CircularBItSet init from oldState with correct order

failsafe-lib · Jul 18, 2016 · 93ca951 · 93ca951
1 parent efcd0a0
commit 93ca951
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Showing 3 changed files with 57 additions and 2 deletions.
diff --git a/src/main/java/net/jodah/failsafe/internal/util/.CircularBitSet.java.swp b/src/main/java/net/jodah/failsafe/internal/util/.CircularBitSet.java.swp
diff --git a/src/main/java/net/jodah/failsafe/internal/util/CircularBitSet.java b/src/main/java/net/jodah/failsafe/internal/util/CircularBitSet.java
@@ -22,8 +22,17 @@ public CircularBitSet(int size, CircularBitSet oldBitSet) {
 
     // Initialize from oldBitSet
     if (oldBitSet != null) {
-      for (int i = 0; i < size && i < oldBitSet.occupiedBits; i++)
-        setNext(oldBitSet.bitSet.get(i));
+      initializeFromOldBits(oldBitSet);
+    }
+  }
+
+  /**
+   * Initialize bitSet from oldBitSet with correct order
+   */
+  private void initializeFromOldBits(CircularBitSet oldBitSet) {
+    int startIndex = oldBitSet.occupiedBits <= size ? 0 : oldBitSet.occupiedBits - size;
+    for (int i = startIndex; i < oldBitSet.occupiedBits; i++) {
+      setNext(oldBitSet.bitSet.get(i));
     }
   }
 

diff --git a/src/test/java/net/jodah/failsafe/internal/util/CircularBitSetTest.java b/src/test/java/net/jodah/failsafe/internal/util/CircularBitSetTest.java
@@ -47,4 +47,50 @@ public void shouldCopyBits() {
     assertEquals(bs3.positiveRatio(), .5);
     assertEquals(bs3.negativeRatio(), .5);
   }
+
+  public void shouldCopyBitsFromFullOldBitsSetWithCorrectOrder() {
+    CircularBitSet bs = new CircularBitSet(4, null);
+    boolean[] prevBits = { true, true, true, false };
+    for (boolean prevBit : prevBits) {
+      bs.setNext(prevBit);
+    }
+
+    CircularBitSet bs2 = new CircularBitSet(2, bs);
+    assertEquals(bs2.occupiedBits(), 2);
+    assertEquals(bs2.positiveRatio(), .5);
+    assertEquals(bs2.negativeRatio(), .5);
+
+    bs2.setNext(true);
+    assertEquals(bs2.occupiedBits(), 2);
+    assertEquals(bs2.positiveRatio(), .5);
+    assertEquals(bs2.negativeRatio(), .5);
+
+    bs2.setNext(true);
+    assertEquals(bs2.occupiedBits(), 2);
+    assertEquals(bs2.positiveRatio(), 1.0);
+    assertEquals(bs2.negativeRatio(), .0);
+  }
+
+  public void shouldCopyBitsFromNonFullOldBitsSetWithCorrectOrder() {
+    CircularBitSet bs = new CircularBitSet(8, null);
+    boolean[] prevBits = { true, true, true, false, false, false };
+    for (boolean prevBit : prevBits) {
+      bs.setNext(prevBit);
+    }
+
+    CircularBitSet bs2 = new CircularBitSet(4, bs);
+    assertEquals(bs2.occupiedBits(), 4);
+    assertEquals(bs2.positiveRatio(), .25);
+    assertEquals(bs2.negativeRatio(), .75);
+
+    bs2.setNext(true);
+    assertEquals(bs2.occupiedBits(), 4);
+    assertEquals(bs2.positiveRatio(), .25);
+    assertEquals(bs2.negativeRatio(), .75);
+
+    bs2.setNext(true);
+    assertEquals(bs2.occupiedBits(), 4);
+    assertEquals(bs2.positiveRatio(), .5);
+    assertEquals(bs2.negativeRatio(), .5);
+  }
 }