/// <summary>
/// Generates a new TimeGuid value and resets the incrementer back to zero. This is the only way that this class can get a new TimeGuid value if its _constantTimeGUID flag is
/// set to True. If the generated TimeGuid is the same as the previous it will sleep for up to 1 second and then try again. Therefore, this function should not be called
/// rapidly in sequence or else performance of calling app will suffer.
/// </summary>
/// <param name="prefix"></param>
/// <returns></returns>
public string RefreshKey(string uniqueIdentifier = "Key")
{
bool keepTrying = true;
while (keepTrying)
{
TimeGuid newGuid = new TimeGuid(DateTime.Now);
if (newGuid == _timeGuid)
{
int millisec = DateTimeOffset.Now.Millisecond;
int sleepTime = 1000 - millisec;
Thread.Sleep(sleepTime);
}
else
{
_timeGuid = newGuid;
keepTrying = false;
}
}
_keyIncrementer = 0;
return(FormatKey(uniqueIdentifier));
}
/// <summary>
/// Generates the random part of the key. Depending on the setting for _constantTimeGUID it may or may not generate a new TimeGuid.
/// If the new TimeGuid is the same as the old (because they were both generated within the same physical second, then it will increment
/// the numeric incrementer by 1. If _constantTimeGUID is true then it will always increment the numeric part by 1.
/// </summary>
/// <returns></returns>
private string IncrementKey(string identifier)
{
string val;
lock ( keyIncrLock ) {
// If the TimeGuid needs to change, then see what new TimeGuid is. If same as existing then we increment the _keyIncrementer
// otherwise we reset KeyIncrementer to zero.
if (!_constantTimeGuid)
{
TimeGuid newGuid = new TimeGuid(DateTime.Now);
if (newGuid == _timeGuid)
{
_keyIncrementer++;
val = FormatKey(identifier);
}
else
{
_keyIncrementer = 0;
_timeGuid = newGuid;
val = FormatKey(identifier);
}
}
else
{
_keyIncrementer++;
val = FormatKey(identifier);
}
} // End Lock
return(val);
}
/// <summary>
/// Creates an object that will generate UniqueKeys. Keys are guaranteed to be unique across this single instance of the object. If you trully need
/// unique keys then use a full Guid.
/// </summary>
/// <param name="keySeparator">The separator to be used to separate the custom identifier and the unique part of the key. Set to empty string for no separator.</param>
/// <param name="timeGuidSeparator">The separator to be used to separate the numerically increasing number at the end of the unique key.</param>
/// <param name="keyIdentifierFirst">Set to True to have the key start with the key identifier. If false the key will end with this identifier.</param>
/// <param name="constantTimeGuid">Set to True to have the same TimeGuid portion of the key. The only unique part will be the number increasing at the end.</param>
public UniqueKeys(string keySeparator = ":", string timeGuidSeparator = "_", bool keyIdentifierFirst = true, bool constantTimeGuid = false)
{
_keyIdentifierFirst = keyIdentifierFirst;
_constantTimeGuid = constantTimeGuid;
_keySeparator = keySeparator;
_tgSeparator = timeGuidSeparator;
// If user wants a constant time guid object then go compute it now.
if (_constantTimeGuid)
{
_timeGuid = new TimeGuid(DateTime.Now);
}
}