1.前書き
TILE38のクライアントプログラムのサンプルを見たくて、色々探していたら、「TILE38紹介」を紹介するという、非常に良いページを見つけました。
私がプログラムを良く忘れるので、このページのプログラムをそのままコピペさせて頂いて、私の備忘録とさせて頂きます(私の環境では、コメントアウト等がちょっと違ったようです)
2. 前提
Tile38のサーバを立ち上げておきます。Dockerを使って立ち上げておくと簡単です。dockerを使わない方法は、https://github.com/tidwall/tile38 に記載があります。
docker pull tile38/tile38
docker run -p 9851:9851 tile38/tile38
3. サンプルプログラム
(1つ目)
package main
import (
//"encoding/json"
"fmt"
"log"
//"reflect"
"github.com/garyburd/redigo/redis"
)
func main() {
// db connect
c, err := redis.Dial("tcp", ":9851")
if err != nil {
log.Fatalf("Could not connect: %v\n", err)
}
defer c.Close()
// SET location
ret, err := c.Do("SET", "location", "me", "POINT", 35.6581, 139.6975)
if err != nil {
log.Fatalf("Could not SET: %v\n", err)
}
fmt.Printf("SET ret:%s\n", ret)
// GET location
ret, err = c.Do("GET", "location", "me")
if err != nil {
log.Fatalf("Could not GET: %v\n", err)
}
fmt.Printf("GET ret:%s\n", ret)
}
(2つめ)
package main
import (
"encoding/json"
"fmt"
"log"
"github.com/garyburd/redigo/redis"
)
type GeoJsonMember struct {
Type string `json:"type"`
CoordinatesRaw json.RawMessage `json:"coordinates,omitempty"`
CoordinatesObj interface{} `json:"-"`
}
type Point [2]float64
type LineString []Point
type Polygon []LineString
func (member *GeoJsonMember) String() string {
return fmt.Sprintf("%s %v", member.Type, member.CoordinatesObj)
}
func (member *GeoJsonMember) setCoordinates() error {
var coordinates interface{}
switch member.Type {
case "Point":
coordinates = new(Point)
case "LineString":
coordinates = new(LineString)
case "Polygon":
coordinates = new(Polygon)
default:
return fmt.Errorf("Unknown type: %v", member.Type)
}
err := json.Unmarshal(member.CoordinatesRaw, &coordinates)
if err != nil {
return fmt.Errorf("json.Unmarshal error: %v", err)
}
member.CoordinatesObj = coordinates
return nil
}
func unmarshalMultiResults(shapes []byte) ([]*GeoJsonMember, error) {
var members []*GeoJsonMember
err := json.Unmarshal(shapes, &members)
if err != nil {
return nil, fmt.Errorf("Unmarshal error: %v", err)
}
for i, member := range members {
err := member.setCoordinates()
if err != nil {
return nil, fmt.Errorf("member[%v]:type:%v coordinates:%v err:%v\n", i, member.Type, member.CoordinatesRaw, err)
}
}
return members, nil
}
func unmarshalSingleResult(shapes []byte) (*GeoJsonMember, error) {
var member GeoJsonMember
err := json.Unmarshal(shapes, &member)
if err != nil {
return nil, fmt.Errorf("Unmarshal error: %v", err)
}
err = member.setCoordinates()
if err != nil {
return nil, fmt.Errorf("type:%v coordinates:%v err:%v\n", member.Type, member.CoordinatesRaw, err)
}
return &member, nil
}
func main() {
// db connect
c, err := redis.Dial("tcp", ":9851")
if err != nil {
log.Fatalf("Could not connect: %v\n", err)
}
defer c.Close()
// SET fleet
for _, data := range [][]interface{}{
{"fleet", "id1", "FIELD", "start", "123456", "FIELD", "end", "789012", "POINT", 35.6581, 139.6975},
{"fleet", "id2", "OBJECT", `{"type":"Point","coordinates":[139.6975,35.6581]}`},
{"fleet", "id3", "OBJECT", `{"type":"LineString","coordinates":[[139.6975,35.6581],[1,1],[2,2]]}`},
{"fleet", "id4", "POINT", 35.6581, 139.6975},
} {
ret, err := c.Do("SET", data...)
if err != nil {
log.Fatalf("Could not SET: %v\n", err)
}
fmt.Printf("SET ret:%#s\n", ret)
}
// SCAN fleet
results, err := redis.Values(c.Do("SCAN", "fleet"))
if err != nil {
log.Fatalf("Could not SCAN: %v\n", err)
}
var cursor int
var members []interface{}
_, err = redis.Scan(results, &cursor, &members)
if err != nil {
fmt.Printf("scan result error: %v", err)
return
}
for len(members) > 0 {
// pick up one record from results as []interface{}
var object []interface{}
members, err = redis.Scan(members, &object)
if err != nil {
fmt.Printf("scan record error: %v", err)
return
}
// scan columns from one record -> [id,json],fields
var id []byte
var json []byte
others, err := redis.Scan(object, &id, &json)
if err != nil {
fmt.Printf("scan columns error: %v", err)
return
}
// unmarshal geojson string to struct
gjm, err := unmarshalSingleResult(json)
if err != nil {
fmt.Printf("unmarshal json error: %v", err)
return
}
fmt.Printf("id:%s json:%s others:%s\n", id, gjm, others)
}
}
4. PruneMobileと組み合わせてみる
ランダムウォークさせている歩行者が、一定のエリアに入った時に、メッセージを送付する。
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