chess.go

package main

import (
	"bufio"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"sync/atomic"
)

type Stats struct {
	Wins  int64
	Draws int64
	Loses int64
}

func process(chfn chan string, global *Stats) {

	var local Stats
	for fn := range chfn {
		f, err := os.Open(fn)
		if err != nil {
			fmt.Fprintln(os.Stderr, fn, err)
			return
		}
		defer f.Close()

		scan := bufio.NewScanner(f)
		for scan.Scan() {
			line := scan.Text()
			if strings.HasPrefix(line, "[Result ") {
				if idx := strings.IndexByte(line, '-'); idx >= 0 {
					switch line[idx-1] {
					case '0':
						local.Loses += 1
					case '1':
						local.Wins += 1
					case '2':
						local.Draws += 1
					}
				}
			}
		}
	}

	atomic.AddInt64(&global.Wins, local.Wins)
	atomic.AddInt64(&global.Draws, local.Draws)
	atomic.AddInt64(&global.Loses, local.Loses)
}

func main() {

	var s Stats
	numfiles := 0

	var exitwg sync.WaitGroup

	chfn := make(chan string)
	for i := 0; i < 16; i++ {
		exitwg.Add(1)
		go func() {
			process(chfn, &s)
			exitwg.Done()
		}()
	}

	filepath.Walk(".", func(path string, info os.FileInfo, err error) error {
		if err == nil && strings.HasSuffix(path, ".pgn") {
			chfn <- path
			numfiles++
		}
		return nil
	})

	close(chfn)
	exitwg.Wait()

	fmt.Printf("%d %+v\n", numfiles, s)
}