// This test verifies that optimization for known cursors works and
// avoids additional walk but it's only valid for multi segmented buffers
public void ReadCursorSeekDoesNotCheckEndIfTrustingEnd()
{
var buffer = Factory.CreateOfSize(3);
var buffer2 = Factory.CreateOfSize(3);
ReadOnlyBuffer <byte> .Seek(buffer.Start, buffer2.End, 2, false);
}
public void MemorySeek(string raw, string search, char expectResult, int expectIndex)
{
var cursors = Factory.CreateWithContent(raw);
Position start = cursors.Start;
Position end = cursors.End;
Position result = default;
var searchFor = search.ToCharArray();
int found = -1;
if (searchFor.Length == 1)
{
found = ReadOnlyBuffer.Seek(start, end, out result, (byte)searchFor[0]);
}
else if (searchFor.Length == 2)
{
found = ReadOnlyBuffer.Seek(start, end, out result, (byte)searchFor[0], (byte)searchFor[1]);
}
else if (searchFor.Length == 3)
{
found = ReadOnlyBuffer.Seek(start, end, out result, (byte)searchFor[0], (byte)searchFor[1], (byte)searchFor[2]);
}
else
{
Assert.False(true, "Invalid test sample.");
}
Assert.Equal(expectResult, found);
Assert.Equal(cursors.Slice(result).ToArray(), Encoding.ASCII.GetBytes(raw.Substring(expectIndex)));
}
public void ReadCursorSeekChecksEndIfNotTrustingEnd()
{
var buffer = Factory.CreateOfSize(3);
var buffer2 = Factory.CreateOfSize(3);
Assert.Throws <InvalidOperationException>(() => ReadOnlyBuffer <byte> .Seek(buffer.Start, buffer2.End, 2, true));
}
public void TestSeekIteratorLimitWithinSameBlock(string input, char seek, char limitAfter, int expectedReturnValue)
{
// Arrange
var afterSeek = (byte)'B';
var buffer = Factory.CreateWithContent(input);
var start = buffer.Start;
var scan1 = buffer.Start;
var veryEnd = buffer.End;
var scan2_1 = scan1;
var scan2_2 = scan1;
var scan3_1 = scan1;
var scan3_2 = scan1;
var scan3_3 = scan1;
var end = buffer.End;
// Act
var endReturnValue = ReadOnlyBuffer.Seek(start, veryEnd, out end, (byte)limitAfter);
if (endReturnValue != -1)
{
end = buffer.Slice(end, 1).End;
}
var returnValue1 = ReadOnlyBuffer.Seek(start, end, out scan1, (byte)seek);
var returnValue2_1 = ReadOnlyBuffer.Seek(start, end, out scan2_1, (byte)seek, afterSeek);
var returnValue2_2 = ReadOnlyBuffer.Seek(start, end, out scan2_2, afterSeek, (byte)seek);
var returnValue3_1 = ReadOnlyBuffer.Seek(start, end, out scan3_1, (byte)seek, afterSeek, afterSeek);
var returnValue3_2 = ReadOnlyBuffer.Seek(start, end, out scan3_2, afterSeek, (byte)seek, afterSeek);
var returnValue3_3 = ReadOnlyBuffer.Seek(start, end, out scan3_3, afterSeek, afterSeek, (byte)seek);
// Assert
Assert.Equal(input.Contains(limitAfter) ? limitAfter : -1, endReturnValue);
Assert.Equal(expectedReturnValue, returnValue1);
Assert.Equal(expectedReturnValue, returnValue2_1);
Assert.Equal(expectedReturnValue, returnValue2_2);
Assert.Equal(expectedReturnValue, returnValue3_1);
Assert.Equal(expectedReturnValue, returnValue3_2);
Assert.Equal(expectedReturnValue, returnValue3_3);
if (expectedReturnValue != -1)
{
var expectedEndIndex = input.IndexOf(seek);
Assert.Equal(buffer.Slice(scan1).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedEndIndex)));
Assert.Equal(buffer.Slice(scan2_1).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedEndIndex)));
Assert.Equal(buffer.Slice(scan2_2).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedEndIndex)));
Assert.Equal(buffer.Slice(scan3_1).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedEndIndex)));
Assert.Equal(buffer.Slice(scan3_2).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedEndIndex)));
Assert.Equal(buffer.Slice(scan3_3).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedEndIndex)));
}
}
private void ParseExtension(ReadOnlyBuffer buffer, out Position consumed, out Position examined)
{
// Chunk-extensions not currently parsed
// Just drain the data
consumed = buffer.Start;
examined = buffer.Start;
do
{
Position extensionCursor;
if (ReadOnlyBuffer.Seek(buffer.Start, buffer.End, out extensionCursor, ByteCR) == -1)
{
// End marker not found yet
consumed = buffer.End;
examined = buffer.End;
AddAndCheckConsumedBytes(buffer.Length);
return;
}
;
var charsToByteCRExclusive = buffer.Slice(0, extensionCursor).Length;
var sufixBuffer = buffer.Slice(extensionCursor);
if (sufixBuffer.Length < 2)
{
consumed = extensionCursor;
examined = buffer.End;
AddAndCheckConsumedBytes(charsToByteCRExclusive);
return;
}
sufixBuffer = sufixBuffer.Slice(0, 2);
var sufixSpan = sufixBuffer.ToSpan();
if (sufixSpan[1] == '\n')
{
// We consumed the \r\n at the end of the extension, so switch modes.
_mode = _inputLength > 0 ? Mode.Data : Mode.Trailer;
consumed = sufixBuffer.End;
examined = sufixBuffer.End;
AddAndCheckConsumedBytes(charsToByteCRExclusive + 2);
}
else
{
// Don't consume suffixSpan[1] in case it is also a \r.
buffer = buffer.Slice(charsToByteCRExclusive + 1);
consumed = extensionCursor;
AddAndCheckConsumedBytes(charsToByteCRExclusive + 1);
}
} while (_mode == Mode.Extension);
}
public void SegmentStartIsConsideredInBoundsCheck()
{
// 0 50 100 0 50 100
// [ ##############] -> [############## ]
// ^c1 ^c2
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 50, 99);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 50);
bufferSegment1.SetNext(bufferSegment2);
var readableBuffer = new ReadOnlyBuffer <byte>(bufferSegment1, 0, bufferSegment2, 50);
var c1 = readableBuffer.Seek(readableBuffer.Start, 25); // segment 1 index 75
var c2 = readableBuffer.Seek(readableBuffer.Start, 55); // segment 2 index 5
var sliced = readableBuffer.Slice(c1, c2);
Assert.Equal(30, sliced.Length);
}
private static void FindAllNewLines(ReadOnlyBuffer buffer)
{
var start = buffer.Start;
var end = buffer.End;
while (true)
{
if (ReadOnlyBuffer.Seek(start, end, out var found, (byte)'\n') == -1)
{
break;
}
start = buffer.Move(found, 1);
}
}
public void MovePrefersNextSegment()
{
var bufferSegment1 = new BufferSegment();
bufferSegment1.SetMemory(new OwnedArray <byte>(new byte[100]), 49, 99);
var bufferSegment2 = new BufferSegment();
bufferSegment2.SetMemory(new OwnedArray <byte>(new byte[100]), 0, 0);
bufferSegment1.SetNext(bufferSegment2);
var readableBuffer = new ReadOnlyBuffer <byte>(bufferSegment1, 0, bufferSegment2, 0);
var c1 = readableBuffer.Seek(readableBuffer.Start, 50);
Assert.Equal(0, c1.Index);
Assert.Equal(bufferSegment2, c1.Segment);
}
private static void FindAllNewLinesReadableBufferReader(ReadOnlyBuffer buffer)
{
var reader = BufferReader.Create(buffer);
var end = buffer.End;
while (!reader.End)
{
var span = reader.Span;
// Trim the start if we have an index
if (reader.Index > 0)
{
span = span.Slice(reader.Index);
}
while (span.Length > 0)
{
var length = span.IndexOf((byte)'\n');
var skip = length;
if (length == -1)
{
var current = reader.Position;
if (ReadOnlyBuffer.Seek(current, end, out var found, (byte)'\n') == -1)
{
// We're done
return;
}
length = span.Length;
skip = (int)buffer.Slice(current, found).Length + 1;
}
else
{
length += 1;
skip = length;
}
span = span.Slice(length);
reader.Skip(skip);
}
}
}
public void TestSeekByteLimitWithinSameBlock(string input, char seek, int limit, int expectedBytesScanned, int expectedReturnValue)
{
// Arrange
var buffer = Factory.CreateWithContent(input);
// Act
var end = limit > input.Length ? buffer.End : buffer.Slice(0, limit).End;
var returnValue = ReadOnlyBuffer.Seek(buffer.Start, end, out Position result, (byte)seek);
var returnValue_1 = ReadOnlyBuffer.Seek(buffer.Start, end, out result, (byte)seek, (byte)seek);
var returnValue_2 = ReadOnlyBuffer.Seek(buffer.Start, end, out result, (byte)seek, (byte)seek, (byte)seek);
// Assert
Assert.Equal(expectedReturnValue, returnValue);
Assert.Equal(expectedReturnValue, returnValue_1);
Assert.Equal(expectedReturnValue, returnValue_2);
if (expectedReturnValue != -1)
{
Assert.Equal(buffer.Slice(result).ToArray(), Encoding.ASCII.GetBytes(input.Substring(expectedBytesScanned - 1)));
}
}
public ParseResult ParseMessage(ReadOnlyBuffer buffer, out Position consumed, out Position examined, out byte[] message)
{
consumed = buffer.Start;
examined = buffer.End;
message = null;
var start = consumed;
var end = examined;
while (buffer.Length > 0)
{
if (ReadOnlyBuffer.Seek(start, end, out var lineEnd, ByteLF) == -1)
{
// For the case of data: Foo\r\n\r\<Anytine except \n>
if (_internalParserState == InternalParseState.ReadEndOfMessage)
{
if (ConvertBufferToSpan(buffer.Slice(start, buffer.End)).Length > 1)
{
throw new FormatException("Expected a \\r\\n frame ending");
}
}
// Partial message. We need to read more.
return(ParseResult.Incomplete);
}
lineEnd = buffer.Move(lineEnd, 1);
var line = ConvertBufferToSpan(buffer.Slice(start, lineEnd));
buffer = buffer.Slice(line.Length);
if (line.Length <= 1)
{
throw new FormatException("There was an error in the frame format");
}
// Skip comments
if (line[0] == ByteColon)
{
start = lineEnd;
consumed = lineEnd;
continue;
}
if (IsMessageEnd(line))
{
_internalParserState = InternalParseState.ReadEndOfMessage;
}
// To ensure that the \n was preceded by a \r
// since messages can't contain \n.
// data: foo\n\bar should be encoded as
// data: foo\r\n
// data: bar\r\n
else if (line[line.Length - _sseLineEnding.Length] != ByteCR)
{
throw new FormatException("Unexpected '\n' in message. A '\n' character can only be used as part of the newline sequence '\r\n'");
}
else
{
EnsureStartsWithDataPrefix(line);
}
var payload = Array.Empty <byte>();
switch (_internalParserState)
{
case InternalParseState.ReadMessagePayload:
EnsureStartsWithDataPrefix(line);
// Slice away the 'data: '
var payloadLength = line.Length - (_dataPrefix.Length + _sseLineEnding.Length);
var newData = line.Slice(_dataPrefix.Length, payloadLength).ToArray();
_data.Add(newData);
start = lineEnd;
consumed = lineEnd;
break;
case InternalParseState.ReadEndOfMessage:
if (_data.Count == 1)
{
payload = _data[0];
}
else if (_data.Count > 1)
{
// Find the final size of the payload
var payloadSize = 0;
foreach (var dataLine in _data)
{
payloadSize += dataLine.Length;
}
payloadSize += _newLine.Length * _data.Count;
// Allocate space in the payload buffer for the data and the new lines.
// Subtract newLine length because we don't want a trailing newline.
payload = new byte[payloadSize - _newLine.Length];
var offset = 0;
foreach (var dataLine in _data)
{
dataLine.CopyTo(payload, offset);
offset += dataLine.Length;
if (offset < payload.Length)
{
_newLine.CopyTo(payload, offset);
offset += _newLine.Length;
}
}
}
message = payload;
consumed = lineEnd;
examined = consumed;
return(ParseResult.Completed);
}
if (buffer.Length > 0 && buffer.First.Span[0] == ByteCR)
{
_internalParserState = InternalParseState.ReadEndOfMessage;
}
}
return(ParseResult.Incomplete);
}
public Position Seek(Position origin, long offset) => _buffer.Seek(origin, offset);
/// <summary>
/// Searches for a byte in the <see cref="ReadOnlyBuffer"/> and returns a sliced <see cref="ReadOnlyBuffer"/> that
/// contains all data up to and excluding the byte, and a <see cref="Position"/> that points to the byte.
/// </summary>
/// <param name="b1">The first byte to search for</param>
/// <param name="slice">A <see cref="ReadOnlyBuffer"/> slice that contains all data up to and excluding the first byte.</param>
/// <param name="cursor">A <see cref="Position"/> that points to the second byte</param>
/// <returns>True if the byte sequence was found, false if not found</returns>
public static bool TrySliceTo(this ReadOnlyBuffer <byte> buffer, byte b1, out ReadOnlyBuffer <byte> slice, out Position cursor)
{
if (buffer.IsEmpty)
{
slice = default;
cursor = default;
return(false);
}
var byte0Vector = GetVector(b1);
var seek = 0;
foreach (var memory in buffer)
{
var currentSpan = memory.Span;
var found = false;
if (Vector.IsHardwareAccelerated)
{
while (currentSpan.Length >= VectorWidth)
{
var data = ReadMachineEndian <Vector <byte> >(currentSpan);
var byte0Equals = Vector.Equals(data, byte0Vector);
if (byte0Equals.Equals(Vector <byte> .Zero))
{
currentSpan = currentSpan.Slice(VectorWidth);
seek += VectorWidth;
}
else
{
var index = FindFirstEqualByte(ref byte0Equals);
seek += index;
found = true;
break;
}
}
}
if (!found)
{
// Slow search
for (int i = 0; i < currentSpan.Length; i++)
{
if (currentSpan[i] == b1)
{
found = true;
break;
}
seek++;
}
}
if (found)
{
cursor = buffer.Seek(buffer.Start, seek);
slice = buffer.Slice(buffer.Start, cursor);
return(true);
}
}
slice = default;
cursor = default;
return(false);
}
