Ultralightweight C++ implementation of a void* vector * that is (mostly) compatible with java.util.Vector. * *
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. * *
Design notes * *
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 do avoid indexing off into the weeds. * *
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 one static flag that is set * when any call to new 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. * *
To do * *
Improve the handling of index out of bounds errors. * * @author Alan Liu */ class U_COMMON_API UVector32 : public UObject { private: int32_t count; int32_t capacity; int32_t maxCapacity; // Limit beyond which capacity is not permitted to grow. int32_t* elements; public: UVector32(UErrorCode &status); UVector32(int32_t initialCapacity, UErrorCode &status); virtual ~UVector32(); /** * Assign this object to another (make this a copy of 'other'). * Use the 'assign' function to assign each element. */ void assign(const UVector32& 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 UVector32& other) const; /** * Equivalent to !operator==() */ inline bool operator!=(const UVector32& other) const; //------------------------------------------------------------ // java.util.Vector API //------------------------------------------------------------ inline void addElement(int32_t elem, UErrorCode &status); void setElementAt(int32_t elem, int32_t index); void insertElementAt(int32_t elem, int32_t index, UErrorCode &status); inline int32_t elementAti(int32_t index) const; UBool equals(const UVector32 &other) const; inline int32_t lastElementi() const; int32_t indexOf(int32_t elem, int32_t startIndex = 0) const; inline UBool contains(int32_t elem) const; UBool containsAll(const UVector32& other) const; UBool removeAll(const UVector32& other); UBool retainAll(const UVector32& other); void removeElementAt(int32_t index); void removeAllElements(); inline int32_t size() const; inline UBool isEmpty() const; // 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 //------------------------------------------------------------ /** * Returns true if this vector contains none of the elements * of the given vector. * @param other vector to be checked for containment * @return true if the test condition is met */ UBool containsNone(const UVector32& other) const; /** * Insert the given integer into this vector at its sorted position. * The current elements are assumed to be sorted already. */ void sortedInsert(int32_t elem, UErrorCode& ec); /** * Returns a pointer to the internal array holding the vector. */ inline int32_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 (32 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 override; private: void _init(int32_t initialCapacity, UErrorCode &status); // Disallow UVector32(const UVector32&) = delete; // Disallow UVector32& operator=(const UVector32&) = delete; // API Functions for Stack operations. // In the original UVector, these were in a separate derived class, UStack. // Here in UVector32, they are all together. public: inline UBool empty() const; // TODO: redundant, same as empty(). Remove it? inline int32_t peeki() const; inline int32_t popi(); inline int32_t push(int32_t i, UErrorCode &status); inline int32_t *reserveBlock(int32_t size, UErrorCode &status); inline int32_t *popFrame(int32_t size); }; // UVector32 inlines inline UBool UVector32::ensureCapacity(int32_t minimumCapacity, UErrorCode &status) { if ((minimumCapacity >= 0) && (capacity >= minimumCapacity)) { return true; } else { return expandCapacity(minimumCapacity, status); } } inline int32_t UVector32::elementAti(int32_t index) const { return (index >= 0 && count > 0 && count - index > 0) ? elements[index] : 0; } inline void UVector32::addElement(int32_t elem, UErrorCode &status) { if (ensureCapacity(count + 1, status)) { elements[count] = elem; count++; } } inline int32_t *UVector32::reserveBlock(int32_t size, UErrorCode &status) { if (ensureCapacity(count+size, status) == false) { return nullptr; } int32_t *rp = elements+count; count += size; return rp; } inline int32_t *UVector32::popFrame(int32_t size) { U_ASSERT(count >= size); count -= size; if (count < 0) { count = 0; } return elements+count-size; } inline int32_t UVector32::size() const { return count; } inline UBool UVector32::isEmpty() const { return count == 0; } inline UBool UVector32::contains(int32_t obj) const { return indexOf(obj) >= 0; } inline int32_t UVector32::lastElementi() const { return elementAti(count-1); } inline bool UVector32::operator!=(const UVector32& other) const { return !operator==(other); } inline int32_t *UVector32::getBuffer() const { return elements; } // UStack inlines inline UBool UVector32::empty() const { return isEmpty(); } inline int32_t UVector32::peeki() const { return lastElementi(); } inline int32_t UVector32::push(int32_t i, UErrorCode &status) { addElement(i, status); return i; } inline int32_t UVector32::popi() { int32_t result = 0; if (count > 0) { count--; result = elements[count]; } return result; } U_NAMESPACE_END #endif