SegmentedArray.cs

Segmented Array Class

I wrote this array class while investigating the error curve in Prime Number Theorem. I wanted to avoid using blocking while using parallel invoke, while using as little memory as possible.

using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
public struct SegmentedArray<T>
{
    private readonly IntA<T>[] _array;
    private readonly int       _size;
    public SegmentedArray(int length, int size)
    {
        _array = new IntA<T>[16];
        _size  = size;
    }
    public void Add(T item, int index, long range, long total)
    {
        if (!_array[index].Allocated)
            _array[index] = new IntA<T>(_size);
        var density = (float)_array[index].Count / range;
        var ssic    = total                      * density;
        _array[index].Add(item, (int)ssic);
    }
    public T[] ToArray()
    {
        var totalCount = 0;
        for (var i = 0; i < 16; ++i)
            if (_array[i].Allocated)
                totalCount += _array[i].Count;
        var ta  = new T[totalCount];
        var ptr = 0;
        for (var i = 0; i < 16; ++i)
            if (_array[i].Allocated)
            {
                var it = _array[i].ToArray();
                _array[i].Zero();
                for (var j = 0; j < it.Length; ++j)
                    ta[ptr++] = it[j];
            }
        return ta;
    }
    [DebuggerDisplay("Count = {Count}")]
    internal struct IntA<T> : IEnumerable<T>
    {
        internal T[]  _array;
        internal bool Allocated;
        public IntA(int cap)
        {
            Count     = 0;
            _array    = new T[cap];
            Allocated = true;
        }
        public int Count
        {
            get;
            private set;
        }
        public T this[int index]
        {
            get
            {
                if (index > _array.Length)
                    throw new Exception("Error: Index out of range.");
                return _array[index];
            }
            set
            {
                if (index > _array.Length)
                    throw new Exception("Error: Index out of range.");
                _array[index] = value;
            }
        }
        IEnumerator<T> IEnumerable<T>.GetEnumerator()
        {
            return GetEnumerator();
        }
        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
        public void Add(T item, int suggestedSize)
        {
            if (Count >= _array.Length)
                Array.Resize(ref _array, suggestedSize);
            _array[Count] = item;
            Count++;
        }
        public T[] ToArray()
        {
            var newtArray = new T[Count];
            Array.Copy(_array, 0, newtArray, 0, Count);
            return newtArray;
        }
        public void Clean()
        {
            var newtArray = new T[Count];
            Array.Copy(_array, 0, newtArray, 0, Count);
            _array = newtArray;
        }
        public void Clear()
        {
            Array.Clear(_array, 0, Count);
            Count = 0;
        }
        public void Zero()
        {
            _array = Array.Empty<T>();
            Count  = 0;
        }
        public IEnumerator<T> GetEnumerator()
        {
            return GetEnum();
        }
        public IEnumerator<T> GetEnum()
        {
            for (var i = 0; i < Count; i++)
                yield return _array[i];
        }
    }
}