public async Task AsyncIfLengthMinusPositionPositiveOverflowsBufferSizeShouldStillBePositive(long length, long position)
{
var baseStream = new DelegateStream(
canReadFunc: () => true,
canSeekFunc: () => true,
lengthFunc: () => length,
positionGetFunc: () => position,
readFunc: (buffer, offset, count) => 0);
var trackingStream = new CallTrackingStream(baseStream);
var dest = Stream.Null;
await trackingStream.CopyToAsync(dest);
// Note: We can't check how many times ReadAsync was called
// here, since trackingStream overrides CopyToAsync and forwards
// to the inner (non-tracking) stream for the implementation
Assert.Same(dest, trackingStream.CopyToAsyncDestination);
Assert.InRange(trackingStream.CopyToAsyncBufferSize, 1, int.MaxValue);
Assert.Equal(CancellationToken.None, trackingStream.CopyToAsyncCancellationToken);
}
public async void AsyncIfLengthIsGreaterThanPositionAndDoesNotOverflowEverythingShouldGoNormally(long length, long position)
{
const int ReadLimit = 7;
// Lambda state
byte[] outerBuffer = null;
int? outerOffset = null;
int? outerCount = null;
int readsLeft = ReadLimit;
var srcBase = new DelegateStream(
canReadFunc: () => true,
canSeekFunc: () => true,
lengthFunc: () => length,
positionGetFunc: () => position,
readFunc: (buffer, offset, count) =>
{
Assert.NotNull(buffer);
Assert.InRange(offset, 0, buffer.Length - count);
Assert.InRange(count, 1, int.MaxValue);
// CopyTo should always pass in the same buffer/offset/count
if (outerBuffer != null)
{
Assert.Same(outerBuffer, buffer);
}
else
{
outerBuffer = buffer;
}
if (outerOffset != null)
{
Assert.Equal(outerOffset, offset);
}
else
{
outerOffset = offset;
}
if (outerCount != null)
{
Assert.Equal(outerCount, count);
}
else
{
outerCount = count;
}
return(--readsLeft); // CopyTo will call Read on this ReadLimit times before stopping
});
var src = new CallTrackingStream(srcBase);
var destBase = new DelegateStream(
canWriteFunc: () => true,
writeFunc: (buffer, offset, count) =>
{
Assert.Same(outerBuffer, buffer);
Assert.Equal(outerOffset, offset);
Assert.Equal(readsLeft, count);
});
var dest = new CallTrackingStream(destBase);
await src.CopyToAsync(dest);
// Since we override CopyToAsync in CallTrackingStream,
// src.Read will actually not get called ReadLimit
// times, src.Inner.Read will. So, we just assert that
// CopyToAsync was called once for src.
Assert.Equal(1, src.TimesCalled(nameof(src.CopyToAsync)));
Assert.Equal(ReadLimit - 1, dest.TimesCalled(nameof(dest.WriteAsync))); // dest.WriteAsync will still get called repeatedly
}