Merge pull request #5 from Nucrea/feature/url-shortener

Feature/url shortener

.gitignore

@@ -21,5 +21,14 @@
 go.work
 go.work.sum
 
+# Binary dir
+.build/
+
 # env file
 .env
+
+.run
+
+# temporary
+coworker/
+webapp/

dockerfile

@@ -8,6 +8,7 @@ RUN go mod download && go mod verify
 EXPOSE 8080
 
 COPY . .
-RUN go build -v -o /usr/local/bin/app ./...
+RUN go build -v -o ./app .
+RUN chmod +x ./app
 
-CMD ["app"]
+CMD ["./app", "-c", "./misc/config.yaml"]

main.go

@@ -1,15 +1,16 @@
 package main
 
 import (
-	"backend/args_parser"
+	"backend/src/args_parser"
-	"backend/config"
+	"backend/src/client_notifier"
-	"backend/logger"
+	"backend/src/config"
-	"backend/src/handlers"
+	"backend/src/core/models"
-	"backend/src/middleware"
+	"backend/src/core/repos"
-	"backend/src/models"
+	"backend/src/core/services"
-	"backend/src/repo"
+	"backend/src/core/utils"
-	"backend/src/services"
+	"backend/src/logger"
-	"backend/src/utils"
+	"backend/src/server/handlers"
+	"backend/src/server/middleware"
 	"crypto/rsa"
 	"crypto/x509"
 	"database/sql"
@@ -75,10 +76,12 @@ func main() {
 
 	jwtUtil := utils.NewJwtUtil(key)
 	passwordUtil := utils.NewPasswordUtil()
-	userRepo := repo.NewUserRepo(sqlDb)
+	userRepo := repos.NewUserRepo(sqlDb)
-	userCache := repo.NewCacheInmem[string, models.UserDTO](60 * 60)
+	userCache := repos.NewCacheInmem[string, models.UserDTO](60 * 60)
-	emailRepo := repo.NewEmailRepo()
+	emailRepo := repos.NewEmailRepo()
-	actionTokenRepo := repo.NewActionTokenRepo(sqlDb)
+	actionTokenRepo := repos.NewActionTokenRepo(sqlDb)
+
+	clientNotifier := client_notifier.NewBasicNotifier()
 
 	userService := services.NewUserService(
 		services.UserServiceDeps{
@@ -92,7 +95,7 @@ func main() {
 	)
 	linkService := services.NewShortlinkSevice(
 		services.NewShortlinkServiceParams{
-			Cache: repo.NewCacheInmem[string, string](7 * 24 * 60 * 60),
+			Cache: repos.NewCacheInmem[string, string](7 * 24 * 60 * 60),
 		},
 	)
 
@@ -116,6 +119,9 @@ func main() {
 	dummyGroup.Use(middleware.NewAuthMiddleware(userService))
 	dummyGroup.GET("/", handlers.NewDummyHandler())
 
+	lpGroup := r.Group("/pooling")
+	lpGroup.GET("/", handlers.NewLongPoolingHandler(clientNotifier))
+
 	listenAddr := fmt.Sprintf(":%d", conf.GetPort())
 	logger.Log().Msgf("server listening on %s", listenAddr)
 

makefile

@@ -0,0 +1,4 @@
+all: release
+
+release:
+	go build -o ./.build/release/backend main.go

src/client_notifier/event.go

@@ -0,0 +1,12 @@
+package client_notifier
+
+type Event struct {
+	Type EventType
+	Data []byte
+}
+
+type EventType string
+
+const (
+	EventTypeEmailConfirmed EventType = "event_email_confirmed"
+)

src/client_notifier/notifier.go

@@ -0,0 +1,57 @@
+package client_notifier
+
+import "sync"
+
+type ClientNotifier interface {
+	RegisterClient(id string) <-chan Event
+	UnregisterClient(id string)
+	NotifyClient(id string, e Event)
+}
+
+type client struct {
+	id        string
+	eventChan chan Event
+}
+
+func NewBasicNotifier() ClientNotifier {
+	return &basicNotifier{
+		m:       &sync.RWMutex{},
+		clients: map[string]client{},
+	}
+}
+
+type basicNotifier struct {
+	m       *sync.RWMutex
+	clients map[string]client
+}
+
+func (p *basicNotifier) RegisterClient(id string) <-chan Event {
+	p.m.Lock()
+	defer p.m.Unlock()
+
+	eventChan := make(chan Event)
+	p.clients[id] = client{
+		id:        id,
+		eventChan: eventChan,
+	}
+
+	return eventChan
+}
+
+func (p *basicNotifier) UnregisterClient(id string) {
+	p.m.Lock()
+	defer p.m.Unlock()
+
+	delete(p.clients, id)
+}
+
+func (p *basicNotifier) NotifyClient(id string, e Event) {
+	p.m.RLock()
+	defer p.m.RUnlock()
+
+	client, ok := p.clients[id]
+	if !ok {
+		return
+	}
+	client.eventChan <- e
+}

src/core/repos/action_token.go

@@ -1,7 +1,7 @@
-package repo
+package repos
 
 import (
-	"backend/src/models"
+	"backend/src/core/models"
 	"context"
 	"database/sql"
 )

src/core/repos/cache_inmem.go

@@ -1,4 +1,4 @@
-package repo
+package repos
 
 import (
 	"sync"

src/core/repos/email_repo.go

@@ -1,4 +1,4 @@
-package repo
+package repos
 
 import (
 	"strings"

src/core/repos/user_repo.go

@@ -1,7 +1,7 @@
-package repo
+package repos
 
 import (
-	"backend/src/models"
+	"backend/src/core/models"
 	"context"
 	"database/sql"
 	"errors"

src/core/services/shortlink_service.go

@@ -1,11 +1,9 @@
 package services
 
 import (
-	"backend/src/repo"
+	"backend/src/core/repos"
+	"backend/src/core/utils"
 	"fmt"
-	"math/rand"
-	"strings"
-	"time"
 )
 
 type ShortlinkService interface {
@@ -15,38 +13,23 @@ type ShortlinkService interface {
 
 type NewShortlinkServiceParams struct {
 	Endpoint string
-	Cache    repo.Cache[string, string]
+	Cache    repos.Cache[string, string]
 }
 
 func NewShortlinkSevice(params NewShortlinkServiceParams) ShortlinkService {
 	return &shortlinkService{
+		randomUtil: *utils.NewRand(),
 		cache:      params.Cache,
 	}
 }
 
 type shortlinkService struct {
-	cache repo.Cache[string, string]
+	randomUtil utils.RandomUtil
-}
+	cache      repos.Cache[string, string]
-
-func (s *shortlinkService) randomStr() string {
-	src := rand.NewSource(time.Now().UnixMicro())
-	randGen := rand.New(src)
-
-	builder := strings.Builder{}
-	for i := 0; i < 9; i++ {
-		offset := 0x41
-		if randGen.Int()%2 == 1 {
-			offset = 0x61
-		}
-
-		byte := offset + (randGen.Int() % 26)
-		builder.WriteRune(rune(byte))
-	}
-	return builder.String()
 }
 
 func (s *shortlinkService) CreateLink(in string) (string, error) {
-	str := s.randomStr()
+	str := s.randomUtil.RandomID(10, utils.CharsetAll)
 	s.cache.Set(str, in, 7*24*60*60)
 	return str, nil
 }

src/core/services/user_service.go

@@ -1,9 +1,9 @@
 package services
 
 import (
-	"backend/src/models"
+	"backend/src/core/models"
-	"backend/src/repo"
+	"backend/src/core/repos"
-	"backend/src/utils"
+	"backend/src/core/utils"
 	"context"
 	"fmt"
 
@@ -32,10 +32,10 @@ func NewUserService(deps UserServiceDeps) UserService {
 type UserServiceDeps struct {
 	Jwt             utils.JwtUtil
 	Password        utils.PasswordUtil
-	UserRepo        repo.UserRepo
+	UserRepo        repos.UserRepo
-	UserCache       repo.Cache[string, models.UserDTO]
+	UserCache       repos.Cache[string, models.UserDTO]
-	EmailRepo       repo.EmailRepo
+	EmailRepo       repos.EmailRepo
-	ActionTokenRepo repo.ActionTokenRepo
+	ActionTokenRepo repos.ActionTokenRepo
 }
 
 type userService struct {

src/core/utils/random.go

@@ -0,0 +1,70 @@
+package utils
+
+import (
+	"math/rand"
+	"strings"
+	"time"
+)
+
+type Charset int
+
+const (
+	CharsetAll Charset = iota
+	CharsetLettersLower
+	CharsetLettersUpper
+	CharsetLetters
+	CharsetNumeric
+)
+
+type charsetPart struct {
+	Offset int
+	Size   int
+}
+
+var charsets = map[Charset][]charsetPart{}
+
+func NewRand() *RandomUtil {
+	charsetLettersLower := charsetPart{ //CharsetLettersLower
+		Offset: 0x41,
+		Size:   26,
+	}
+
+	charsetLettersUpper := charsetPart{ //CharsetLettersUpper
+		Offset: 0x61,
+		Size:   26,
+	}
+
+	charsetNumeric := charsetPart{ //CharsetLettersNumeric
+		Offset: 0x30,
+		Size:   10,
+	}
+
+	charsets = map[Charset][]charsetPart{
+		CharsetNumeric:      {charsetNumeric},
+		CharsetLettersLower: {charsetLettersLower},
+		CharsetLettersUpper: {charsetLettersUpper},
+		CharsetLetters:      {charsetLettersLower, charsetLettersUpper},
+		CharsetAll:          {charsetLettersLower, charsetLettersUpper, charsetNumeric},
+	}
+
+	return &RandomUtil{}
+}
+
+type RandomUtil struct{}
+
+func (r *RandomUtil) RandomID(outputLenght int, charset Charset) string {
+	src := rand.NewSource(time.Now().UnixMicro())
+	randGen := rand.New(src)
+
+	charsetData := charsets[charset]
+
+	builder := strings.Builder{}
+	for i := 0; i < outputLenght; i++ {
+		charsetIdx := randGen.Int() % len(charsetData)
+		charsetPart := charsetData[charsetIdx]
+
+		byte := charsetPart.Offset + (randGen.Int() % charsetPart.Size)
+		builder.WriteRune(rune(byte))
+	}
+	return builder.String()
+}

src/leader_elector/elector.go

@@ -0,0 +1,25 @@
+package leader_elector
+
+import (
+	"context"
+	"database/sql"
+)
+
+func Lock(ctx context.Context, db *sql.DB, lockName, id string) error {
+	query := `
+	update locks (id)
+		set id = $1
+		where name == lockName and timestamp < $1 returning id
+	on conflict
+		insert into locks(id, name) values($1, $2);`
+
+	row := db.QueryRowContext(ctx, query, id)
+
+	result := ""
+	err := row.Scan(&result)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

src/server/handlers/long_pooling_handler.go

@@ -0,0 +1,27 @@
+package handlers
+
+import (
+	"backend/src/client_notifier"
+	"backend/src/server/utils"
+
+	"github.com/gin-gonic/gin"
+)
+
+func NewLongPoolingHandler(notifier client_notifier.ClientNotifier) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		user := utils.GetUserFromRequest(c)
+		if user == nil {
+			c.Data(403, "plain/text", []byte("Unauthorized"))
+			return
+		}
+
+		eventChan := notifier.RegisterClient(user.Id)
+
+		select {
+		case <-c.Done():
+			notifier.UnregisterClient(user.Id)
+		case event := <-eventChan:
+			c.Data(200, "application/json", event.Data)
+		}
+	}
+}

src/server/handlers/shortlink_handlers.go

@@ -1,7 +1,7 @@
 package handlers
 
 import (
-	"backend/src/services"
+	"backend/src/core/services"
 	"encoding/json"
 	"fmt"
 	"net/url"

src/server/handlers/user_create_handler.go

@@ -1,7 +1,7 @@
 package handlers
 
 import (
-	"backend/src/services"
+	"backend/src/core/services"
 	"encoding/json"
 
 	"github.com/gin-gonic/gin"

src/server/handlers/user_login_handler.go

@@ -1,7 +1,7 @@
 package handlers
 
 import (
-	"backend/src/services"
+	"backend/src/core/services"
 	"encoding/json"
 
 	"github.com/gin-gonic/gin"

src/server/middleware/auth.go

@@ -1,7 +1,7 @@
 package middleware
 
 import (
-	"backend/src/services"
+	"backend/src/core/services"
 	"fmt"
 
 	"github.com/gin-gonic/gin"

src/server/middleware/request_log.go

@@ -1,7 +1,7 @@
 package middleware
 
 import (
-	"backend/logger"
+	"backend/src/logger"
 	"time"
 
 	"github.com/gin-gonic/gin"

src/server/utils/user.go

@@ -0,0 +1,14 @@
+package utils
+
+import (
+	"backend/src/core/models"
+
+	"github.com/gin-gonic/gin"
+)
+
+func GetUserFromRequest(c *gin.Context) *models.UserDTO {
+	if user, ok := c.Get("user"); ok {
+		return user.(*models.UserDTO)
+	}
+	return nil
+}