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 *
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package org.hsqldb.lib;

import java.util.NoSuchElementException;

Maintains an ordered  integer->integer lookup table, consisting of two
columns, one for keys, the other for values. Equal keys are allowed.
The table is sorted on either the key or value column, depending on the calls to
setKeysSearchTarget() or setValuesSearchTarget(). By default, the table is
sorted on values. Equal values are sorted by key.

findXXX() methods return the array index into the list
pair containing a matching key or value, or  or -1 if not found.

Sorting methods originally contributed by Tony Lai (tony_lai@users dot sourceforge.net).
Non-recursive implementation of fast quicksort added by Sergio Bossa sbtourist@users dot sourceforge.net)
Author:
Fred Toussi (fredt@users dot sourceforge.net)
Version:
2.5.0
Since:
1.8.0/**
 * Maintains an ordered  integer->integer lookup table, consisting of two
 * columns, one for keys, the other for values. Equal keys are allowed.
 *
 * The table is sorted on either the key or value column, depending on the calls to
 * setKeysSearchTarget() or setValuesSearchTarget(). By default, the table is
 * sorted on values. Equal values are sorted by key.<p>
 *
 * findXXX() methods return the array index into the list
 * pair containing a matching key or value, or  or -1 if not found.<p>
 *
 * Sorting methods originally contributed by Tony Lai (tony_lai@users dot sourceforge.net).
 * Non-recursive implementation of fast quicksort added by Sergio Bossa sbtourist@users dot sourceforge.net)
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.5.0
 * @since 1.8.0
 */
public class DoubleIntIndex implements LongLookup {

    private int           count = 0;
    private int           capacity;
    private boolean       sorted       = true;
    private boolean       sortOnValues = true;
    private final boolean fixedSize;
    private int[]         keys;
    private int[]         values;

//
    private int targetSearchValue;

    public DoubleIntIndex(int capacity) {

        this(capacity, false);

        sortOnValues = false;
    }

    public DoubleIntIndex(int capacity, boolean fixedSize) {

        this.capacity  = capacity;
        keys           = new int[capacity];
        values         = new int[capacity];
        this.fixedSize = fixedSize;
    }

    public int getKey(int i) {

        if (i < 0 || i >= count) {
            throw new IndexOutOfBoundsException();
        }

        return keys[i];
    }

    public long getLongKey(int i) {

        if (i < 0 || i >= count) {
            throw new IndexOutOfBoundsException();
        }

        return keys[i] & 0xffffffffL;
    }

    public long getLongValue(int i) {
        return values[i];
    }

    public int getValue(int i) {

        if (i < 0 || i >= count) {
            throw new IndexOutOfBoundsException();
        }

        return values[i];
    }

    
Modifies an existing pair.
Params:
i – the index
key – the key/**
     * Modifies an existing pair.
     * @param i the index
     * @param key the key
     */
    public void setKey(int i, int key) {

        if (i < 0 || i >= count) {
            throw new IndexOutOfBoundsException();
        }

        if (!sortOnValues) {
            sorted = false;
        }

        keys[i] = key;
    }

    
Modifies an existing pair.
Params:
i – the index
value – the value/**
     * Modifies an existing pair.
     * @param i the index
     * @param value the value
     */
    public void setValue(int i, int value) {

        if (i < 0 || i >= count) {
            throw new IndexOutOfBoundsException();
        }

        if (sortOnValues) {
            sorted = false;
        }

        values[i] = value;
    }

    
Modifies an existing pair.
Params:
i – the index
value – the value/**
     * Modifies an existing pair.
     * @param i the index
     * @param value the value
     */
    public void setLongValue(int i, long value) {

        if (i < 0 || i >= count) {
            throw new IndexOutOfBoundsException();
        }

        if (sortOnValues) {
            sorted = false;
        }

        values[i] = (int) value;
    }

    public int size() {
        return count;
    }

    public int capacity() {
        return capacity;
    }

    public int[] getKeys() {
        return keys;
    }

    public int[] getValues() {
        return values;
    }

    public long getTotalValues() {

        long total = 0;

        for (int i = 0; i < count; i++) {
            total += values[i];
        }

        return total;
    }

    public void setSize(int newSize) {
        count = newSize;
    }

    public boolean addUnsorted(long key, long value) {

        if (key > Integer.MAX_VALUE || key < Integer.MIN_VALUE) {
            throw new IllegalArgumentException();
        }

        if (value > Integer.MAX_VALUE || value < Integer.MIN_VALUE) {
            throw new IllegalArgumentException();
        }

        return addUnsorted((int) key, (int) value);
    }

    
Adds a pair into the table.
Params:
key – the key
value – the value
Returns:
true or false depending on success/**
     * Adds a pair into the table.
     *
     * @param key the key
     * @param value the value
     * @return true or false depending on success
     */
    public boolean addUnsorted(int key, int value) {

        if (count == capacity) {
            if (fixedSize) {
                return false;
            } else {
                doubleCapacity();
            }
        }

        if (sorted && count != 0) {
            if (sortOnValues) {
                if (value < values[count - 1]) {
                    sorted = false;
                }
            } else {
                if (key < keys[count - 1]) {
                    sorted = false;
                }
            }
        }

        keys[count]   = key;
        values[count] = value;

        count++;

        return true;
    }

    public boolean addUnsorted(LongLookup other) {

        if (!ensureCapacityToAdd(other.size())) {
            return false;
        }

        sorted = false;

        for (int i = 0; i < other.size(); i++) {
            long key   = other.getLongKey(i);
            long value = other.getLongValue(i);

            this.addUnsorted(key, value);
        }

        return true;
    }

    private boolean ensureCapacityToAdd(int extra) {

        if (count + extra > capacity) {
            if (fixedSize) {
                return false;
            } else {
                while (count + extra > capacity) {
                    doubleCapacity();
                }
            }
        }

        return true;
    }

    
Adds a key, value pair into the table with the guarantee that the key
is equal or larger than the largest existing key. This prevents a sort
from taking place on next call to find()
Params:
key – the key
value – the value
Returns:
true or false depending on success/**
     * Adds a key, value pair into the table with the guarantee that the key
     * is equal or larger than the largest existing key. This prevents a sort
     * from taking place on next call to find()
     *
     * @param key the key
     * @param value the value
     * @return true or false depending on success
     */
    public boolean addSorted(int key, int value) {

        if (count == capacity) {
            if (fixedSize) {
                return false;
            } else {
                doubleCapacity();
            }
        }

        if (count != 0) {
            if (sortOnValues) {
                if (value < values[count - 1]) {
                    return false;
                } else if (value == values[count - 1]
                           && key < keys[count - 1]) {
                    return false;
                }
            } else {
                if (key < keys[count - 1]) {
                    return false;
                }
            }
        }

        keys[count]   = key;
        values[count] = value;

        count++;

        return true;
    }

    
Adds a pair, ensuring no duplicate key xor value already exists in the
current search target column.
Params:
key – the key
value – the value
Returns:
true or false depending on success/**
     * Adds a pair, ensuring no duplicate key xor value already exists in the
     * current search target column.
     * @param key the key
     * @param value the value
     * @return true or false depending on success
     */
    public boolean addUnique(int key, int value) {

        if (count == capacity) {
            if (fixedSize) {
                return false;
            } else {
                doubleCapacity();
            }
        }

        if (!sorted) {
            fastQuickSort();
        }

        targetSearchValue = sortOnValues ? value
                                         : key;

        int i = binaryEmptySlotSearch();

        if (i == -1) {
            return false;
        }

        if (count != i) {
            moveRows(i, i + 1, count - i);
        }

        keys[i]   = key;
        values[i] = value;

        count++;

        return true;
    }

    public int add(long key, long value) {

        if (key > Integer.MAX_VALUE || key < Integer.MIN_VALUE) {
            throw new IllegalArgumentException();
        }

        if (value > Integer.MAX_VALUE || value < Integer.MIN_VALUE) {
            throw new IllegalArgumentException();
        }

        return add((int) key, (int) value);
    }

    
Adds a pair, maintaining sort order on
current search target column.
Params:
key – the key
value – the value
Returns:
index of added key or -1 if full/**
     * Adds a pair, maintaining sort order on
     * current search target column.
     * @param key the key
     * @param value the value
     * @return index of added key or -1 if full
     */
    public int add(int key, int value) {

        if (count == capacity) {
            if (fixedSize) {
                return -1;
            } else {
                doubleCapacity();
            }
        }

        if (!sorted) {
            fastQuickSort();
        }

        targetSearchValue = sortOnValues ? value
                                         : key;

        int i = binarySlotSearch(true);

        if (count != i) {
            moveRows(i, i + 1, count - i);
        }

        keys[i]   = key;
        values[i] = value;

        count++;

        return i;
    }

    public long lookup(long key) throws NoSuchElementException {

        if (key > Integer.MAX_VALUE || key < Integer.MIN_VALUE) {
            throw new NoSuchElementException();
        }

        return lookup((int) key);
    }

    public int lookup(int key) throws NoSuchElementException {

        if (sortOnValues) {
            sorted       = false;
            sortOnValues = false;
        }

        int i = findFirstEqualKeyIndex(key);

        if (i == -1) {
            throw new NoSuchElementException();
        }

        return getValue(i);
    }

    public long lookup(long key, long def) {

        if (key > Integer.MAX_VALUE || key < Integer.MIN_VALUE) {
            return def;
        }

        if (sortOnValues) {
            sorted       = false;
            sortOnValues = false;
        }

        int i = findFirstEqualKeyIndex((int) key);

        if (i == -1) {
            return def;
        }

        return getValue(i);
    }

    public int lookup(int key, int def) {

        if (sortOnValues) {
            sorted       = false;
            sortOnValues = false;
        }

        int i = findFirstEqualKeyIndex(key);

        if (i == -1) {
            return def;
        }

        return getValue(i);
    }

    public void clear() {
        removeAll();
    }

    public int lookupFirstGreaterEqual(int key) throws NoSuchElementException {

        if (sortOnValues) {
            sorted       = false;
            sortOnValues = false;
        }

        int i = findFirstGreaterEqualKeyIndex(key);

        if (i == -1) {
            throw new NoSuchElementException();
        }

        return getValue(i);
    }

    public void setValuesSearchTarget() {

        if (!sortOnValues) {
            sorted = false;
        }

        sortOnValues = true;
    }

    public void setKeysSearchTarget() {

        if (sortOnValues) {
            sorted = false;
        }

        sortOnValues = false;
    }

    
Params:
value – the value
Returns:
the index/**
     * @param value the value
     * @return the index
     */
    public int findFirstGreaterEqualKeyIndex(int value) {

        int index = findFirstGreaterEqualSlotIndex(value);

        return index == count ? -1
                              : index;
    }

    
Params:
value – the value
Returns:
the index/**
     * @param value the value
     * @return the index
     */
    public int findFirstEqualKeyIndex(int value) {

        if (!sorted) {
            fastQuickSort();
        }

        targetSearchValue = value;

        return binaryFirstSearch();
    }

    public boolean compactLookupAsIntervals() {

        if (size() == 0) {
            return false;
        }

        setKeysSearchTarget();

        if (!sorted) {
            fastQuickSort();
        }

        int base = 0;

        for (int i = 1; i < count; i++) {
            long limit = keys[base] + values[base];

            if (limit == keys[i]) {
                values[base] += values[i];    // base updated
            } else {
                base++;

                keys[base]   = keys[i];
                values[base] = values[i];
            }
        }

        for (int i = base + 1; i < count; i++) {
            keys[i]   = 0;
            values[i] = 0;
        }

        if (count != base + 1) {
            setSize(base + 1);

            return true;
        }

        return false;
    }

    
This method is similar to findFirstGreaterEqualKeyIndex(int) but
returns the index of the empty row past the end of the array if
the search value is larger than all the values / keys in the searched
column.
Params:
value – the value
Returns:
the index/**
     * This method is similar to findFirstGreaterEqualKeyIndex(int) but
     * returns the index of the empty row past the end of the array if
     * the search value is larger than all the values / keys in the searched
     * column.
     * @param value the value
     * @return the index
     */
    public int findFirstGreaterEqualSlotIndex(int value) {

        if (!sorted) {
            fastQuickSort();
        }

        targetSearchValue = value;

        return binarySlotSearch(false);
    }

    
Returns the index of the lowest element == the given search target,
or -1
Returns:
index or -1 if not found/**
     * Returns the index of the lowest element == the given search target,
     * or -1
     * @return index or -1 if not found
     */
    private int binaryFirstSearch() {

        int low     = 0;
        int high    = count;
        int mid     = 0;
        int compare = 0;
        int found   = count;

        while (low < high) {
            mid     = (low + high) >>> 1;
            compare = compare(mid);

            if (compare < 0) {
                high = mid;
            } else if (compare > 0) {
                low = mid + 1;
            } else {
                high  = mid;
                found = mid;
            }
        }

        return found == count ? -1
                              : found;
    }

    
Returns the index of the lowest element >= the given search target,
or count
    @return the index
/**
     * Returns the index of the lowest element >= the given search target,
     * or count
     *     @return the index
     */
    private int binarySlotSearch(boolean fullCompare) {

        int low     = 0;
        int high    = count;
        int mid     = 0;
        int compare = 0;

        while (low < high) {
            mid     = (low + high) >>> 1;
            compare = compare(mid);

            if (compare <= 0) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        return low;
    }

    
Returns the index of the lowest element > the given search target
or count or -1 if target is found
Returns:
the index/**
     * Returns the index of the lowest element > the given search target
     * or count or -1 if target is found
     * @return the index
     */
    private int binaryEmptySlotSearch() {

        int low     = 0;
        int high    = count;
        int mid     = 0;
        int compare = 0;

        while (low < high) {
            mid     = (low + high) >>> 1;
            compare = compare(mid);

            if (compare < 0) {
                high = mid;
            } else if (compare > 0) {
                low = mid + 1;
            } else {
                return -1;
            }
        }

        return low;
    }

    public void sortOnKeys() {

        sortOnValues = false;

        fastQuickSort();
    }

    public void sortOnValues() {

        sortOnValues = true;

        fastQuickSort();
    }

    public void sort() {

        if (sortOnValues || count <= 1024 * 16) {
            fastQuickSortRecursive();
        } else {
            fastQuickSort();
        }
    }

    
fast quicksort using a stack on the heap to reduce stack use
/**
     * fast quicksort using a stack on the heap to reduce stack use
     */
    private void fastQuickSort() {

        DoubleIntIndex indices   = new DoubleIntIndex(32768);
        int            threshold = 16;

        indices.push(0, count - 1);

        while (indices.size() > 0) {
            int start = indices.peekKey();
            int end   = indices.peekValue();

            indices.pop();

            if (end - start >= threshold) {
                int pivot = partition(start, end,
                                      start + ((end - start) >>> 1));

                indices.push(start, pivot - 1);
                indices.push(pivot + 1, end);
            } else {
                insertionSort(start, end);
            }
        }

        sorted = true;
    }

    private int partition(int start, int end, int pivot) {

        int store = start;

        swap(pivot, end);

        for (int i = start; i <= end - 1; i++) {
            if (lessThan(i, end)) {
                swap(i, store);

                store++;
            }
        }

        swap(store, end);

        return store;
    }

    
fast quicksort with recursive quicksort implementation
/**
     * fast quicksort with recursive quicksort implementation
     */
    private void fastQuickSortRecursive() {

        quickSort(0, count - 1);
        insertionSort(0, count - 1);

        sorted = true;
    }

    private void quickSort(int l, int r) {

        int M = 16;
        int i;
        int j;
        int v;

        if ((r - l) > M) {
            i = (r + l) >>> 1;

            if (lessThan(i, l)) {
                swap(l, i);    // Tri-Median Method!
            }

            if (lessThan(r, l)) {
                swap(l, r);
            }

            if (lessThan(r, i)) {
                swap(i, r);
            }

            j = r - 1;

            swap(i, j);

            i = l;
            v = j;

            for (;;) {
                while (lessThan(++i, v)) {}

                while (lessThan(v, --j)) {}

                if (j < i) {
                    break;
                }

                swap(i, j);
            }

            swap(i, r - 1);
            quickSort(l, j);
            quickSort(i + 1, r);
        }
    }

    private void insertionSort(int lo0, int hi0) {

        int i;
        int j;

        for (i = lo0 + 1; i <= hi0; i++) {
            j = i;

            while ((j > lo0) && lessThan(i, j - 1)) {
                j--;
            }

            if (i != j) {
                moveAndInsertRow(i, j);
            }
        }
    }

    protected void moveAndInsertRow(int i, int j) {

        int col1 = keys[i];
        int col2 = values[i];

        moveRows(j, j + 1, i - j);

        keys[j]   = col1;
        values[j] = col2;
    }

    protected void swap(int i1, int i2) {

        int col1 = keys[i1];
        int col2 = values[i1];

        keys[i1]   = keys[i2];
        values[i1] = values[i2];
        keys[i2]   = col1;
        values[i2] = col2;
    }

    
Check if targeted column value in the row indexed i is less than the
search target object.
Params:
i – the index
Returns:
-1, 0 or +1/**
     * Check if targeted column value in the row indexed i is less than the
     * search target object.
     * @param i the index
     * @return -1, 0 or +1
     */
    protected int compare(int i) {

        if (sortOnValues) {
            if (targetSearchValue > values[i]) {
                return 1;
            } else if (targetSearchValue < values[i]) {
                return -1;
            } else {
                return 0;
            }
        }

        if (targetSearchValue > keys[i]) {
            return 1;
        } else if (targetSearchValue < keys[i]) {
            return -1;
        }

        return 0;
    }

    
Check if row indexed i is less than row indexed j
Params:
i – the first index
j – the second index
Returns:
true or false/**
     * Check if row indexed i is less than row indexed j
     * @param i the first index
     * @param j the second index
     * @return true or false
     */
    protected boolean lessThan(int i, int j) {

        if (sortOnValues) {
            if (values[i] < values[j]) {
                return true;
            } else if (values[i] > values[j]) {
                return false;
            }
        }

        if (keys[i] < keys[j]) {
            return true;
        }

        return false;
    }

    protected void moveRows(int fromIndex, int toIndex, int rows) {
        System.arraycopy(keys, fromIndex, keys, toIndex, rows);
        System.arraycopy(values, fromIndex, values, toIndex, rows);
    }

    protected void doubleCapacity() {

        keys     = (int[]) ArrayUtil.resizeArray(keys, capacity * 2);
        values   = (int[]) ArrayUtil.resizeArray(values, capacity * 2);
        capacity *= 2;
    }

    public void removeRange(int start, int limit) {

        ArrayUtil.adjustArray(ArrayUtil.CLASS_CODE_INT, keys, count, start,
                              start - limit);
        ArrayUtil.adjustArray(ArrayUtil.CLASS_CODE_INT, values, count, start,
                              start - limit);

        count -= (limit - start);
    }

    public void removeAll() {

        ArrayUtil.clearArray(ArrayUtil.CLASS_CODE_INT, keys, 0, count);
        ArrayUtil.clearArray(ArrayUtil.CLASS_CODE_INT, values, 0, count);

        count  = 0;
        sorted = true;
    }

    public void copyTo(DoubleIntIndex other) {

        System.arraycopy(keys, 0, other.keys, 0, count);
        System.arraycopy(values, 0, other.values, 0, count);
        other.setSize(count);
    }

    public final void remove(int position) {

        moveRows(position + 1, position, count - position - 1);

        count--;

        keys[count]   = 0;
        values[count] = 0;
    }

    
peek the key at top of stack. Uses the data structure as a stack.
Returns:
int key/**
     * peek the key at top of stack. Uses the data structure as a stack.
     * @return int key
     */
    int peekKey() {
        return getKey(count - 1);
    }

    
peek the value at top of stack
Returns:
int value/**
     * peek the value at top of stack
     * @return int value
     */
    int peekValue() {
        return getValue(count - 1);
    }

    
pop the pair at top of stack
Returns:
boolean if there was an element/**
     * pop the pair at top of stack
     * @return boolean if there was an element
     */
    boolean pop() {

        if (count > 0) {
            count--;

            return true;
        }

        return false;
    }

    
push key, value pair
Returns:
boolean true if successful/**
     * push key, value pair
     * @return boolean true if successful
     */
    boolean push(int key, int value) {
        return addUnsorted(key, value);
    }
}