--- jsr166/src/main/java/util/ArrayList.java 2016/11/30 03:31:47 1.45
+++ jsr166/src/main/java/util/ArrayList.java 2017/05/06 06:49:45 1.50
@@ -91,7 +91,7 @@ import java.util.function.UnaryOperator;
* should be used only to detect bugs.
*
*
This class is a member of the
- *
+ *
* Java Collections Framework.
*
* @param the type of elements in this list
@@ -578,8 +578,9 @@ public class ArrayList extends Abstra
*/
public void clear() {
modCount++;
- Arrays.fill(elementData, 0, size, null);
- size = 0;
+ final Object[] es = elementData;
+ for (int to = size, i = size = 0; i < to; i++)
+ es[i] = null;
}
/**
@@ -669,13 +670,17 @@ public class ArrayList extends Abstra
outOfBoundsMsg(fromIndex, toIndex));
}
modCount++;
- final Object[] es = elementData;
- final int oldSize = size;
- System.arraycopy(es, toIndex, es, fromIndex, oldSize - toIndex);
- Arrays.fill(es, size -= (toIndex - fromIndex), oldSize, null);
+ shiftTailOverGap(elementData, fromIndex, toIndex);
// checkInvariants();
}
+ /** Erases the gap from lo to hi, by sliding down following elements. */
+ private void shiftTailOverGap(Object[] es, int lo, int hi) {
+ System.arraycopy(es, hi, es, lo, size - hi);
+ for (int to = size, i = (size -= hi - lo); i < to; i++)
+ es[i] = null;
+ }
+
/**
* A version of rangeCheck used by add and addAll.
*/
@@ -761,10 +766,8 @@ public class ArrayList extends Abstra
w += end - r;
throw ex;
} finally {
- final int oldSize = size, deleted = end - w;
- modCount += deleted;
- System.arraycopy(es, end, es, w, oldSize - end);
- Arrays.fill(es, size -= deleted, oldSize, null);
+ modCount += end - w;
+ shiftTailOverGap(es, w, end);
}
}
// checkInvariants();
@@ -772,15 +775,17 @@ public class ArrayList extends Abstra
}
/**
- * Save the state of the {@code ArrayList} instance to a stream (that
- * is, serialize it).
+ * Saves the state of the {@code ArrayList} instance to a stream
+ * (that is, serializes it).
*
+ * @param s the stream
+ * @throws java.io.IOException if an I/O error occurs
* @serialData The length of the array backing the {@code ArrayList}
* instance is emitted (int), followed by all of its elements
* (each an {@code Object}) in the proper order.
*/
private void writeObject(java.io.ObjectOutputStream s)
- throws java.io.IOException{
+ throws java.io.IOException {
// Write out element count, and any hidden stuff
int expectedModCount = modCount;
s.defaultWriteObject();
@@ -799,8 +804,12 @@ public class ArrayList extends Abstra
}
/**
- * Reconstitute the {@code ArrayList} instance from a stream (that is,
- * deserialize it).
+ * Reconstitutes the {@code ArrayList} instance from a stream (that is,
+ * deserializes it).
+ * @param s the stream
+ * @throws ClassNotFoundException if the class of a serialized object
+ * could not be found
+ * @throws java.io.IOException if an I/O error occurs
*/
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
@@ -1362,6 +1371,9 @@ public class ArrayList extends Abstra
}
}
+ /**
+ * @throws NullPointerException {@inheritDoc}
+ */
@Override
public void forEach(Consumer super E> action) {
Objects.requireNonNull(action);
@@ -1431,7 +1443,7 @@ public class ArrayList extends Abstra
private int fence; // -1 until used; then one past last index
private int expectedModCount; // initialized when fence set
- /** Create new spliterator covering the given range */
+ /** Creates new spliterator covering the given range. */
ArrayListSpliterator(int origin, int fence, int expectedModCount) {
this.index = origin;
this.fence = fence;
@@ -1513,6 +1525,9 @@ public class ArrayList extends Abstra
return (bits[i >> 6] & (1L << i)) == 0;
}
+ /**
+ * @throws NullPointerException {@inheritDoc}
+ */
@Override
public boolean removeIf(Predicate super E> filter) {
return removeIf(filter, 0, size);
@@ -1547,9 +1562,7 @@ public class ArrayList extends Abstra
for (i = beg; i < end; i++)
if (isClear(deathRow, i - beg))
es[w++] = es[i];
- final int oldSize = size;
- System.arraycopy(es, end, es, w, oldSize - end);
- Arrays.fill(es, size -= (end - w), oldSize, null);
+ shiftTailOverGap(es, w, end);
// checkInvariants();
return true;
} else {