public void StreamPeek2()
{
var gAbcsString = "abcdefghijklmnopqrstuvwxyz";
var gAbcs = StringUtilities.GetEncodedText(gAbcsString, SKTextEncoding.Utf8);
var memStream = new SKMemoryStream(gAbcs);
for (var bufferSize = 1; bufferSize < memStream.Length; bufferSize++)
{
var bufferedStream = new SKFrontBufferedManagedStream(memStream, bufferSize);
var peeked = 0;
for (var i = 1; !bufferedStream.IsAtEnd; i++)
{
var unpeekableBytes = compare_peek_to_read(bufferedStream, i);
if (unpeekableBytes > 0)
{
// This could not have returned a number greater than i.
Assert.True(unpeekableBytes <= i);
// We have reached the end of the buffer. Verify that it was at least
// bufferSize.
Assert.True(peeked + i - unpeekableBytes >= bufferSize);
// No more peeking is supported.
break;
}
peeked += i;
}
}
}
public void IncrementalBuffering(int bufferSize)
{
var memStream = new SKMemoryStream(gAbcs);
var bufferedStream = new SKFrontBufferedManagedStream(memStream, bufferSize);
test_hasLength(bufferedStream, memStream);
// First, test reading less than the max buffer size.
test_read(bufferedStream, gAbcs, bufferSize / 2);
// Now test rewinding back to the beginning and reading less than what was
// already buffered.
test_rewind(bufferedStream, true);
test_read(bufferedStream, gAbcs, bufferSize / 4);
// Now test reading part of what was buffered, and buffering new data.
test_read(bufferedStream, gAbcs.Skip(bufferSize / 4).ToArray(), bufferSize / 2);
// Now test reading what was buffered, buffering new data, and
// reading directly from the stream.
test_rewind(bufferedStream, true);
test_read(bufferedStream, gAbcs, bufferSize << 1);
// We have reached the end of the buffer, so rewinding will fail.
// This test assumes that the stream is larger than the buffer; otherwise the
// result of rewind should be true.
test_rewind(bufferedStream, false);
}
public void InitialOffset(int bufferSize)
{
var memStream = new SKMemoryStream(gAbcs);
// Skip a few characters into the memStream, so that bufferedStream represents an offset into
// the stream it wraps.
var arbitraryOffset = 17;
memStream.Skip(arbitraryOffset);
var bufferedStream = new SKFrontBufferedManagedStream(memStream, bufferSize);
// Since SkMemoryStream has a length, bufferedStream must also.
Assert.True(bufferedStream.HasLength);
var amountToRead = 10;
var bufferedLength = bufferedStream.Length;
var currentPosition = 0;
// Read the stream in chunks. After each read, the position must match currentPosition,
// which sums the amount attempted to read, unless the end of the stream has been reached.
// Importantly, the end should not have been reached until currentPosition == bufferedLength.
while (currentPosition < bufferedLength)
{
Assert.False(bufferedStream.IsAtEnd);
test_read(bufferedStream, gAbcs.Skip(arbitraryOffset + currentPosition).ToArray(), amountToRead);
currentPosition = Math.Min(currentPosition + amountToRead, bufferedLength);
Assert.Equal(currentPosition, memStream.Position - arbitraryOffset);
}
Assert.True(bufferedStream.IsAtEnd);
Assert.Equal(bufferedLength, currentPosition);
}
public void PerfectlySizedBuffer(int bufferSize)
{
var memStream = new SKMemoryStream(gAbcs);
var bufferedStream = new SKFrontBufferedManagedStream(memStream, bufferSize);
test_hasLength(bufferedStream, memStream);
// Read exactly the amount that fits in the buffer.
test_read(bufferedStream, gAbcs, bufferSize);
// Rewinding should succeed.
test_rewind(bufferedStream, true);
// Once again reading buffered info should succeed
test_read(bufferedStream, gAbcs, bufferSize);
// Read past the size of the buffer. At this point, we cannot return.
test_read(bufferedStream, gAbcs.Skip(memStream.Position).ToArray(), 1);
test_rewind(bufferedStream, false);
}
public void StreamPeek3()
{
var gAbcsString = "abcdefghijklmnopqrstuvwxyz";
var gAbcs = StringUtilities.GetEncodedText(gAbcsString, SKTextEncoding.Utf8);
for (var bufferSize = 1; bufferSize < gAbcs.Length; bufferSize++)
{
var memStream = new SKMemoryStream(gAbcs);
var bufferedStream = new SKFrontBufferedManagedStream(memStream, bufferSize);
var bytesToPeek = bufferSize + 1;
var peekStorage = SKData.Create(bytesToPeek);
var readStorage = SKData.Create(bytesToPeek);
for (var start = 0; start <= bufferSize; start++)
{
// Skip to the starting point
Assert.Equal(start, bufferedStream.Skip(start));
var bytesPeeked = bufferedStream.Peek(peekStorage.Data, bytesToPeek);
if (0 == bytesPeeked)
{
// Peeking should only fail completely if we have read/skipped beyond the buffer.
Assert.True(start >= bufferSize);
break;
}
// Only read the amount that was successfully peeked.
var bytesRead = bufferedStream.Read(readStorage.Data, bytesPeeked);
Assert.Equal(bytesPeeked, bytesRead);
Assert.Equal(peekStorage.ToArray().Take(bytesPeeked), readStorage.ToArray().Take(bytesPeeked));
// This should be safe to rewind.
Assert.True(bufferedStream.Rewind());
}
}
}
public void SkippingDoesNotPreventReading(int bufferSize)
{
var memStream = new SKMemoryStream(gAbcs);
var bufferedStream = new SKFrontBufferedManagedStream(memStream, bufferSize);
test_hasLength(bufferedStream, memStream);
// Skip half the buffer.
bufferedStream.Skip(bufferSize / 2);
// Rewind, then read part of the buffer, which should have been read.
test_rewind(bufferedStream, true);
test_read(bufferedStream, gAbcs, bufferSize / 4);
// Now skip beyond the buffered piece, but still within the total buffer.
bufferedStream.Skip(bufferSize / 2);
// Test that reading will still work.
test_read(bufferedStream, gAbcs.Skip(memStream.Position).ToArray(), bufferSize / 4);
test_rewind(bufferedStream, true);
test_read(bufferedStream, gAbcs, bufferSize);
}
public void LengthCombinations(int bufferSize)
{
{
var stream = new LengthOptionalStream(true, true);
var buffered = new SKFrontBufferedManagedStream(stream, bufferSize);
test_hasLength(buffered, stream);
}
{
var stream = new LengthOptionalStream(true, false);
var buffered = new SKFrontBufferedManagedStream(stream, bufferSize);
test_hasLength(buffered, stream);
}
{
var stream = new LengthOptionalStream(false, true);
var buffered = new SKFrontBufferedManagedStream(stream, bufferSize);
test_hasLength(buffered, stream);
}
{
var stream = new LengthOptionalStream(false, false);
var buffered = new SKFrontBufferedManagedStream(stream, bufferSize);
test_hasLength(buffered, stream);
}
}
