vendoring NetVips

vendor/NetVips/VipsBlob.cs

@@ -0,0 +1,64 @@
+using System;
+using System.Runtime.InteropServices;
+
+namespace NetVips;
+
+/// <summary>
+/// Manage a <see cref="Internal.VipsBlob"/>.
+/// </summary>
+internal class VipsBlob : SafeHandle
+{
+    /// <summary>
+    /// Initializes a new instance of the <see cref="VipsBlob"/> class
+    /// with the specified pointer to wrap around.
+    /// </summary>
+    /// <param name="pointer">The pointer to wrap around.</param>
+    internal VipsBlob(nint pointer) : base(IntPtr.Zero, true)
+    {
+        // record the pointer we were given to manage
+        SetHandle(pointer);
+    }
+
+    /// <summary>
+    /// Get the data from a <see cref="Internal.VipsBlob"/>.
+    /// </summary>
+    /// <param name="length">Return number of bytes of data.</param>
+    /// <returns>A <see langword="nint"/> containing the data.</returns>
+    internal nint GetData(out nuint length)
+    {
+        return Internal.VipsBlob.Get(this, out length);
+    }
+
+    /// <summary>
+    /// Decreases the reference count of the blob.
+    /// When its reference count drops to 0, the blob is finalized (i.e. its memory is freed).
+    /// </summary>
+    /// <returns><see langword="true"/> if the handle is released successfully; otherwise,
+    /// in the event of a catastrophic failure, <see langword="false"/>.</returns>
+    protected override bool ReleaseHandle()
+    {
+        if (!IsInvalid)
+        {
+            // Free the VipsArea
+            Internal.VipsArea.Unref(handle);
+        }
+
+        return true;
+    }
+
+    /// <summary>
+    /// Gets a value indicating whether the handle is invalid.
+    /// </summary>
+    /// <returns><see langword="true"/> if the handle is not valid; otherwise, <see langword="false"/>.</returns>
+    public override bool IsInvalid => handle == IntPtr.Zero;
+
+    /// <summary>
+    /// Get the number of bytes of data.
+    /// </summary>
+    internal ulong Length => Marshal.PtrToStructure<Internal.VipsArea.Struct>(handle).Length;
+
+    /// <summary>
+    /// Get the reference count of the blob. Handy for debugging.
+    /// </summary>
+    internal int RefCount => Marshal.PtrToStructure<Internal.VipsArea.Struct>(handle).Count;
+}