The bufio package in Go provides buffered input and output functionality. It is used to efficiently read and write data from and to I/O sources, such as files, network connections, and other streams.
The main purpose of the bufio package is to improve I/O performance by reducing the number of system calls made for reading or writing small amounts of data. It achieves this by introducing a buffer that allows data to be read or written in chunks, rather than one byte at a time. This can significantly improve the efficiency, especially when dealing with large amounts of data or slow I/O sources.
The package provides several types such as bufio.Reader and bufio.Writer, which wrap existing I/O sources and provide additional methods for efficient reading and writing. For instance, the bufio.Reader type provides methods like ReadString, ReadBytes, and ReadLine, which allow reading data in various formats. Similarly, the bufio.Writer type provides methods like WriteString and WriteByte, which are optimally used with buffered output.
Overall, the bufio package is an essential part of Go's standard library as it improves I/O performance and provides convenient methods for buffered reading and writing of data.