parallel.go

package main

import (
	"bufio"
	"fmt"
	"io"
	"log"
	"os"
	"strings"
	"sync"

	"github.com/jmoiron/sqlx"
)

const maxPacketSize = 16777216

func readDump(path string) {
	file, err := os.Open(path)
	if err != nil {
		log.Println(err)
	}
	log.Println("Opened file", path, "for reading")
	defer file.Close()
	wg := new(sync.WaitGroup)
	rows := make(chan string)
	for w := 1; w <= 4; w++ {
		wg.Add(1)
		go insertRow(rows, wg, w)
	}

	go func() {
		r := bufio.NewReaderSize(file, maxPacketSize)
		for {
			line, err := r.ReadString(10)
			if err == io.EOF {
				break
			}
			rows <- line
		}
		close(rows)
	}()

	// Wait for goroutines to finish
	wg.Wait()

}

func insertRow(rows <-chan string, wg *sync.WaitGroup, w int) {
	defer wg.Done()
	db, err := sqlx.Connect("mysql", dsn)
	if err != nil {
		log.Println("Error connecting to database: ", err)
	}
	defer db.Close()
	for row := range rows {
		if strings.HasPrefix(row, "INSERT INTO") {
			var srow string
			if len(row) > 100 {
				srow = row[:100]
			} else {
				srow = row
			}
			// This is our row to insert
			fmt.Println(fmt.Sprintf("[%d]", w), srow)
			_, err := db.Exec(row)
			if err != nil {
				log.Println("Error executing query: ", err)
			}
		}
	}
}