public void GetProductType(char t1, char t2, WmoBulletinProductTypes expectedTypes)
{
var actualType = WmoBulletinProductTypesHelper.GetProductTypes((byte)t1, (byte)t2);
Assert.That(actualType, Is.EqualTo(expectedTypes));
}
private async IAsyncEnumerable <WmoBulletin> ReadPipeAsync(PipeReader reader, [EnumeratorCancellation] CancellationToken token)
{
var builders = new Dictionary <byte[], BulletinBuilder>(new ByteArrayEqualityComparer());
BulletinBuilder builder = null;
var part = Part.None;
byte marker = 0;
int blockLength = 0;
int reportLength = 0;
int totalLength = 0;
while (true)
{
var result = await reader.ReadAsync(token);
if (result.IsCanceled)
{
break;
}
var data = result.Buffer;
foreach (var bulletin in ProcessSequence())
{
yield return(bulletin);
}
reader.AdvanceTo(data.Start, data.End);
if (result.IsCompleted)
{
break;
}
IEnumerable <WmoBulletin> ProcessSequence()
{
bool canContinue = true;
while (canContinue)
{
switch (part)
{
case Part.None:
canContinue = ProcessPartNone();
break;
case Part.FlagFieldSeparator when !data.IsEmpty:
canContinue = ProcessFlagFieldSeparator();
break;
case Part.BulletinHeading when !data.IsEmpty:
canContinue = ProcessBulletinHeading();
break;
case Part.Report:
canContinue = ProcessReport();
break;
case Part.End:
if (!builder.IsMultipart || builder.Part == BulletinPart.Last)
{
yield return(builder.Build());
builder.Reset();
}
part = Part.None;
marker = 0;
blockLength = 0;
totalLength = 0;
reportLength = 0;
break;
default:
throw new EndOfStreamException("Unexpected end of stream at " + data.End.GetInteger());
}
}
bool ProcessPartNone()
{
if (data.IsEmpty)
{
return(false);
}
marker = data.First.Span[0];
if (marker != StarMarker && marker != HashMarker)
{
throw GetInvalidFormatException(data.Start);
}
part = Part.FlagFieldSeparator;
return(true);
}
bool ProcessFlagFieldSeparator()
{
int length = marker == StarMarker ? 19 : Math.Max(18, blockLength);
if (data.Length < length)
{
return(false);
}
Span <byte> span = stackalloc byte[length];
data.Slice(0, length).CopyTo(span);
if (marker == StarMarker)
{
ValidateMarkers(span, 0, StarMarkers);
totalLength = GetNumber(span.Slice(4, 10), data.GetPosition(4));
ValidateMarkers(span, 14, StarMarkers);
if (span[18] != (byte)'\n')
{
throw GetInvalidFormatException(data.GetPosition(18));
}
}
else
{
ValidateMarkers(span, 0, HashMarkers);
blockLength = GetNumber(span.Slice(4, 3), data.Start);
if (blockLength > length)
{
return(true); // We will allocate enough buffer on next loop.
}
bool isVariable = blockLength > 18;
totalLength = GetNumber(span.Slice(7, isVariable ? 11 : 6), data.GetPosition(7));
ValidateMarkers(span, blockLength - 5, HashMarkers);
if (span[blockLength - 1] != (byte)'\n')
{
throw GetInvalidFormatException(data.GetPosition(18));
}
}
data = data.Slice(length);
part = Part.BulletinHeading;
return(true);
void ValidateMarkers(in ReadOnlySpan <byte> span, int offset, in ReadOnlyMemory <byte> pattern)
{
if (!span.Slice(offset, pattern.Length).SequenceEqual(pattern.Span))
{
throw GetInvalidFormatException(data.GetPosition(offset));
}
}
}
bool ProcessBulletinHeading()
{
var lineEnd = data.PositionOf((byte)'\n');
if (lineEnd == null)
{
return(false);
}
var end = data.PositionOf((byte)'\r');
if (end == null || !data.GetPosition(2, end.Value).Equals(lineEnd.Value))
{
throw GetInvalidFormatException(lineEnd.Value);
}
var slice = data.Slice(data.Start, end.Value);
if (slice.IsSingleSegment)
{
BuildHeading(slice.First.Span);
}
else
{
Span <byte> span = stackalloc byte[(int)slice.Length];
slice.CopyTo(span);
BuildHeading(span);
}
reportLength = totalLength - (int)slice.Length - 3;
data = data.Slice(lineEnd.Value).Slice(1);
part = Part.Report;
return(true);
void BuildHeading(in ReadOnlySpan <byte> span)
{
if (span.Length < 18)
{
throw GetInvalidFormatException(end.Value);
}
var type = WmoBulletinType.Normal;
bool multipart = false;
ushort index = 0;
if (span.Length >= 20)
{
if (span.Length < 22)
{
throw GetInvalidFormatException(end.Value);
}
switch (span[19])
{
case (byte)'C':
type = WmoBulletinType.Correction;
index = span[21];
break;
case (byte)'R':
type = WmoBulletinType.Delayed;
index = span[21];
break;
case (byte)'A':
type = WmoBulletinType.Amendment;
index = span[21];
break;
case (byte)'P':
multipart = true;
var key = span.Slice(0, 18).ToArray();
if (builders.TryGetValue(key, out builder))
{
builder.Part = span[20] == (byte)'Z'
? BulletinPart.Last
: BulletinPart.Middle;
if (builder.Part == BulletinPart.Last)
{
builders.Remove(key);
}
}
else
{
builder = new BulletinBuilder(this)
{
IsMultipart = true, Part = BulletinPart.First
};
builders.Add(key, builder);
}
index = (ushort)((ushort)(span[20] << 8) | (ushort)span[21]);
if (index < builder.Index)
{
throw GetInvalidFormatException(data.GetPosition(20),
"Invalid message part order.");
}
break;
}
}
if (builder == null || (builder.IsMultipart && !multipart))
{
builder = new BulletinBuilder(this);
}
builder.Type = type;
builder.Index = index;
builder.T1 = span[0];
builder.T2 = span[1];
builder.A1 = span[2];
builder.A2 = span[3];
builder.ii = checked ((byte)((span[4] - '0') * 10 + (span[5] - '0')));
builder.Location = BinaryPrimitives.ReadUInt32LittleEndian(span.Slice(7, 4));
int day = GetNumber(span.Slice(12, 2), data.GetPosition(12));
int hour = GetNumber(span.Slice(14, 2), data.GetPosition(14));
int minute = GetNumber(span.Slice(16, 2), data.GetPosition(16));
builder.Time = new DayHourMinute(day, hour, minute);
var productTypes = WmoBulletinProductTypesHelper.GetProductTypes(builder.T1, builder.T2);
byte productTypesBits = (byte)productTypes;
if (productTypesBits == 0)
{
builder.ProductType = _expectedProductType ?? throw new InvalidOperationException();
}
else if (IsPowerOf2(productTypesBits))
{
var productType = FromBit(productTypes);
builder.ProductType = (_expectedProductType == null || _expectedProductType == productType)
? productType
: throw new InvalidOperationException();
}
else if (_expectedProductType != null && (productTypesBits & (1 << (byte)_expectedProductType.Value)) != 0)
{
builder.ProductType = _expectedProductType.Value;
}
else
{
throw new InvalidOperationException();
}
}
}
bool ProcessReport()
{
if (data.Length < reportLength)
{
if (result.IsCompleted)
{
part = Part.End;
return(true);
}
return(false);
}
var reportSlice = data.Slice(data.Start, reportLength);
if (_supplementaryIdentificationLineResolver != null)
{
var supplementaryIdentificationLine = _supplementaryIdentificationLineResolver.Invoke(ref reportSlice, builder.T1, builder.T2);
builder.SupplementaryIdentificationLine ??= supplementaryIdentificationLine;
}
switch (builder.ProductType)
{
case WmoBulletinProductType.DecodableText:
SetDecodableTextReport();
break;
case WmoBulletinProductType.PlainText:
case WmoBulletinProductType.Xml:
SetPlainTextReport();
break;
case WmoBulletinProductType.Binary:
SetBinaryReport();
break;
default:
throw new ArgumentOutOfRangeException();
}
data = data.Slice(reportLength);
part = Part.End;
return(true);
void SetDecodableTextReport()
{
do
{
var(end, isBulletinEnd) = GetEndPosition();
var slice = reportSlice.Slice(reportSlice.Start, end);
string report;
if (slice.IsSingleSegment)
{
report = GetAsciiString(slice.First.Span);
}
else
{
Span <byte> span = stackalloc byte[(int)slice.Length];
slice.CopyTo(span);
report = GetAsciiString(span);
}
builder.TextReports.Add(report);
if (isBulletinEnd)
{
break;
}
reportSlice = reportSlice.Slice(end).Slice(1);
} while (!reportSlice.IsEmpty);
}
void SetPlainTextReport()
{
string report;
if (reportSlice.IsSingleSegment)
{
report = GetAsciiString(reportSlice.First.Span);
}
else
{
Span <byte> span = stackalloc byte[(int)reportSlice.Length];
reportSlice.CopyTo(span);
report = GetAsciiString(span);
}
builder.TextReports.Add(report);
}
void SetBinaryReport()
{
Span <byte> span;
if (builder.BinaryReport == null)
{
builder.BinaryReport = new byte[reportSlice.Length];
span = builder.BinaryReport;
}
else
{
var binaryReport = builder.BinaryReport;
var initialLength = binaryReport.Length;
Array.Resize(ref binaryReport, initialLength + (int)reportSlice.Length);
builder.BinaryReport = binaryReport;
span = builder.BinaryReport.AsSpan(initialLength);
}
reportSlice.CopyTo(span);
}
(SequencePosition end, bool isBulletinEnd) GetEndPosition()
{
var reportEnd = reportSlice.PositionOf((byte)'=');
return(reportEnd != null
? (reportEnd.Value, false)
: (reportSlice.End, true));
}
}
Exception GetInvalidFormatException(in SequencePosition pos, string msg = null)
{
return(new InvalidOperationException("Invalid file format")); // TODO: Use custom exception
}