tmf: buf 495911 Fix timestamp transform fast for small timestamps

[deliverable/tracecompass.git] / tmf / org.eclipse.tracecompass.tmf.core / src / org / eclipse / tracecompass / internal / tmf / core / synchronization / TmfTimestampTransformLinearFast.java

diff --git a/tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/internal/tmf/core/synchronization/TmfTimestampTransformLinearFast.java b/tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/internal/tmf/core/synchronization/TmfTimestampTransformLinearFast.java
index 30531a60f6e921b6988d91bad7a688a821755d6b..3e9c0f89d2d8152faa0dc79dafc6127f12773a4a 100644 (file)
--- a/tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/internal/tmf/core/synchronization/TmfTimestampTransformLinearFast.java
+++ b/tmf/org.eclipse.tracecompass.tmf.core/src/org/eclipse/tracecompass/internal/tmf/core/synchronization/TmfTimestampTransformLinearFast.java
@@ -13,6 +13,8 @@
 
 package org.eclipse.tracecompass.internal.tmf.core.synchronization;
 
+import java.io.IOException;
+import java.io.ObjectInputStream;
 import java.math.BigDecimal;
 import java.math.MathContext;
 
@@ -73,8 +75,7 @@ public class TmfTimestampTransformLinearFast implements ITmfTimestampTransformIn
     private final int fDeltaBits;
     private final int fHashCode;
 
-    private long fOffset;
-
+    private transient long fOffset;
     private transient long fRangeStart;
     private transient long fScaleMiss;
     private transient long fScaleHit;
@@ -151,8 +152,7 @@ public class TmfTimestampTransformLinearFast implements ITmfTimestampTransformIn
         fDeltaBits = Math.max(Math.min(width, DECIMAL_BITS), 0);
         fDeltaMax = 1 << fDeltaBits;
         fAlphaLong = fAlpha.multiply(BigDecimal.valueOf(fDeltaMax), MC).longValue();
-        fRangeStart = 0L;
-        fOffset = 0L;
+        rescale(0);
         fScaleMiss = 0;
         fScaleHit = 0;
         fHashCode = HASHER.newHasher()
@@ -185,8 +185,7 @@ public class TmfTimestampTransformLinearFast implements ITmfTimestampTransformIn
              *
              * TODO: use exact math arithmetic to detect overflow when switching to Java 8
              */
-            fRangeStart = timestamp - (timestamp % fDeltaMax);
-            fOffset = BigDecimal.valueOf(fRangeStart).multiply(fAlpha, MC).add(fBeta, MC).longValue();
+            rescale(timestamp);
             delta = Math.abs(timestamp - fRangeStart);
             fScaleMiss++;
         } else {
@@ -195,6 +194,11 @@ public class TmfTimestampTransformLinearFast implements ITmfTimestampTransformIn
         return ((fAlphaLong * delta) >> fDeltaBits) + fOffset;
     }
 
+    private void rescale(long timestamp) {
+        fRangeStart = timestamp - (timestamp % fDeltaMax);
+        fOffset = BigDecimal.valueOf(fRangeStart).multiply(fAlpha, MC).add(fBeta, MC).longValue();
+    }
+
     //-------------------------------------------------------------------------
     // Transform composition
     //-------------------------------------------------------------------------
@@ -308,4 +312,12 @@ public class TmfTimestampTransformLinearFast implements ITmfTimestampTransformIn
         return fHashCode;
     }
 
+    // Deserialization method, make sure there is a first scaling
+    private void readObject(ObjectInputStream stream)
+            throws IOException, ClassNotFoundException {
+        stream.defaultReadObject();
+
+        rescale(0);
+    }
+
 }
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