writer

type FileConfig struct {
	RelayDir string // directory to store relay log files.
	Filename string // the startup relay log filename, if not set then a fake RotateEvent must be the first event.
}

type FileWriter struct {
	// contains filtered or unexported fields
}

type RecoverResult struct {
	// true if recover operation has done and successfully.
	// false if no recover operation has done or unsuccessfully.
	Recovered bool
	// the latest binlog position after recover operation has done.
	LatestPos gmysql.Position
	// the latest binlog GTID set after recover operation has done.
	LatestGTIDs gtid.Set
}

type Result struct {
	Ignore       bool   // whether the event ignored by the writer
	IgnoreReason string // why the writer ignore the event
}

type Writer interface {
	// Start prepares the writer for writing binlog events.
	Start() error

	// Close closes the writer and release the resource.
	Close() error

	// Recover tries to recover the binlog file or any other memory structure associate with this writer.
	// It is often used to recover a binlog file with some corrupt/incomplete binlog events/transactions at the end of the file.
	// It is not safe for concurrent use by multiple goroutines.
	// It should be called before writing to the file.
	Recover() (RecoverResult, error)

	// WriteEvent writes an binlog event's data into disk or any other places.
	// It is not safe for concurrent use by multiple goroutines.
	WriteEvent(ev *replication.BinlogEvent) (Result, error)

	// Flush flushes the buffered data to a stable storage or sends through the network.
	// It is not safe for concurrent use by multiple goroutines.
	Flush() error
}