bytedeco#391 Move out Index as an interface and separate a `Default…

…Index` and a `CustomStridesIndex` to keep the previous logic

src/main/java/org/bytedeco/javacpp/indexer/CustomStridesIndex.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2016-2019 Samuel Audet
+ *
+ * Licensed either under the Apache License, Version 2.0, or (at your option)
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (subject to the "Classpath" exception),
+ * either version 2, or any later version (collectively, the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *     http://www.gnu.org/licenses/
+ *     http://www.gnu.org/software/classpath/license.html
+ *
+ * or as provided in the LICENSE.txt file that accompanied this code.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.bytedeco.javacpp.indexer;
+
+/**
+ * TODO
+ *
+ * @author Matteo Di Giovinazzo
+ */
+public class CustomStridesIndex implements Index {
+
+    protected final long[] strides;
+
+    /**
+     * TODO
+     *
+     * @param strides The number of elements to skip to reach the next element in a given dimension.
+     *                {@code strides[i] > strides[i + 1] && strides[strides.length - 1] == 1} preferred.
+     */
+    protected CustomStridesIndex(long[] strides) {
+        this.strides = strides;
+    }
+
+    public static Index customStrides(long[] strides) {
+        return new CustomStridesIndex(strides);
+    }
+
+    @Override
+    public long index(long i) {
+        return i * strides[0];
+    }
+
+    @Override
+    public long index(long i, long j) {
+        return i * strides[0] + j * strides[1];
+    }
+
+    @Override
+    public long index(long i, long j, long k) {
+        return i * strides[0] + j * strides[1] + k * strides[2];
+    }
+
+    /**
+     * Computes the linear index as the dot product of indices and strides.
+     *
+     * @param indices of each dimension
+     * @return index to access array or buffer
+     */
+    @Override
+    public long index(long... indices) {
+        long index = 0;
+        for (int i = 0; i < indices.length && i < strides.length; i++) {
+            index += indices[i] * strides[i];
+        }
+        return index;
+    }
+}

src/main/java/org/bytedeco/javacpp/indexer/DefaultIndex.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2016-2019 Samuel Audet
+ *
+ * Licensed either under the Apache License, Version 2.0, or (at your option)
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (subject to the "Classpath" exception),
+ * either version 2, or any later version (collectively, the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *     http://www.gnu.org/licenses/
+ *     http://www.gnu.org/software/classpath/license.html
+ *
+ * or as provided in the LICENSE.txt file that accompanied this code.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.bytedeco.javacpp.indexer;
+
+/**
+ * TODO
+ *
+ * @author Matteo Di Giovinazzo
+ */
+public class DefaultIndex extends CustomStridesIndex {
+
+    protected DefaultIndex(long... sizes) {
+        super(strides(sizes));
+    }
+
+    public static Index defaultIndex(long[] sizes) {
+        return new DefaultIndex(sizes);
+    }
+
+    /**
+     * Returns default (row-major contiguous) strides for the given sizes.
+     */
+    public static long[] strides(long... sizes) {
+        long[] strides = new long[sizes.length];
+        strides[sizes.length - 1] = 1;
+        for (int i = sizes.length - 2; i >= 0; i--) {
+            strides[i] = strides[i + 1] * sizes[i + 1];
+        }
+        return strides;
+    }
+
+}

src/main/java/org/bytedeco/javacpp/indexer/Index.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2016-2019 Samuel Audet
+ *
+ * Licensed either under the Apache License, Version 2.0, or (at your option)
+ * under the terms of the GNU General Public License as published by
+ * the Free Software Foundation (subject to the "Classpath" exception),
+ * either version 2, or any later version (collectively, the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *     http://www.gnu.org/licenses/
+ *     http://www.gnu.org/software/classpath/license.html
+ *
+ * or as provided in the LICENSE.txt file that accompanied this code.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.bytedeco.javacpp.indexer;
+
+/**
+ * TODO
+ *
+ * @author Matteo Di Giovinazzo
+ */
+public interface Index {
+
+    /**
+     * TODO
+     *
+     * @param i
+     * @return
+     */
+    long index(long i);
+
+    /**
+     * TODO
+     *
+     * @param i
+     * @param j
+     * @return
+     */
+    long index(long i, long j);
+
+    /**
+     * TODO
+     *
+     * @param i
+     * @param j
+     * @param k
+     * @return
+     */
+    long index(long i, long j, long k);
+
+    /**
+     * TODO
+     *
+     * @param indices
+     * @return
+     */
+    long index(long... indices);
+
+}

src/main/java/org/bytedeco/javacpp/indexer/Indexer.java

@@ -22,9 +22,13 @@
 
 package org.bytedeco.javacpp.indexer;
 
-import java.nio.Buffer;
 import org.bytedeco.javacpp.Pointer;
 
+import java.nio.Buffer;
+
+import static org.bytedeco.javacpp.indexer.CustomStridesIndex.customStrides;
+import static org.bytedeco.javacpp.indexer.DefaultIndex.defaultIndex;
+
 /**
  * Top-level class of all data indexers, providing easy-to-use and efficient
  * multidimensional access to primitive arrays, NIO buffers, and the raw memory interface.
@@ -49,7 +53,7 @@ public abstract class Indexer implements AutoCloseable {
         release();
     }
 
-    protected static final long[] ONE_STRIDE = { 1 };
+    @Deprecated protected static final long[] ONE_STRIDE = { 1 };
 
     /**
      * The number of elements in each dimension.
@@ -60,23 +64,42 @@ public abstract class Indexer implements AutoCloseable {
      * The number of elements to skip to reach the next element in a given dimension.
      * {@code strides[i] > strides[i + 1] && strides[strides.length - 1] == 1} preferred.
      */
-    protected long[] strides;
+    @Deprecated protected long[] strides;
+    /**
+     * TODO
+     */
+    protected Index index;
+
+    /** Constructor to set the {@link #sizes}. */
+    protected Indexer(long[] sizes) {
+        this(sizes, defaultIndex(sizes));
+        // XXX: access to strides for backward compatiility
+        assert index instanceof DefaultIndex;
+        this.strides = ((DefaultIndex) index).strides;
+    }
 
-    /** Constructor to set the {@link #sizes} and {@link #strides}. */
-    protected Indexer(long[] sizes, long[] strides) {
+    /** Constructor to set the {@link #sizes} and {@link #index}. */
+    protected Indexer(long[] sizes, Index index) {
         this.sizes = sizes;
+        this.index = index;
+        // XXX: what value should have strides in this case?
+    }
+
+    /** Constructor to set the {@link #sizes} and {@link #strides}. */
+    @Deprecated protected Indexer(long[] sizes, long[] strides) {
+        this(sizes, customStrides(strides));
         this.strides = strides;
     }
 
     /** Returns {@link #sizes} */
     public long[] sizes() { return sizes; }
     /** Returns {@link #strides} */
-    public long[] strides() { return strides; }
+    @Deprecated public long[] strides() { return strides; }
 
     /** Returns {@code sizes[i]} */
     public long size(int i) { return sizes[i]; }
     /** Returns {@code strides[i]} */
-    public long stride(int i) { return strides[i]; }
+    @Deprecated public long stride(int i) { return strides[i]; }
 
     /** Returns {@code sizes.length > 0 && sizes.length < 4 ? sizes[0] : -1} */
     @Deprecated public long rows() { return sizes.length > 0 && sizes.length < 4 ? sizes[0] : -1; }
@@ -99,45 +122,11 @@ protected static final long checkIndex(long i, long size) {
     /**
      * Returns default (row-major contiguous) strides for the given sizes.
      */
+    @Deprecated
     public static long[] strides(long... sizes) {
-        long[] strides = new long[sizes.length];
-        strides[sizes.length - 1] = 1;
-        for (int i = sizes.length - 2; i >= 0; i--) {
-            strides[i] = strides[i + 1] * sizes[i + 1];
-        }
-        return strides;
+        return DefaultIndex.strides(sizes);
     }
 
-    protected class Index {
-        public long index(long i) {
-            return i * strides[0];
-        }
-
-        public long index(long i, long j) {
-            return i * strides[0] + j * strides[1];
-        }
-
-        public long index(long i, long j, long k) {
-            return i * strides[0] + j * strides[1] + k * strides[2];
-        }
-
-        /**
-         * Computes the linear index as the dot product of indices and strides.
-         *
-         * @param indices of each dimension
-         * @return index to access array or buffer
-         */
-        public long index(long... indices) {
-            long index = 0;
-            for (int i = 0; i < indices.length && i < strides.length; i++) {
-                index += indices[i] * strides[i];
-            }
-            return index;
-        }
-    }
-
-    protected Index index = new Index();
-
     /** Returns {@code index.index(i)}. */
     public long index(long i) {
         return index.index(i);

src/test/java/org/bytedeco/javacpp/IndexerTest.java

@@ -42,6 +42,7 @@
 import org.bytedeco.javacpp.indexer.UShortIndexer;
 import org.bytedeco.javacpp.indexer.UIntIndexer;
 import org.bytedeco.javacpp.indexer.ULongIndexer;
+import org.bytedeco.javacpp.indexer.DefaultIndex;
 import org.bytedeco.javacpp.tools.Builder;
 import org.junit.AfterClass;
 import org.junit.BeforeClass;
@@ -74,7 +75,7 @@ public class IndexerTest {
     }
 
     static class TestIndexer extends Indexer {
-        TestIndexer(long[] sizes) { super(sizes, Indexer.strides(sizes)); }
+        TestIndexer(long[] sizes) { super(sizes, DefaultIndex.strides(sizes)); }
         public void release() { }
         public double getDouble(long... indices) { return 0; }
         public Indexer putDouble(long[] indices, double value) { return this; }
@@ -83,7 +84,7 @@ public void release() { }
     @Test public void testIndexer() {
         System.out.println("Indexer");
         long[] sizes = {640, 480, 3};
-        long[] strides = Indexer.strides(sizes);
+        long[] strides = DefaultIndex.strides(sizes);
         System.out.println(Arrays.toString(strides));
         assertEquals(1440, strides[0]);
         assertEquals(   3, strides[1]);