Merge "Implement ResizableIntArray.fill"
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commit
2f6a90ac31
2 changed files with 138 additions and 28 deletions
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@ -28,38 +28,49 @@ public class ResizableIntArray {
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}
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public int get(final int index) {
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if (index < 0 || index >= mLength) {
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throw new ArrayIndexOutOfBoundsException("length=" + mLength + "; index=" + index);
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if (index < mLength) {
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return mArray[index];
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}
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return mArray[index];
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throw new ArrayIndexOutOfBoundsException("length=" + mLength + "; index=" + index);
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}
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public void add(final int index, final int val) {
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if (mLength < index + 1) {
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if (index < mLength) {
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mArray[index] = val;
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} else {
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mLength = index;
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add(val);
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} else {
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mArray[index] = val;
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}
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}
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public void add(final int val) {
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final int nextLength = mLength + 1;
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ensureCapacity(nextLength);
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mArray[mLength] = val;
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mLength = nextLength;
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final int currentLength = mLength;
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ensureCapacity(currentLength + 1);
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mArray[currentLength] = val;
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mLength = currentLength + 1;
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}
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/**
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* Calculate the new capacity of {@code mArray}.
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* @param minimumCapacity the minimum capacity that the {@code mArray} should have.
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* @return the new capacity that the {@code mArray} should have. Returns zero when there is no
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* need to expand {@code mArray}.
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*/
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private int calculateCapacity(final int minimumCapacity) {
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final int currentCapcity = mArray.length;
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if (currentCapcity < minimumCapacity) {
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final int nextCapacity = currentCapcity * 2;
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// The following is the same as return Math.max(minimumCapacity, nextCapacity);
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return minimumCapacity > nextCapacity ? minimumCapacity : nextCapacity;
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}
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return 0;
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}
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private void ensureCapacity(final int minimumCapacity) {
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if (mArray.length < minimumCapacity) {
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final int nextCapacity = mArray.length * 2;
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// The following is the same as newLength =
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// Math.max(minimumCapacity, nextCapacity);
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final int newLength = minimumCapacity > nextCapacity
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? minimumCapacity
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: nextCapacity;
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final int newCapacity = calculateCapacity(minimumCapacity);
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if (newCapacity > 0) {
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// TODO: Implement primitive array pool.
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mArray = Arrays.copyOf(mArray, newLength);
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mArray = Arrays.copyOf(mArray, newCapacity);
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}
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}
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@ -89,17 +100,35 @@ public class ResizableIntArray {
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}
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public void copy(final ResizableIntArray ip) {
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// TODO: Avoid useless coping of values.
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ensureCapacity(ip.mLength);
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final int newCapacity = calculateCapacity(ip.mLength);
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if (newCapacity > 0) {
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// TODO: Implement primitive array pool.
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mArray = new int[newCapacity];
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}
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System.arraycopy(ip.mArray, 0, mArray, 0, ip.mLength);
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mLength = ip.mLength;
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}
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public void append(final ResizableIntArray src, final int startPos, final int length) {
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if (length == 0) {
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return;
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}
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final int currentLength = mLength;
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final int newLength = currentLength + length;
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ensureCapacity(newLength);
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System.arraycopy(src.mArray, startPos, mArray, currentLength, length);
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mLength = newLength;
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}
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public void fill(final int value, final int startPos, final int length) {
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if (startPos < 0 || length < 0) {
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throw new IllegalArgumentException("startPos=" + startPos + "; length=" + length);
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}
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final int endPos = startPos + length;
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ensureCapacity(endPos);
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Arrays.fill(mArray, startPos, endPos, value);
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if (mLength < endPos) {
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mLength = endPos;
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}
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}
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}
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@ -37,8 +37,12 @@ public class ResizableIntArrayTests extends AndroidTestCase {
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for (int i = 0; i < limit; i++) {
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src.add(i);
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assertEquals("length after add " + i, i + 1, src.getLength());
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if (i == DEFAULT_CAPACITY) array2 = src.getPrimitiveArray();
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if (i == DEFAULT_CAPACITY * 2) array3 = src.getPrimitiveArray();
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if (i == DEFAULT_CAPACITY) {
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array2 = src.getPrimitiveArray();
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}
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if (i == DEFAULT_CAPACITY * 2) {
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array3 = src.getPrimitiveArray();
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}
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if (i < DEFAULT_CAPACITY) {
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assertSame("array after add " + i, array, src.getPrimitiveArray());
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} else if (i < DEFAULT_CAPACITY * 2) {
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@ -110,7 +114,9 @@ public class ResizableIntArrayTests extends AndroidTestCase {
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for (int i = 0; i < DEFAULT_CAPACITY; i++) {
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src.add(i);
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assertEquals("length after add " + i, i + 1, src.getLength());
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if (i == smallerLength) array3 = src.getPrimitiveArray();
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if (i == smallerLength) {
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array3 = src.getPrimitiveArray();
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}
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if (i < smallerLength) {
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assertSame("array after add " + i, array2, src.getPrimitiveArray());
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} else if (i < smallerLength * 2) {
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@ -133,11 +139,13 @@ public class ResizableIntArrayTests extends AndroidTestCase {
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assertEquals("length after larger setLength", largerLength, src.getLength());
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assertNotSame("array after larger setLength", array, array2);
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assertEquals("array length after larger setLength", largerLength, array2.length);
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for (int i = 0; i < DEFAULT_CAPACITY; i++) {
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assertEquals("value at " + i, i, src.get(i));
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}
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for (int i = DEFAULT_CAPACITY; i < largerLength; i++) {
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assertEquals("value at " + i, 0, src.get(i));
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for (int i = 0; i < largerLength; i++) {
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final int v = src.get(i);
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if (i < DEFAULT_CAPACITY) {
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assertEquals("value at " + i, i, v);
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} else {
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assertEquals("value at " + i, 0, v);
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}
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}
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final int smallerLength = DEFAULT_CAPACITY / 2;
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@ -236,6 +244,79 @@ public class ResizableIntArrayTests extends AndroidTestCase {
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src.getPrimitiveArray(), 0, dst.getPrimitiveArray(), dstLen + srcLen, srcLen);
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}
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public void testFill() {
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final int srcLen = DEFAULT_CAPACITY;
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final ResizableIntArray src = new ResizableIntArray(srcLen);
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for (int i = 0; i < srcLen; i++) {
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src.add(i);
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}
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final int[] array = src.getPrimitiveArray();
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final int startPos = srcLen / 3;
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final int length = srcLen / 3;
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final int endPos = startPos + length;
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assertTrue(startPos >= 1);
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final int value = 123;
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try {
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src.fill(value, -1, length);
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fail("fill from -1 shouldn't succeed");
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} catch (IllegalArgumentException e) {
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// success
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}
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try {
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src.fill(value, startPos, -1);
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fail("fill negative length shouldn't succeed");
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} catch (IllegalArgumentException e) {
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// success
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}
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src.fill(value, startPos, length);
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assertEquals("length after fill", srcLen, src.getLength());
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assertSame("array after fill", array, src.getPrimitiveArray());
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for (int i = 0; i < srcLen; i++) {
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final int v = src.get(i);
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if (i >= startPos && i < endPos) {
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assertEquals("new values after fill at " + i, value, v);
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} else {
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assertEquals("unmodified values after fill at " + i, i, v);
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}
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}
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final int length2 = srcLen * 2 - startPos;
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final int largeEnd = startPos + length2;
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assertTrue(largeEnd > srcLen);
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final int value2 = 456;
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src.fill(value2, startPos, length2);
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assertEquals("length after large fill", largeEnd, src.getLength());
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assertNotSame("array after large fill", array, src.getPrimitiveArray());
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for (int i = 0; i < largeEnd; i++) {
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final int v = src.get(i);
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if (i >= startPos && i < largeEnd) {
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assertEquals("new values after large fill at " + i, value2, v);
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} else {
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assertEquals("unmodified values after large fill at " + i, i, v);
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}
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}
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final int startPos2 = largeEnd + length2;
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final int endPos2 = startPos2 + length2;
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final int value3 = 789;
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src.fill(value3, startPos2, length2);
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assertEquals("length after disjoint fill", endPos2, src.getLength());
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for (int i = 0; i < endPos2; i++) {
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final int v = src.get(i);
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if (i >= startPos2 && i < endPos2) {
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assertEquals("new values after disjoint fill at " + i, value3, v);
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} else if (i >= startPos && i < largeEnd) {
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assertEquals("unmodified values after disjoint fill at " + i, value2, v);
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} else if (i < startPos) {
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assertEquals("unmodified values after disjoint fill at " + i, i, v);
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} else {
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assertEquals("gap values after disjoint fill at " + i, 0, v);
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}
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}
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}
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private static void assertArrayEquals(String message, int[] expecteds, int expectedPos,
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int[] actuals, int actualPos, int length) {
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if (expecteds == null && actuals == null) {
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