Merge pull request #2133 from evolutional/cs-bounds-check

C#: added #define BYTEBUFFER_NO_BOUNDS_CHECK 

2 files changed, 35 insertions, 5 deletions

diff --git a/net/FlatBuffers/ByteBuffer.cs b/net/FlatBuffers/ByteBuffer.cs
index 5fa1ac7a..37a2c7e6 100755
--- a/net/FlatBuffers/ByteBuffer.cs
+++ b/net/FlatBuffers/ByteBuffer.cs
@@ -14,7 +14,20 @@
  * limitations under the License.
  */
 
-//#define UNSAFE_BYTEBUFFER  // uncomment this line to use faster ByteBuffer
+// There are 2 #defines that have an impact on performance of this ByteBuffer implementation
+//
+//      UNSAFE_BYTEBUFFER 
+//          This will use unsafe code to manipulate the underlying byte array. This
+//          can yield a reasonable performance increase.
+//
+//      BYTEBUFFER_NO_BOUNDS_CHECK
+//          This will disable the bounds check asserts to the byte array. This can
+//          yield a small performance gain in normal code..
+//
+// Using UNSAFE_BYTEBUFFER and BYTEBUFFER_NO_BOUNDS_CHECK together can yield a
+// performance gain of ~15% for some operations, however doing so is potentially 
+// dangerous. Do so at your own risk!
+//
 
 using System;
 
@@ -22,9 +35,6 @@ namespace FlatBuffers
 {
     /// <summary>
     /// Class to mimic Java's ByteBuffer which is used heavily in Flatbuffers.
-    /// If your execution environment allows unsafe code, you should enable
-    /// unsafe code in your project and #define UNSAFE_BYTEBUFFER to use a
-    /// MUCH faster version of ByteBuffer.
     /// </summary>
     public class ByteBuffer
     {
@@ -126,11 +136,14 @@ namespace FlatBuffers
         }
 #endif // !UNSAFE_BYTEBUFFER
 
+
         private void AssertOffsetAndLength(int offset, int length)
         {
+            #if !BYTEBUFFER_NO_BOUNDS_CHECK
             if (offset < 0 ||
                 offset > _buffer.Length - length)
                 throw new ArgumentOutOfRangeException();
+            #endif
         }
 
         public void PutSbyte(int offset, sbyte value)
@@ -200,7 +213,6 @@ namespace FlatBuffers
         public unsafe void PutUlong(int offset, ulong value)
         {
             AssertOffsetAndLength(offset, sizeof(ulong));
-
             fixed (byte* ptr = _buffer)
             {
                 *(ulong*)(ptr + offset) = BitConverter.IsLittleEndian
diff --git a/tests/FlatBuffers.Test/ByteBufferTests.cs b/tests/FlatBuffers.Test/ByteBufferTests.cs
index b86c3658..3324f12a 100644
--- a/tests/FlatBuffers.Test/ByteBufferTests.cs
+++ b/tests/FlatBuffers.Test/ByteBufferTests.cs
@@ -40,6 +40,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual((byte)99, buffer[0]);
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutByteCannotPutAtOffsetPastLength()
         {
@@ -47,6 +48,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.PutByte(1, 99));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutShortPopulatesBufferCorrectly()
@@ -60,6 +62,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual((byte)0, buffer[1]);
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutShortCannotPutAtOffsetPastLength()
         {
@@ -67,7 +70,9 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.PutShort(2, 99));
         }
+#endif
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutShortChecksLength()
         {
@@ -83,6 +88,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.PutShort(1, 99));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutIntPopulatesBufferCorrectly()
@@ -98,6 +104,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual(0x0A, buffer[3]);
         }
 
+ #if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutIntCannotPutAtOffsetPastLength()
         {
@@ -121,6 +128,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.PutInt(2, 0x0A0B0C0D));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutLongPopulatesBufferCorrectly()
@@ -140,6 +148,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual(0x01, buffer[7]);
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_PutLongCannotPutAtOffsetPastLength()
         {
@@ -163,6 +172,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.PutLong(2, 0x010203040A0B0C0D));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetByteReturnsCorrectData()
@@ -173,6 +183,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual((byte)99, uut.Get(0));
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetByteChecksOffset()
         {
@@ -180,6 +191,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(()=>uut.Get(1));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetShortReturnsCorrectData()
@@ -191,6 +203,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual(1, uut.GetShort(0));
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetShortChecksOffset()
         {
@@ -206,6 +219,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.GetShort(1));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetIntReturnsCorrectData()
@@ -219,6 +233,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual(0x0A0B0C0D, uut.GetInt(0));
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetIntChecksOffset()
         {
@@ -234,6 +249,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.GetInt(0));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetLongReturnsCorrectData()
@@ -251,6 +267,7 @@ namespace FlatBuffers.Test
             Assert.AreEqual(0x010203040A0B0C0D, uut.GetLong(0));
         }
 
+#if !BYTEBUFFER_NO_BOUNDS_CHECK
         [FlatBuffersTestMethod]
         public void ByteBuffer_GetLongChecksOffset()
         {
@@ -266,6 +283,7 @@ namespace FlatBuffers.Test
             var uut = new ByteBuffer(buffer);
             Assert.Throws<ArgumentOutOfRangeException>(() => uut.GetLong(0));
         }
+#endif
 
         [FlatBuffersTestMethod]
         public void ByteBuffer_ReverseBytesUshort()