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      1 /*
      2 **********************************************************************
      3 *   Copyright (C) 1999-2011, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 **********************************************************************
      6 */
      7 
      8 //
      9 //  UVector32 is a class implementing a vector of 32 bit integers.
     10 //            It is similar to UVector, but holds int32_t values rather than pointers.
     11 //            Most of the code is unchanged from UVector.
     12 //
     13 
     14 #ifndef UVECTOR32_H
     15 #define UVECTOR32_H
     16 
     17 #include "unicode/utypes.h"
     18 #include "unicode/uobject.h"
     19 #include "uhash.h"
     20 #include "uassert.h"
     21 
     22 U_NAMESPACE_BEGIN
     23 
     24 
     25 
     26 /**
     27  * <p>Ultralightweight C++ implementation of a <tt>void*</tt> vector
     28  * that is (mostly) compatible with java.util.Vector.
     29  *
     30  * <p>This is a very simple implementation, written to satisfy an
     31  * immediate porting need.  As such, it is not completely fleshed out,
     32  * and it aims for simplicity and conformity.  Nonetheless, it serves
     33  * its purpose (porting code from java that uses java.util.Vector)
     34  * well, and it could be easily made into a more robust vector class.
     35  *
     36  * <p><b>Design notes</b>
     37  *
     38  * <p>There is index bounds checking, but little is done about it.  If
     39  * indices are out of bounds, either nothing happens, or zero is
     40  * returned.  We <em>do</em> avoid indexing off into the weeds.
     41  *
     42  * <p>There is detection of out of memory, but the handling is very
     43  * coarse-grained -- similar to UnicodeString's protocol, but even
     44  * coarser.  The class contains <em>one static flag</em> that is set
     45  * when any call to <tt>new</tt> returns zero.  This allows the caller
     46  * to use several vectors and make just one check at the end to see if
     47  * a memory failure occurred.  This is more efficient than making a
     48  * check after each call on each vector when doing many operations on
     49  * multiple vectors.  The single static flag works best when memory
     50  * failures are infrequent, and when recovery options are limited or
     51  * nonexistent.
     52  *
     53  * <p><b>To do</b>
     54  *
     55  * <p>Improve the handling of index out of bounds errors.
     56  *
     57  * @author Alan Liu
     58  */
     59 class U_COMMON_API UVector32 : public UObject {
     60 private:
     61     int32_t   count;
     62 
     63     int32_t   capacity;
     64 
     65     int32_t   maxCapacity;   // Limit beyond which capacity is not permitted to grow.
     66 
     67     int32_t*  elements;
     68 
     69 public:
     70     UVector32(UErrorCode &status);
     71 
     72     UVector32(int32_t initialCapacity, UErrorCode &status);
     73 
     74     virtual ~UVector32();
     75 
     76     /**
     77      * Assign this object to another (make this a copy of 'other').
     78      * Use the 'assign' function to assign each element.
     79      */
     80     void assign(const UVector32& other, UErrorCode &ec);
     81 
     82     /**
     83      * Compare this vector with another.  They will be considered
     84      * equal if they are of the same size and all elements are equal,
     85      * as compared using this object's comparer.
     86      */
     87     UBool operator==(const UVector32& other);
     88 
     89     /**
     90      * Equivalent to !operator==()
     91      */
     92     inline UBool operator!=(const UVector32& other);
     93 
     94     //------------------------------------------------------------
     95     // java.util.Vector API
     96     //------------------------------------------------------------
     97 
     98     void addElement(int32_t elem, UErrorCode &status);
     99 
    100     void setElementAt(int32_t elem, int32_t index);
    101 
    102     void insertElementAt(int32_t elem, int32_t index, UErrorCode &status);
    103 
    104     int32_t elementAti(int32_t index) const;
    105 
    106     UBool equals(const UVector32 &other) const;
    107 
    108     int32_t lastElementi(void) const;
    109 
    110     int32_t indexOf(int32_t elem, int32_t startIndex = 0) const;
    111 
    112     UBool contains(int32_t elem) const;
    113 
    114     UBool containsAll(const UVector32& other) const;
    115 
    116     UBool removeAll(const UVector32& other);
    117 
    118     UBool retainAll(const UVector32& other);
    119 
    120     void removeElementAt(int32_t index);
    121 
    122     void removeAllElements();
    123 
    124     int32_t size(void) const;
    125 
    126     UBool isEmpty(void) const;
    127 
    128     // Inline.  Use this one for speedy size check.
    129     inline UBool ensureCapacity(int32_t minimumCapacity, UErrorCode &status);
    130 
    131     // Out-of-line, handles actual growth.  Called by ensureCapacity() when necessary.
    132     UBool expandCapacity(int32_t minimumCapacity, UErrorCode &status);
    133 
    134     /**
    135      * Change the size of this vector as follows: If newSize is
    136      * smaller, then truncate the array, possibly deleting held
    137      * elements for i >= newSize.  If newSize is larger, grow the
    138      * array, filling in new slows with zero.
    139      */
    140     void setSize(int32_t newSize);
    141 
    142     //------------------------------------------------------------
    143     // New API
    144     //------------------------------------------------------------
    145 
    146     /**
    147      * Returns true if this vector contains none of the elements
    148      * of the given vector.
    149      * @param other vector to be checked for containment
    150      * @return true if the test condition is met
    151      */
    152     UBool containsNone(const UVector32& other) const;
    153 
    154 
    155     /**
    156      * Insert the given integer into this vector at its sorted position.
    157      * The current elements are assumed to be sorted already.
    158      */
    159     void sortedInsert(int32_t elem, UErrorCode& ec);
    160 
    161     /**
    162      * Returns a pointer to the internal array holding the vector.
    163      */
    164     int32_t *getBuffer() const;
    165 
    166     /**
    167      * Set the maximum allowed buffer capacity for this vector/stack.
    168      * Default with no limit set is unlimited, go until malloc() fails.
    169      * A Limit of zero means unlimited capacity.
    170      * Units are vector elements (32 bits each), not bytes.
    171      */
    172     void setMaxCapacity(int32_t limit);
    173 
    174     /**
    175      * ICU "poor man's RTTI", returns a UClassID for this class.
    176      */
    177     static UClassID U_EXPORT2 getStaticClassID();
    178 
    179     /**
    180      * ICU "poor man's RTTI", returns a UClassID for the actual class.
    181      */
    182     virtual UClassID getDynamicClassID() const;
    183 
    184 private:
    185     void _init(int32_t initialCapacity, UErrorCode &status);
    186 
    187     // Disallow
    188     UVector32(const UVector32&);
    189 
    190     // Disallow
    191     UVector32& operator=(const UVector32&);
    192 
    193 
    194     //  API Functions for Stack operations.
    195     //  In the original UVector, these were in a separate derived class, UStack.
    196     //  Here in UVector32, they are all together.
    197 public:
    198     UBool empty(void) const;   // TODO:  redundant, same as empty().  Remove it?
    199 
    200     int32_t peeki(void) const;
    201 
    202     int32_t popi(void);
    203 
    204     int32_t push(int32_t i, UErrorCode &status);
    205 
    206     int32_t *reserveBlock(int32_t size, UErrorCode &status);
    207     int32_t *popFrame(int32_t size);
    208 };
    209 
    210 
    211 // UVector32 inlines
    212 
    213 inline UBool UVector32::ensureCapacity(int32_t minimumCapacity, UErrorCode &status) {
    214     if ((minimumCapacity >= 0) && (capacity >= minimumCapacity)) {
    215         return TRUE;
    216     } else {
    217         return expandCapacity(minimumCapacity, status);
    218     }
    219 }
    220 
    221 inline int32_t UVector32::elementAti(int32_t index) const {
    222     return (index >= 0 && count > 0 && count - index > 0) ? elements[index] : 0;
    223 }
    224 
    225 
    226 inline void UVector32::addElement(int32_t elem, UErrorCode &status) {
    227     if (ensureCapacity(count + 1, status)) {
    228         elements[count] = elem;
    229         count++;
    230     }
    231 }
    232 
    233 inline int32_t *UVector32::reserveBlock(int32_t size, UErrorCode &status) {
    234     if (ensureCapacity(count+size, status) == FALSE) {
    235         return NULL;
    236     }
    237     int32_t  *rp = elements+count;
    238     count += size;
    239     return rp;
    240 }
    241 
    242 inline int32_t *UVector32::popFrame(int32_t size) {
    243     U_ASSERT(count >= size);
    244     count -= size;
    245     if (count < 0) {
    246         count = 0;
    247     }
    248     return elements+count-size;
    249 }
    250 
    251 
    252 
    253 inline int32_t UVector32::size(void) const {
    254     return count;
    255 }
    256 
    257 inline UBool UVector32::isEmpty(void) const {
    258     return count == 0;
    259 }
    260 
    261 inline UBool UVector32::contains(int32_t obj) const {
    262     return indexOf(obj) >= 0;
    263 }
    264 
    265 inline int32_t UVector32::lastElementi(void) const {
    266     return elementAti(count-1);
    267 }
    268 
    269 inline UBool UVector32::operator!=(const UVector32& other) {
    270     return !operator==(other);
    271 }
    272 
    273 inline int32_t *UVector32::getBuffer() const {
    274     return elements;
    275 }
    276 
    277 
    278 // UStack inlines
    279 
    280 inline UBool UVector32::empty(void) const {
    281     return isEmpty();
    282 }
    283 
    284 inline int32_t UVector32::peeki(void) const {
    285     return lastElementi();
    286 }
    287 
    288 inline int32_t UVector32::push(int32_t i, UErrorCode &status) {
    289     addElement(i, status);
    290     return i;
    291 }
    292 
    293 inline int32_t UVector32::popi(void) {
    294     int32_t result = 0;
    295     if (count > 0) {
    296         count--;
    297         result = elements[count];
    298     }
    299     return result;
    300 }
    301 
    302 U_NAMESPACE_END
    303 
    304 #endif
    305