Merge pull request #535 from CommunityToolkit/dev/stream-read-exactly

Use Stream.ReadExactly on .NET 7

Author: Sergio0694

src/CommunityToolkit.HighPerformance/Extensions/StreamExtensions.cs

@@ -198,15 +198,21 @@ public static void Write(this Stream stream, ReadOnlySpan<byte> buffer)
     /// <typeparam name="T">The type of value to read.</typeparam>
     /// <param name="stream">The source <see cref="Stream"/> instance to read from.</param>
     /// <returns>The <typeparamref name="T"/> value read from <paramref name="stream"/>.</returns>
-    /// <exception cref="InvalidOperationException">Thrown if <paramref name="stream"/> reaches the end.</exception>
+    /// <exception cref="EndOfStreamException">Thrown if <paramref name="stream"/> reaches the end.</exception>
 #if NETSTANDARD2_1_OR_GREATER
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
 #endif
     public static unsafe T Read<T>(this Stream stream)
         where T : unmanaged
     {
-#if NETSTANDARD2_1_OR_GREATER
-        T result = default;
+#if NET7_0_OR_GREATER
+        T result;
+
+        stream.ReadExactly(new Span<byte>(&result, sizeof(T)));
+
+        return result;
+#elif NETSTANDARD2_1_OR_GREATER
+        T result;
         int bytesOffset = 0;
 
         // As per Stream.Read's documentation:
@@ -220,7 +226,7 @@ public static unsafe T Read<T>(this Stream stream)
             // A return value of 0 indicates that the end of the stream has been reached
             if (bytesRead == 0)
             {
-                ThrowInvalidOperationExceptionForEndOfStream();
+                ThrowEndOfStreamException();
             }
 
             bytesOffset += bytesRead;
@@ -240,7 +246,7 @@ public static unsafe T Read<T>(this Stream stream)
 
                 if (bytesRead == 0)
                 {
-                    ThrowInvalidOperationExceptionForEndOfStream();
+                    ThrowEndOfStreamException();
                 }
 
                 bytesOffset += bytesRead;
@@ -293,11 +299,13 @@ public static unsafe void Write<T>(this Stream stream, in T value)
 #endif
     }
 
+#if !NET7_0_OR_GREATER
     /// <summary>
-    /// Throws an <see cref="InvalidOperationException"/> when <see cref="Read{T}"/> fails.
+    /// Throws an <see cref="EndOfStreamException"/> when <see cref="Read{T}"/> fails.
     /// </summary>
-    private static void ThrowInvalidOperationExceptionForEndOfStream()
+    private static void ThrowEndOfStreamException()
     {
-        throw new InvalidOperationException("The stream didn't contain enough data to read the requested item.");
+        throw new EndOfStreamException("The stream didn't contain enough data to read the requested item.");
     }
+#endif
 }

tests/CommunityToolkit.HighPerformance.UnitTests/Extensions/Test_StreamExtensions.cs

@@ -34,7 +34,7 @@ public void Test_StreamExtensions_ReadWrite()
         Assert.AreEqual(3.14f, stream.Read<float>());
         Assert.AreEqual(unchecked(uint.MaxValue * 324823489204ul), stream.Read<ulong>());
 
-        _ = Assert.ThrowsException<InvalidOperationException>(() => stream.Read<long>());
+        _ = Assert.ThrowsException<EndOfStreamException>(() => stream.Read<long>());
     }
 
     // See https://github.com/CommunityToolkit/dotnet/issues/513
@@ -55,7 +55,7 @@ public void Test_StreamExtensions_ReadWrite_WithBufferedStream()
         Assert.AreEqual(3.14f, stream.Read<float>());
         Assert.AreEqual(unchecked(uint.MaxValue * 324823489204ul), stream.Read<ulong>());
 
-        _ = Assert.ThrowsException<InvalidOperationException>(() => stream.Read<long>());
+        _ = Assert.ThrowsException<EndOfStreamException>(() => stream.Read<long>());
     }
 
     private sealed class BufferedStream : MemoryStream