/// <summary>
/// Reads a char string value from the buffer.
/// </summary>
private int ReadField(
TsCCpxContext context,
CharString field,
int fieldIndex,
ArrayList fieldValues,
out object fieldValue
)
{
fieldValue = null;
byte[] buffer = context.Buffer;
// initialize serialization parameters.
int charWidth = (field.CharWidthSpecified) ? (int)field.CharWidth : (int)context.CharWidth;
int charCount = (field.LengthSpecified) ? (int)field.Length : -1;
// apply defaults for built in types.
if (field.GetType() == typeof(Ascii))
{
charWidth = 1;
}
else if (field.GetType() == typeof(Unicode))
{
charWidth = 2;
}
if (field.CharCountRef != null)
{
charCount = ReadReference(context, field, fieldIndex, fieldValues, field.CharCountRef);
}
// find null terminator
if (charCount == -1)
{
charCount = 0;
for (int ii = context.Index; ii < context.Buffer.Length - charWidth + 1; ii += charWidth)
{
charCount++;
bool isNull = true;
for (int jj = 0; jj < charWidth; jj++)
{
if (context.Buffer[ii + jj] != 0)
{
isNull = false;
break;
}
}
if (isNull)
{
break;
}
}
}
// check if there is enough data left.
if (buffer.Length - context.Index < charWidth * charCount)
{
throw new TsCCpxInvalidDataInBufferException("Unexpected end of buffer.");
}
if (charWidth > 2)
{
// copy bytes.
byte[] bytes = new byte[charCount * charWidth];
for (int ii = 0; ii < charCount * charWidth; ii++)
{
bytes[ii] = buffer[context.Index + ii];
}
// swap bytes.
if (context.BigEndian)
{
for (int ii = 0; ii < bytes.Length; ii += charWidth)
{
SwapBytes(bytes, 0, charWidth);
}
}
fieldValue = bytes;
}
else
{
// copy characters.
char[] chars = new char[charCount];
for (int ii = 0; ii < charCount; ii++)
{
if (charWidth == 1)
{
chars[ii] = System.Convert.ToChar(buffer[context.Index + ii]);
}
else
{
byte[] charBytes = new byte[]
{
buffer[context.Index + 2 * ii],
buffer[context.Index + 2 * ii + 1]
};
if (context.BigEndian)
{
SwapBytes(charBytes, 0, 2);
}
chars[ii] = BitConverter.ToChar(charBytes, 0);
}
}
fieldValue = new string(chars).TrimEnd(new char[] { '\0' });
}
return(charCount * charWidth);
}
/// <summary>
/// Writes a char string value to the buffer.
/// </summary>
private int WriteField(
TsCCpxContext context,
CharString field,
int fieldIndex,
TsCCpxComplexValue[] fieldValues,
object fieldValue
)
{
byte[] buffer = context.Buffer;
// initialize serialization parameters.
int charWidth = (field.CharWidthSpecified) ? (int)field.CharWidth : (int)context.CharWidth;
int charCount = (field.LengthSpecified) ? (int)field.Length : -1;
// apply defaults for built in types.
if (field.GetType() == typeof(Ascii))
{
charWidth = 1;
}
else if (field.GetType() == typeof(Unicode))
{
charWidth = 2;
}
byte[] bytes = null;
if (charCount == -1)
{
// extra wide characters stored as byte arrays
if (charWidth > 2)
{
if (fieldValue.GetType() != typeof(byte[]))
{
throw new TsCCpxInvalidDataToWriteException("Field value is not a byte array.");
}
bytes = (byte[])fieldValue;
charCount = bytes.Length / charWidth;
}
// convert string to byte array.
else
{
if (fieldValue.GetType() != typeof(string))
{
throw new TsCCpxInvalidDataToWriteException("Field value is not a string.");
}
string stringValue = (string)fieldValue;
charCount = stringValue.Length + 1;
// calculate length of ascii string by forcing pure unicode characters to two ascii chars.
if (charWidth == 1)
{
charCount = 1;
foreach (char unicodeChar in stringValue)
{
charCount++;
byte[] charBytes = BitConverter.GetBytes(unicodeChar);
if (charBytes[1] != 0)
{
charCount++;
}
}
}
}
}
// update the char count reference.
if (field.CharCountRef != null)
{
WriteReference(context, field, fieldIndex, fieldValues, field.CharCountRef, charCount);
}
if (buffer != null)
{
// copy string to buffer.
if (bytes == null)
{
string stringValue = (string)fieldValue;
bytes = new byte[charWidth * charCount];
int index = 0;
for (int ii = 0; ii < stringValue.Length; ii++)
{
if (index >= bytes.Length)
{
break;
}
byte[] charBytes = BitConverter.GetBytes(stringValue[ii]);
bytes[index++] = charBytes[0];
if (charWidth == 2 || charBytes[1] != 0)
{
bytes[index++] = charBytes[1];
}
}
}
// check if there is enough data left.
if (buffer.Length - context.Index < bytes.Length)
{
throw new TsCCpxInvalidDataToWriteException("Unexpected end of buffer.");
}
// write bytes to buffer.
for (int ii = 0; ii < bytes.Length; ii++)
{
buffer[context.Index + ii] = bytes[ii];
}
// swap bytes.
if (context.BigEndian && charWidth > 1)
{
for (int ii = 0; ii < bytes.Length; ii += charWidth)
{
SwapBytes(buffer, context.Index + ii, charWidth);
}
}
}
return(charCount * charWidth);
}
