TryWrap / TryUnwrap API - returns false if destination buffer is too small

Author: oleg-st

src/ZstdSharp.Test/ZstdNetTests.cs

@@ -234,6 +234,29 @@ public void Decompress_throwsArgumentOutOfRangeException_onTooBigData(bool useDi
             }
         }
 
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public void Decompress_tryUnwrap_onTooBigData(bool useDictionary)
+        {
+            var data = GenerateSample();
+            var dict = useDictionary ? BuildDictionary() : null;
+
+            byte[] compressed;
+            using (var compressor = new Compressor())
+            {
+                compressor.LoadDictionary(dict);
+                compressed = compressor.Wrap(data).ToArray();
+            }
+
+            using (var decompressor = new Decompressor())
+            {
+                decompressor.LoadDictionary(dict);
+                var dest = new byte[20];
+                Assert.False(decompressor.TryUnwrap(compressed, dest, out _));
+            }
+        }
+
         [Theory]
         [InlineData(false)]
         [InlineData(true)]
@@ -389,6 +412,21 @@ public void Compress_throwsDstSizeTooSmall_whenDestinationBufferIsTooSmall(bool
             Assert.Equal(ZSTD_ErrorCode.ZSTD_error_dstSize_tooSmall, ex.Code);
         }
 
+        [Theory]
+        [InlineData(false)]
+        [InlineData(true)]
+        public void Compress_tryWrap_whenDestinationBufferIsTooSmall(bool useDictionary)
+        {
+            var data = GenerateSample();
+            var dict = useDictionary ? BuildDictionary() : null;
+            var compressed = new byte[20];
+            const int offset = 4;
+
+            using var compressor = new Compressor();
+            compressor.LoadDictionary(dict);
+            Assert.False(compressor.TryWrap(data, compressed, offset, out _));
+        }
+
         [Theory]
         [InlineData(false)]
         [InlineData(true)]

src/ZstdSharp/Compressor.cs

@@ -101,6 +101,36 @@ public int Wrap(ArraySegment<byte> src, ArraySegment<byte> dest)
         public int Wrap(byte[] src, int srcOffset, int srcLength, byte[] dst, int dstOffset, int dstLength) 
             => Wrap(new ReadOnlySpan<byte>(src, srcOffset, srcLength), new Span<byte>(dst, dstOffset, dstLength));
 
+        public bool TryWrap(byte[] src, byte[] dest, int offset, out int written)
+            => TryWrap(src, new Span<byte>(dest, offset, dest.Length - offset), out written);
+
+        public bool TryWrap(ReadOnlySpan<byte> src, Span<byte> dest, out int written)
+        {
+            EnsureNotDisposed();
+            fixed (byte* srcPtr = src)
+            fixed (byte* destPtr = dest)
+            {
+                var returnValue =
+                    Methods.ZSTD_compress2(cctx, destPtr, (nuint) dest.Length, srcPtr, (nuint) src.Length);
+
+                if (returnValue == unchecked(0 - (nuint)ZSTD_ErrorCode.ZSTD_error_dstSize_tooSmall))
+                {
+                    written = default;
+                    return false;
+                }
+
+                returnValue.EnsureZstdSuccess();
+                written = (int) returnValue;
+                return true;
+            }
+        }
+
+        public bool TryWrap(ArraySegment<byte> src, ArraySegment<byte> dest, out int written)
+            => TryWrap((ReadOnlySpan<byte>)src, dest, out written);
+
+        public bool TryWrap(byte[] src, int srcOffset, int srcLength, byte[] dst, int dstOffset, int dstLength, out int written)
+            => TryWrap(new ReadOnlySpan<byte>(src, srcOffset, srcLength), new Span<byte>(dst, dstOffset, dstLength), out written);
+
         private void ReleaseUnmanagedResources()
         {
             if (cctx != null)

src/ZstdSharp/Decompressor.cs

@@ -90,6 +90,33 @@ public int Unwrap(ReadOnlySpan<byte> src, Span<byte> dest)
         public int Unwrap(byte[] src, int srcOffset, int srcLength, byte[] dst, int dstOffset, int dstLength)
             => Unwrap(new ReadOnlySpan<byte>(src, srcOffset, srcLength), new Span<byte>(dst, dstOffset, dstLength));
 
+        public bool TryUnwrap(byte[] src, byte[] dest, int offset, out int written)
+            => TryUnwrap(src, new Span<byte>(dest, offset, dest.Length - offset), out written);
+
+        public bool TryUnwrap(ReadOnlySpan<byte> src, Span<byte> dest, out int written)
+        {
+            EnsureNotDisposed();
+            fixed (byte* srcPtr = src)
+            fixed (byte* destPtr = dest)
+            {
+                var returnValue =
+                    Methods.ZSTD_decompressDCtx(dctx, destPtr, (nuint) dest.Length, srcPtr, (nuint) src.Length);
+
+                if (returnValue == unchecked(0 - (nuint)ZSTD_ErrorCode.ZSTD_error_dstSize_tooSmall))
+                {
+                    written = default;
+                    return false;
+                }
+
+                returnValue.EnsureZstdSuccess();
+                written = (int) returnValue;
+                return true;
+            }
+        }
+
+        public bool TryUnwrap(byte[] src, int srcOffset, int srcLength, byte[] dst, int dstOffset, int dstLength, out int written)
+            => TryUnwrap(new ReadOnlySpan<byte>(src, srcOffset, srcLength), new Span<byte>(dst, dstOffset, dstLength), out written);
+
         private void ReleaseUnmanagedResources()
         {
             if (dctx != null)

src/ZstdSharp/ZstdSharp.csproj

@@ -42,7 +42,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
     <PackageReference Include="InlineIL.Fody" Version="1.7.0" PrivateAssets="all" />
-    <PackageReference Include="InlineMethod.Fody" Version="0.5.1" PrivateAssets="all" />
+    <PackageReference Include="InlineMethod.Fody" Version="0.6.0" PrivateAssets="all" />
   </ItemGroup>
 
 </Project>