ArrayPoolMemoryManager factory methods

src/ImageSharp/Configuration.cs

@@ -86,7 +86,7 @@ namespace SixLabors.ImageSharp
         /// <summary>
         /// Gets or sets the <see cref="MemoryManager"/> that is currently in use.
         /// </summary>
-        public MemoryManager MemoryManager { get; set; } = new ArrayPoolMemoryManager();
+        public MemoryManager MemoryManager { get; set; } = ArrayPoolMemoryManager.CreateWithNormalPooling();
 
         /// <summary>
         /// Gets the maximum header size of all the formats.

src/ImageSharp/Memory/ArrayPoolMemoryManager.CommonFactoryMethods.cs

@@ -0,0 +1,46 @@
+namespace SixLabors.ImageSharp.Memory
+{
+    /// <summary>
+    /// Contains common factory methods and configuration constants.
+    /// </summary>
+    public partial class ArrayPoolMemoryManager
+    {
+        /// <summary>
+        /// The default value for: maximum size of pooled arrays in bytes.
+        /// Currently set to 32MB, which is equivalent to 8 megapixels of raw <see cref="Rgba32"/> data.
+        /// </summary>
+        internal const int DefaultMaxPooledBufferSizeInBytes = 32 * 1024 * 1024;
+
+        /// <summary>
+        /// The value for: The threshold to pool arrays in <see cref="largeArrayPool"/> which has less buckets for memory safety.
+        /// </summary>
+        private const int DefaultBufferSelectorThresholdInBytes = 8 * 1024 * 1024;
+
+        /// <summary>
+        /// This is the default. Should be good for most use cases.
+        /// </summary>
+        /// <returns>The memory manager</returns>
+        public static ArrayPoolMemoryManager CreateWithNormalPooling()
+        {
+            return new ArrayPoolMemoryManager(DefaultMaxPooledBufferSizeInBytes, DefaultBufferSelectorThresholdInBytes, 8, 24);
+        }
+
+        /// <summary>
+        /// For environments with limited memory capabilities. Only small images are pooled, which can result in reduced througput.
+        /// </summary>
+        /// <returns>The memory manager</returns>
+        public static ArrayPoolMemoryManager CreateWithModeratePooling()
+        {
+            return new ArrayPoolMemoryManager(1024 * 1024, 1024 * 16, 16, 24);
+        }
+
+        /// <summary>
+        /// RAM is not an issue for me, gimme maximum througput!
+        /// </summary>
+        /// <returns>The memory manager</returns>
+        public static ArrayPoolMemoryManager CreateWithAggressivePooling()
+        {
+            return new ArrayPoolMemoryManager(128 * 1024 * 1024, 32 * 1024 * 1024, 16, 32);
+        }
+    }
+}

src/ImageSharp/Memory/ArrayPoolMemoryManager.cs

@@ -11,17 +11,6 @@ namespace SixLabors.ImageSharp.Memory
     /// </summary>
     public partial class ArrayPoolMemoryManager : MemoryManager
     {
-        /// <summary>
-        /// The default value for: maximum size of pooled arrays in bytes.
-        /// Currently set to 32MB, which is equivalent to 8 megapixels of raw <see cref="Rgba32"/> data.
-        /// </summary>
-        internal const int DefaultMaxPooledBufferSizeInBytes = 32 * 1024 * 1024;
-
-        /// <summary>
-        /// The value for: The threshold to pool arrays in <see cref="largeArrayPool"/> which has less buckets for memory safety.
-        /// </summary>
-        private const int DefaultLargeBufferThresholdInBytes = 8 * 1024 * 1024;
-
         /// <summary>
         /// The <see cref="ArrayPool{T}"/> for small-to-medium buffers which is not kept clean.
         /// </summary>
@@ -40,7 +29,7 @@ namespace SixLabors.ImageSharp.Memory
         /// Initializes a new instance of the <see cref="ArrayPoolMemoryManager"/> class.
         /// </summary>
         public ArrayPoolMemoryManager()
-            : this(DefaultMaxPooledBufferSizeInBytes, DefaultLargeBufferThresholdInBytes)
+            : this(DefaultMaxPooledBufferSizeInBytes, DefaultBufferSelectorThresholdInBytes)
         {
         }
 

tests/ImageSharp.Tests/Memory/ArrayPoolMemoryManagerTests.cs

@@ -19,7 +19,7 @@ namespace SixLabors.ImageSharp.Tests.Memory
 
         private const int PoolSelectorThresholdInBytes = MaxPooledBufferSizeInBytes / 2;
 
-        private MemoryManager MemoryManager { get; } = new ArrayPoolMemoryManager(MaxPooledBufferSizeInBytes, PoolSelectorThresholdInBytes);
+        private MemoryManager MemoryManager { get; set; } = new ArrayPoolMemoryManager(MaxPooledBufferSizeInBytes, PoolSelectorThresholdInBytes);
         
         /// <summary>
         /// Rent a buffer -> return it -> re-rent -> verify if it's span points to the previous location
@@ -161,5 +161,31 @@ namespace SixLabors.ImageSharp.Tests.Memory
             
             Assert.False(Unsafe.AreSame(ref ptr2Small, ref large.DangerousGetPinnableReference()));
         }
+
+        [Fact]
+        public void CreateWithAggressivePooling()
+        {
+            this.MemoryManager = ArrayPoolMemoryManager.CreateWithAggressivePooling();
+
+            Assert.True(this.CheckIsRentingPooledBuffer<Rgba32>(4096 * 4096));
+        }
+
+        [Fact]
+        public void CreateWithNormalPooling()
+        {
+            this.MemoryManager = ArrayPoolMemoryManager.CreateWithNormalPooling();
+
+            Assert.False(this.CheckIsRentingPooledBuffer<Rgba32>(2 * 4096 * 4096));
+            Assert.True(this.CheckIsRentingPooledBuffer<Rgba32>(2048 * 2048));
+        }
+
+        [Fact]
+        public void CreateWithModeratePooling()
+        {
+            this.MemoryManager = ArrayPoolMemoryManager.CreateWithModeratePooling();
+
+            Assert.False(this.CheckIsRentingPooledBuffer<Rgba32>(2048 * 2048));
+            Assert.True(this.CheckIsRentingPooledBuffer<Rgba32>(1024 * 16));
+        }
     }
 }