Implement command pipelining, finish LIST ACTIVE command implementation

README.md

@@ -14,7 +14,7 @@
 #### Commands
 - :heavy_check_mark: `CAPABILITIES`
 - :heavy_check_mark: `DATE`
-- :construction: `LIST`
+- :heavy_check_mark: `LIST ACTIVE`
 - :heavy_check_mark: `LIST NEWSGROUPS`
 - :heavy_check_mark: `MODE READER`
 - :heavy_check_mark: `QUIT`

internal/backend/sqlite/migrations/001_init_schema.sql

@@ -3,10 +3,11 @@
 CREATE TABLE IF NOT EXISTS groups(
     id INTEGER PRIMARY KEY AUTOINCREMENT,
     group_name TEXT UNIQUE NOT NULL,
-    description TEXT
+    description TEXT,
+    created_at UNSIGNED BIG INT NOT NULL
 );
 CREATE TABLE IF NOT EXISTS articles(
-    id TEXT PRIMARY KEY,
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
     date INTEGER NOT NULL,
     path TEXT,
     reply_to TEXT,
@@ -15,7 +16,7 @@ CREATE TABLE IF NOT EXISTS articles(
     body TEXT NOT NULL
 );
 CREATE TABLE IF NOT EXISTS articles_to_groups(
-    article_id TEXT NOT NULL,
+    article_id INTEGER NOT NULL,
     group_id INTEGER NOT NULL,
     FOREIGN KEY (article_id) REFERENCES articles(id) ON DELETE CASCADE,
     FOREIGN KEY (group_id) REFERENCES groups(id) ON DELETE CASCADE

internal/backend/sqlite/sqlite.go

@@ -43,5 +43,15 @@ func (sb *SQLiteBackend) ListGroups() ([]models.Group, error) {
 
 func (sb *SQLiteBackend) GetArticlesCount(g models.Group) (int, error) {
 	var count int
-	return count, sb.db.Select(&count, "SELECT COUNT(*) FROM articles_to_groups WHERE group_id = ?", g.ID)
+	return count, sb.db.Get(&count, "SELECT COUNT(*) FROM articles_to_groups WHERE group_id = ?", g.ID)
+}
+
+func (sb *SQLiteBackend) GetGroupHighWaterMark(g models.Group) (int, error) {
+	var waterMark int
+	return waterMark, sb.db.Get(&waterMark, "SELECT article_id FROM articles_to_groups WHERE group_id = ? ORDER BY article_id DESC LIMIT 1", g.ID)
+}
+
+func (sb *SQLiteBackend) GetGroupLowWaterMark(g models.Group) (int, error) {
+	var waterMark int
+	return waterMark, sb.db.Get(&waterMark, "SELECT article_id FROM articles_to_groups WHERE group_id = ? ORDER BY article_id LIMIT 1", g.ID)
 }

internal/backend/storage_backend.go

@@ -9,4 +9,6 @@ const (
 type StorageBackend interface {
 	ListGroups() ([]models.Group, error)
 	GetArticlesCount(g models.Group) (int, error)
+	GetGroupLowWaterMark(g models.Group) (int, error)
+	GetGroupHighWaterMark(g models.Group) (int, error)
 }

internal/models/group.go

@@ -4,4 +4,5 @@ type Group struct {
 	ID          int     `db:"id"`
 	GroupName   string  `db:"group_name"`
 	Description *string `db:"description"`
+	CreatedAt   uint64  `db:"created_at"`
 }

internal/protocol/constants.go

@@ -29,7 +29,7 @@ const (
 const (
 	MessageNNTPServiceReadyPostingProhibited = "201 YANS NNTP Service Ready, posting prohibited"
 	MessageReaderModePostingProhibited       = "201 Reader mode, posting prohibited"
-	MessageNNTPServiceExitsNormally          = "205 NNTP Service exits normally"
+	MessageNNTPServiceExitsNormally          = "205 NNTP Service exits normally, bye!"
 	MessageUnknownCommand                    = "500 Unknown command"
 	MessageErrorHappened                     = "403 Failed to process command:"
 	MessageListOfNewsgroupsFollows           = "215 list of newsgroups follows"

internal/server/handler.go

@@ -9,14 +9,14 @@ import (
 )
 
 type Handler struct {
-	handlers map[string]func(s *Session, arguments []string) error
+	handlers map[string]func(s *Session, arguments []string, id uint) error
 	backend  backend.StorageBackend
 }
 
 func NewHandler(b backend.StorageBackend) *Handler {
 	h := &Handler{}
 	h.backend = b
-	h.handlers = map[string]func(s *Session, arguments []string) error{
+	h.handlers = map[string]func(s *Session, arguments []string, id uint) error{
 		protocol.CommandCapabilities: h.handleCapabilities,
 		protocol.CommandDate:         h.handleDate,
 		protocol.CommandQuit:         h.handleQuit,
@@ -26,21 +26,25 @@ func NewHandler(b backend.StorageBackend) *Handler {
 	return h
 }
 
-func (h *Handler) handleCapabilities(s *Session, arguments []string) error {
+func (h *Handler) handleCapabilities(s *Session, arguments []string, id uint) error {
+	s.tconn.StartResponse(id)
+	defer s.tconn.EndResponse(id)
 	return s.tconn.PrintfLine(s.capabilities.String())
 }
 
-func (h *Handler) handleDate(s *Session, arguments []string) error {
+func (h *Handler) handleDate(s *Session, arguments []string, id uint) error {
+	s.tconn.StartResponse(id)
+	defer s.tconn.EndResponse(id)
 	return s.tconn.PrintfLine("111 %s", time.Now().UTC().Format("20060102150405"))
 }
 
-func (h *Handler) handleQuit(s *Session, arguments []string) error {
+func (h *Handler) handleQuit(s *Session, arguments []string, id uint) error {
 	s.tconn.PrintfLine(protocol.MessageNNTPServiceExitsNormally)
 	s.conn.Close()
 	return nil
 }
 
-func (h *Handler) handleList(s *Session, arguments []string) error {
+func (h *Handler) handleList(s *Session, arguments []string, id uint) error {
 	sb := strings.Builder{}
 
 	listType := ""
@@ -48,6 +52,9 @@ func (h *Handler) handleList(s *Session, arguments []string) error {
 		listType = arguments[0]
 	}
 
+	s.tconn.StartResponse(id)
+	defer s.tconn.EndResponse(id)
+
 	switch listType {
 	case "":
 		fallthrough
@@ -60,9 +67,25 @@ func (h *Handler) handleList(s *Session, arguments []string) error {
 			sb.Write([]byte(protocol.MessageListOfNewsgroupsFollows + protocol.CRLF))
 			for _, v := range groups {
 				// TODO set high/low mark and posting status to actual values
+				c, err := h.backend.GetArticlesCount(v)
+				if err != nil {
+					return err
+				}
+				if c > 0 {
+					highWaterMark, err := h.backend.GetGroupHighWaterMark(v)
+					if err != nil {
+						return err
+					}
+					lowWaterMark, err := h.backend.GetGroupLowWaterMark(v)
+					if err != nil {
+						return err
+					}
+					sb.Write([]byte(fmt.Sprintf("%s %d %d n"+protocol.CRLF, v.GroupName, highWaterMark, lowWaterMark)))
+				} else {
 					sb.Write([]byte(fmt.Sprintf("%s 0 0 n"+protocol.CRLF, v.GroupName)))
 				}
 			}
+		}
 	case "NEWSGROUPS":
 		{
 			groups, err := h.backend.ListGroups()
@@ -90,7 +113,7 @@ func (h *Handler) handleList(s *Session, arguments []string) error {
 	return s.tconn.PrintfLine(sb.String())
 }
 
-func (h *Handler) handleModeReader(s *Session, arguments []string) error {
+func (h *Handler) handleModeReader(s *Session, arguments []string, id uint) error {
 	if len(arguments) == 0 || arguments[0] != "READER" {
 		return s.tconn.PrintfLine(protocol.MessageSyntaxError)
 	}
@@ -104,7 +127,7 @@ func (h *Handler) handleModeReader(s *Session, arguments []string) error {
 	return s.tconn.PrintfLine(protocol.MessageReaderModePostingProhibited) // TODO vary on auth status
 }
 
-func (h *Handler) Handle(s *Session, message string) error {
+func (h *Handler) Handle(s *Session, message string, id uint) error {
 	splittedMessage := strings.Split(message, " ")
 	for i, v := range splittedMessage {
 		splittedMessage[i] = strings.TrimSpace(v)
@@ -112,7 +135,9 @@ func (h *Handler) Handle(s *Session, message string) error {
 	cmdName := splittedMessage[0]
 	handler, ok := h.handlers[cmdName]
 	if !ok {
+		s.tconn.StartResponse(id)
+		defer s.tconn.EndResponse(id)
 		return s.tconn.PrintfLine(protocol.MessageUnknownCommand)
 	}
-	return handler(s, splittedMessage[1:])
+	return handler(s, splittedMessage[1:], id)
 }

internal/server/session.go

@@ -70,6 +70,8 @@ func (s *Session) loop() {
 			break
 		default:
 			{
+				id := s.tconn.Next()
+				s.tconn.StartRequest(id)
 				message, err := s.tconn.ReadLine()
 				if err != nil {
 					if err == io.EOF || err.(*net.OpError).Unwrap() == net.ErrClosed {
@@ -80,8 +82,9 @@ func (s *Session) loop() {
 					}
 					return
 				}
+				s.tconn.EndRequest(id)
 				log.Printf("Received message from %s: %s", s.conn.RemoteAddr().String(), message) // for debugging
-				err = s.h.Handle(s, message)
+				err = s.h.Handle(s, message, id)
 				if err != nil {
 					log.Print(err)
 					s.tconn.PrintfLine("%s %s", protocol.MessageErrorHappened, err.Error())