Add location service (micro#29)

* Add location service

* Update README.md

go.mod

@@ -8,6 +8,7 @@ require (
 	github.com/golang/protobuf v1.4.3
 	github.com/google/uuid v1.1.2
 	github.com/gosimple/slug v1.9.0
+	github.com/hailocab/go-geoindex v0.0.0-20160127134810-64631bfe9711
 	github.com/micro/dev v0.0.0-20201111162228-80c2b20de2db
 	github.com/micro/go-micro/v2 v2.9.1 // indirect
 	github.com/micro/micro/v3 v3.0.0-beta.7

go.sum

@@ -260,6 +260,8 @@ github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgf
 github.com/grpc-ecosystem/grpc-gateway v1.8.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/grpc-ecosystem/grpc-gateway v1.9.5/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
 github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542/go.mod h1:Ow0tF8D4Kplbc8s8sSb3V2oUCygFHVp8gC3Dn6U4MNI=
+github.com/hailocab/go-geoindex v0.0.0-20160127134810-64631bfe9711 h1:Oi8hPOZX0gaM2sPVXse2bMpfOjP47a7O61YuB6Z4sGk=
+github.com/hailocab/go-geoindex v0.0.0-20160127134810-64631bfe9711/go.mod h1:+v2qJ3UZe4q2GfgZO4od004F/cMgJbmPSs7dD/ZMUkY=
 github.com/hashicorp/errwrap v0.0.0-20141028054710-7554cd9344ce/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
 github.com/hashicorp/go-cleanhttp v0.5.1 h1:dH3aiDG9Jvb5r5+bYHsikaOUIpcM0xvgMXVoDkXMzJM=
 github.com/hashicorp/go-cleanhttp v0.5.1/go.mod h1:JpRdi6/HCYpAwUzNwuwqhbovhLtngrth3wmdIIUrZ80=

location/.gitignore

@@ -0,0 +1,2 @@
+
+location

location/Dockerfile

@@ -0,0 +1,3 @@
+FROM alpine
+ADD location /location
+ENTRYPOINT [ "/location" ]

location/Makefile

@@ -0,0 +1,22 @@
+
+GOPATH:=$(shell go env GOPATH)
+.PHONY: init
+init:
+	go get -u github.com/golang/protobuf/proto
+	go get -u github.com/golang/protobuf/protoc-gen-go
+	go get github.com/micro/micro/v3/cmd/protoc-gen-micro
+.PHONY: proto
+proto:
+	protoc --proto_path=. --micro_out=. --go_out=:. proto/location.proto
+
+.PHONY: build
+build:
+	go build -o location *.go
+
+.PHONY: test
+test:
+	go test -v ./... -cover
+
+.PHONY: docker
+docker:
+	docker build . -t location:latest

location/README.md

@@ -0,0 +1,23 @@
+# Location Service
+
+A realtime GPS location tracking and search service
+
+Generated with
+
+```
+micro new location
+```
+
+## Usage
+
+Generate the proto code
+
+```
+make proto
+```
+
+Run the service
+
+```
+micro run .
+```

location/domain/domain.go

@@ -0,0 +1,104 @@
+package domain
+
+import (
+	"sync"
+
+	geo "github.com/hailocab/go-geoindex"
+	"github.com/micro/micro/v3/service/errors"
+	common "github.com/micro/services/location/proto"
+)
+
+var (
+	mtx          sync.RWMutex
+	defaultIndex = geo.NewPointsIndex(geo.Km(0.5))
+)
+
+type Entity struct {
+	ID        string
+	Type      string
+	Latitude  float64
+	Longitude float64
+	Timestamp int64
+}
+
+func (e *Entity) Id() string {
+	return e.ID
+}
+
+func (e *Entity) Lat() float64 {
+	return e.Latitude
+}
+
+func (e *Entity) Lon() float64 {
+	return e.Longitude
+}
+
+func (e *Entity) ToProto() *common.Entity {
+	return &common.Entity{
+		Id:   e.ID,
+		Type: e.Type,
+		Location: &common.Point{
+			Latitude:  e.Latitude,
+			Longitude: e.Longitude,
+			Timestamp: e.Timestamp,
+		},
+	}
+}
+
+func ProtoToEntity(e *common.Entity) *Entity {
+	return &Entity{
+		ID:        e.Id,
+		Type:      e.Type,
+		Latitude:  e.Location.Latitude,
+		Longitude: e.Location.Longitude,
+		Timestamp: e.Location.Timestamp,
+	}
+}
+
+func Read(id string) (*Entity, error) {
+	mtx.RLock()
+	defer mtx.RUnlock()
+
+	p := defaultIndex.Get(id)
+	if p == nil {
+		return nil, errors.NotFound("location.read", "Not found")
+	}
+
+	entity, ok := p.(*Entity)
+	if !ok {
+		return nil, errors.InternalServerError("location.read", "Error reading entity")
+	}
+
+	return entity, nil
+}
+
+func Save(e *Entity) {
+	mtx.Lock()
+	defaultIndex.Add(e)
+	mtx.Unlock()
+}
+
+func Search(typ string, entity *Entity, radius float64, numEntities int) []*Entity {
+	mtx.RLock()
+	defer mtx.RUnlock()
+
+	points := defaultIndex.KNearest(entity, numEntities, geo.Meters(radius), func(p geo.Point) bool {
+		e, ok := p.(*Entity)
+		if !ok || e.Type != typ {
+			return false
+		}
+		return true
+	})
+
+	var entities []*Entity
+
+	for _, point := range points {
+		e, ok := point.(*Entity)
+		if !ok {
+			continue
+		}
+		entities = append(entities, e)
+	}
+
+	return entities
+}

location/generate.go

@@ -0,0 +1,3 @@
+package main
+
+//go:generate make proto

location/handler/handler.go

@@ -0,0 +1,67 @@
+package handler
+
+import (
+	"context"
+	"log"
+
+	"github.com/micro/micro/v3/service"
+	"github.com/micro/micro/v3/service/errors"
+	"github.com/micro/services/location/domain"
+	loc "github.com/micro/services/location/proto"
+	"github.com/micro/services/location/subscriber"
+)
+
+type Location struct{}
+
+func (l *Location) Read(ctx context.Context, req *loc.ReadRequest, rsp *loc.ReadResponse) error {
+	log.Print("Received Location.Read request")
+
+	id := req.Id
+
+	if len(id) == 0 {
+		return errors.BadRequest("location.read", "Require Id")
+	}
+
+	entity, err := domain.Read(id)
+	if err != nil {
+		return err
+	}
+
+	rsp.Entity = entity.ToProto()
+
+	return nil
+}
+
+func (l *Location) Save(ctx context.Context, req *loc.SaveRequest, rsp *loc.SaveResponse) error {
+	log.Print("Received Location.Save request")
+
+	entity := req.GetEntity()
+
+	if entity.GetLocation() == nil {
+		return errors.BadRequest("location.save", "Require location")
+	}
+
+	p := service.NewEvent(subscriber.Topic)
+	if err := p.Publish(ctx, entity); err != nil {
+		return errors.InternalServerError("location.save", err.Error())
+	}
+
+	return nil
+}
+
+func (l *Location) Search(ctx context.Context, req *loc.SearchRequest, rsp *loc.SearchResponse) error {
+	log.Print("Received Location.Search request")
+
+	entity := &domain.Entity{
+		Latitude:  req.Center.Latitude,
+		Longitude: req.Center.Longitude,
+	}
+
+	entities := domain.Search(req.Type, entity, req.Radius, int(req.NumEntities))
+
+	for _, e := range entities {
+		rsp.Entities = append(rsp.Entities, e.ToProto())
+	}
+
+	return nil
+}

location/main.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"log"
+
+	"github.com/micro/micro/v3/service"
+	"github.com/micro/services/location/handler"
+	pb "github.com/micro/services/location/proto"
+	"github.com/micro/services/location/subscriber"
+)
+
+func main() {
+	location := service.New(
+		service.Name("location"),
+	)
+
+	pb.RegisterLocationHandler(location.Server(), new(handler.Location))
+
+	service.Subscribe(subscriber.Topic, new(subscriber.Location))
+
+	if err := location.Run(); err != nil {
+		log.Fatal(err)
+	}
+}

location/micro.mu

@@ -0,0 +1 @@
+service location