return getElementType().getAlignment();
  35     }
  36
  37     /**
  38      * Sometimes, strings are encoded as an array of 1-byte integers (each one
  39      * being an UTF-8 byte).
  40      *
  41      * @return true if this array is in fact an UTF-8 string. false if it's a
  42      *         "normal" array of generic Definition's.
  43      */
  44     public boolean isString() {
  45         IDeclaration elementType = getElementType();
  46         if (elementType instanceof IntegerDeclaration) {
  47             IntegerDeclaration elemInt = (IntegerDeclaration) elementType;
  48             return elemInt.isCharacter();
  49         }
  50         return false;
  51     }
  52
  53     /**
  54      * If an array contains 8 bit aligned 8 bit ints, it can be bulk read.
  55      *
  56      * @return true if this array 1 byte aligned. false if it's a "normal" array
  57      *         of generic Definition's.
  58      * @since 1.0
  59      */
  60     public boolean isAlignedBytes() {
  61         IDeclaration elementType = getElementType();
  62         if (elementType instanceof IntegerDeclaration) {
  63             IntegerDeclaration elemInt = (IntegerDeclaration) elementType;
  64             return (elemInt.getLength() == BITS_PER_BYTE) && ((getAlignment() & BIT_MASK) == 0);
  65         }
  66         return false;
  67     }
  68
  69 }