tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/internal/tmf/core/synchronization/TmfConstantTransform.java

   1 /*******************************************************************************
   2  * Copyright (c) 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  *   Matthew Khouzam - Initial API and implementation
  11  *******************************************************************************/
  12
  13 package org.eclipse.tracecompass.internal.tmf.core.synchronization;
  14
  15 import java.util.Objects;
  16
  17 import org.eclipse.jdt.annotation.NonNull;
  18 import org.eclipse.tracecompass.tmf.core.synchronization.ITmfTimestampTransform;
  19 import org.eclipse.tracecompass.tmf.core.synchronization.TimestampTransformFactory;
  20 import org.eclipse.tracecompass.tmf.core.timestamp.ITmfTimestamp;
  21
  22 /**
  23  * Constant transform, just offset your timestamp with another.
  24  *
  25  * @author Matthew Khouzam
  26  */
  27 public class TmfConstantTransform implements ITmfTimestampTransformInvertible {
  28
  29     /**
  30      * Serial ID
  31      */
  32     private static final long serialVersionUID = 417299521984404532L;
  33     private final long fOffset;
  34
  35     /**
  36      * Default constructor
  37      */
  38     public TmfConstantTransform() {
  39         // we really should be using an identity transform here.
  40         fOffset = 0;
  41     }
  42
  43     /**
  44      * Constructor with offset
  45      *
  46      * @param offset
  47      *            The offset of the linear transform in nanoseconds
  48      */
  49     public TmfConstantTransform(long offset) {
  50         fOffset = offset;
  51     }
  52
  53     /**
  54      * Constructor with offset timestamp
  55      *
  56      * @param offset
  57      *            The offset of the linear transform
  58      */
  59     public TmfConstantTransform(@NonNull ITmfTimestamp offset) {
  60         this(offset.toNanos());
  61     }
  62
  63     @Override
  64     public ITmfTimestamp transform(ITmfTimestamp timestamp) {
  65         return timestamp.normalize(fOffset, ITmfTimestamp.NANOSECOND_SCALE);
  66     }
  67
  68     /**
  69      * {@inheritDoc}
  70      *
  71      * @param timestamp
  72      *            the timestamp in nanoseconds
  73      * @return the timestamp in nanoseconds
  74      */
  75     @Override
  76     public long transform(long timestamp) {
  77         return fOffset + timestamp;
  78     }
  79
  80     @Override
  81     public ITmfTimestampTransform composeWith(ITmfTimestampTransform composeWith) {
  82         if (composeWith.equals(TmfTimestampTransform.IDENTITY)) {
  83             /* If composing with identity, just return this */
  84             return this;
  85         } else if (composeWith instanceof TmfConstantTransform) {
  86             TmfConstantTransform tct = (TmfConstantTransform) composeWith;
  87             final long offset = fOffset + tct.fOffset;
  88             if (offset == 0) {
  89                 return TmfTimestampTransform.IDENTITY;
  90             }
  91             return new TmfConstantTransform(offset);
  92         } else if (composeWith instanceof TmfTimestampTransformLinear) {
  93             throw new UnsupportedOperationException("Cannot compose a constant and linear transform yet"); //$NON-NLS-1$
  94         } else {
  95             /*
  96              * We do not know what to do with this kind of transform, just
  97              * return this
  98              */
  99             return this;
 100         }
 101     }
 102
 103     @Override
 104     public ITmfTimestampTransform inverse() {
 105         return TimestampTransformFactory.createWithOffset(-1 * fOffset);
 106     }
 107
 108     @Override
 109     public int hashCode() {
 110         return Objects.hash(fOffset);
 111     }
 112
 113     @Override
 114     public boolean equals(Object obj) {
 115         if (this == obj) {
 116             return true;
 117         }
 118         if (obj == null) {
 119             return false;
 120         }
 121         if (getClass() != obj.getClass()) {
 122             return false;
 123         }
 124         TmfConstantTransform other = (TmfConstantTransform) obj;
 125         return (fOffset == other.fOffset);
 126     }
 127
 128     @Override
 129     public String toString() {
 130         StringBuilder builder = new StringBuilder();
 131         builder.append("TmfConstantTransform [ offset = "); //$NON-NLS-1$
 132         builder.append(fOffset);
 133         builder.append(" ]"); //$NON-NLS-1$
 134         return builder.toString();
 135     }
 136
 137 }