Introduce Bitfield interface w/ Int32 and Int32Array impl. deprecating IntBitfield

IntBitfield's 64bit bit-size is exceeding its use-case,
making it less efficient and complicated.

Bitfield offers a fast path implementation for 32 bits
as well as a int[] implementation.

TODO: 32 bit Unaligned putInt32(..) and getInt32(..),
currently throwing UnsupportedOperationException for int[] impl.

1 files changed, 136 insertions, 0 deletions

diff --git a/src/java/jogamp/common/util/Int32ArrayBitfield.java b/src/java/jogamp/common/util/Int32ArrayBitfield.java
new file mode 100644
index 0000000..d0ce669
--- /dev/null
+++ b/src/java/jogamp/common/util/Int32ArrayBitfield.java
@@ -0,0 +1,136 @@
+/**
+ * Copyright 2015 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+package jogamp.common.util;
+
+import com.jogamp.common.util.Bitfield;
+
+/**
+ * Simple bitfield interface for efficient storage access in O(1).
+ * <p>
+ * Implementation uses a 32bit integer array for storage.
+ * </p>
+ */
+public class Int32ArrayBitfield implements Bitfield {
+    private static final int UNIT_SHIFT = 5;
+    private final int[] storage;
+    private final int bitSize;
+
+    /**
+     * @param storageBitSize
+     */
+    public Int32ArrayBitfield(final int storageBitSize) {
+        final int units = Math.max(1, ( storageBitSize + 7 ) >>> UNIT_SHIFT);
+        this.storage = new int[units];
+        this.bitSize = units << UNIT_SHIFT;
+    }
+
+    @Override
+    public int getStorageBitSize() {
+        return bitSize;
+    }
+
+    private final void check(final int limit, final int bitnum) throws ArrayIndexOutOfBoundsException {
+        if( 0 > bitnum || bitnum >= limit ) {
+            throw new ArrayIndexOutOfBoundsException("Bitnum should be within [0.."+(limit-1)+"], but is "+bitnum);
+        }
+    }
+
+    @Override
+    public final int getInt32(final int rightBitnum) throws ArrayIndexOutOfBoundsException {
+        check(bitSize-31, rightBitnum);
+        if( 0 == rightBitnum % 32 ) {
+            // fast path
+            return storage[rightBitnum >>> UNIT_SHIFT];
+        } else {
+            // slow path
+            throw new UnsupportedOperationException("todo: non-32bit alignment");
+        }
+    }
+
+    @Override
+    public final void putInt32(final int rightBitnum, final int mask) throws ArrayIndexOutOfBoundsException {
+        check(bitSize-31, rightBitnum);
+        if( 0 == rightBitnum % 32 ) {
+            // fast path
+            storage[rightBitnum >>> UNIT_SHIFT] = mask;
+        } else {
+            // slow path
+            throw new UnsupportedOperationException("todo: non-32bit alignment");
+        }
+    }
+
+    @Override
+    public final boolean get(final int bitnum) throws ArrayIndexOutOfBoundsException {
+        check(bitSize, bitnum);
+        final int u = bitnum >>> UNIT_SHIFT;
+        final int b = bitnum - ( u << UNIT_SHIFT );
+        return 0 != ( storage[u] & ( 1 << b ) ) ;
+    }
+
+    @Override
+    public final boolean put(final int bitnum, final boolean bit) throws ArrayIndexOutOfBoundsException {
+        check(bitSize, bitnum);
+        final int u = bitnum >>> UNIT_SHIFT;
+        final int b = bitnum - ( u << UNIT_SHIFT );
+        final int m = 1 << b;
+        final boolean prev = 0 != ( storage[u] & m ) ;
+        if( prev != bit ) {
+            if( bit ) {
+                storage[u] |=  m;
+            } else {
+                storage[u] &= ~m;
+            }
+        }
+        return prev;
+    }
+    @Override
+    public final void set(final int bitnum) throws ArrayIndexOutOfBoundsException {
+        check(bitSize, bitnum);
+        final int u = bitnum >>> UNIT_SHIFT;
+        final int b = bitnum - ( u << UNIT_SHIFT );
+        final int m = 1 << b;
+        storage[u] |=  m;
+    }
+    @Override
+    public final void clear (final int bitnum) throws ArrayIndexOutOfBoundsException {
+        check(bitSize, bitnum);
+        final int u = bitnum >>> UNIT_SHIFT;
+        final int b = bitnum - ( u << UNIT_SHIFT );
+        final int m = 1 << b;
+        storage[u] &= ~m;
+    }
+
+    @Override
+    public int getBitCount() {
+        int c = 0;
+        for(int i = storage.length-1; i>=0; i--) {
+            c += Bitfield.Util.getBitCount(storage[i]);
+        }
+        return c;
+    }
+}