text: // Copyright (C) 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.
       */
      UBool operator==(const UVector64& other);
  
      /**
       * Equivalent to !operator==()
       */
      inline UBool operator!=(const UVector64& other);
  
      //------------------------------------------------------------
      // subset of java.util.Vector API
      //------------------------------------------------------------
  
      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);
      
      int64_t elementAti(int32_t index) const;
  
      //UBool equals(const UVector64 &other) const;
  
      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();
  
      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.
       */
      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;
      
      int64_t popi(void);
      
      int64_t push(int64_t i, UErrorCode &status);
  
      int64_t *reserveBlock(int32_t size, UErrorCode &status);
      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 UBool 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
  