[Proxool-cvs] proxool/src/java/org/logicalcobwebs/cglib/util ParallelSorter.java,NONE,1.1 ParallelSorterEmitter.java,NONE,1.1 SorterTemplate.java,NONE,1.1 StringSwitcher.java,NONE,1.1

[<bil...@us...>]

Update of /cvsroot/proxool/proxool/src/java/org/logicalcobwebs/cglib/util
In directory sc8-pr-cvs1:/tmp/cvs-serv25673/src/java/org/logicalcobwebs/cglib/util

Added Files:
	ParallelSorter.java ParallelSorterEmitter.java 
	SorterTemplate.java StringSwitcher.java 
Log Message:
Repackaged Cglib project

--- NEW FILE: ParallelSorter.java ---
/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact ap...@ap....
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 THE APACHE SOFTWARE FOUNDATION OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.logicalcobwebs.cglib.util;

import java.lang.reflect.*;
import java.util.Comparator;
import org.logicalcobwebs.cglib.core.*;
import org.logicalcobwebs.asm.ClassVisitor;

/**
 * For the efficient sorting of multiple arrays in parallel.
 * <p>
 * Given two arrays of equal length and varying types, the standard
 * technique for sorting them in parallel is to create a new temporary
 * object for each row, store the objects in a temporary array, sort the
 * array using a custom comparator, and the extract the original values
 * back into their respective arrays. This is wasteful in both time and
 * memory.
 * <p>
 * This class generates bytecode customized to the particular set of
 * arrays you need to sort, in such a way that both arrays are sorted
 * in-place, simultaneously.
 * <p>
 * Two sorting algorithms are provided.
 * Quicksort is best when you only need to sort by a single column, as
 * it requires very few comparisons and swaps. Mergesort is best used
 * when sorting multiple columns, as it is a "stable" sort--that is, it
 * does not affect the relative order of equal objects from previous sorts.
 * <p>
 * The mergesort algorithm here is an "in-place" variant, which while
 * slower, does not require a temporary array.
 *
 * @author Chris Nokleberg
 */
abstract public class ParallelSorter extends SorterTemplate {
    protected Object[] a;
    private Comparer comparer;
    
    protected ParallelSorter() {
    }

    abstract public ParallelSorter newInstance(Object[] arrays);

    /**
     * Create a new ParallelSorter object for a set of arrays. You may
     * sort the arrays multiple times via the same ParallelSorter object.
     * @param arrays An array of arrays to sort. The arrays may be a mix
     * of primitive and non-primitive types, but should all be the same
     * length.
     * @param loader ClassLoader for generated class, uses "current" if null
     */
    public static ParallelSorter create(Object[] arrays) {
        Generator gen = new Generator();
        gen.setArrays(arrays);
        return gen.create();
    }

    private int len() {
        return ((Object[])a[0]).length;
    }

    /**
     * Sort the arrays using the quicksort algorithm.
     * @param index array (column) to sort by
     */
    public void quickSort(int index) {
        quickSort(index, 0, len(), null);
    }

    /**
     * Sort the arrays using the quicksort algorithm.
     * @param index array (column) to sort by
     * @param lo starting array index (row), inclusive
     * @param hi ending array index (row), exclusive
     */
    public void quickSort(int index, int lo, int hi) {
        quickSort(index, lo, hi, null);
    }

    /**
     * Sort the arrays using the quicksort algorithm.
     * @param index array (column) to sort by
     * @param cmp Comparator to use if the specified column is non-primitive
     */
    public void quickSort(int index, Comparator cmp) {
        quickSort(index, 0, len(), cmp);
    }

    /**
     * Sort the arrays using the quicksort algorithm.
     * @param index array (column) to sort by
     * @param lo starting array index (row), inclusive
     * @param hi ending array index (row), exclusive
     * @param cmp Comparator to use if the specified column is non-primitive
     */
    public void quickSort(int index, int lo, int hi, Comparator cmp) {
        chooseComparer(index, cmp);
        super.quickSort(lo, hi - 1);
    }

    /**
     * @param index array (column) to sort by
     */
    public void mergeSort(int index) {
        mergeSort(index, 0, len(), null);
    }

    /**
     * Sort the arrays using an in-place merge sort.
     * @param index array (column) to sort by
     * @param lo starting array index (row), inclusive
     * @param hi ending array index (row), exclusive
     */
    public void mergeSort(int index, int lo, int hi) {
        mergeSort(index, lo, hi, null);
    }

    /**
     * Sort the arrays using an in-place merge sort.
     * @param index array (column) to sort by
     * @param lo starting array index (row), inclusive
     * @param hi ending array index (row), exclusive
     */
    public void mergeSort(int index, Comparator cmp) {
        mergeSort(index, 0, len(), cmp);
    }

    /**
     * Sort the arrays using an in-place merge sort.
     * @param index array (column) to sort by
     * @param lo starting array index (row), inclusive
     * @param hi ending array index (row), exclusive
     * @param cmp Comparator to use if the specified column is non-primitive
     */
    public void mergeSort(int index, int lo, int hi, Comparator cmp) {
        chooseComparer(index, cmp);
        super.mergeSort(lo, hi - 1);
    }
    
    private void chooseComparer(int index, Comparator cmp) {
        Object array = a[index];
        Class type = array.getClass().getComponentType();
        if (type.equals(Integer.TYPE)) {
            comparer = new IntComparer((int[])array);
        } else if (type.equals(Long.TYPE)) {
            comparer = new LongComparer((long[])array);
        } else if (type.equals(Double.TYPE)) {
            comparer = new DoubleComparer((double[])array);
        } else if (type.equals(Float.TYPE)) {
            comparer = new FloatComparer((float[])array);
        } else if (type.equals(Short.TYPE)) {
            comparer = new ShortComparer((short[])array);
        } else if (type.equals(Byte.TYPE)) {
            comparer = new ByteComparer((byte[])array);
        } else if (cmp != null) {
            comparer = new ComparatorComparer((Object[])array, cmp);
        } else {
            comparer = new ObjectComparer((Object[])array);
        } 
    }

    protected int compare(int i, int j) {
        return comparer.compare(i, j);
    }

    interface Comparer {
        int compare(int i, int j);
    }

    static class ComparatorComparer implements Comparer {
        private Object[] a;
        private Comparator cmp;

        public ComparatorComparer(Object[] a, Comparator cmp) {
            this.a = a;
            this.cmp = cmp;
        }

        public int compare(int i, int j) {
            return cmp.compare(a[i], a[j]);
        }
    }
    
    static class ObjectComparer implements Comparer {
        private Object[] a;
        public ObjectComparer(Object[] a) { this.a = a; }
        public int compare(int i, int j) {
            return ((Comparable)a[i]).compareTo(a[j]);
        }
    }

    static class IntComparer implements Comparer {
        private int[] a;
        public IntComparer(int[] a) { this.a = a; }
        public int compare(int i, int j) { return a[i] - a[j]; }
    }

    static class LongComparer implements Comparer {
        private long[] a;
        public LongComparer(long[] a) { this.a = a; }
        public int compare(int i, int j) {
            long vi = a[i];
            long vj = a[j];
            return (vi == vj) ? 0 : (vi > vj) ? 1 : -1;
        }
    }

    static class FloatComparer implements Comparer {
        private float[] a;
        public FloatComparer(float[] a) { this.a = a; }
        public int compare(int i, int j) {
            float vi = a[i];
            float vj = a[j];
            return (vi == vj) ? 0 : (vi > vj) ? 1 : -1;
        }
    }
    
    static class DoubleComparer implements Comparer {
        private double[] a;
        public DoubleComparer(double[] a) { this.a = a; }
        public int compare(int i, int j) {
            double vi = a[i];
            double vj = a[j];
            return (vi == vj) ? 0 : (vi > vj) ? 1 : -1;
        }
    }

    static class ShortComparer implements Comparer {
        private short[] a;
        public ShortComparer(short[] a) { this.a = a; }
        public int compare(int i, int j) { return a[i] - a[j]; }
    }

    static class ByteComparer implements Comparer {
        private byte[] a;
        public ByteComparer(byte[] a) { this.a = a; }
        public int compare(int i, int j) { return a[i] - a[j]; }
    }

    public static class Generator extends AbstractClassGenerator {
        private static final Source SOURCE = new Source(ParallelSorter.class.getName());

        private Object[] arrays;

        public Generator() {
            super(SOURCE);
        }

        protected ClassLoader getDefaultClassLoader() {
            return null; // TODO
        }

        public void setArrays(Object[] arrays) {
            this.arrays = arrays;
        }

        public ParallelSorter create() {
            return (ParallelSorter)super.create(ClassesKey.create(arrays));
        }

        public void generateClass(ClassVisitor v) throws Exception {
            if (arrays.length == 0) {
                throw new IllegalArgumentException("No arrays specified to sort");
            }
            for (int i = 0; i < arrays.length; i++) {
                if (!arrays[i].getClass().isArray()) {
                    throw new IllegalArgumentException(arrays[i].getClass() + " is not an array");
                }
            }
            new ParallelSorterEmitter(v, getClassName(), arrays);
        }
        
        protected Object firstInstance(Class type) {
            return ((ParallelSorter)ReflectUtils.newInstance(type)).newInstance(arrays);
        }

        protected Object nextInstance(Object instance) {
            return ((ParallelSorter)instance).newInstance(arrays);
        }
    }
}

--- NEW FILE: ParallelSorterEmitter.java ---
/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact ap...@ap....
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 THE APACHE SOFTWARE FOUNDATION OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.logicalcobwebs.cglib.util;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import org.logicalcobwebs.cglib.core.*;
import org.logicalcobwebs.asm.ClassVisitor;
import org.logicalcobwebs.asm.Type;

class ParallelSorterEmitter extends ClassEmitter {
    private static final Signature CSTRUCT_OBJECT_ARRAY =
      TypeUtils.parseConstructor("Object[]");
    private static final Signature NEW_INSTANCE =
      TypeUtils.parseSignature("org.logicalcobwebs.cglib.util.ParallelSorter newInstance(Object[])");
    private static final Signature SWAP =
      TypeUtils.parseSignature("void swap(int, int)");
    private static final Type PARALLEL_SORTER =
      TypeUtils.parseType("org.logicalcobwebs.cglib.util.ParallelSorter");

    public ParallelSorterEmitter(ClassVisitor v, String className, Object[] arrays) {
        super(v);
        begin_class(Constants.ACC_PUBLIC, className, PARALLEL_SORTER, null, Constants.SOURCE_FILE);
        EmitUtils.null_constructor(this);
        EmitUtils.factory_method(this, NEW_INSTANCE);
        generateConstructor(arrays);
        generateSwap(arrays);
        end_class();
    }

    private String getFieldName(int index) {
        return "FIELD_" + index;
    }

    private void generateConstructor(Object[] arrays) {
        CodeEmitter e = begin_method(Constants.ACC_PUBLIC, CSTRUCT_OBJECT_ARRAY, null, null);
        e.load_this();
        e.super_invoke_constructor();
        e.load_this();
        e.load_arg(0);
        e.super_putfield("a", Constants.TYPE_OBJECT_ARRAY);
        for (int i = 0; i < arrays.length; i++) {
            Type type = Type.getType(arrays[i].getClass());
            declare_field(Constants.ACC_PRIVATE, getFieldName(i), type, null, null);
            e.load_this();
            e.load_arg(0);
            e.push(i);
            e.aaload();
            e.checkcast(type);
            e.putfield(getFieldName(i));
        }
        e.return_value();
        e.end_method();
    }

    private void generateSwap(final Object[] arrays) {
        CodeEmitter e = begin_method(Constants.ACC_PUBLIC, SWAP, null, null);
        for (int i = 0; i < arrays.length; i++) {
            Type type = Type.getType(arrays[i].getClass());
            Type component = TypeUtils.getComponentType(type);
            Local T = e.make_local(type);

            e.load_this();
            e.getfield(getFieldName(i));
            e.store_local(T);

            e.load_local(T);
            e.load_arg(0);

            e.load_local(T);
            e.load_arg(1);
            e.array_load(component);
                
            e.load_local(T);
            e.load_arg(1);

            e.load_local(T);
            e.load_arg(0);
            e.array_load(component);

            e.array_store(component);
            e.array_store(component);
        }
        e.return_value();
        e.end_method();
    }
}

--- NEW FILE: SorterTemplate.java ---
/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact ap...@ap....
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 THE APACHE SOFTWARE FOUNDATION OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.logicalcobwebs.cglib.util;

import java.util.*;

abstract class SorterTemplate {
    private static final int MERGESORT_THRESHOLD = 12;
    private static final int QUICKSORT_THRESHOLD = 7;

    abstract protected void swap(int i, int j);
    abstract protected int compare(int i, int j);

    protected void quickSort(int lo, int hi) {
        quickSortHelper(lo, hi);
        insertionSort(lo, hi);
    }

    private void quickSortHelper(int lo, int hi) {
        for (;;) {
            int diff = hi - lo;
            if (diff <= QUICKSORT_THRESHOLD) {
                break;
            }
            int i = (hi + lo) / 2;
            if (compare(lo, i) > 0) {
                swap(lo, i);
            }
            if (compare(lo, hi) > 0) {
                swap(lo, hi);
            }
            if (compare(i, hi) > 0) {
                swap(i, hi);
            }
            int j = hi - 1;
            swap(i, j);
            i = lo;
            int v = j;
            for (;;) {
                while (compare(++i, v) < 0) {
                    /* nothing */;
                }
                while (compare(--j, v) > 0) {
                    /* nothing */;
                }
                if (j < i) {
                    break;
                }
                swap(i, j);
            }
            swap(i, hi - 1);
            if (j - lo <= hi - i + 1) {
                quickSortHelper(lo, j);
                lo = i + 1;
            } else {
                quickSortHelper(i + 1, hi);
                hi = j;
            }
        }
    }
    
    private void insertionSort(int lo, int hi) {
        for (int i = lo + 1 ; i <= hi; i++) {
            for (int j = i; j > lo; j--) {
                if (compare(j - 1, j) > 0) {
                    swap(j - 1, j);
                } else {
                    break;
                }
            }
        }
    }

    protected void mergeSort(int lo, int hi) {
        int diff = hi - lo;
        if (diff <= MERGESORT_THRESHOLD) {
            insertionSort(lo, hi);
            return;
        }
        int mid = lo + diff / 2;
        mergeSort(lo, mid);
        mergeSort(mid, hi);
        merge(lo, mid, hi, mid - lo, hi - mid);
    }

    private void merge(int lo, int pivot, int hi, int len1, int len2) {
        if (len1 == 0 || len2 == 0) {
            return;
        }
        if (len1 + len2 == 2) {
            if (compare(pivot, lo) < 0) {
                swap(pivot, lo);
            }
            return;
        }
        int first_cut, second_cut;
        int len11, len22;
        if (len1 > len2) {
            len11 = len1 / 2;
            first_cut = lo + len11;
            second_cut = lower(pivot, hi, first_cut);
            len22 = second_cut - pivot;
        } else {
            len22 = len2 / 2;
            second_cut = pivot + len22;
            first_cut = upper(lo, pivot, second_cut);
            len11 = first_cut - lo;
        }
        rotate(first_cut, pivot, second_cut);
        int new_mid = first_cut + len22;
        merge(lo, first_cut, new_mid, len11, len22);
        merge(new_mid, second_cut, hi, len1 - len11, len2 - len22);
    }

    private void rotate(int lo, int mid, int hi) {
        int lot = lo;
        int hit = mid - 1;
        while (lot < hit) {
            swap(lot++, hit--);
        }
        lot = mid; hit = hi - 1;
        while (lot < hit) {
            swap(lot++, hit--);
        }
        lot = lo; hit = hi - 1;
        while (lot < hit) {
            swap(lot++, hit--);
        }
    }

    private int lower(int lo, int hi, int val) {
        int len = hi - lo;
        while (len > 0) {
            int half = len / 2;
            int mid= lo + half;
            if (compare(mid, val) < 0) {
                lo = mid + 1;
                len = len - half -1;
            } else {
                len = half;
            }
        }
        return lo;
    }

    private int upper(int lo, int hi, int val) {
        int len = hi - lo;
        while (len > 0) {
            int half = len / 2;
            int mid = lo + half;
            if (compare(val, mid) < 0) {
                len = half;
            } else {
                lo = mid + 1;
                len = len - half -1;
            }
        }
        return lo;
    }
}

--- NEW FILE: StringSwitcher.java ---
/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  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.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact ap...@ap....
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 THE APACHE SOFTWARE FOUNDATION OR
 * ITS 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.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.logicalcobwebs.cglib.util;

import java.util.*;
import org.logicalcobwebs.cglib.core.*;
import org.logicalcobwebs.asm.ClassVisitor;
import org.logicalcobwebs.asm.Label;
import org.logicalcobwebs.asm.Type;

/**
 * This class implements a simple String->int mapping for a fixed set of keys.
 */
abstract public class StringSwitcher {
    private static final Type STRING_SWITCHER =
      TypeUtils.parseType("org.logicalcobwebs.cglib.util.StringSwitcher");
    private static final Signature INT_VALUE =
      TypeUtils.parseSignature("int intValue(String)");
    private static final StringSwitcherKey KEY_FACTORY =
      (StringSwitcherKey)KeyFactory.create(StringSwitcherKey.class);

    interface StringSwitcherKey {
        public Object newInstance(String[] strings, int[] ints, boolean fixedInput);
    }

    /**
     * Helper method to create a StringSwitcher.
     * For finer control over the generated instance, use a new instance of StringSwitcher.Generator
     * instead of this static method.
     * @param strings the array of String keys; must be the same length as the value array
     * @param ints the array of integer results; must be the same length as the key array
     * @param fixedInput if false, an unknown key will be returned from {@link #intValue} as <code>-1</code>; if true,
     * the result will be undefined, and the resulting code will be faster
     */
    public static StringSwitcher create(String[] strings, int[] ints, boolean fixedInput) {
        Generator gen = new Generator();
        gen.setStrings(strings);
        gen.setInts(ints);
        gen.setFixedInput(fixedInput);
        return gen.create();
    }

    protected StringSwitcher() {
    }

    /**
     * Return the integer associated with the given key.
     * @param s the key
     * @return the associated integer value, or <code>-1</code> if the key is unknown (unless
     * <code>fixedInput</code> was specified when this <code>StringSwitcher</code> was created,
     * in which case the return value for an unknown key is undefined)
     */
    abstract public int intValue(String s);

    public static class Generator extends AbstractClassGenerator {
        private static final Source SOURCE = new Source(StringSwitcher.class.getName());

        private String[] strings;
        private int[] ints;
        private boolean fixedInput;
        
        public Generator() {
            super(SOURCE);
        }

        /**
         * Set the array of recognized Strings.
         * @param strings the array of String keys; must be the same length as the value array
         * @see #setInts
         */
        public void setStrings(String[] strings) {
            this.strings = strings;
        }

        /**
         * Set the array of integer results.
         * @param ints the array of integer results; must be the same length as the key array
         * @see #setStrings
         */
        public void setInts(int[] ints) {
            this.ints = ints;
        }

        /**
         * Configure how unknown String keys will be handled.
         * @param fixedInput if false, an unknown key will be returned from {@link #intValue} as <code>-1</code>; if true,
         * the result will be undefined, and the resulting code will be faster
         */
        public void setFixedInput(boolean fixedInput) {
            this.fixedInput = fixedInput;
        }

        protected ClassLoader getDefaultClassLoader() {
            return getClass().getClassLoader();
        }

        /**
         * Generate the <code>StringSwitcher</code>.
         */
        public StringSwitcher create() {
            setNamePrefix(StringSwitcher.class.getName());
            Object key = KEY_FACTORY.newInstance(strings, ints, fixedInput);
            return (StringSwitcher)super.create(key);
        }

        public void generateClass(ClassVisitor v) throws Exception {
            ClassEmitter ce = new ClassEmitter(v);
            ce.begin_class(Constants.ACC_PUBLIC,
                           getClassName(),
                           STRING_SWITCHER,
                           null,
                           Constants.SOURCE_FILE);
            EmitUtils.null_constructor(ce);
            final CodeEmitter e = ce.begin_method(Constants.ACC_PUBLIC, INT_VALUE, null, null);
            e.load_arg(0);
            final List stringList = Arrays.asList(strings);
            int style = fixedInput ? Constants.SWITCH_STYLE_HASHONLY : Constants.SWITCH_STYLE_HASH;
            EmitUtils.string_switch(e, strings, style, new ObjectSwitchCallback() {
                public void processCase(Object key, Label end) {
                    e.push(ints[stringList.indexOf(key)]);
                    e.return_value();
                }
                public void processDefault() {
                    e.push(-1);
                    e.return_value();
                }
            });
            e.end_method();
            ce.end_class();
        }

        protected Object firstInstance(Class type) {
            return (StringSwitcher)ReflectUtils.newInstance(type);
        }

        protected Object nextInstance(Object instance) {
            return instance;
        }
    }
}