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Added NativeMemoryStream.ReadToPtr and WriteFromPtr methods to interact with allocated memory.

pull/180/head
dahall 2020-09-10 10:13:56 -06:00
parent 258b01886e
commit a8ef6e11c8
1 changed files with 36 additions and 0 deletions
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36
Core/InteropServices/NativeMemoryStream.cs
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@ -279,6 +279,24 @@ namespace Vanara.InteropServices
return p != IntPtr.Zero ? (T?)(T)p.Convert((uint)Capacity - (uint)Position, typeof(T), CharSet.Auto) : null;
}
/// <summary>Copies a specified number of bytes from the stream to a memory location.</summary>
/// <param name="ptr">
/// The pointer to the memory location that will recieve the bytes. The caller must ensure that sufficient memory has been allocated
/// to this pointer.
/// </param>
/// <param name="bytesToRead">The number of bytes to read.</param>
public void ReadToPtr(IntPtr ptr, long bytesToRead)
{
if (ptr == IntPtr.Zero) throw new ArgumentNullException(nameof(ptr));
if (bytesToRead < 0) throw new ArgumentOutOfRangeException(nameof(bytesToRead));
ThrowIfDisposed();
if (!CanRead) throw new NotSupportedException();
if (bytesToRead == 0) return;
if (Position + bytesToRead > Capacity) throw new ArgumentOutOfRangeException(nameof(bytesToRead));
PositionPtr.CopyTo(ptr, bytesToRead);
Position = position + bytesToRead;
}
/// <summary>Sets the position within the current stream.</summary>
/// <param name="offset">A byte offset relative to the <paramref name="origin"/> parameter.</param>
/// <param name="origin">
@ -390,6 +408,24 @@ namespace Vanara.InteropServices
}
}
/// <summary>Writes bytes from a memory location into the stream.</summary>
/// <param name="ptr">
/// The pointer to the memory location from which to retrieve the bytes to write. The caller must ensure that this memory location
/// has at least <paramref name="bytesToWrite"/> of allocated memory.
/// </param>
/// <param name="bytesToWrite">The number of bytes to write from <paramref name="ptr"/>.</param>
public void WriteFromPtr(IntPtr ptr, long bytesToWrite)
{
if (ptr == IntPtr.Zero) throw new ArgumentNullException(nameof(ptr));
if (bytesToWrite < 0) throw new ArgumentOutOfRangeException(nameof(bytesToWrite));
ThrowIfDisposed();
if (access == FileAccess.Read) throw new NotSupportedException();
EnsureCapacity(Position + bytesToWrite);
ptr.CopyTo(PositionPtr, bytesToWrite);
position += bytesToWrite;
length += bytesToWrite;
}
/// <summary>Writes the specified value into the stream. This function should fail if the object cannot be blitted.</summary>
/// <param name="value">The value to write.</param>
public virtual void WriteObject(object value)