// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;
 
namespace MS.Internal.AutomationProxies
{
    internal sealed class SafeCoTaskMem : SafeHandleZeroOrMinusOneIsInvalid
    {
        // This constructor is used by the P/Invoke marshaling layer
        // to allocate a SafeHandle instance.  P/Invoke then does the
        // appropriate method call, storing the handle in this class.
        private SafeCoTaskMem() : base(true) {}
 
        internal SafeCoTaskMem(int length) : base(true)
        {
            SetHandle(Marshal.AllocCoTaskMem(length * sizeof (char)));
        }
 
        internal string GetStringAuto()
        {
            return Marshal.PtrToStringAuto(handle);
        }
 
        internal string GetStringUni(int length)
        {
            // Convert the local unmanaged buffer in to a string object
            return Marshal.PtrToStringUni(handle, length);
        }
 
        protected override bool ReleaseHandle()
        {
            Marshal.FreeCoTaskMem(handle);
            return true;
        }
    }
}