optimize queries more

contrib/backends/srndv2/src/srnd/database.go

@@ -65,6 +65,11 @@ type PostingStats struct {
 	History []PostingStatsEntry
 }
 
+// newsgroup, first, last
+type NewsgroupListEntry [3]string
+
+type NewsgroupList []NewsgroupListEntry
+
 type Database interface {
 	Close()
 	CreateTables()
@@ -322,6 +327,9 @@ type Database interface {
 
 	// get post message-id where hash is similar to string
 	GetCitesByPostHashLike(like string) ([]MessageIDTuple, error)
+
+	// get newsgroup list with watermarks
+	GetNewsgroupList() (NewsgroupList, error)
 }
 
 func NewDatabase(db_type, schema, host, port, user, password string) Database {

contrib/backends/srndv2/src/srnd/nntp.go

@@ -1030,19 +1030,18 @@ func (self *nntpConnection) handleLine(daemon *NNTPDaemon, code int, line string
 					conn.PrintfLine("411 No Such Newsgroup")
 				}
 			} else if cmd == "LIST" && parts[1] == "NEWSGROUPS" {
-				conn.PrintfLine("215 list of newsgroups follows")
 				// handle list command
-				groups := daemon.database.GetAllNewsgroups()
+				list, err := daemon.database.GetNewsgroupList()
-				dw := conn.DotWriter()
+				if err == nil {
-				for _, group := range groups {
+					conn.PrintfLine("215 list of newsgroups follows")
-					last, first, err := daemon.database.GetLastAndFirstForGroup(group)
+					dw := conn.DotWriter()
-					if err == nil {
+					for _, entry := range list {
-						io.WriteString(dw, fmt.Sprintf("%s %d %d y\r\n", group, first, last))
+						io.WriteString(dw, fmt.Sprintf("%s %s %s y\r\n", entry[0], entry[1], entry[2]))
-					} else {
-						log.Println("cannot get last/first ids for group", group, err)
 					}
+					dw.Close()
+				} else {
+					conn.PrintfLine("500 failed to get list: %s", err.Error())
 				}
-				dw.Close()
 			} else if cmd == "STAT" {
 				if len(self.group) == 0 {
 					if len(parts) == 2 {
@@ -1135,19 +1134,17 @@ func (self *nntpConnection) handleLine(daemon *NNTPDaemon, code int, line string
 			}
 		} else {
 			if line == "LIST" {
-				conn.PrintfLine("215 list of newsgroups follows")
+				list, err := daemon.database.GetNewsgroupList()
-				// handle list command
+				if err == nil {
-				groups := daemon.database.GetAllNewsgroups()
+					conn.PrintfLine("215 list of newsgroups follows")
-				dw := conn.DotWriter()
+					dw := conn.DotWriter()
-				for _, group := range groups {
+					for _, entry := range list {
-					last, first, err := daemon.database.GetLastAndFirstForGroup(group)
+						io.WriteString(dw, fmt.Sprintf("%s %s %s y\r\n", entry[0], entry[1], entry[2]))
-					if err == nil {
-						io.WriteString(dw, fmt.Sprintf("%s %d %d y\r\n", group, first, last))
-					} else {
-						log.Println("cannot get last/first ids for group", group, err)
 					}
+					dw.Close()
+				} else {
+					conn.PrintfLine("500 failed to get list: %s", err.Error())
 				}
-				dw.Close()
 			} else if line == "POST" {
 				if !self.authenticated {
 					// needs tls to work if not logged in

contrib/backends/srndv2/src/srnd/postgres.go

@@ -146,6 +146,7 @@ const SearchByHash_2 = "SearchByHash_2"
 const GetNNTPPostsInGroup = "GetNNTPPostsInGroup"
 const GetCitesByPostHashLike = "GetCitesByPostHashLike"
 const GetYearlyPostHistory = "GetYearlyPostHistory"
+const GetNewsgroupList = "GetNewsgroupList"
 
 func (self *PostgresDatabase) prepareStatements() {
 	self.stmt = map[string]string{
@@ -191,6 +192,7 @@ func (self *PostgresDatabase) prepareStatements() {
 		GetMessageIDByHash:              "SELECT message_id, message_newsgroup FROM Articles WHERE message_id_hash = $1 LIMIT 1",
 		CheckEncIPBanned:                "SELECT 1 FROM EncIPBans WHERE encaddr = $1",
 		GetFirstAndLastForGroup:         "WITH x(min_no, max_no) AS ( SELECT MIN(message_no) AS min_no, MAX(message_no) AS max_no FROM ArticleNumbers WHERE newsgroup = $1) SELECT CASE WHEN min_no IS NULL THEN 0 ELSE min_no END AS min_no FROM x UNION SELECT CASE WHEN max_no IS NULL THEN 1 ELSE max_no END AS max_no FROM x",
+		GetNewsgroupList:                "SELECT newsgroup, min(message_no), max(message_no) FROM ArticlePosts GROUP BY newsgroup",
 		GetMessageIDForNNTPID:           "SELECT message_id FROM ArticleNumbers WHERE newsgroup = $1 AND message_no = $2 LIMIT 1",
 		GetNNTPIDForMessageID:           "SELECT message_no FROM ArticleNumbers WHERE newsgroup = $1 AND message_id = $2 LIMIT 1",
 		IsExpired:                       "WITH x(msgid) AS ( SELECT message_id FROM Articles WHERE message_id = $1 INTERSECT ( SELECT message_id FROM ArticlePosts WHERE message_id = $1 ) ) SELECT COUNT(*) FROM x",
@@ -1893,3 +1895,19 @@ func (self *PostgresDatabase) SearchByHash(prefix, group, text string, chnl chan
 	close(chnl)
 	return
 }
+
+func (self *PostgresDatabase) GetNewsgroupList() (list NewsgroupList, err error) {
+	var rows *sql.Rows
+	rows, err = self.conn.Query(self.stmt[GetNewsgroupList])
+	if err == nil {
+		for rows.Next() {
+			var l NewsgroupListEntry
+			var lo, hi int64
+			rows.Scan(&l[0], &lo, &hi)
+			l[1] = fmt.Sprintf("%d", lo)
+			l[2] = fmt.Sprintf("%d", hi)
+		}
+		rows.Close()
+	}
+	return
+}