Add CappedMemoryStream

jose-jwt/compression/CappedMemoryStream.cs

@@ -0,0 +1,34 @@
+using System;
+using System.IO;
+
+namespace Jose;
+
+public class CappedMemoryStream : MemoryStream
+{
+    private readonly long maxCapacity;
+
+    public CappedMemoryStream(long maxCapacity)
+    {
+        this.maxCapacity = maxCapacity;
+    }
+
+    public override void Write(byte[] buffer, int offset, int count)
+    {
+        if (Length + Math.Min(count, buffer.Length - offset) > maxCapacity)
+        {
+            throw new NotSupportedException("Exceeding maximum memory stream size.");
+        }
+
+        base.Write(buffer, offset, count);
+    }
+
+    public override void WriteByte(byte value)
+    {
+        if (Length + 1 > maxCapacity)
+        {
+            throw new NotSupportedException("Exceeding maximum memory stream size.");
+        }
+
+        base.WriteByte(value);
+    }
+}