/// <summary>
/// Read a string from the stream.
/// <remarks>
/// We optimize strings by maintaining a hash table of each unique string
/// we have seen. Each string is sent with as an integer index into the table.
/// When a new string is encountered, it's index is followed by the string value.
/// </remarks>
/// </summary>
/// <returns>Returns the string</returns>
public string ReadString()
{
// Dropping string tables is pretty easy!
if (m_MajorVersion > 1)
{
return(ReadStringDirect());
}
/*
* The rest of this method is for protocol version 1.0
*/
string stringValue; // string to be returned
var index = (int)ReadUInt32();
if (index == 0)
{
return(null);
}
// check if this is a token we've never seen before.
// If so, the value follows and we should add it to the token list.
if (--index == m_Strings.Count)
{
stringValue = ReadStringDirect();
m_Strings.AddOrGet(stringValue);
}
else
{
stringValue = m_Strings[index];
CompensateForPossibleSerializationError(stringValue);
}
return(stringValue);
}
/// <summary>
/// Write a string to the stream.
/// <remarks>
/// We optimize strings by maintaining a hash table of each unique string
/// we have seen. Each string is sent with as an integer index into the table.
/// When a new string is encountered, it's index is followed by the string value.
/// </remarks>
/// </summary>
public void Write(string value)
{
if (m_MajorVersion > 1)
{
WriteString(value);
return;
}
if (value == null)
{
WriteByte(0);
return;
}
// The AddOrGet method first checks if the string is already in the table.
// If so, it just returns the existing index. Otherwise, it adds the
// string to the end of the table and returns the index. In that case,
// we can detect that this is the first time that a string has been
// seen by checking if the returned index is too large relative to the
// Count property before the AddOrGet.
int newStringIndex = m_Strings.Count + 1; // this line must be called before AddOrGet
int stringIndex = m_Strings.AddOrGet(value) + 1;
Write((UInt32)stringIndex);
// If we've just added a new string to the table, the index should be equal to
// the previous count of strings. We have added 1 to the index values because we
// use zero-based indexing in the string table but 1-based indexing over the wire.
if (stringIndex == newStringIndex)
{
WriteString(value);
}
else if (stringIndex > newStringIndex)
{
throw new GibraltarException(
"Something went wrong with string serialization, we got a bogus index from our string table: " + stringIndex);
}
}
