From 2dc31dcd188d031a6704a613decee88b074aad8f Mon Sep 17 00:00:00 2001
From: "Brian S. O'Neill" <bronee@gmail.com>
Date: Wed, 14 May 2008 23:46:11 +0000
Subject: Moved utility comparators to util package.

---
 .../com/amazon/carbonado/util/Comparators.java     | 315 +++++++++++++++++++++
 1 file changed, 315 insertions(+)
 create mode 100644 src/main/java/com/amazon/carbonado/util/Comparators.java

(limited to 'src/main/java/com/amazon/carbonado/util')

diff --git a/src/main/java/com/amazon/carbonado/util/Comparators.java b/src/main/java/com/amazon/carbonado/util/Comparators.java
new file mode 100644
index 0000000..c3ba418
--- /dev/null
+++ b/src/main/java/com/amazon/carbonado/util/Comparators.java
@@ -0,0 +1,315 @@
+/*
+ * Copyright 2007 Amazon Technologies, Inc. or its affiliates.
+ * Amazon, Amazon.com and Carbonado are trademarks or registered trademarks
+ * of Amazon Technologies, Inc. or its affiliates.  All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (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
+ *
+ * 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 com.amazon.carbonado.util;
+
+import java.util.Comparator;
+
+import org.cojen.classfile.TypeDesc;
+
+/**
+ * Collection of utility comparators.
+ *
+ * @author Brian S O'Neill
+ */
+public class Comparators {
+    /**
+     * Returns a comparator which can sort single or multi-dimensional arrays
+     * of primitves or Comparables.
+     *
+     * @param unsigned applicable only to arrays of bytes, shorts, ints, or longs
+     * @return null if unsupported
+     */
+    public static <T> Comparator<T> arrayComparator(Class<T> arrayType, boolean unsigned) {
+        if (!arrayType.isArray()) {
+            throw new IllegalArgumentException();
+        }
+
+        Comparator c;
+
+        TypeDesc componentType = TypeDesc.forClass(arrayType.getComponentType());
+        switch (componentType.getTypeCode()) {
+        case TypeDesc.BYTE_CODE:
+            c = unsigned ? UnsignedByteArray : SignedByteArray;
+            break;
+        case TypeDesc.SHORT_CODE:
+            c = unsigned ? UnsignedShortArray : SignedShortArray;
+            break;
+        case TypeDesc.INT_CODE:
+            c = unsigned ? UnsignedIntArray : SignedIntArray;
+            break;
+        case TypeDesc.LONG_CODE:
+            c = unsigned ? UnsignedLongArray : SignedLongArray;
+            break;
+        case TypeDesc.BOOLEAN_CODE:
+            c = BooleanArray;
+            break;
+        case TypeDesc.CHAR_CODE:
+            c = CharArray;
+            break;
+        case TypeDesc.FLOAT_CODE:
+            c = FloatArray;
+            break;
+        case TypeDesc.DOUBLE_CODE:
+            c = DoubleArray;
+            break;
+        case TypeDesc.OBJECT_CODE: default:
+            if (componentType.isArray()) {
+                c = new ComparatorArray(arrayComparator(componentType.toClass(), unsigned));
+            } else if (Comparable.class.isAssignableFrom(componentType.toClass())) {
+                c = ComparableArray;
+            } else {
+                c = null;
+            }
+            break;
+        }
+
+        return (Comparator<T>) c;
+    }
+
+    private static final Comparator<byte[]> SignedByteArray = new Comparator<byte[]>() {
+        public int compare(byte[] a, byte[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                byte ai = a[i];
+                byte bi = b[i];
+                if (ai != bi) {
+                    return ai - bi;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<byte[]> UnsignedByteArray = new Comparator<byte[]>() {
+        public int compare(byte[] a, byte[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                byte ai = a[i];
+                byte bi = b[i];
+                if (ai != bi) {
+                    return (ai & 0xff) - (bi & 0xff);
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<short[]> SignedShortArray = new Comparator<short[]>() {
+        public int compare(short[] a, short[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                short ai = a[i];
+                short bi = b[i];
+                if (ai != bi) {
+                    return ai - bi;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<short[]> UnsignedShortArray = new Comparator<short[]>() {
+        public int compare(short[] a, short[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                short ai = a[i];
+                short bi = b[i];
+                if (ai != bi) {
+                    return (ai & 0xffff) - (bi & 0xffff);
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<int[]> SignedIntArray = new Comparator<int[]>() {
+        public int compare(int[] a, int[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                int ai = a[i];
+                int bi = b[i];
+                if (ai != bi) {
+                    return ai < bi ? -1 : 1;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<int[]> UnsignedIntArray = new Comparator<int[]>() {
+        public int compare(int[] a, int[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                int ai = a[i];
+                int bi = b[i];
+                if (ai != bi) {
+                    return (ai & 0xffffffffL) < (bi & 0xffffffffL) ? -1 : 1;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<long[]> SignedLongArray = new Comparator<long[]>() {
+        public int compare(long[] a, long[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                long ai = a[i];
+                long bi = b[i];
+                if (ai != bi) {
+                    return ai < bi ? -1 : 1;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<long[]> UnsignedLongArray = new Comparator<long[]>() {
+        public int compare(long[] a, long[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                long ai = a[i];
+                long bi = b[i];
+                if (ai != bi) {
+                    long sai = ai >>> 1;
+                    long sbi = bi >>> 1;
+                    if (sai < sbi) {
+                        return -1;
+                    }
+                    if (sai > sbi) {
+                        return 1;
+                    }
+                    return (ai & 1) == 0 ? -1 : 1;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<boolean[]> BooleanArray = new Comparator<boolean[]>() {
+        public int compare(boolean[] a, boolean[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                boolean ai = a[i];
+                boolean bi = b[i];
+                if (ai != bi) {
+                    return ai ? 1 : -1;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<char[]> CharArray = new Comparator<char[]>() {
+        public int compare(char[] a, char[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                char ai = a[i];
+                char bi = b[i];
+                if (ai != bi) {
+                    return ai - bi;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<float[]> FloatArray = new Comparator<float[]>() {
+        public int compare(float[] a, float[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                float ai = a[i];
+                float bi = b[i];
+                if (ai != bi) {
+                    return Float.compare(ai, bi);
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<double[]> DoubleArray = new Comparator<double[]>() {
+        public int compare(double[] a, double[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                double ai = a[i];
+                double bi = b[i];
+                if (ai != bi) {
+                    return Double.compare(ai, bi);
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static final Comparator<Comparable[]> ComparableArray = new Comparator<Comparable[]>()
+    {
+        public int compare(Comparable[] a, Comparable[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                Comparable ai = a[i];
+                Comparable bi = b[i];
+                if (ai == bi) {
+                    continue;
+                }
+                if (ai == null) {
+                    return 1;
+                }
+                if (bi == null) {
+                    return -1;
+                }
+                int compare = ai.compareTo(bi);
+                if (compare != 0) {
+                    return compare;
+                }
+            }
+            return a.length - b.length;
+        }
+    };
+
+    private static class ComparatorArray implements Comparator<Object[]> {
+        private final Comparator<Object> mComparator;
+
+        ComparatorArray(Comparator<Object> comparator) {
+            mComparator = comparator;
+        }
+
+        public int compare(Object[] a, Object[] b) {
+            int len = Math.min(a.length, b.length);
+            for (int i=0; i<len; i++) {
+                Object ai = a[i];
+                Object bi = b[i];
+                if (ai == bi) {
+                    continue;
+                }
+                if (ai == null) {
+                    return 1;
+                }
+                if (bi == null) {
+                    return -1;
+                }
+                int compare = mComparator.compare(ai, bi);
+                if (compare != 0) {
+                    return compare;
+                }
+            }
+            return a.length - b.length;
+        }
+    }
+}
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