src/java.base/share/classes/java/util/stream/SpinedBuffer.java
changeset 47216 71c04702a3d5
parent 25859 3317bb8137f4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/util/stream/SpinedBuffer.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,1061 @@
+/*
+ * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.util.stream;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Objects;
+import java.util.PrimitiveIterator;
+import java.util.Spliterator;
+import java.util.Spliterators;
+import java.util.function.Consumer;
+import java.util.function.DoubleConsumer;
+import java.util.function.IntConsumer;
+import java.util.function.IntFunction;
+import java.util.function.LongConsumer;
+
+/**
+ * An ordered collection of elements.  Elements can be added, but not removed.
+ * Goes through a building phase, during which elements can be added, and a
+ * traversal phase, during which elements can be traversed in order but no
+ * further modifications are possible.
+ *
+ * <p> One or more arrays are used to store elements. The use of a multiple
+ * arrays has better performance characteristics than a single array used by
+ * {@link ArrayList}, as when the capacity of the list needs to be increased
+ * no copying of elements is required.  This is usually beneficial in the case
+ * where the results will be traversed a small number of times.
+ *
+ * @param <E> the type of elements in this list
+ * @since 1.8
+ */
+class SpinedBuffer<E>
+        extends AbstractSpinedBuffer
+        implements Consumer<E>, Iterable<E> {
+
+    /*
+     * We optimistically hope that all the data will fit into the first chunk,
+     * so we try to avoid inflating the spine[] and priorElementCount[] arrays
+     * prematurely.  So methods must be prepared to deal with these arrays being
+     * null.  If spine is non-null, then spineIndex points to the current chunk
+     * within the spine, otherwise it is zero.  The spine and priorElementCount
+     * arrays are always the same size, and for any i <= spineIndex,
+     * priorElementCount[i] is the sum of the sizes of all the prior chunks.
+     *
+     * The curChunk pointer is always valid.  The elementIndex is the index of
+     * the next element to be written in curChunk; this may be past the end of
+     * curChunk so we have to check before writing. When we inflate the spine
+     * array, curChunk becomes the first element in it.  When we clear the
+     * buffer, we discard all chunks except the first one, which we clear,
+     * restoring it to the initial single-chunk state.
+     */
+
+    /**
+     * Chunk that we're currently writing into; may or may not be aliased with
+     * the first element of the spine.
+     */
+    protected E[] curChunk;
+
+    /**
+     * All chunks, or null if there is only one chunk.
+     */
+    protected E[][] spine;
+
+    /**
+     * Constructs an empty list with the specified initial capacity.
+     *
+     * @param  initialCapacity  the initial capacity of the list
+     * @throws IllegalArgumentException if the specified initial capacity
+     *         is negative
+     */
+    @SuppressWarnings("unchecked")
+    SpinedBuffer(int initialCapacity) {
+        super(initialCapacity);
+        curChunk = (E[]) new Object[1 << initialChunkPower];
+    }
+
+    /**
+     * Constructs an empty list with an initial capacity of sixteen.
+     */
+    @SuppressWarnings("unchecked")
+    SpinedBuffer() {
+        super();
+        curChunk = (E[]) new Object[1 << initialChunkPower];
+    }
+
+    /**
+     * Returns the current capacity of the buffer
+     */
+    protected long capacity() {
+        return (spineIndex == 0)
+               ? curChunk.length
+               : priorElementCount[spineIndex] + spine[spineIndex].length;
+    }
+
+    @SuppressWarnings("unchecked")
+    private void inflateSpine() {
+        if (spine == null) {
+            spine = (E[][]) new Object[MIN_SPINE_SIZE][];
+            priorElementCount = new long[MIN_SPINE_SIZE];
+            spine[0] = curChunk;
+        }
+    }
+
+    /**
+     * Ensure that the buffer has at least capacity to hold the target size
+     */
+    @SuppressWarnings("unchecked")
+    protected final void ensureCapacity(long targetSize) {
+        long capacity = capacity();
+        if (targetSize > capacity) {
+            inflateSpine();
+            for (int i=spineIndex+1; targetSize > capacity; i++) {
+                if (i >= spine.length) {
+                    int newSpineSize = spine.length * 2;
+                    spine = Arrays.copyOf(spine, newSpineSize);
+                    priorElementCount = Arrays.copyOf(priorElementCount, newSpineSize);
+                }
+                int nextChunkSize = chunkSize(i);
+                spine[i] = (E[]) new Object[nextChunkSize];
+                priorElementCount[i] = priorElementCount[i-1] + spine[i-1].length;
+                capacity += nextChunkSize;
+            }
+        }
+    }
+
+    /**
+     * Force the buffer to increase its capacity.
+     */
+    protected void increaseCapacity() {
+        ensureCapacity(capacity() + 1);
+    }
+
+    /**
+     * Retrieve the element at the specified index.
+     */
+    public E get(long index) {
+        // @@@ can further optimize by caching last seen spineIndex,
+        // which is going to be right most of the time
+
+        // Casts to int are safe since the spine array index is the index minus
+        // the prior element count from the current spine
+        if (spineIndex == 0) {
+            if (index < elementIndex)
+                return curChunk[((int) index)];
+            else
+                throw new IndexOutOfBoundsException(Long.toString(index));
+        }
+
+        if (index >= count())
+            throw new IndexOutOfBoundsException(Long.toString(index));
+
+        for (int j=0; j <= spineIndex; j++)
+            if (index < priorElementCount[j] + spine[j].length)
+                return spine[j][((int) (index - priorElementCount[j]))];
+
+        throw new IndexOutOfBoundsException(Long.toString(index));
+    }
+
+    /**
+     * Copy the elements, starting at the specified offset, into the specified
+     * array.
+     */
+    public void copyInto(E[] array, int offset) {
+        long finalOffset = offset + count();
+        if (finalOffset > array.length || finalOffset < offset) {
+            throw new IndexOutOfBoundsException("does not fit");
+        }
+
+        if (spineIndex == 0)
+            System.arraycopy(curChunk, 0, array, offset, elementIndex);
+        else {
+            // full chunks
+            for (int i=0; i < spineIndex; i++) {
+                System.arraycopy(spine[i], 0, array, offset, spine[i].length);
+                offset += spine[i].length;
+            }
+            if (elementIndex > 0)
+                System.arraycopy(curChunk, 0, array, offset, elementIndex);
+        }
+    }
+
+    /**
+     * Create a new array using the specified array factory, and copy the
+     * elements into it.
+     */
+    public E[] asArray(IntFunction<E[]> arrayFactory) {
+        long size = count();
+        if (size >= Nodes.MAX_ARRAY_SIZE)
+            throw new IllegalArgumentException(Nodes.BAD_SIZE);
+        E[] result = arrayFactory.apply((int) size);
+        copyInto(result, 0);
+        return result;
+    }
+
+    @Override
+    public void clear() {
+        if (spine != null) {
+            curChunk = spine[0];
+            for (int i=0; i<curChunk.length; i++)
+                curChunk[i] = null;
+            spine = null;
+            priorElementCount = null;
+        }
+        else {
+            for (int i=0; i<elementIndex; i++)
+                curChunk[i] = null;
+        }
+        elementIndex = 0;
+        spineIndex = 0;
+    }
+
+    @Override
+    public Iterator<E> iterator() {
+        return Spliterators.iterator(spliterator());
+    }
+
+    @Override
+    public void forEach(Consumer<? super E> consumer) {
+        // completed chunks, if any
+        for (int j = 0; j < spineIndex; j++)
+            for (E t : spine[j])
+                consumer.accept(t);
+
+        // current chunk
+        for (int i=0; i<elementIndex; i++)
+            consumer.accept(curChunk[i]);
+    }
+
+    @Override
+    public void accept(E e) {
+        if (elementIndex == curChunk.length) {
+            inflateSpine();
+            if (spineIndex+1 >= spine.length || spine[spineIndex+1] == null)
+                increaseCapacity();
+            elementIndex = 0;
+            ++spineIndex;
+            curChunk = spine[spineIndex];
+        }
+        curChunk[elementIndex++] = e;
+    }
+
+    @Override
+    public String toString() {
+        List<E> list = new ArrayList<>();
+        forEach(list::add);
+        return "SpinedBuffer:" + list.toString();
+    }
+
+    private static final int SPLITERATOR_CHARACTERISTICS
+            = Spliterator.SIZED | Spliterator.ORDERED | Spliterator.SUBSIZED;
+
+    /**
+     * Return a {@link Spliterator} describing the contents of the buffer.
+     */
+    public Spliterator<E> spliterator() {
+        class Splitr implements Spliterator<E> {
+            // The current spine index
+            int splSpineIndex;
+
+            // Last spine index
+            final int lastSpineIndex;
+
+            // The current element index into the current spine
+            int splElementIndex;
+
+            // Last spine's last element index + 1
+            final int lastSpineElementFence;
+
+            // When splSpineIndex >= lastSpineIndex and
+            // splElementIndex >= lastSpineElementFence then
+            // this spliterator is fully traversed
+            // tryAdvance can set splSpineIndex > spineIndex if the last spine is full
+
+            // The current spine array
+            E[] splChunk;
+
+            Splitr(int firstSpineIndex, int lastSpineIndex,
+                   int firstSpineElementIndex, int lastSpineElementFence) {
+                this.splSpineIndex = firstSpineIndex;
+                this.lastSpineIndex = lastSpineIndex;
+                this.splElementIndex = firstSpineElementIndex;
+                this.lastSpineElementFence = lastSpineElementFence;
+                assert spine != null || firstSpineIndex == 0 && lastSpineIndex == 0;
+                splChunk = (spine == null) ? curChunk : spine[firstSpineIndex];
+            }
+
+            @Override
+            public long estimateSize() {
+                return (splSpineIndex == lastSpineIndex)
+                       ? (long) lastSpineElementFence - splElementIndex
+                       : // # of elements prior to end -
+                       priorElementCount[lastSpineIndex] + lastSpineElementFence -
+                       // # of elements prior to current
+                       priorElementCount[splSpineIndex] - splElementIndex;
+            }
+
+            @Override
+            public int characteristics() {
+                return SPLITERATOR_CHARACTERISTICS;
+            }
+
+            @Override
+            public boolean tryAdvance(Consumer<? super E> consumer) {
+                Objects.requireNonNull(consumer);
+
+                if (splSpineIndex < lastSpineIndex
+                    || (splSpineIndex == lastSpineIndex && splElementIndex < lastSpineElementFence)) {
+                    consumer.accept(splChunk[splElementIndex++]);
+
+                    if (splElementIndex == splChunk.length) {
+                        splElementIndex = 0;
+                        ++splSpineIndex;
+                        if (spine != null && splSpineIndex <= lastSpineIndex)
+                            splChunk = spine[splSpineIndex];
+                    }
+                    return true;
+                }
+                return false;
+            }
+
+            @Override
+            public void forEachRemaining(Consumer<? super E> consumer) {
+                Objects.requireNonNull(consumer);
+
+                if (splSpineIndex < lastSpineIndex
+                    || (splSpineIndex == lastSpineIndex && splElementIndex < lastSpineElementFence)) {
+                    int i = splElementIndex;
+                    // completed chunks, if any
+                    for (int sp = splSpineIndex; sp < lastSpineIndex; sp++) {
+                        E[] chunk = spine[sp];
+                        for (; i < chunk.length; i++) {
+                            consumer.accept(chunk[i]);
+                        }
+                        i = 0;
+                    }
+                    // last (or current uncompleted) chunk
+                    E[] chunk = (splSpineIndex == lastSpineIndex) ? splChunk : spine[lastSpineIndex];
+                    int hElementIndex = lastSpineElementFence;
+                    for (; i < hElementIndex; i++) {
+                        consumer.accept(chunk[i]);
+                    }
+                    // mark consumed
+                    splSpineIndex = lastSpineIndex;
+                    splElementIndex = lastSpineElementFence;
+                }
+            }
+
+            @Override
+            public Spliterator<E> trySplit() {
+                if (splSpineIndex < lastSpineIndex) {
+                    // split just before last chunk (if it is full this means 50:50 split)
+                    Spliterator<E> ret = new Splitr(splSpineIndex, lastSpineIndex - 1,
+                                                    splElementIndex, spine[lastSpineIndex-1].length);
+                    // position to start of last chunk
+                    splSpineIndex = lastSpineIndex;
+                    splElementIndex = 0;
+                    splChunk = spine[splSpineIndex];
+                    return ret;
+                }
+                else if (splSpineIndex == lastSpineIndex) {
+                    int t = (lastSpineElementFence - splElementIndex) / 2;
+                    if (t == 0)
+                        return null;
+                    else {
+                        Spliterator<E> ret = Arrays.spliterator(splChunk, splElementIndex, splElementIndex + t);
+                        splElementIndex += t;
+                        return ret;
+                    }
+                }
+                else {
+                    return null;
+                }
+            }
+        }
+        return new Splitr(0, spineIndex, 0, elementIndex);
+    }
+
+    /**
+     * An ordered collection of primitive values.  Elements can be added, but
+     * not removed. Goes through a building phase, during which elements can be
+     * added, and a traversal phase, during which elements can be traversed in
+     * order but no further modifications are possible.
+     *
+     * <p> One or more arrays are used to store elements. The use of a multiple
+     * arrays has better performance characteristics than a single array used by
+     * {@link ArrayList}, as when the capacity of the list needs to be increased
+     * no copying of elements is required.  This is usually beneficial in the case
+     * where the results will be traversed a small number of times.
+     *
+     * @param <E> the wrapper type for this primitive type
+     * @param <T_ARR> the array type for this primitive type
+     * @param <T_CONS> the Consumer type for this primitive type
+     */
+    abstract static class OfPrimitive<E, T_ARR, T_CONS>
+            extends AbstractSpinedBuffer implements Iterable<E> {
+
+        /*
+         * We optimistically hope that all the data will fit into the first chunk,
+         * so we try to avoid inflating the spine[] and priorElementCount[] arrays
+         * prematurely.  So methods must be prepared to deal with these arrays being
+         * null.  If spine is non-null, then spineIndex points to the current chunk
+         * within the spine, otherwise it is zero.  The spine and priorElementCount
+         * arrays are always the same size, and for any i <= spineIndex,
+         * priorElementCount[i] is the sum of the sizes of all the prior chunks.
+         *
+         * The curChunk pointer is always valid.  The elementIndex is the index of
+         * the next element to be written in curChunk; this may be past the end of
+         * curChunk so we have to check before writing. When we inflate the spine
+         * array, curChunk becomes the first element in it.  When we clear the
+         * buffer, we discard all chunks except the first one, which we clear,
+         * restoring it to the initial single-chunk state.
+         */
+
+        // The chunk we're currently writing into
+        T_ARR curChunk;
+
+        // All chunks, or null if there is only one chunk
+        T_ARR[] spine;
+
+        /**
+         * Constructs an empty list with the specified initial capacity.
+         *
+         * @param  initialCapacity  the initial capacity of the list
+         * @throws IllegalArgumentException if the specified initial capacity
+         *         is negative
+         */
+        OfPrimitive(int initialCapacity) {
+            super(initialCapacity);
+            curChunk = newArray(1 << initialChunkPower);
+        }
+
+        /**
+         * Constructs an empty list with an initial capacity of sixteen.
+         */
+        OfPrimitive() {
+            super();
+            curChunk = newArray(1 << initialChunkPower);
+        }
+
+        @Override
+        public abstract Iterator<E> iterator();
+
+        @Override
+        public abstract void forEach(Consumer<? super E> consumer);
+
+        /** Create a new array-of-array of the proper type and size */
+        protected abstract T_ARR[] newArrayArray(int size);
+
+        /** Create a new array of the proper type and size */
+        public abstract T_ARR newArray(int size);
+
+        /** Get the length of an array */
+        protected abstract int arrayLength(T_ARR array);
+
+        /** Iterate an array with the provided consumer */
+        protected abstract void arrayForEach(T_ARR array, int from, int to,
+                                             T_CONS consumer);
+
+        protected long capacity() {
+            return (spineIndex == 0)
+                   ? arrayLength(curChunk)
+                   : priorElementCount[spineIndex] + arrayLength(spine[spineIndex]);
+        }
+
+        private void inflateSpine() {
+            if (spine == null) {
+                spine = newArrayArray(MIN_SPINE_SIZE);
+                priorElementCount = new long[MIN_SPINE_SIZE];
+                spine[0] = curChunk;
+            }
+        }
+
+        protected final void ensureCapacity(long targetSize) {
+            long capacity = capacity();
+            if (targetSize > capacity) {
+                inflateSpine();
+                for (int i=spineIndex+1; targetSize > capacity; i++) {
+                    if (i >= spine.length) {
+                        int newSpineSize = spine.length * 2;
+                        spine = Arrays.copyOf(spine, newSpineSize);
+                        priorElementCount = Arrays.copyOf(priorElementCount, newSpineSize);
+                    }
+                    int nextChunkSize = chunkSize(i);
+                    spine[i] = newArray(nextChunkSize);
+                    priorElementCount[i] = priorElementCount[i-1] + arrayLength(spine[i - 1]);
+                    capacity += nextChunkSize;
+                }
+            }
+        }
+
+        protected void increaseCapacity() {
+            ensureCapacity(capacity() + 1);
+        }
+
+        protected int chunkFor(long index) {
+            if (spineIndex == 0) {
+                if (index < elementIndex)
+                    return 0;
+                else
+                    throw new IndexOutOfBoundsException(Long.toString(index));
+            }
+
+            if (index >= count())
+                throw new IndexOutOfBoundsException(Long.toString(index));
+
+            for (int j=0; j <= spineIndex; j++)
+                if (index < priorElementCount[j] + arrayLength(spine[j]))
+                    return j;
+
+            throw new IndexOutOfBoundsException(Long.toString(index));
+        }
+
+        public void copyInto(T_ARR array, int offset) {
+            long finalOffset = offset + count();
+            if (finalOffset > arrayLength(array) || finalOffset < offset) {
+                throw new IndexOutOfBoundsException("does not fit");
+            }
+
+            if (spineIndex == 0)
+                System.arraycopy(curChunk, 0, array, offset, elementIndex);
+            else {
+                // full chunks
+                for (int i=0; i < spineIndex; i++) {
+                    System.arraycopy(spine[i], 0, array, offset, arrayLength(spine[i]));
+                    offset += arrayLength(spine[i]);
+                }
+                if (elementIndex > 0)
+                    System.arraycopy(curChunk, 0, array, offset, elementIndex);
+            }
+        }
+
+        public T_ARR asPrimitiveArray() {
+            long size = count();
+            if (size >= Nodes.MAX_ARRAY_SIZE)
+                throw new IllegalArgumentException(Nodes.BAD_SIZE);
+            T_ARR result = newArray((int) size);
+            copyInto(result, 0);
+            return result;
+        }
+
+        protected void preAccept() {
+            if (elementIndex == arrayLength(curChunk)) {
+                inflateSpine();
+                if (spineIndex+1 >= spine.length || spine[spineIndex+1] == null)
+                    increaseCapacity();
+                elementIndex = 0;
+                ++spineIndex;
+                curChunk = spine[spineIndex];
+            }
+        }
+
+        public void clear() {
+            if (spine != null) {
+                curChunk = spine[0];
+                spine = null;
+                priorElementCount = null;
+            }
+            elementIndex = 0;
+            spineIndex = 0;
+        }
+
+        @SuppressWarnings("overloads")
+        public void forEach(T_CONS consumer) {
+            // completed chunks, if any
+            for (int j = 0; j < spineIndex; j++)
+                arrayForEach(spine[j], 0, arrayLength(spine[j]), consumer);
+
+            // current chunk
+            arrayForEach(curChunk, 0, elementIndex, consumer);
+        }
+
+        abstract class BaseSpliterator<T_SPLITR extends Spliterator.OfPrimitive<E, T_CONS, T_SPLITR>>
+                implements Spliterator.OfPrimitive<E, T_CONS, T_SPLITR> {
+            // The current spine index
+            int splSpineIndex;
+
+            // Last spine index
+            final int lastSpineIndex;
+
+            // The current element index into the current spine
+            int splElementIndex;
+
+            // Last spine's last element index + 1
+            final int lastSpineElementFence;
+
+            // When splSpineIndex >= lastSpineIndex and
+            // splElementIndex >= lastSpineElementFence then
+            // this spliterator is fully traversed
+            // tryAdvance can set splSpineIndex > spineIndex if the last spine is full
+
+            // The current spine array
+            T_ARR splChunk;
+
+            BaseSpliterator(int firstSpineIndex, int lastSpineIndex,
+                            int firstSpineElementIndex, int lastSpineElementFence) {
+                this.splSpineIndex = firstSpineIndex;
+                this.lastSpineIndex = lastSpineIndex;
+                this.splElementIndex = firstSpineElementIndex;
+                this.lastSpineElementFence = lastSpineElementFence;
+                assert spine != null || firstSpineIndex == 0 && lastSpineIndex == 0;
+                splChunk = (spine == null) ? curChunk : spine[firstSpineIndex];
+            }
+
+            abstract T_SPLITR newSpliterator(int firstSpineIndex, int lastSpineIndex,
+                                             int firstSpineElementIndex, int lastSpineElementFence);
+
+            abstract void arrayForOne(T_ARR array, int index, T_CONS consumer);
+
+            abstract T_SPLITR arraySpliterator(T_ARR array, int offset, int len);
+
+            @Override
+            public long estimateSize() {
+                return (splSpineIndex == lastSpineIndex)
+                       ? (long) lastSpineElementFence - splElementIndex
+                       : // # of elements prior to end -
+                       priorElementCount[lastSpineIndex] + lastSpineElementFence -
+                       // # of elements prior to current
+                       priorElementCount[splSpineIndex] - splElementIndex;
+            }
+
+            @Override
+            public int characteristics() {
+                return SPLITERATOR_CHARACTERISTICS;
+            }
+
+            @Override
+            public boolean tryAdvance(T_CONS consumer) {
+                Objects.requireNonNull(consumer);
+
+                if (splSpineIndex < lastSpineIndex
+                    || (splSpineIndex == lastSpineIndex && splElementIndex < lastSpineElementFence)) {
+                    arrayForOne(splChunk, splElementIndex++, consumer);
+
+                    if (splElementIndex == arrayLength(splChunk)) {
+                        splElementIndex = 0;
+                        ++splSpineIndex;
+                        if (spine != null && splSpineIndex <= lastSpineIndex)
+                            splChunk = spine[splSpineIndex];
+                    }
+                    return true;
+                }
+                return false;
+            }
+
+            @Override
+            public void forEachRemaining(T_CONS consumer) {
+                Objects.requireNonNull(consumer);
+
+                if (splSpineIndex < lastSpineIndex
+                    || (splSpineIndex == lastSpineIndex && splElementIndex < lastSpineElementFence)) {
+                    int i = splElementIndex;
+                    // completed chunks, if any
+                    for (int sp = splSpineIndex; sp < lastSpineIndex; sp++) {
+                        T_ARR chunk = spine[sp];
+                        arrayForEach(chunk, i, arrayLength(chunk), consumer);
+                        i = 0;
+                    }
+                    // last (or current uncompleted) chunk
+                    T_ARR chunk = (splSpineIndex == lastSpineIndex) ? splChunk : spine[lastSpineIndex];
+                    arrayForEach(chunk, i, lastSpineElementFence, consumer);
+                    // mark consumed
+                    splSpineIndex = lastSpineIndex;
+                    splElementIndex = lastSpineElementFence;
+                }
+            }
+
+            @Override
+            public T_SPLITR trySplit() {
+                if (splSpineIndex < lastSpineIndex) {
+                    // split just before last chunk (if it is full this means 50:50 split)
+                    T_SPLITR ret = newSpliterator(splSpineIndex, lastSpineIndex - 1,
+                                                  splElementIndex, arrayLength(spine[lastSpineIndex - 1]));
+                    // position us to start of last chunk
+                    splSpineIndex = lastSpineIndex;
+                    splElementIndex = 0;
+                    splChunk = spine[splSpineIndex];
+                    return ret;
+                }
+                else if (splSpineIndex == lastSpineIndex) {
+                    int t = (lastSpineElementFence - splElementIndex) / 2;
+                    if (t == 0)
+                        return null;
+                    else {
+                        T_SPLITR ret = arraySpliterator(splChunk, splElementIndex, t);
+                        splElementIndex += t;
+                        return ret;
+                    }
+                }
+                else {
+                    return null;
+                }
+            }
+        }
+    }
+
+    /**
+     * An ordered collection of {@code int} values.
+     */
+    static class OfInt extends SpinedBuffer.OfPrimitive<Integer, int[], IntConsumer>
+            implements IntConsumer {
+        OfInt() { }
+
+        OfInt(int initialCapacity) {
+            super(initialCapacity);
+        }
+
+        @Override
+        public void forEach(Consumer<? super Integer> consumer) {
+            if (consumer instanceof IntConsumer) {
+                forEach((IntConsumer) consumer);
+            }
+            else {
+                if (Tripwire.ENABLED)
+                    Tripwire.trip(getClass(), "{0} calling SpinedBuffer.OfInt.forEach(Consumer)");
+                spliterator().forEachRemaining(consumer);
+            }
+        }
+
+        @Override
+        protected int[][] newArrayArray(int size) {
+            return new int[size][];
+        }
+
+        @Override
+        public int[] newArray(int size) {
+            return new int[size];
+        }
+
+        @Override
+        protected int arrayLength(int[] array) {
+            return array.length;
+        }
+
+        @Override
+        protected void arrayForEach(int[] array,
+                                    int from, int to,
+                                    IntConsumer consumer) {
+            for (int i = from; i < to; i++)
+                consumer.accept(array[i]);
+        }
+
+        @Override
+        public void accept(int i) {
+            preAccept();
+            curChunk[elementIndex++] = i;
+        }
+
+        public int get(long index) {
+            // Casts to int are safe since the spine array index is the index minus
+            // the prior element count from the current spine
+            int ch = chunkFor(index);
+            if (spineIndex == 0 && ch == 0)
+                return curChunk[(int) index];
+            else
+                return spine[ch][(int) (index - priorElementCount[ch])];
+        }
+
+        @Override
+        public PrimitiveIterator.OfInt iterator() {
+            return Spliterators.iterator(spliterator());
+        }
+
+        public Spliterator.OfInt spliterator() {
+            class Splitr extends BaseSpliterator<Spliterator.OfInt>
+                    implements Spliterator.OfInt {
+                Splitr(int firstSpineIndex, int lastSpineIndex,
+                       int firstSpineElementIndex, int lastSpineElementFence) {
+                    super(firstSpineIndex, lastSpineIndex,
+                          firstSpineElementIndex, lastSpineElementFence);
+                }
+
+                @Override
+                Splitr newSpliterator(int firstSpineIndex, int lastSpineIndex,
+                                      int firstSpineElementIndex, int lastSpineElementFence) {
+                    return new Splitr(firstSpineIndex, lastSpineIndex,
+                                      firstSpineElementIndex, lastSpineElementFence);
+                }
+
+                @Override
+                void arrayForOne(int[] array, int index, IntConsumer consumer) {
+                    consumer.accept(array[index]);
+                }
+
+                @Override
+                Spliterator.OfInt arraySpliterator(int[] array, int offset, int len) {
+                    return Arrays.spliterator(array, offset, offset+len);
+                }
+            }
+            return new Splitr(0, spineIndex, 0, elementIndex);
+        }
+
+        @Override
+        public String toString() {
+            int[] array = asPrimitiveArray();
+            if (array.length < 200) {
+                return String.format("%s[length=%d, chunks=%d]%s",
+                                     getClass().getSimpleName(), array.length,
+                                     spineIndex, Arrays.toString(array));
+            }
+            else {
+                int[] array2 = Arrays.copyOf(array, 200);
+                return String.format("%s[length=%d, chunks=%d]%s...",
+                                     getClass().getSimpleName(), array.length,
+                                     spineIndex, Arrays.toString(array2));
+            }
+        }
+    }
+
+    /**
+     * An ordered collection of {@code long} values.
+     */
+    static class OfLong extends SpinedBuffer.OfPrimitive<Long, long[], LongConsumer>
+            implements LongConsumer {
+        OfLong() { }
+
+        OfLong(int initialCapacity) {
+            super(initialCapacity);
+        }
+
+        @Override
+        public void forEach(Consumer<? super Long> consumer) {
+            if (consumer instanceof LongConsumer) {
+                forEach((LongConsumer) consumer);
+            }
+            else {
+                if (Tripwire.ENABLED)
+                    Tripwire.trip(getClass(), "{0} calling SpinedBuffer.OfLong.forEach(Consumer)");
+                spliterator().forEachRemaining(consumer);
+            }
+        }
+
+        @Override
+        protected long[][] newArrayArray(int size) {
+            return new long[size][];
+        }
+
+        @Override
+        public long[] newArray(int size) {
+            return new long[size];
+        }
+
+        @Override
+        protected int arrayLength(long[] array) {
+            return array.length;
+        }
+
+        @Override
+        protected void arrayForEach(long[] array,
+                                    int from, int to,
+                                    LongConsumer consumer) {
+            for (int i = from; i < to; i++)
+                consumer.accept(array[i]);
+        }
+
+        @Override
+        public void accept(long i) {
+            preAccept();
+            curChunk[elementIndex++] = i;
+        }
+
+        public long get(long index) {
+            // Casts to int are safe since the spine array index is the index minus
+            // the prior element count from the current spine
+            int ch = chunkFor(index);
+            if (spineIndex == 0 && ch == 0)
+                return curChunk[(int) index];
+            else
+                return spine[ch][(int) (index - priorElementCount[ch])];
+        }
+
+        @Override
+        public PrimitiveIterator.OfLong iterator() {
+            return Spliterators.iterator(spliterator());
+        }
+
+
+        public Spliterator.OfLong spliterator() {
+            class Splitr extends BaseSpliterator<Spliterator.OfLong>
+                    implements Spliterator.OfLong {
+                Splitr(int firstSpineIndex, int lastSpineIndex,
+                       int firstSpineElementIndex, int lastSpineElementFence) {
+                    super(firstSpineIndex, lastSpineIndex,
+                          firstSpineElementIndex, lastSpineElementFence);
+                }
+
+                @Override
+                Splitr newSpliterator(int firstSpineIndex, int lastSpineIndex,
+                                      int firstSpineElementIndex, int lastSpineElementFence) {
+                    return new Splitr(firstSpineIndex, lastSpineIndex,
+                                      firstSpineElementIndex, lastSpineElementFence);
+                }
+
+                @Override
+                void arrayForOne(long[] array, int index, LongConsumer consumer) {
+                    consumer.accept(array[index]);
+                }
+
+                @Override
+                Spliterator.OfLong arraySpliterator(long[] array, int offset, int len) {
+                    return Arrays.spliterator(array, offset, offset+len);
+                }
+            }
+            return new Splitr(0, spineIndex, 0, elementIndex);
+        }
+
+        @Override
+        public String toString() {
+            long[] array = asPrimitiveArray();
+            if (array.length < 200) {
+                return String.format("%s[length=%d, chunks=%d]%s",
+                                     getClass().getSimpleName(), array.length,
+                                     spineIndex, Arrays.toString(array));
+            }
+            else {
+                long[] array2 = Arrays.copyOf(array, 200);
+                return String.format("%s[length=%d, chunks=%d]%s...",
+                                     getClass().getSimpleName(), array.length,
+                                     spineIndex, Arrays.toString(array2));
+            }
+        }
+    }
+
+    /**
+     * An ordered collection of {@code double} values.
+     */
+    static class OfDouble
+            extends SpinedBuffer.OfPrimitive<Double, double[], DoubleConsumer>
+            implements DoubleConsumer {
+        OfDouble() { }
+
+        OfDouble(int initialCapacity) {
+            super(initialCapacity);
+        }
+
+        @Override
+        public void forEach(Consumer<? super Double> consumer) {
+            if (consumer instanceof DoubleConsumer) {
+                forEach((DoubleConsumer) consumer);
+            }
+            else {
+                if (Tripwire.ENABLED)
+                    Tripwire.trip(getClass(), "{0} calling SpinedBuffer.OfDouble.forEach(Consumer)");
+                spliterator().forEachRemaining(consumer);
+            }
+        }
+
+        @Override
+        protected double[][] newArrayArray(int size) {
+            return new double[size][];
+        }
+
+        @Override
+        public double[] newArray(int size) {
+            return new double[size];
+        }
+
+        @Override
+        protected int arrayLength(double[] array) {
+            return array.length;
+        }
+
+        @Override
+        protected void arrayForEach(double[] array,
+                                    int from, int to,
+                                    DoubleConsumer consumer) {
+            for (int i = from; i < to; i++)
+                consumer.accept(array[i]);
+        }
+
+        @Override
+        public void accept(double i) {
+            preAccept();
+            curChunk[elementIndex++] = i;
+        }
+
+        public double get(long index) {
+            // Casts to int are safe since the spine array index is the index minus
+            // the prior element count from the current spine
+            int ch = chunkFor(index);
+            if (spineIndex == 0 && ch == 0)
+                return curChunk[(int) index];
+            else
+                return spine[ch][(int) (index - priorElementCount[ch])];
+        }
+
+        @Override
+        public PrimitiveIterator.OfDouble iterator() {
+            return Spliterators.iterator(spliterator());
+        }
+
+        public Spliterator.OfDouble spliterator() {
+            class Splitr extends BaseSpliterator<Spliterator.OfDouble>
+                    implements Spliterator.OfDouble {
+                Splitr(int firstSpineIndex, int lastSpineIndex,
+                       int firstSpineElementIndex, int lastSpineElementFence) {
+                    super(firstSpineIndex, lastSpineIndex,
+                          firstSpineElementIndex, lastSpineElementFence);
+                }
+
+                @Override
+                Splitr newSpliterator(int firstSpineIndex, int lastSpineIndex,
+                                      int firstSpineElementIndex, int lastSpineElementFence) {
+                    return new Splitr(firstSpineIndex, lastSpineIndex,
+                                      firstSpineElementIndex, lastSpineElementFence);
+                }
+
+                @Override
+                void arrayForOne(double[] array, int index, DoubleConsumer consumer) {
+                    consumer.accept(array[index]);
+                }
+
+                @Override
+                Spliterator.OfDouble arraySpliterator(double[] array, int offset, int len) {
+                    return Arrays.spliterator(array, offset, offset+len);
+                }
+            }
+            return new Splitr(0, spineIndex, 0, elementIndex);
+        }
+
+        @Override
+        public String toString() {
+            double[] array = asPrimitiveArray();
+            if (array.length < 200) {
+                return String.format("%s[length=%d, chunks=%d]%s",
+                                     getClass().getSimpleName(), array.length,
+                                     spineIndex, Arrays.toString(array));
+            }
+            else {
+                double[] array2 = Arrays.copyOf(array, 200);
+                return String.format("%s[length=%d, chunks=%d]%s...",
+                                     getClass().getSimpleName(), array.length,
+                                     spineIndex, Arrays.toString(array2));
+            }
+        }
+    }
+}
+