FastTimeMarshalJSON avoids one of the extra allocations that time.MarshalJSON is making.

JSONFormat is the format used by FastMarshalJSON.

RFC3339NanoFixed is our own version of RFC339Nano because we want one that pads the nano seconds part with zeros to ensure the timestamps are aligned in the logs.

JSONLog represents a log message, typically a single entry from a given log stream.

JSONLogs is based on JSONLog.