// © 2016 and later: Unicode, Inc. and others.

// License & terms of use: http://www.unicode.org/copyright.html

/*

**********************************************************************

*   Copyright (C) 1999-2014, International Business Machines

*   Corporation and others.  All Rights Reserved.

**********************************************************************

*/

//

//  UVector64 is a class implementing a vector of 64 bit integers.

//            It is similar to UVector32, but holds int64_t values rather than int32_t.

//            Most of the code is unchanged from UVector.

//

#ifndef UVECTOR64_H

#define UVECTOR64_H

#include "unicode/utypes.h"

#include "unicode/uobject.h"

#include "uhash.h"

#include "uassert.h"

U_NAMESPACE_BEGIN

/**

 * <p>Ultralightweight C++ implementation of an <tt>int64_t</tt> vector

 * that has a subset of methods from UVector32

 *

 * <p>This is a very simple implementation, written to satisfy an

 * immediate porting need.  As such, it is not completely fleshed out,

 * and it aims for simplicity and conformity.  Nonetheless, it serves

 * its purpose (porting code from java that uses java.util.Vector)

 * well, and it could be easily made into a more robust vector class.

 *

 * <p><b>Design notes</b>

 *

 * <p>There is index bounds checking, but little is done about it.  If

 * indices are out of bounds, either nothing happens, or zero is

 * returned.  We <em>do</em> avoid indexing off into the weeds.

 *

 * <p>There is detection of out of memory, but the handling is very

 * coarse-grained -- similar to UnicodeString's protocol, but even

 * coarser.  The class contains <em>one static flag</em> that is set

 * when any call to <tt>new</tt> returns zero.  This allows the caller

 * to use several vectors and make just one check at the end to see if

 * a memory failure occurred.  This is more efficient than making a

 * check after each call on each vector when doing many operations on

 * multiple vectors.  The single static flag works best when memory

 * failures are infrequent, and when recovery options are limited or

 * nonexistent.

 *

 * <p><b>To do</b>

 *

 * <p>Improve the handling of index out of bounds errors.

 *

 */

class U_COMMON_API UVector64 : public UObject {

private:

    int32_t   count;

    int32_t   capacity;

    int32_t   maxCapacity;   // Limit beyond which capacity is not permitted to grow.

    int64_t*  elements;

public:

    UVector64(UErrorCode &status);

    UVector64(int32_t initialCapacity, UErrorCode &status);

    virtual ~UVector64();

    /**

     * Assign this object to another (make this a copy of 'other').

     * Use the 'assign' function to assign each element.

     */

    void assign(const UVector64& other, UErrorCode &ec);

    /**

     * Compare this vector with another.  They will be considered

     * equal if they are of the same size and all elements are equal,

     * as compared using this object's comparer.

     */

    bool operator==(const UVector64& other);

    /**

     * Equivalent to !operator==()

     */

    inline bool operator!=(const UVector64& other);

    //------------------------------------------------------------

    // subset of java.util.Vector API

    //------------------------------------------------------------

    inline void addElement(int64_t elem, UErrorCode &status);

    void setElementAt(int64_t elem, int32_t index);

    void insertElementAt(int64_t elem, int32_t index, UErrorCode &status);

    inline int64_t elementAti(int32_t index) const;

    //UBool equals(const UVector64 &other) const;

    inline int64_t lastElementi(void) const;

    //int32_t indexOf(int64_t elem, int32_t startIndex = 0) const;

    //UBool contains(int64_t elem) const;

    //UBool containsAll(const UVector64& other) const;

    //UBool removeAll(const UVector64& other);

    //UBool retainAll(const UVector64& other);

    //void removeElementAt(int32_t index);

    void removeAllElements();

    inline int32_t size(void) const;

    inline UBool isEmpty(void) const { return count == 0; }

    // Inline.  Use this one for speedy size check.

    inline UBool ensureCapacity(int32_t minimumCapacity, UErrorCode &status);

    // Out-of-line, handles actual growth.  Called by ensureCapacity() when necessary.

    UBool expandCapacity(int32_t minimumCapacity, UErrorCode &status);

    /**

     * Change the size of this vector as follows: If newSize is

     * smaller, then truncate the array, possibly deleting held

     * elements for i >= newSize.  If newSize is larger, grow the

     * array, filling in new slows with zero.

     */

    void setSize(int32_t newSize);

    //------------------------------------------------------------

    // New API

    //------------------------------------------------------------

    //UBool containsNone(const UVector64& other) const;

    //void sortedInsert(int64_t elem, UErrorCode& ec);

    /**

     * Returns a pointer to the internal array holding the vector.

     */

    inline int64_t *getBuffer() const;

    /**

     * Set the maximum allowed buffer capacity for this vector/stack.

     * Default with no limit set is unlimited, go until malloc() fails.

     * A Limit of zero means unlimited capacity.

     * Units are vector elements (64 bits each), not bytes.

     */

    void setMaxCapacity(int32_t limit);

    /**

     * ICU "poor man's RTTI", returns a UClassID for this class.

     */

    static UClassID U_EXPORT2 getStaticClassID();

    /**

     * ICU "poor man's RTTI", returns a UClassID for the actual class.

     */

    virtual UClassID getDynamicClassID() const;

private:

    void _init(int32_t initialCapacity, UErrorCode &status);

    // Disallow

    UVector64(const UVector64&);

    // Disallow

    UVector64& operator=(const UVector64&);

    //  API Functions for Stack operations.

    //  In the original UVector, these were in a separate derived class, UStack.

    //  Here in UVector64, they are all together.

public:

    //UBool empty(void) const;   // TODO:  redundant, same as empty().  Remove it?

    //int64_t peeki(void) const;

    inline int64_t popi(void);

    inline int64_t push(int64_t i, UErrorCode &status);

    inline int64_t *reserveBlock(int32_t size, UErrorCode &status);

    inline int64_t *popFrame(int32_t size);

};

// UVector64 inlines

inline UBool UVector64::ensureCapacity(int32_t minimumCapacity, UErrorCode &status) {

    if ((minimumCapacity >= 0) && (capacity >= minimumCapacity)) {

        return true;

    } else {

        return expandCapacity(minimumCapacity, status);

    }

}

inline int64_t UVector64::elementAti(int32_t index) const {

    return (0 <= index && index < count) ? elements[index] : 0;

}

inline void UVector64::addElement(int64_t elem, UErrorCode &status) {

    if (ensureCapacity(count + 1, status)) {

        elements[count] = elem;

        count++;

    }

}

inline int64_t *UVector64::reserveBlock(int32_t size, UErrorCode &status) {

    if (ensureCapacity(count+size, status) == false) {

        return NULL;

    }

    int64_t  *rp = elements+count;

    count += size;

    return rp;

}

inline int64_t *UVector64::popFrame(int32_t size) {

    U_ASSERT(count >= size);

    count -= size;

    if (count < 0) {

        count = 0;

    }

    return elements+count-size;

}

inline int32_t UVector64::size(void) const {

    return count;

}

inline int64_t UVector64::lastElementi(void) const {

    return elementAti(count-1);

}

inline bool UVector64::operator!=(const UVector64& other) {

    return !operator==(other);

}

inline int64_t *UVector64::getBuffer() const {

    return elements;

}

// UStack inlines

inline int64_t UVector64::push(int64_t i, UErrorCode &status) {

    addElement(i, status);

    return i;

}

inline int64_t UVector64::popi(void) {

    int64_t result = 0;

    if (count > 0) {

        count--;

        result = elements[count];

    }

    return result;

}

U_NAMESPACE_END

#endif