path: root/src/include/vector

/* IBM_PROLOG_BEGIN_TAG                                                   */
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/* $Source: src/include/vector $                                          */
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/* [+] International Business Machines Corp.                              */
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#ifndef stl_vector
#define stl_vector

/**
 * @file vector
 * @brief simple stl vector template class declaration.
 */

#include <stddef.h>

#if !defined( __STDC_LIMIT_MACROS)
#define __STDC_LIMIT_MACROS
#endif
#include <stdint.h>
#include <new>
#include <algorithm>
#include <assert.h>
#include <initializer_list>

namespace std
{

    /**
     * @class vector
     * subset of stl vector
     * @note Does not support allocators, reverse iterators.
     */
    template <class T>
        class vector
        {
            public:

                typedef T * iterator;
                typedef const T * const_iterator;
                typedef T & reference;
                typedef const T & const_reference;
                typedef size_t size_type;
                typedef size_t difference_type;
                //  typedef ptrdiff_t difference_type;
                typedef T value_type;
                typedef T * pointer;
                typedef const T * const_pointer;


            protected:

                pointer iv_start;
                pointer iv_finish;
                pointer iv_end_of_storage;

            public:

                /**
                 * Constructor default
                 * @post     The vector is created with no elements. size() == 0, capacity() == 0
                 */
                __attribute__ ((always_inline))
                vector(void)
                   :
                        iv_start(NULL),
                        iv_finish(NULL),
                        iv_end_of_storage(NULL)
                {}


                /**
                 * Constructor to create a vector of size n elements of value.
                 * @param[in] n number of elements to create
                 * @param[in] value used to create the n elements
                 * @post     The vector is created with n elements of value.
                 *           Storage allocated. size() == n, capacity() == n
                 */
                explicit vector(size_type n, const T& value = T())
                    :
                        iv_start(NULL),
                        iv_finish(NULL),
                        iv_end_of_storage(NULL)
                {
                    reserve(n);
                    iv_finish = iv_start+n;
                    ctor_fill(iv_start,iv_finish,value);
                }


                /**
                 * COPY CTOR create a vector from another vector
                 * @param[in] x  source vector
                 * @post     vector of x.size() is created from x with same # nodes
                 *           size() == capacity() == x.size()
                 */
                vector(const vector<T>& x)
                    :
                        iv_start(NULL),
                        iv_finish(NULL),
                        iv_end_of_storage(NULL)
                {
                    reserve(x.size());
                    iv_finish = ctor_copy(x.iv_start, x.iv_finish, iv_start);
                }

                /**
                 * CTOR create a vector from initializer_list
                 * @param[in] init_list Initializer list
                 * @returns  None.
                 * @post     vector is created with init_list items
                 */
                vector(std::initializer_list<T> init_list)
                    :
                        iv_start(NULL),
                        iv_finish(NULL),
                        iv_end_of_storage(NULL)
                {
                    for (auto&& i: init_list)
                    {
                        push_back(i);
                    }
                }

                /**
                 * CTOR create a vector from a container slice
                 * @param[in] first iterator first in source sequence
                 * @param[in] last  iterator one past end of source sequence
                 * @returns  None.
                 * @pre      last > first; first,last contained within source vector
                 * @post     vector is created from slice given
                 */
                template<typename InputIterator>
                    vector(InputIterator first, InputIterator last)
                    :
                        iv_start(NULL),
                        iv_finish(NULL),
                        iv_end_of_storage(NULL)
                {
                    //    assert(last >= first);
                    // input iterators only support operator ( ++i, i++,==,!=,*,->,=)
                    size_type n = 0;
                    for(InputIterator i = first; i != last; ++i) ++n;
                    reserve(n);
                    iv_finish = ctor_copy(first,last,iv_start);
                }

                /**
                 * DTOR
                 * @post     Storage released
                 */
                __attribute__ ((always_inline))
                ~vector()
                {
                    clear();  // call dtors
                    free_storage(iv_start);
                }

                /**
                 * Assignment operator.
                 * @param[in] x   A vector.
                 * @return  A vector (for the purpose of multiple assigns).
                 * @pre     None.
                 * @post    *this == x, this->capacity() == x.size().
                 *           All previously obtained iterators are invalid.
                 */
                vector<T>& operator=(const vector<T>& x)
                {
                    clear();
                    reserve(x.size());
                    iv_finish = ctor_copy(x.iv_start, x.iv_finish, iv_start);
                    return(*this);
                }

                // Iterators --------------------

                /**
                 * Get iterator to the first vector element
                 * @return iterator of rist vector element
                 * @pre None.
                 * @post None.
                 */
                __attribute__ ((always_inline))
                iterator begin()
                {
                    return (iv_start);
                }

                /**
                 * Get const_iterator to the first vector element
                 * @return const_iterator of rist vector element
                 * @pre None.
                 * @post None.
                 */
                __attribute__ ((always_inline))
                const_iterator begin() const
                {
                    return (iv_start);
                }

                /**
                 * Get iterator to the last vector element + 1
                 * @return iterator
                 * @pre None.
                 * @post None.
                 */
                __attribute__ ((always_inline))
                iterator end()
                {
                    return (iv_finish);
                }

                /**
                 * Get const_iterator to the last vector element + 1
                 * @return const_iterator
                 * @pre None.
                 * @post None.
                 */
                __attribute__ ((always_inline))
                const_iterator end() const
                {
                    return (iv_finish);
                }

                /* TODO - Implement only if needed
                reverse_iterator rbegin()
                {
                    return(iv_finish -1);
                }

                const_reverse_iterator rend()
                {
                    return (iv_start - 1);
                }
                */

                //  Capacity -----------------------------------------------

                /**
                 * Get the number of elements in the container
                 * @return number of elements in the container
                 */
                __attribute__ ((always_inline))
                size_type size() const
                {
                    return(iv_finish - iv_start);
                }

                /**
                 * Return the maximum potential size the container could reach.
                 * @return number of the maximum element count this container could reach
                 */
                __attribute__ ((always_inline))
                size_type max_size() const
                {
                    return UINT64_MAX/sizeof(T);
                }

                /**
                 * Resize the vector to contain n elements
                 * @param[in]  n new size
                 * @param[in] x object used to copy to any added elements if size() is increased
                 * @post All previously obtained iterators are invalid.
                 * @node if n < size(), vector is truncated.
                 *       if n > size(), vector is padded with copies of x
                 */
                void resize( size_type n, T x = T());

                /**
                 * Get the number of elements the vector can hold before needing to reallocate storage.
                 * @return element capacity of the vector
                 * @pre   None.
                 * @post  None.
                 */
                __attribute__ ((always_inline))
                size_type capacity() const
                {
                    return(iv_end_of_storage - iv_start);
                }

                /**
                 * Query for empty container
                 * @return bool, true if size()==0 else false.
                 * @pre none
                 * @post none
                 */
                __attribute__ ((always_inline))
                bool empty() const
                {
                    return(size() == 0);
                }

                 /**
                  * Reserve storage for a given number of elements
                  * @param[in] n The requested capacity of the vector
                  * @pre  None
                  * @post If current cpacity() < n then new capcity == n; else no change.
                  *       All previously obtained iterators are invalid
                  */
                void reserve(size_type n);

                // - Element Access -----------------------------------

                /**
                 * Access a mutable reference to an element in the container
                 * @param An index into the vector
                 * @return A reference to an element
                 * @pre    0 <= n < size()
                 * @post   None.
                 */
                __attribute__ ((always_inline))
                reference operator[](size_type n)
                {
                    return(*(iv_start + n));
                }

                /**
                 * Access a mutable reference to an element in the container
                 * @param[in] index An index into the vector
                 * @return A reference to an element
                 * @pre    0 <= n < size()
                 * @post   None.
                 * @note no exception handling
                 */
                __attribute__ ((always_inline))
                reference at(size_type index)
                {
                    assert(index < size());
                    return(*(iv_start + index));
                }

                /**
                 * Get an immutable reference to an element in the container
                 * @param[in] index An index into the vector
                 * @return A const_reference to an object or type T
                 * @pre    0 <= n < size()
                 * @post   None.
                 */
                __attribute__ ((always_inline))
                const_reference operator[](size_type index) const
                {
                    assert(index < size());
                    return(*(iv_start + index));
                }

                /**
                 * Get an immutable reference to an element in the container
                 * @param[in] index An index into the vector
                 * @return A const_reference to an object or type T
                 * @pre    0 <= n < size()
                 * @post   None.
                 * @note no exception handling
                 */
                __attribute__ ((always_inline))
                const_reference at(size_type index) const
                {
                    assert(index < size());
                    return(*(iv_start + index));
                }

                /**
                 * Get a mutable reference to the first element in the container
                 * @return reference to first element
                 * @pre none
                 * @post None
                 */
                __attribute__ ((always_inline))
                reference front()
                {
                    return *iv_start;
                }

                /**
                 * Get an Immutable reference to the first element in the container
                 * @return const_reference to first element
                 * @pre none
                 * @post None
                 */
                __attribute__ ((always_inline))
                const_reference front() const
                {
                    return *iv_start;
                }

                /**
                 * Get a mutable reference to the last element in the container
                 * @return reference to last element
                 * @pre none
                 * @post None
                 */
                __attribute__ ((always_inline))
                reference back()
                {
                    return *(iv_finish-1);
                }

                /**
                 * Get an Immutable reference to the last element in the container
                 * @return reference to last element
                 * @pre none
                 * @post None
                 */
                __attribute__ ((always_inline))
                const_reference back() const
                {
                    return *(iv_finish-1);
                }

                /*
                 * direct access to the underlying array
                 * (C++11)
                 */
                T * data()
                {
                    return iv_start;
                }

                // -- Modifiers -----------------------------

                /*
                 * Assign new content to the vector object
                 * @param[n] first iterator to first element to copy in
                 * @param[n] last  iterator to last element + 1 to copy in
                 */
                template <class InputIterator>
                    void assign (InputIterator first, InputIterator last)
                {
                    clear();
                    size_type n = 0;
                    for(InputIterator i = first; i != last; ++i) ++n;
                    reserve(n);
                    iv_finish = ctor_copy(first,last,iv_start);
                }


                /*
                 * Assign new content to the vector object
                 * @param[in] n number of elements to assign
                 * @param[in] x reference to element to copy in
                 */
                void assign ( size_type n, const T& x)
                {
                    clear();
                    reserve(n);
                    ctor_fill_n(iv_start,n,x);
                    iv_finish = iv_start + n;
                }


                /**
                 * Add element to the back of the container
                 * @param[in] x reference to object used to create new element
                 * @pre none
                 * @post All previously obtained iterators are invalid.
                 */
                __attribute__ ((always_inline))
                void push_back(const T& x)
                {
                    reserve(size() + 1);
                    new (iv_finish++) T(x);
                }

                /**
                 * Remove the last element in the container
                 * @return nothing
                 * @pre size() > 0
                 * @post size() decreased by one
                 */
                __attribute__ ((always_inline))
                void pop_back()
                {
                    erase(iv_finish-1,iv_finish);
                }

                /**
                 * Insert an element into the container at a given position
                 * @param[in] position iterator to position to insert
                 * @param[in] x reference of element to insert
                 * @pre  begin() <= position < end()
                 * @post Element inserted at position, storage adjusted as needed.
                 *       All previously obtained iterators are invalid.
                 */
                iterator insert(iterator position, const T& x)
                {
                    // iv_start will change if the vector gets resized - so save the offset for
                    // return.
                    difference_type offset = position - iv_start;
                    insert(position, 1, x);
                    return (iv_start + offset);
                }

                /**
                 * Insert a number of copies of a given elements at a given position
                 * @param[in] postion iterator, postion to insert elements
                 * @param[in] n number of elements to insert
                 * @param[in] x A reference to the object to uses to create the new elements
                 * @pre   begin() <= postion < end()
                 * @post  All previously obtained iterators are invalid.
                 */
                void insert (iterator position, size_type n, const T& x);

                /**
                 * Insert a slice into the current container at a given position
                 * @param[in] position iterator, position to insert slice
                 * @param[in] first iterator to first element of slice insert
                 * @param[in] last  iterator to last element + 1 of slice to insert
                 * @pre   begin() <= postion <= end(), first < last.
                 * @post Elements inserted at postition. Storage adjusted as needed.
                 *       All previously obtained iterators are invalid.
                 * @note element pointed to by last is not inserted.
                 */
                template <class InputIterator>
                    void insert (iterator position, InputIterator first,
                                 InputIterator last);


                /**
                 * Remove an element from the container
                 * @param[in] position iterator, position of element to remove
                 * @return new location of the element that followed the last
                 * element erased, or end() if the operation erased
                 * the last element in the sequence.
                 * @pre begin() <= position < end()
                 * @post All previously obtained iterators are invalid.
                 */
                __attribute__ ((always_inline))
                iterator erase(iterator position)
                {
                    return erase(position,position+1);
                }

                /**
                 * Remove a slice of elements from the container
                 * @param[in] first iterator, postion of the first element to remove
                 * @param[in] last iterator, postion of the last element + 1 to remove
                 * @return new location of the element that followed the last
                 * element erased, or end() if the operation erased
                 * the last element in the sequence.
                 * @pre begin() <= first,last <= end(), first <= last.
                 * @post  All previously obtained iterators are invalid.
                 * @note The element pointed to be last is not deleted.
                 */
                iterator erase(iterator first, iterator last)
                {
                    assert(last >= first);
                    assert(first >= iv_start);
                    assert(first <= iv_finish);
                    assert(last >= iv_start);
                    assert(last <= iv_finish);

                    last = copy(last,iv_finish,first);
                    while(last != iv_finish)
                    {
                        --iv_finish;
                        iv_finish->~T();
                    }
                    return first;
                }


                /**
                 * Swap this vector with another
                 * @param reference to another vector of this type
                 */
                void swap(vector<T>& x)
                {
                    std::swap(iv_start,x.iv_start);
                    std::swap(iv_finish,x.iv_finish);
                    std::swap(iv_end_of_storage,x.iv_end_of_storage);
                }

                /**
                 * Clear the vector
                 * @pre none.
                 * @post size() = 0, All previously obtained iterators are invalid
                 * @note capacity unchanged
                 */
                void clear ()
                {
                    while(iv_finish != iv_start)
                    {
                        --iv_finish;
                        (iv_finish)->~T();
                    }
                }

            private:

                /**
                 * Copy constructs elements into raw storage
                 * @param[in] first iterator of first element to copy
                 * @pararm[in] last iterator of last element + 1 to copy
                 * @param[in] destination iterator of destination
                 * @post elements moved
                 */
                template <class InputIterator, class OutputIterator>
                    OutputIterator
                    ctor_copy(InputIterator first,
                              InputIterator last,
                              OutputIterator destination)
                    {
                        while(first != last)
                        {
                            new (destination) T(*first);
                            ++destination;
                            ++first;
                        }
                        return(destination);
                    }

                /**
                 * Copy constructs elements into raw storage
                 * @param[in] first iterator of first element to copy
                 * @param[in] last iterator of last element + 1 to copy
                 * @param[in] destination iterator to end of destination + 1
                 * @post elements moved
                 */
                template <class BidirectionalIterator1, class BidirectionalIterator2>
                    BidirectionalIterator2
                    ctor_copy_backward ( BidirectionalIterator1 first,
                                         BidirectionalIterator1 last,
                                         BidirectionalIterator2 destination)
                    {
                        while(last != first)
                        {
                            --destination;
                            --last;
                            new(destination) T(*last);
                        }
                        return destination;
                    }

                /**
                 * fill by copy construct ino raw storage
                 * @param[in] first itertor fo first element
                 * @param[in] last iterator to last element + 1
                 * @param[in] value to use to fill
                 */
                template < class ForwardIterator, class Tp >
                    void
                    ctor_fill (ForwardIterator first, ForwardIterator last, const Tp& value )
                    {
                        while (first != last)
                        {
                            new (first) T(value);
                            ++first;
                        }
                    }

                /**
                 * fill by copy construct into raw storage
                 * @param[in] first iterator first location to fill
                 * @param[in] n number of elements to fill
                 * @param[in] value to use to fill
                 */
                template < class OutputIterator, class Size, class Tp >
                    void
                    ctor_fill_n( OutputIterator first, Size n, const Tp& value )
                    {
                        for(; n>0; --n)
                        {
                            new (first) T(value);
                            ++first;
                        }
                    }


                /**
                 * Free all the storage allocated to this vector
                 * @param[in] i_start iterator to start of storage block
                 */
                 __attribute__ ((always_inline))
                 void free_storage(iterator i_start)
                 {
                     delete [] (uint8_t *)i_start;
                 }

                 /**
                  * Allocate storage for this vector
                  * @param[in] n, number of elements required
                  */
                 __attribute__ ((always_inline))
                 iterator allocate_storage(size_type n)
                 {
                     return (iterator) new uint8_t[n * sizeof(T)];
                 }

                /**
                 * debug dump
                 */
                //void dump(const char * msg = "")
                //{
                //    puts(msg);
                //    printf("vector_dump::start 0x%016lx finish 0x%016lx eos 0x%016lx\n",
                //           (uint64_t)iv_start, (uint64_t)iv_finish, (uint64_t)iv_end_of_storage);
                //}
        };

    template <class T, class U>
    bool operator==(const vector<T>& l, const vector<U>& r)
    {
        if (l.size() != r.size()) return false;
        auto p = l.begin();
        auto q = r.begin();

        while(p != l.end())
        {
            if (*p != *q) return false;
            ++p; ++q;
        }

        return true;
    }

}; // end namespace std

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

template <class T>
void std::vector<T>::reserve(size_type n)
{
    size_type c = capacity();
    if(n > c)
    {
        // if requested new capacity < 10% of current capacity then increase by 10%
        size_type dif = n - c;
        size_type inc = 1 + (c/size_type(10));
        if(dif < inc)
        {
            n += inc;
        }

        iterator newStart = allocate_storage(n);
        if(NULL == iv_start)
        {
            iv_finish = newStart;
        }
        else
        {
            iterator newFinish = ctor_copy(iv_start, iv_finish, newStart);
            clear();
            iv_finish = newFinish;
            free_storage(iv_start);
        }
        iv_end_of_storage = newStart + n;
        iv_start = newStart;
    }
}


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

template <class T>
void std::vector<T>::insert (iterator position, size_type n, const T& x)
{
    //assert (position >= iv_start);
    //assert (position <= iv_finish);
    size_type new_size = size() + n;
    if(position == end())
    {
        reserve(new_size);
        while(n--) new (iv_finish++) T(x);
    }
    else if(new_size > capacity())
    {
        vector<T> new_vec;
        new_vec.reserve(new_size);
        for(const_iterator i = begin(); i != end(); ++i)
        {
            if(i == position)
            {
                while(n--) new_vec.push_back(x);
            }
            new_vec.push_back(*i);
        }
        swap(new_vec);  // swap this with new_vec
    }
    else  // already have enough space
    {
        size_type m = iv_finish - position;  // # of existing elements to move
        pointer new_finish = iv_finish + n;
        if(m < n)
        {
            ctor_copy_backward(position,iv_finish,new_finish);
            while(n--)
            {
                if(position < iv_finish) *position = x;
                else new (position) T(x);
                ++position;
            }
        }
        else // n <= m
        {
            ctor_copy_backward(iv_finish-n,iv_finish,new_finish);  // raw storage copy
            copy_backward(position, iv_finish-n, iv_finish);       // operator= copy
            fill_n(position,n,x);
        }
        iv_finish = new_finish;
    }
}

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

template <class T>
template <class InputIterator>
void std::vector<T>::insert (iterator position,
                             InputIterator first,
                             InputIterator last)
// Should only move storage if there is not room
// InputIterators are not random access  (eg. can't do diff = last - first)
{
    size_type n = 0;
    for(InputIterator i = first; i != last; ++i) ++n;
    size_type new_size = size() + n;

    if(position == end())
    {
        reserve(new_size);
        iv_finish = ctor_copy(first,last,iv_finish);
    }
    else if(new_size > capacity())  // make a new vector
    {
        vector<T> new_vec;
        new_vec.reserve(new_size);
        for(const_iterator i = begin(); i != end(); ++i)
        {
            if(i == position)
            {
                while(n--) new_vec.push_back(*first++);
            }
            new_vec.push_back(*i);
        }
        swap(new_vec);
    }
    else  // already have enough space
    {
        size_type m = iv_finish - position;  // # of exising elements to adjust
        if(m < n)
        {
            ctor_copy_backward(position,iv_finish,iv_finish+n); // cp all existing elements to raw storage
            while(first != last)
            {
                if(position < iv_finish) *position = *first; // cp new elements to existing element locations
                else new (position) T(*first);               // cp remaining new elements to raw storage
                ++position;
                ++first;
            }
        }
        else // n <= m
        {
            ctor_copy_backward(iv_finish-n, iv_finish, iv_finish+n); // cp existing elements to raw storage
            copy_backward(position, iv_finish-n, iv_finish);  // cp rest of existing elements to existing locations
            copy(first,last,position);                        // cp in new elements to existing locations
        }
        iv_finish += n;
    }
}

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

template <class T>
void std::vector<T>::resize(size_type n, T x)
{
    size_type sz = size();
    if(n < sz)
    {
        erase(iv_start + n,iv_finish);
    }
    else if(n > sz)
    {
        insert(iv_finish,n-sz,x);
    }
    // else n == size() do nothing
}

#endif
/* vim: set filetype=cpp : */