Buffer

In Go, buffer is a region of memory used to temporarily store data while it's being transfered between two places, such as between a file and memory or between a network connection and application. Buffers are particularly useful in scenarios where you need to build up or process data incrementally. Go provides buffering utilities, most notably in the bytes and bufio packages.

1. Buffering with bytes.Buffer

The bytes.Buffer type in Go's bytes package is a dynamic buffer for efficiently building and manipulating byte slices.

package main

import (
	"bytes"
	"fmt"
)

func main() {
	var buf bytes.Buffer

	buf.WriteString("Hello")
	buf.WriteString(" World!")
	fmt.Println(buf.String()) // Output : Hello World!
}

2. Buffering with bufio.Writer

The bufio package provides buffering for io.Writer and io.Reader interfaces. This is particularly useful when working with files or network I/O to reduce the number of I/O operations, which can improve performance.

package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	// Create a file
	file, err := os.Create("example.txt")
	if err != nil {
		fmt.Println("Error creating file:", err)
		return
	}
	defer file.Close()

	// Create a buffered writer
	writer := bufio.NewWriter(file)

	// Write data to buffer (not directly to the file)
	writer.WriteString("Buffered writing to a file1.\n")
	writer.WriteString("Buffered writing to a file2.\n")

	// Flush the buffer to write data to the file
	writer.Flush()
}