/// <summary>
/// Generates a unique, sequential, Base36 string; you control the len
/// The first 10 characters are the microseconds elapsed since the InService DateTime
/// (constant field you hardcode in this file).
/// The next 2 characters are a compressed checksum of the MD5 of this host.
/// The next 1 character is a reserved constant of 36 ('Z' in Base36).
/// The last 3 characters are random number less than 46655 additional for additional uniqueness.
/// </summary>
/// <returns>Returns a unique, sequential, 16-character Base36 string</returns>
public string NewId(bool delimited)
{
// Keep access sequential so threads cannot accidentally
// read another thread's values within this method:
// Microseconds since InService (using Stopwatch) provides the
// first n chars (n = _numTimestampCharacters):
lock (_sb)
{
_sb.Clear();
long microseconds = ConcurrentStopwatch.GetMicroseconds();
string base36Microseconds = Base36Converter.FromLong(microseconds);
if (base36Microseconds.Length > this._numTimestampCharacters)
{
base36Microseconds = base36Microseconds.Substring(0, this._numTimestampCharacters);
}
_sb.Append(base36Microseconds.PadLeft(this._numTimestampCharacters, '0'));
if (_numServerCharacters > 0)
{
_sb.Append(_hostHash.Substring(0, _numServerCharacters));
}
if (!string.IsNullOrWhiteSpace(this._reservedValue))
{
_sb.Append(this._reservedValue);
}
// Add the random component:
_sb.Append(GetRandomBase36DigitsSafe());
if (!delimited || string.IsNullOrWhiteSpace(_delimiter) || this._delimiterPositions == null)
{
return(_sb.ToString());
}
foreach (var pos in this._delimiterPositions)
{
_sb.Insert(pos, this._delimiter);
}
return(_sb.ToString());
}
}
/// <summary>
/// Return the elapsed microseconds since the in-service DateTime; will never
/// return the same value twice. Uses a high-resolution Stopwatch (not DateTime.Now)
/// to measure durations.
/// </summary>
/// <returns></returns>
internal static long GetMicroseconds()
{
return(ConcurrentStopwatch.GetMicroseconds());
}
