ItemList.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / wpf / src / Shared / MS / Utility / ItemList.cs / 1305600 / ItemList.cs
                        

                        
                            using System; 
using MS.Internal.WindowsBase;

namespace MS.Utility
{ 
    //
    // ItemStructList 
    // 

    [FriendAccessAllowed] // Built into Base, also used by Framework. 
    internal struct ItemStructList
    {
        public ItemStructList(int capacity)
        { 
            List = new T[capacity];
            Count = 0; 
        } 

 
        //
        // Non-lock-required Read methods
        // (Always safe to call when locking "safe" write operations are used)
        // 

        public T[] List; 
        public int Count; 

        public void EnsureIndex(int index) 
        {
            int delta = (index + 1) - Count;
            if (delta > 0)
            { 
                Add(delta);
            } 
        } 

        public bool IsValidIndex(int index) 
        {
            return (index >= 0 && index < Count);
        }
 
        public int IndexOf(T value)
        { 
            int index = -1; 

            for (int i = 0; i < Count; i++) 
            {
                if (List[i].Equals(value))
                {
                    index = i; 
                    break;
                } 
            } 

            return index; 
        }

        public bool Contains(T value)
        { 
            return (IndexOf(value) != -1);
        } 
 

        // 
        // Lock-required Write operations
        // "Safe" methods for Reader lock-free operation
        //
 
        // Increase size by one, new value is provided
        public void Add(T item) 
        { 
            // Add without Count adjustment (incr Count after valid item added)
            int index = Add(1, false); 
            List[index] = item;
            Count++;
        }
 
        // Increase size by one, new value is provided
        public void Add(ref T item) 
        { 
            // Add without Count adjustment (incr Count after valid item added)
            int index = Add(1, false); 
            List[index] = item;
            Count++;
        }
 
        // Increase size by one, new value is default value
        public int Add() 
        { 
            return Add(1, true);
        } 

        // Increase size of array by delta, fill with default values
        public int Add(int delta)
        { 
            return Add(delta, true);
        } 
 
        // Increase size of array by delta, fill with default values
        // Allow disable of automatic Count increment so that cases where 
        // non-default values are to be added to the list can be done before
        // count is changed. This is important for non-locking scenarios
        // (i.e. count is adjusted after array size changes)
        private int Add(int delta, bool incrCount) 
        {
            if (List != null) 
            { 
                if ((Count + delta) > List.Length)
                { 
                    T[] newList = new T[Math.Max(List.Length * 2, Count + delta)];
                    List.CopyTo(newList, 0);
                    List = newList;
                } 
            }
            else 
            { 
                List = new T[Math.Max(delta, 2)];
            } 

            // New arrays auto-initialized to default entry values
            // Any resued entried have already been cleared out by Remove or Clear
 
            int index = Count;
 
            // Optional adjustment of Count 
            if (incrCount)
            { 
                // Adjust count after resize so that array bounds and data
                // are never invalid (good for locking writes without synchronized reads)
                Count += delta;
            } 

            return index; 
        } 

        public void Sort() 
        {
            if (List != null)
            {
                Array.Sort(List, 0, Count); 
            }
        } 
 
        public void AppendTo(ref ItemStructList destinationList)
        { 
            for (int i = 0; i < Count; i++)
            {
                destinationList.Add(ref List[i]);
            } 
        }
 
        public T[] ToArray() 
        {
            T[] array = new T[Count]; 
            Array.Copy(List, 0, array, 0, Count);

            return array;
        } 

 
        // 
        // Lock-required Write operations
        // "UNSafe" methods for Reader lock-free operation 
        //
        // If any of these methods are called, the entire class is considered
        // unsafe for Reader lock-free operation for that point on (meaning
        // Reader locks must be taken) 
        //
 
        public void Clear() 
        {
            // Return now unused entries back to default 
            Array.Clear(List, 0, Count);

            Count = 0;
        } 

        public void Remove(T value) 
        { 
            int index = IndexOf(value);
            if (index != -1) 
            {
                // Shift entries down
                Array.Copy(List, index + 1, List, index, (Count - index - 1));
 
                // Return now unused entries back to default
                Array.Clear(List, Count - 1, 1); 
 
                Count--;
            } 
        }
    }
}
 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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