Fix README.md and add FormattingSink.

README.md

@@ -1,5 +1,7 @@
 # gdlogging Godot addon
 
+This is a composable logging addon for version 4 of the [Godot game engine](https://godotengine.org/).
+
 ## Usage
 
 ```gdscript
@@ -44,6 +46,7 @@ timer.stop()
 * `DirSink`: Outputs messages to log files and rotates them. Uses a thread for file io.
 * `Logger`: Can receive messages from other Loggers and Sinks. Users will call the log functions which format the message.
 * `MemoryWindowSink`: Keeps `n` log messages in memory. Can be used to display the last `n` messages in a GUI.
+* `FormattingSink`: Formats messages and forwards them to another sink.
 
 ## Log Levels
 
@@ -57,7 +60,7 @@ timer.stop()
 
 ```gdscript
 class MyLogRecordFormatter extends Log.LogRecordFormatter:
-  func format(log_record: Dictionary, raw_message: String) -> String:
+  func format(log_record: Dictionary) -> String:
     var time_unix: float = log_record["time_unix"]
     var level: Log.LogLevel = log_record["level"]
 		var unformatted_message: String = log_record["unformatted_message"]

logger.gd

@@ -188,6 +188,7 @@ class BufferedSink extends LogSink:
 		_write_bulks_buffered()
 		_sink.flush_buffer()
 
+	## Set to 0 to disable interval flushing.
 	func set_buffer_flush_interval_msec(p_buffer_flush_interval_msec: int) -> void:
 		_buffer_flush_interval_usec = p_buffer_flush_interval_msec * 1000
 
@@ -197,7 +198,7 @@ class BufferedSink extends LogSink:
 			return
 		_buffer_log_records.append_array(p_log_records)
 		_buffer_formatted_messages.append_array(p_formatted_messages)
-		var max_wait_exceeded := Time.get_ticks_usec() - _last_buffer_write_out_time_usec > _buffer_flush_interval_usec
+		var max_wait_exceeded := _buffer_flush_interval_usec != 0 and Time.get_ticks_usec() - _last_buffer_write_out_time_usec > _buffer_flush_interval_usec
 		if (_buffer_log_records.size() >= _buffer_size) \
 			or max_wait_exceeded:
 			_write_bulks_buffered()
@@ -418,6 +419,29 @@ class MemoryWindowSink extends LogSink:
 			"log_records": _log_records,
 		}
 
+class FormattingSink extends LogSink:
+	var _sink: LogSink
+	var _log_record_formatter: LogRecordFormatter
+
+	func _init(p_sink: LogSink, p_log_record_formatter: LogRecordFormatter) -> void:
+		_sink = p_sink
+		_log_record_formatter = p_log_record_formatter
+
+	func write_bulks(p_log_records: Array[Dictionary], p_formatted_messages: PackedStringArray) -> void:
+		var formatted_messages := PackedStringArray()
+		for i in range(p_log_records.size()):
+			var log_record := p_log_records[i]
+			var formatted_message := _log_record_formatter.format(log_record)
+			formatted_messages.append(formatted_message)
+		_sink.write_bulks(p_log_records, formatted_messages)
+
+	func flush_buffer() -> void:
+		_sink.flush_buffer()
+
+	func close() -> void:
+		flush_buffer()
+		_sink.close()
+
 ## Left pads a string with a character to a given length.
 static func pad_string(p_string: String, p_length: int, p_pad_char: String = " ") -> String:
 	var pad_length := p_length - p_string.length()