Buffer pooling in Wrap

Author: dscheg

README.md

@@ -89,8 +89,8 @@ Consider using `ThreadStatic` or pool of compressors for bulk processing.
 * `GetCompressBound` returns required destination buffer size for source data of size `size`.
 
   ```c#
-  static int GetCompressBound(int size)
-  static ulong GetCompressBoundLong(ulong size)
+  static int GetCompressBound(int size);
+  static ulong GetCompressBoundLong(ulong size);
   ```
 
 ### CompressionStream class

ZstdNet/Compressor.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Buffers;
 using size_t = System.UIntPtr;
 
 namespace ZstdNet
@@ -48,15 +49,20 @@ public byte[] Wrap(ReadOnlySpan<byte> src)
 		{
 			//NOTE: Wrap tries its best, but if src is uncompressible and the size is too large, ZSTD_error_dstSize_tooSmall will be thrown
 			var dstCapacity = Math.Min(Consts.MaxByteArrayLength, GetCompressBoundLong((ulong)src.Length));
-			var dst = new byte[dstCapacity];
-
-			var dstSize = Wrap(src, new Span<byte>(dst));
-			if(dstCapacity == (ulong)dstSize)
-				return dst;
-
-			var result = new byte[dstSize];
-			Array.Copy(dst, result, dstSize);
-			return result;
+			var dst = ArrayPool<byte>.Shared.Rent((int)dstCapacity);
+
+			try
+			{
+				var dstSize = Wrap(src, new Span<byte>(dst));
+
+				var result = new byte[dstSize];
+				Array.Copy(dst, result, dstSize);
+				return result;
+			}
+			finally
+			{
+				ArrayPool<byte>.Shared.Return(dst);
+			}
 		}
 
 		public static int GetCompressBound(int size)

appveyor.yml

@@ -1,8 +1,10 @@
 version: 1.0.{build}
 image: Visual Studio 2019
+install:
+- appveyor DownloadFile https://dist.nuget.org/win-x86-commandline/v5.8.0/nuget.exe
 before_build:
-- cmd: nuget restore
+- nuget restore
 build:
   verbosity: minimal
-cache:
-  - packages -> **\packages.config
+#cache:
+#  - packages -> **\packages.config