private List<Cursor> GetCursorsFromEventKeys(IList<string> eventKeys, TopicLookup topics)
{
var list = new List<Cursor>(eventKeys.Count);
foreach (var eventKey in eventKeys)
{
var cursor = new Cursor(eventKey, GetMessageId(topics, eventKey), _stringMinifier.Minify(eventKey));
list.Add(cursor);
}
return list;
}
public static Cursor Clone(Cursor cursor)
{
return new Cursor(cursor.Key, cursor.Id, cursor._escapedKey);
}
private void AddCursorForStream(int streamIndex, List<Cursor> cursors)
{
ScaleoutMapping maxMapping = _streams[streamIndex].MaxMapping;
ulong id = UInt64.MaxValue;
string key = streamIndex.ToString(CultureInfo.InvariantCulture);
if (maxMapping != null)
{
id = maxMapping.Id;
}
var newCursor = new Cursor(key, id);
cursors.Add(newCursor);
}
public static List<Cursor> GetCursors(string cursor, string prefix, Func<string, object, string> keyMaximizer, object state)
{
// Technically GetCursors should never be called with a null value, so this is extra cautious
if (String.IsNullOrEmpty(cursor))
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
// If the cursor does not begin with the prefix stream, it isn't necessarily a formatting problem.
// The cursor with a different prefix might have had different, but also valid, formatting.
// Null should be returned so new cursors will be generated
if (!cursor.StartsWith(prefix, StringComparison.Ordinal))
{
return null;
}
var signals = new HashSet<string>();
var cursors = new List<Cursor>();
string currentKey = null;
string currentEscapedKey = null;
ulong currentId;
bool escape = false;
bool consumingKey = true;
var sb = new StringBuilder();
var sbEscaped = new StringBuilder();
Cursor parsedCursor;
for (int i = prefix.Length; i < cursor.Length; i++)
{
var ch = cursor[i];
// escape can only be true if we are consuming the key
if (escape)
{
if (ch != '\\' && ch != ',' && ch != '|')
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
sb.Append(ch);
sbEscaped.Append(ch);
escape = false;
}
else
{
if (ch == '\\')
{
if (!consumingKey)
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
sbEscaped.Append('\\');
escape = true;
}
else if (ch == ',')
{
if (!consumingKey)
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
// For now String.Empty is an acceptable key, but this should change once we verify
// that empty keys cannot be created legitimately.
currentKey = keyMaximizer(sb.ToString(), state);
// If the keyMap cannot find a key, we cannot create an array of cursors.
// This most likely means there was an AppDomain restart or a misbehaving client.
if (currentKey == null)
{
return null;
}
// Don't allow duplicate keys
if (!signals.Add(currentKey))
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
currentEscapedKey = sbEscaped.ToString();
sb.Clear();
sbEscaped.Clear();
consumingKey = false;
}
else if (ch == '|')
{
if (consumingKey)
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
ParseCursorId(sb, out currentId);
parsedCursor = new Cursor(currentKey, currentId, currentEscapedKey);
cursors.Add(parsedCursor);
sb.Clear();
consumingKey = true;
}
else
{
sb.Append(ch);
if (consumingKey)
{
sbEscaped.Append(ch);
}
}
}
}
if (consumingKey)
{
throw new FormatException(Resources.Error_InvalidCursorFormat);
}
ParseCursorId(sb, out currentId);
parsedCursor = new Cursor(currentKey, currentId, currentEscapedKey);
cursors.Add(parsedCursor);
return cursors;
}
