Mobile Atlas Creator sqlitdb 图片导出

macimage.go

package main

import (
	"flag"
	"fmt"
	"os"
	"path/filepath"

	"github.com/cheggaaa/pb"
	"github.com/typepress/db"
	_ "github.com/typepress/db/sqlite"
)

func main() {
	flag.Parse()
	if dir == "" {
		dir, _ = os.Getwd()
		dir = filepath.Join(dir, fmt.Sprint(z))
	}
	settings := db.Settings{
		Database: sqlitdb,
	}
	dbh, err := db.Open("sqlite", settings)
	if err != nil {
		fmt.Println(err)
		flag.Usage()
		return
	}
	defer dbh.Close()
	tiles, err := dbh.Collection("tiles")
	if err != nil {
		fmt.Println(err)
		return
	}
	t := Tiles{}
	err = tiles.Find().Sort(`-x`, `-y`).One(&t)
	gX, gY := t.X, t.Y
	if err == nil {
		err = tiles.Find().Sort(`x`, `y`).One(&t)
		lX, lY = t.X, t.Y
	}
	res := tiles.Find()
	if err == nil {
		cnt, err = res.Count()
	}
	if err != nil {
		fmt.Println(err)
		return
	}
	pX := gX - lX + 1
	pY := gY - lY + 1
	if pX*pY != cnt {
		fmt.Println("error:", pX, pY, "not equal", cnt)
		return
	}
	defer res.Close()
	pX = uint64(len(fmt.Sprint(pX)))
	pY = uint64(len(fmt.Sprint(pY)))
	format = fmt.Sprintf("%dz%%.%ddx%%.%dd", z, pX, pY)
	bar := pb.StartNew(int(cnt))
	for {
		err = res.Next(&t)
		if err != nil {
			if err != db.ErrNoMoreRows {
				fmt.Println(err)
				return
			} else {
				bar.FinishPrint("The End!")
				break
			}
		}
		storeImg(&t)
		bar.Increment()
	}
}

var z int = 17
var dir string
var sqlitdb string
var cnt, lX, lY uint64
var format string

func init() {
	flag.IntVar(&z, "z", 0, "zoom level")
	flag.StringVar(&dir, "o", "", "directory for output")
	flag.StringVar(&sqlitdb, "db", "", "Mobile Atlas Creator sqlitdb full filename")
}

type Tiles struct {
	X     uint64 `field:"x"`
	Y     uint64 `field:"y"`
	Image string `field:"image"`
}

const JPG = "\xff\xd8" // FF E0|E1|E2|E3|E8
const PNG = "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A"

func storeImg(t *Tiles) {
	name := fmt.Sprintf(format, t.Y-lY, t.X-lX)
	if len(t.Image) < 8 {
		fmt.Printf("Unknow image format: %x : %s \n", name, t.Image[:])
		return
	}
	var ext string
	if JPG == string(t.Image[:2]) {
		ext = ".jpg"
	} else if PNG == string(t.Image[:8]) {
		ext = ".png"
	} else {
		fmt.Printf("Unknow image format: %x : %s \n", name, t.Image[:8])
		return
	}
	f, err := os.Create(filepath.Join(dir, name+ext))
	if err != nil {
		fmt.Println(err)
		return
	}
	defer f.Close()
	f.WriteString(t.Image)
}