From c98eb5c42a4e0b7aa6710dbd69faaadcb25dab1a Mon Sep 17 00:00:00 2001
From: Matt Nadareski <mnadareski@outlook.com>
Date: Sat, 23 Aug 2025 21:11:41 -0400
Subject: [PATCH] Add "here to the end" constructors

---
 SabreTools.IO.Test/Streams/ViewStreamTests.cs | 28 ++++++++++++++--
 SabreTools.IO/Streams/ViewStream.cs           | 33 +++++++++++++++++++
 2 files changed, 59 insertions(+), 2 deletions(-)

diff --git a/SabreTools.IO.Test/Streams/ViewStreamTests.cs b/SabreTools.IO.Test/Streams/ViewStreamTests.cs
index 13f9953..560a4ae 100644
--- a/SabreTools.IO.Test/Streams/ViewStreamTests.cs
+++ b/SabreTools.IO.Test/Streams/ViewStreamTests.cs
@@ -9,11 +9,23 @@ namespace SabreTools.IO.Test.Streams
     {
         #region Constructor
 
+        [Theory]
+        [InlineData(0, 0, 0)]
+        [InlineData(1024, 0, 1024)]
+        [InlineData(1024, 256, 768)]
+        public void Constructor_Array(int size, long offset, long expectedLength)
+        {
+            byte[] data = new byte[size];
+            var stream = new ViewStream(data, offset);
+            Assert.Equal(expectedLength, stream.Length);
+            Assert.Equal(0, stream.Position);
+        }
+
         [Theory]
         [InlineData(0, 0, 0, 0)]
         [InlineData(1024, 0, 1024, 1024)]
         [InlineData(1024, 256, 512, 512)]
-        public void Constructor_Array(int size, long offset, long length, long expectedLength)
+        public void Constructor_Array_Length(int size, long offset, long length, long expectedLength)
         {
             byte[] data = new byte[size];
             var stream = new ViewStream(data, offset, length);
@@ -47,11 +59,23 @@ namespace SabreTools.IO.Test.Streams
             Assert.Throws<ArgumentOutOfRangeException>(() => _ = new ViewStream(data, offset, length));
         }
 
+        [Theory]
+        [InlineData(0, 0, 0)]
+        [InlineData(1024, 0, 1024)]
+        [InlineData(1024, 256, 768)]
+        public void Constructor_Stream(int size, long offset, long expectedLength)
+        {
+            Stream data = new MemoryStream(new byte[size]);
+            var stream = new ViewStream(data, offset);
+            Assert.Equal(expectedLength, stream.Length);
+            Assert.Equal(0, stream.Position);
+        }
+
         [Theory]
         [InlineData(0, 0, 0, 0)]
         [InlineData(1024, 0, 1024, 1024)]
         [InlineData(1024, 256, 512, 512)]
-        public void Constructor_Stream(int size, long offset, long length, long expectedLength)
+        public void Constructor_Stream_Length(int size, long offset, long length, long expectedLength)
         {
             Stream data = new MemoryStream(new byte[size]);
             var stream = new ViewStream(data, offset, length);
diff --git a/SabreTools.IO/Streams/ViewStream.cs b/SabreTools.IO/Streams/ViewStream.cs
index 790f355..dad4fe6 100644
--- a/SabreTools.IO/Streams/ViewStream.cs
+++ b/SabreTools.IO/Streams/ViewStream.cs
@@ -89,6 +89,23 @@ namespace SabreTools.IO.Streams
 
         #region Constructors
 
+        /// <summary>
+        /// Construct a new ViewStream from a Stream
+        /// </summary>
+        public ViewStream(Stream data, long offset)
+        {
+            if (!data.CanRead)
+                throw new ArgumentException(nameof(data));
+            if (offset < 0 || offset > data.Length)
+                throw new ArgumentOutOfRangeException(nameof(offset));
+
+            _source = data;
+            _initialPosition = offset;
+            _length = data.Length - offset;
+
+            _source.Seek(_initialPosition, SeekOrigin.Begin);
+        }
+
         /// <summary>
         /// Construct a new ViewStream from a Stream
         /// </summary>
@@ -108,6 +125,22 @@ namespace SabreTools.IO.Streams
             _source.Seek(_initialPosition, SeekOrigin.Begin);
         }
 
+         /// <summary>
+        /// Construct a new ViewStream from a byte array
+        /// </summary>
+        public ViewStream(byte[] data, long offset)
+        {
+            if (offset < 0 || offset > data.Length)
+                throw new ArgumentOutOfRangeException(nameof(offset));
+
+            long length = data.Length - offset;
+            _source = new MemoryStream(data, (int)offset, (int)length);
+            _initialPosition = 0;
+            _length = length;
+
+            _source.Seek(_initialPosition, SeekOrigin.Begin);
+        }
+
         /// <summary>
         /// Construct a new ViewStream from a byte array
         /// </summary>