challenge.go

package main

import (
	"bufio"
	"fmt"
	"log"
	"os"
	"runtime"
	"strings"
	"sync"
)

func init() {
	runtime.GOMAXPROCS(runtime.NumCPU())
}

func main() {
	file, err := os.Open("muestra.log")
	if err != nil {
		log.Fatalf("open file: %v", err)
	}
	defer file.Close()

	// Channels for the data
	lines := make(chan string)
	results := make(chan map[string]string)

	// This will tell us when we finished with all the lines
	var wg sync.WaitGroup

	go func() {
		scanner := bufio.NewScanner(file)
		for scanner.Scan() {
			wg.Add(1)
			lines <- scanner.Text()
		}
		if err := scanner.Err(); err != nil {
			log.Fatalf("scanning file: %v", err)
		}
		close(lines)
	}()

	keys := []string{
		"RemoteHost",
		"RemoteLogName",
		"RemoteUser",
		"TimeReceived",
		"RequestMethod",
		"RequestURL",
		"RequestHTTP",
		"Status",
		"ResponseBytes",
		"RequestHeaderUserAgent",
		"Cached",
		"ContentType",
		"Node",
		"RTime",
		"Company",
		"Referrer",
	}

	// This will be invoked every time a line is available
	for line := range lines {
		go func(line string) {
			// Free up a WaitGroup
			defer wg.Done()

			r := make(map[string]string)

			// Split the line
			segments := strings.Split(line, " ")

			for i, k := range keys {
				// Prevent index out of range runtime error
				if i > len(segments) {
					break
				}

				switch k {
				case "TimeReceived":
					r[k] = strings.Trim(segments[i], "[]")
				case "RequestMethod":
					r[k] = strings.TrimLeft(segments[i], "\"")
				case "RequestHTTP":
					r[k] = strings.TrimRight(segments[i], "\"")
				default:
					r[k] = segments[i]
				}
			}

			results <- r
		}(line)
	}

	// Close the results channell once all the data was consumed
	go func() {
		wg.Wait()
		close(results)
	}()

	// Read all your sweet results here. Do whatever you want with them
	count := 0
	for range results {
		count++
	}

	// To read your result:
	// for r := range results {
	// 	// Do something witht r
	// }

	fmt.Printf("Processed %v lines\n", count)
}