public void Test_MemoryBufferWriterOfT_AllocateAndGetMemoryAndSpan()
{
Memory <byte> memory = new byte[256];
var writer = new MemoryBufferWriter <byte>(memory);
Assert.AreEqual(writer.Capacity, 256);
Assert.AreEqual(writer.FreeCapacity, 256);
Assert.AreEqual(writer.WrittenCount, 0);
Assert.IsTrue(writer.WrittenMemory.IsEmpty);
Assert.IsTrue(writer.WrittenSpan.IsEmpty);
Span <byte> span = writer.GetSpan(43);
Assert.AreEqual(span.Length, memory.Length);
writer.Advance(43);
Assert.AreEqual(writer.Capacity, 256);
Assert.AreEqual(writer.FreeCapacity, 256 - 43);
Assert.AreEqual(writer.WrittenCount, 43);
Assert.AreEqual(writer.WrittenMemory.Length, 43);
Assert.AreEqual(writer.WrittenSpan.Length, 43);
Assert.AreEqual(memory.Length - 43, writer.GetSpan().Length);
Assert.AreEqual(memory.Length - 43, writer.GetMemory().Length);
Assert.AreEqual(memory.Length - 43, writer.GetSpan(22).Length);
Assert.AreEqual(memory.Length - 43, writer.GetMemory(22).Length);
Assert.ThrowsException <ArgumentOutOfRangeException>(() => writer.Advance(-1));
Assert.ThrowsException <ArgumentOutOfRangeException>(() => writer.GetMemory(-1));
Assert.ThrowsException <ArgumentException>(() => writer.GetSpan(1024));
Assert.ThrowsException <ArgumentException>(() => writer.GetMemory(1024));
Assert.ThrowsException <ArgumentException>(() => writer.Advance(1024));
}
public void GetMemoryAllocatesNewSegmentWhenInsufficientSpaceInCurrentSegment()
{
// Have the buffer writer rent only the minimum size segments from the pool.
using (var bufferWriter = new MemoryBufferWriter(MinimumSegmentSize))
{
var data = new byte[MinimumSegmentSize];
new Random().NextBytes(data);
// Write half the minimum segment size
bufferWriter.Write(data.AsSpan(0, MinimumSegmentSize / 2));
// Request a new buffer of MinimumSegmentSize
var buffer = bufferWriter.GetMemory(MinimumSegmentSize);
Assert.Equal(MinimumSegmentSize, buffer.Length);
// Write to the buffer
bufferWriter.Write(data);
// Verify the data was all written correctly
var expectedOutput = new byte[MinimumSegmentSize + (MinimumSegmentSize / 2)];
data.AsSpan(0, MinimumSegmentSize / 2).CopyTo(expectedOutput.AsSpan(0, MinimumSegmentSize / 2));
data.CopyTo(expectedOutput, MinimumSegmentSize / 2);
Assert.Equal(expectedOutput, bufferWriter.ToArray());
}
}