private static int Read7Bit(ReadBuffer readBuffer)
{
var position = readBuffer.Position;
readBuffer.Fill(1);
byte currentByte;
var result = 0;
while (((currentByte = readBuffer[readBuffer.Index++]) & 0x80) > 0)
{
result |= currentByte & 0x7F;
// - 1 accounts for the fact that we must not overwrite the sign bit by shifting in bits
const int DiscardBitsMask =
Constants.AllBitsSetInt << (Constants.BitsPerInt - Constants.BitsPerEncodedByte - 1);
if ((result & DiscardBitsMask) != 0)
{
throw CreateEmberException(
"The identifier number or subidentifier at position {0} exceeds the expected range.", position);
}
result <<= Constants.BitsPerEncodedByte;
readBuffer.Fill(1);
}
result |= currentByte;
return(result);
}
/// <summary>See <i>"X.690"</i><cite>X.690</cite>, chapter 8.1.3.</summary>
private static int?ReadLength(ReadBuffer readBuffer)
{
var position = readBuffer.Position;
readBuffer.Fill(1);
var leadingOctet = readBuffer[readBuffer.Index++];
if ((leadingOctet & 0x80) > 0)
{
var length = leadingOctet & 0x7F;
if (length == 0)
{
return(null);
}
readBuffer.Fill(length);
var result = Read8Bit(readBuffer, length, false);
if (result > int.MaxValue)
{
throw CreateEmberException("The length at position {0} exceeds the expected range.", position);
}
return((int)result);
}
else
{
return(leadingOctet);
}
}
/// <summary>See <i>"X.690"</i><cite>X.690</cite>, chapter 8.1.2.</summary>
private static EmberId ReadIdentifier(ReadBuffer readBuffer)
{
readBuffer.Fill(1);
var leadingOctet = readBuffer[readBuffer.Index++];
var theClass = (Class)(leadingOctet & 0xC0);
var isConstructed = (leadingOctet & 0x20) > 0;
var number = leadingOctet & 0x1F;
return(new EmberId(theClass, isConstructed, (number <= 30) ? number : Read7Bit(readBuffer)));
}
private static int Read7Bit(ReadBuffer readBuffer)
{
var position = readBuffer.Position;
readBuffer.Fill(1);
byte currentByte;
var result = 0;
while (((currentByte = readBuffer[readBuffer.Index++]) & 0x80) > 0)
{
result |= currentByte & 0x7F;
// - 1 accounts for the fact that we must not overwrite the sign bit by shifting in bits
const int DiscardBitsMask =
Constants.AllBitsSetInt << (Constants.BitsPerInt - Constants.BitsPerEncodedByte - 1);
if ((result & DiscardBitsMask) != 0)
{
throw CreateEmberException(
"The identifier number or subidentifier at position {0} exceeds the expected range.", position);
}
result <<= Constants.BitsPerEncodedByte;
readBuffer.Fill(1);
}
result |= currentByte;
return result;
}
/// <summary>See <i>"X.690"</i><cite>X.690</cite>, chapter 8.1.3.</summary>
private static int? ReadLength(ReadBuffer readBuffer)
{
var position = readBuffer.Position;
readBuffer.Fill(1);
var leadingOctet = readBuffer[readBuffer.Index++];
if ((leadingOctet & 0x80) > 0)
{
var length = leadingOctet & 0x7F;
if (length == 0)
{
return null;
}
readBuffer.Fill(length);
var result = Read8Bit(readBuffer, length, false);
if (result > int.MaxValue)
{
throw CreateEmberException("The length at position {0} exceeds the expected range.", position);
}
return (int)result;
}
else
{
return leadingOctet;
}
}
/// <summary>See <i>"X.690"</i><cite>X.690</cite>, chapter 8.1.2.</summary>
private static EmberId ReadIdentifier(ReadBuffer readBuffer)
{
readBuffer.Fill(1);
var leadingOctet = readBuffer[readBuffer.Index++];
var theClass = (Class)(leadingOctet & 0xC0);
var isConstructed = (leadingOctet & 0x20) > 0;
var number = leadingOctet & 0x1F;
return new EmberId(theClass, isConstructed, (number <= 30) ? number : Read7Bit(readBuffer));
}