User persistence to sqlite.

src/irc/persistence.go

@@ -27,7 +27,9 @@ type Queryable interface {
 	QueryRow(string, ...interface{}) *sql.Row
 }
 
-type TransactionFunc func(Queryable) bool
+type Savable interface {
+	Save(q Queryable) bool
+}
 
 //
 // general
@@ -36,7 +38,7 @@ type TransactionFunc func(Queryable) bool
 func NewDatabase() *Database {
 	db, err := sql.Open("sqlite3", "ergonomadic.db")
 	if err != nil {
-		panic("cannot open database")
+		log.Fatalln("cannot open database")
 	}
 	return &Database{db}
 }
@@ -48,7 +50,7 @@ func NewTransaction(tx *sql.Tx) *Transaction {
 func readLines(filename string) <-chan string {
 	file, err := os.Open(filename)
 	if err != nil {
-		panic(err)
+		log.Fatalln(err)
 	}
 	reader := bufio.NewReader(file)
 	lines := make(chan string)
@@ -56,7 +58,7 @@ func readLines(filename string) <-chan string {
 		defer file.Close()
 		defer close(lines)
 		for {
-			line, err := reader.ReadString('\n')
+			line, err := reader.ReadString(';')
 			if err != nil {
 				break
 			}
@@ -70,28 +72,24 @@ func readLines(filename string) <-chan string {
 	return lines
 }
 
-func (db *Database) execSqlFile(filename string) {
+func (db *Database) ExecSqlFile(filename string) *Database {
 	db.Transact(func(q Queryable) bool {
 		for line := range readLines(filepath.Join("sql", filename)) {
 			log.Println(line)
-			q.Exec(line)
+			_, err := q.Exec(line)
+			if err != nil {
+				log.Fatalln(err)
+			}
 		}
 		return true
 	})
+	return db
 }
 
-func (db *Database) InitTables() {
-	db.execSqlFile("init.sql")
-}
-
-func (db *Database) DropTables() {
-	db.execSqlFile("drop.sql")
-}
-
-func (db *Database) Transact(txf TransactionFunc) {
+func (db *Database) Transact(txf func(Queryable) bool) {
 	tx, err := db.Begin()
 	if err != nil {
-		panic(err)
+		log.Panicln(err)
 	}
 	if txf(tx) {
 		tx.Commit()
@@ -100,6 +98,28 @@ func (db *Database) Transact(txf TransactionFunc) {
 	}
 }
 
+func (db *Database) Save(s Savable) {
+	db.Transact(func(tx Queryable) bool {
+		return s.Save(tx)
+	})
+}
+
+//
+// general purpose sql
+//
+
+func FindId(q Queryable, sql string, args ...interface{}) (rowId RowId, err error) {
+	row := q.QueryRow(sql, args...)
+	err = row.Scan(&rowId)
+	return
+}
+
+func Count(q Queryable, sql string, args ...interface{}) (count uint, err error) {
+	row := q.QueryRow(sql, args...)
+	err = row.Scan(&count)
+	return
+}
+
 //
 // data
 //
@@ -117,25 +137,39 @@ type ChannelRow struct {
 
 // user
 
-func FindUserByNick(q Queryable, nick string) (ur *UserRow) {
-	ur = new(UserRow)
-	row := q.QueryRow("SELECT * FROM user LIMIT 1 WHERE nick = ?", nick)
-	err := row.Scan(&ur.id, &ur.nick, &ur.hash)
+func FindAllUsers(q Queryable) (urs []UserRow, err error) {
+	var rows *sql.Rows
+	rows, err = q.Query("SELECT id, nick, hash FROM user")
 	if err != nil {
-		ur = nil
+		return
+	}
+	urs = make([]UserRow, 0)
+	for rows.Next() {
+		ur := UserRow{}
+		err = rows.Scan(&(ur.id), &(ur.nick), &(ur.hash))
+		if err != nil {
+			return
+		}
+		urs = append(urs, ur)
 	}
 	return
 }
 
-func FindUserIdByNick(q Queryable, nick string) (rowId RowId, err error) {
-	row := q.QueryRow("SELECT id FROM user WHERE nick = ?", nick)
-	err = row.Scan(&rowId)
+func FindUserByNick(q Queryable, nick string) (ur *UserRow, err error) {
+	ur = &UserRow{}
+	row := q.QueryRow("SELECT id, nick, hash FROM user LIMIT 1 WHERE nick = ?",
+		nick)
+	err = row.Scan(&(ur.id), &(ur.nick), &(ur.hash))
 	return
 }
 
+func FindUserIdByNick(q Queryable, nick string) (RowId, error) {
+	return FindId(q, "SELECT id FROM user WHERE nick = ?", nick)
+}
+
 func FindChannelByName(q Queryable, name string) (cr *ChannelRow) {
 	cr = new(ChannelRow)
-	row := q.QueryRow("SELECT * FROM channel LIMIT 1 WHERE name = ?", name)
+	row := q.QueryRow("SELECT id, name FROM channel LIMIT 1 WHERE name = ?", name)
 	err := row.Scan(&(cr.id), &(cr.name))
 	if err != nil {
 		cr = nil
@@ -185,25 +219,31 @@ func InsertUserChannels(q Queryable, userId RowId, channelIds []RowId) (err erro
 
 // channel
 
-func FindChannelIdByName(q Queryable, name string) (channelId RowId, err error) {
-	row := q.QueryRow("SELECT id FROM channel WHERE name = ?", name)
-	err = row.Scan(&channelId)
-	return
+func FindChannelIdByName(q Queryable, name string) (RowId, error) {
+	return FindId(q, "SELECT id FROM channel WHERE name = ?", name)
 }
 
-func FindChannelsForUser(q Queryable, userId RowId) (crs []ChannelRow) {
-	rows, err := q.Query(`SELECT * FROM channel WHERE id IN
-(SELECT channel_id from user_channel WHERE user_id = ?)`, userId)
+func FindChannelsForUser(q Queryable, userId RowId) (crs []ChannelRow, err error) {
+	query := ` FROM channel WHERE id IN
+(SELECT channel_id from user_channel WHERE user_id = ?)`
+	count, err := Count(q, "SELECT COUNT(id)"+query, userId)
 	if err != nil {
-		panic(err)
+		return
 	}
-	crs = make([]ChannelRow, 0)
+	rows, err := q.Query("SELECT id, name"+query, userId)
+	if err != nil {
+		return
+	}
+	crs = make([]ChannelRow, count)
+	var i = 0
 	for rows.Next() {
 		cr := ChannelRow{}
-		if err := rows.Scan(&(cr.id), &(cr.name)); err != nil {
-			panic(err)
+		err = rows.Scan(&(cr.id), &(cr.name))
+		if err != nil {
+			return
 		}
-		crs = append(crs, cr)
+		crs[i] = cr
+		i++
 	}
 	return
 }