extractnumbers.go

package main

import (
	"fmt"
	"github.com/qedus/osmpbf"
	"io"
	"log"
	"os"
	"runtime"
	"time"
)

type CountRecord struct {
	Uid       int32
	Timestamp time.Time
}

func main() {
	nCPU := runtime.NumCPU()
	runtime.GOMAXPROCS(nCPU)

	if len(os.Args) != 2 {
		fmt.Println("Pass in path to metro extract")
		os.Exit(1)
	}
	f, err := os.Open(os.Args[1])
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	d := osmpbf.NewDecoder(f)
	err = d.Start(nCPU)
	if err != nil {
		log.Fatal(err)
	}

	countChan := make(chan *CountRecord, 255)
	doneCounting := make(chan bool)

	now := time.Now()
	yearsAgo := 0
	monthsAgo := 0
	daysAgo := 90
	cutoff := now.AddDate(-yearsAgo, -monthsAgo, -daysAgo)

	users := make(map[int32]int)
	nFeatures := 0

	go func() {
		for cr := range countChan {
			if cutoff.After(cr.Timestamp) {
				continue
			}
			users[cr.Uid]++
			nFeatures++
		}
		doneCounting <- true
	}()

	for {
		if v, err := d.Decode(); err == io.EOF {
			break
		} else if err != nil {
			log.Fatal(err)
		} else {
			switch v := v.(type) {
			case *osmpbf.Node:
				countChan <- &CountRecord{
					Uid:       v.Info.Uid,
					Timestamp: v.Info.Timestamp,
				}
			case *osmpbf.Way:
				countChan <- &CountRecord{
					Uid:       v.Info.Uid,
					Timestamp: v.Info.Timestamp,
				}
			case *osmpbf.Relation:
				countChan <- &CountRecord{
					Uid:       v.Info.Uid,
					Timestamp: v.Info.Timestamp,
				}
			default:
				log.Fatalf("unknown type %T\n", v)
			}
		}
	}
	close(countChan)
	<-doneCounting

	nUsers := len(users)
	fmt.Printf("Active users: %d\n", nUsers)
	fmt.Printf("Features updated: %d\n", nFeatures)

}