how couchbase sync gateway generate the document revision id

CSG-revision.go

func createRevID(generation int, parentRevID string, body Body) string {
	// This should produce the same results as TouchDB.
	digester := md5.New()
	digester.Write([]byte{byte(len(parentRevID))})
	digester.Write([]byte(parentRevID))
	digester.Write(canonicalEncoding(stripSpecialProperties(body)))
	return fmt.Sprintf("%d-%x", generation, digester.Sum(nil))
}