AnyBitmap: Use stream to save image instead of byte[] to fix OutOfMemoryException

`OutOfMemoryException` is causing by the giant array of byte which memory on x86 can't hold it.

Author: mee-ironsoftware

IronSoftware.Drawing/IronSoftware.Drawing.Common.Tests/UnitTests/AnyBitmapFunctionality.cs

@@ -879,7 +879,7 @@ public void CastAnyBitmap_from_SixLabors()
             image.Save("expected.bmp");
             anyBitmap.SaveAs("result.bmp");
 
-            AssertImageAreEqual("expected.bmp", "result.bmp", true);
+            AssertLargeImageAreEqual("expected.bmp", "result.bmp", true);
         }
 
     }

IronSoftware.Drawing/IronSoftware.Drawing.Common.Tests/UnitTests/Compare.cs

@@ -1,4 +1,5 @@
 using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing;
 using System;
 using System.IO;
 using System.Linq;
@@ -14,43 +15,74 @@ protected Compare(ITestOutputHelper output) : base(output)
         {
         }
 
-        protected static void AssertImageAreEqual(string expectedImagePath, string resultImagePath, bool isCleanAll = false)
+        protected static void AssertLargeImageAreEqual(string expectedImagePath, string resultImagePath, bool isCleanAll = false)
         {
-            string assertName = "AssertImage.AreEqual";
+            using SixLabors.ImageSharp.Image<Rgba32> expectedImageSharp = SixLabors.ImageSharp.Image.Load<Rgba32>(expectedImagePath);
+            using SixLabors.ImageSharp.Image<Rgba32> actualImageSharp = SixLabors.ImageSharp.Image.Load<Rgba32>(resultImagePath);
 
-            var expected = AnyBitmap.FromFile(expectedImagePath);
-            var actual = AnyBitmap.FromFile(resultImagePath);
+            CleanCompareResultFile(expectedImagePath, resultImagePath, isCleanAll);
 
-            if (isCleanAll)
-            {
-                CleanResultFile(expectedImagePath);
-            }
+            expectedImageSharp.Mutate(x => x.Resize(100, 100));
+            actualImageSharp.Mutate(x => x.Resize(100, 100));
 
-            CleanResultFile(resultImagePath);
+            AssertImageAreEqual(expectedImageSharp, actualImageSharp);
+        }
 
-            //Test to see if we have the same size of image
-            if (expected.Width != actual.Width || expected.Height != actual.Height)
-            {
-                throw new AssertActualExpectedException($"Expected:<Height {expected.Height}, Width {expected.Width}>.", $"Actual:<Height {actual.Height},Width {actual.Width}>.", $"{assertName} failed.");
-            }
+        protected static void AssertImageAreEqual(string expectedImagePath, string resultImagePath, bool isCleanAll = false)
+        {
+            using var expected = AnyBitmap.FromFile(expectedImagePath);
+            using var actual = AnyBitmap.FromFile(resultImagePath);
 
-            //Convert each image to a byte array
-            byte[] btImageExpected = expected.ExportBytes();
-            byte[] btImageActual = expected.ExportBytes();
+            CleanCompareResultFile(expectedImagePath, resultImagePath, isCleanAll);
 
-            //Compute a hash for each image
-            var shaM = SHA256.Create();
-            byte[] hash1 = shaM.ComputeHash(btImageExpected);
-            byte[] hash2 = shaM.ComputeHash(btImageActual);
+            AssertImageAreEqual(expected, actual);
+        }
 
-            //Compare the hash values
-            for (int i = 0; i < hash1.Length && i < hash2.Length; i++)
+        protected static void AssertImageAreEqual(AnyBitmap expected, AnyBitmap actual)
+        {
+            try
             {
-                if (hash1[i] != hash2[i])
+                string assertName = "AssertImage.AreEqual";
+
+                //Test to see if we have the same size of image
+                if (expected.Width != actual.Width || expected.Height != actual.Height)
                 {
-                    throw new AssertActualExpectedException($"Expected:<hash value {hash1[i]}>.", $"Actual:<hash value {hash2[i]}>.", $"{assertName} failed.");
+                    throw new AssertActualExpectedException($"Expected:<Height {expected.Height}, Width {expected.Width}>.", $"Actual:<Height {actual.Height},Width {actual.Width}>.", $"{assertName} failed.");
                 }
+
+                //Convert each image to a byte array
+                byte[] btImageExpected = expected.ExportBytes();
+                byte[] btImageActual = expected.ExportBytes();
+
+                //Compute a hash for each image
+                var shaM = SHA256.Create();
+                byte[] hash1 = shaM.ComputeHash(btImageExpected);
+                byte[] hash2 = shaM.ComputeHash(btImageActual);
+
+                //Compare the hash values
+                for (int i = 0; i < hash1.Length && i < hash2.Length; i++)
+                {
+                    if (hash1[i] != hash2[i])
+                    {
+                        throw new AssertActualExpectedException($"Expected:<hash value {hash1[i]}>.", $"Actual:<hash value {hash2[i]}>.", $"{assertName} failed.");
+                    }
+                }
+            }
+            finally
+            {
+                expected?.Dispose();
+                actual?.Dispose();
+            }
+        }
+
+        private static void CleanCompareResultFile(string expectedImagePath, string resultImagePath, bool isCleanAll)
+        {
+            if (isCleanAll)
+            {
+                CleanResultFile(expectedImagePath);
             }
+
+            CleanResultFile(resultImagePath);
         }
 
         protected static void CleanResultFile(string filename)
@@ -60,6 +92,7 @@ protected static void CleanResultFile(string filename)
                 File.Delete(filename);
             }
         }
+
         protected static void AssertStreamAreEqual(MemoryStream expected, MemoryStream actual)
         {
             string assertName = "AssertStream.AreEqual";

IronSoftware.Drawing/IronSoftware.Drawing.Common/AnyBitmap.cs

@@ -174,7 +174,7 @@ public AnyBitmap Clone(Rectangle rectangle)
         public byte[] ExportBytes(
             ImageFormat format = ImageFormat.Default, int lossy = 100)
         {
-            MemoryStream mem = new();
+            using MemoryStream mem = new();
             ExportStream(mem, format, lossy);
             byte[] byteArray = mem.ToArray();
 
@@ -202,13 +202,7 @@ public void ExportFile(
             ImageFormat format = ImageFormat.Default,
             int lossy = 100)
         {
-            using (MemoryStream mem = new())
-            {
-                ExportStream(mem, format, lossy);
-                byte[] byteArray = mem.ToArray();
-
-                File.WriteAllBytes(file, byteArray);
-            }
+            SaveAs(file, format, lossy);
         }
 
         /// <summary>
@@ -346,7 +340,8 @@ public void SaveAs(string file)
         /// <seealso cref="TrySaveAs(string)"/>
         public void SaveAs(string file, ImageFormat format, int lossy = 100)
         {
-            File.WriteAllBytes(file, ExportBytes(format, lossy));
+            using var fileStream = new FileStream(file, FileMode.Create);
+            ExportStream(fileStream, format, lossy);
         }
 
         /// <summary>