/// <summary>
/// Reads a number of elements from a memory location into the provided buffer starting at the specified index.
/// </summary>
/// <typeparam name="T">The structure type</typeparam>
/// <param name="buffer">The destination buffer.</param>
/// <param name="source">The source memory location.</param>
/// <param name="index">The start index within <paramref name="buffer"/>.</param>
/// <param name="count">The number of elements to read.</param>
public static unsafe void ReadArray <T>(T[] buffer, IntPtr source, int index, int count)
where T : struct
{
uint elementSize = (uint)SizeOf <T>();
if (buffer == null)
{
throw new ArgumentNullException(nameof(buffer));
}
if (count < 0)
{
throw new ArgumentOutOfRangeException(nameof(count));
}
if (index < 0)
{
throw new ArgumentOutOfRangeException(nameof(index));
}
if (buffer.Length - index < count)
{
throw new ArgumentException("Invalid offset into array specified by index and count");
}
void *ptr = source.ToPointer();
byte *p = (byte *)FastStructure.GetPtr <T>(ref buffer[0]);
Buffer.MemoryCopy(ptr, p + (index * elementSize), elementSize * count, elementSize * count);
}
/// <summary>
/// Writes an array of <typeparamref name="T"/> into the buffer
/// </summary>
/// <typeparam name="T">A structure type</typeparam>
/// <param name="source">An array of <typeparamref name="T"/> to be written. The length of this array controls the number of elements to be written.</param>
/// <param name="bufferPosition">The offset within the buffer region of the shared memory to write to.</param>
//protected virtual void Write<T>(T[] source, long bufferPosition = 0)
// where T : struct
//{
// Write<T>(source, 0, bufferPosition);
//}
/// <summary>
/// Writes an array of <typeparamref name="T"/> into the buffer
/// </summary>
/// <typeparam name="T">A structure type</typeparam>
/// <param name="source">An array of <typeparamref name="T"/> to be written. The length of this array controls the number of elements to be written.</param>
/// <param name="index">The index within the array to start writing from.</param>
/// <param name="bufferPosition">The offset within the buffer region of the shared memory to write to.</param>
//protected virtual void Write<T>(T[] source, int index, long bufferPosition = 0)
// where T : struct
//{
// FastStructure.WriteArray<T>((IntPtr)(BufferStartPtr + bufferPosition), source, index, source.Length - index);
//}
/// <summary>
/// Writes an array of <typeparamref name="T"/> into the buffer
/// </summary>
/// <typeparam name="T">A structure type</typeparam>
/// <param name="source">The source data to be written to the buffer</param>
/// <param name="index">The start index within <paramref name="source"/>.</param>
/// <param name="count">The number of elements to write.</param>
/// <param name="bufferPosition">The offset within the buffer region of the shared memory to write to.</param>
protected virtual void WriteArray <T>(T[] source, int index, int count, long bufferPosition = 0)
where T : struct
{
FastStructure.WriteArray <T>((IntPtr)(BufferStartPtr + bufferPosition), source, index, count);
}
/// <summary>
/// Loads the generic value type <typeparamref name="T"/> from a pointer. This is achieved by emitting a <see cref="DynamicMethod"/> that returns the value in the memory location as a <typeparamref name="T"/>.
/// <para>The equivalent non-generic C# code:</para>
/// <code>
/// unsafe MyStruct ReadFromPointer(byte* pointer)
/// {
/// return *(MyStruct*)pointer;
/// }
/// </code>
/// </summary>
/// <typeparam name="T">Any value/structure type</typeparam>
/// <param name="pointer">Unsafe pointer to memory to load the value from</param>
/// <returns>The newly loaded value</returns>
public static unsafe T PtrToStructure <T>(IntPtr pointer)
where T : struct
{
return(FastStructure <T> .PtrToStructure(pointer));
}
/// <summary>
/// Writes the generic value type <typeparamref name="T"/> to the location specified by a pointer. This is achieved by emitting a <see cref="DynamicMethod"/> that copies the value from the referenced structure into the specified memory location.
/// <para>There is no exact equivalent possible in C#, the closest possible (generates the same IL) is the following code:</para>
/// <code>
/// unsafe void WriteToPointer(ref SharedHeader dest, ref SharedHeader src)
/// {
/// dest = src;
/// }
/// </code>
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="pointer"></param>
/// <param name="structure"></param>
public static unsafe void StructureToPtr <T>(ref T structure, IntPtr pointer)
where T : struct
{
FastStructure <T> .StructureToPtr(ref structure, pointer);
}
/// <summary>
/// Retrieve a pointer to the passed generic structure type. This is achieved by emitting a <see cref="DynamicMethod"/> to retrieve a pointer to the structure.
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="structure"></param>
/// <returns>A pointer to the provided structure in memory.</returns>
/// <see cref="FastStructure{T}.GetPtr"/>
public static unsafe void *GetPtr <T>(ref T structure)
where T : struct
{
return(FastStructure <T> .GetPtr(ref structure));
}
