public bool readOptional(int tag, OptionalFormat format)
{
return(_is.readOpt(tag, format));
}
public bool writeOptional(int tag, OptionalFormat format)
{
return(_os.writeOpt(tag, format));
}
internal override bool readOptional(int readTag, OptionalFormat expectedFormat)
{
if(_current == null)
{
return _stream.readOptImpl(readTag, expectedFormat);
}
else if((_current.sliceFlags & Protocol.FLAG_HAS_OPTIONAL_MEMBERS) != 0)
{
return _stream.readOptImpl(readTag, expectedFormat);
}
return false;
}
internal virtual bool readOptional(int tag, OptionalFormat format)
{
return false;
}
private void skipOptional(OptionalFormat format)
{
switch(format)
{
case OptionalFormat.F1:
{
skip(1);
break;
}
case OptionalFormat.F2:
{
skip(2);
break;
}
case OptionalFormat.F4:
{
skip(4);
break;
}
case OptionalFormat.F8:
{
skip(8);
break;
}
case OptionalFormat.Size:
{
skipSize();
break;
}
case OptionalFormat.VSize:
{
skip(readSize());
break;
}
case OptionalFormat.FSize:
{
skip(readInt());
break;
}
case OptionalFormat.Class:
{
readValue(null);
break;
}
}
}
private bool readOptImpl(int readTag, OptionalFormat expectedFormat)
{
if(isEncoding_1_0())
{
return false; // Optional members aren't supported with the 1.0 encoding.
}
while(true)
{
if(_buf.b.position() >= _encapsStack.start + _encapsStack.sz)
{
return false; // End of encapsulation also indicates end of optionals.
}
int v = readByte();
if(v == Protocol.OPTIONAL_END_MARKER)
{
_buf.b.position(_buf.b.position() - 1); // Rewind.
return false;
}
OptionalFormat format = (OptionalFormat)(v & 0x07); // First 3 bits.
int tag = v >> 3;
if(tag == 30)
{
tag = readSize();
}
if(tag > readTag)
{
int offset = tag < 30 ? 1 : (tag < 255 ? 2 : 6); // Rewind
_buf.b.position(_buf.b.position() - offset);
return false; // No optional data members with the requested tag.
}
else if(tag < readTag)
{
skipOptional(format); // Skip optional data members
}
else
{
if(format != expectedFormat)
{
throw new MarshalException("invalid optional data member `" + tag + "': unexpected format");
}
return true;
}
}
}
/// <summary>
/// Determine if an optional value is available for reading.
/// </summary>
/// <param name="tag">The tag associated with the value.</param>
/// <param name="expectedFormat">The optional format for the value.</param>
/// <returns>True if the value is present, false otherwise.</returns>
public bool readOptional(int tag, OptionalFormat expectedFormat)
{
Debug.Assert(_encapsStack != null);
if(_encapsStack.decoder != null)
{
return _encapsStack.decoder.readOptional(tag, expectedFormat);
}
else
{
return readOptImpl(tag, expectedFormat);
}
}