Encapsulate SQL statements and refactor Save functions as transactionable.

.gitignore

@@ -1,3 +1,4 @@
 pkg
 bin
 src/code.google.com/
+ergonomadic.db

README.md

@@ -1,19 +1,26 @@
 # Ergonomadic
 
-## A Go IRC Daemon
+Ergonomadic is an IRC daemon written from scratch in Go. It supports (or will)
+multiple concurrent connections for the same nick.
 
-Ergonomadic is an IRC daemon written from scratch in Go.
-
-### Why?
+## Why?
 
 I wanted to learn Go.
 
-### What's with the name?
+## What's with the name?
 
 "Ergonomadic" is an anagram of "Go IRC Daemon".
 
-### Helpful Documentation
+## Helpful Documentation
 
-- [IRC Channel Management](http://tools.ietf.org/html/rfc2811)
-- [IRC Client Protocol](http://tools.ietf.org/html/rfc2812)
-- [IRC Server Protocol](http://tools.ietf.org/html/rfc2813)
+- [RFC 2811: IRC Channel Management](http://tools.ietf.org/html/rfc2811)
+- [RFC 2812: IRC Client Protocol](http://tools.ietf.org/html/rfc2812)
+- [RFC 2813: IRC Server Protocol](http://tools.ietf.org/html/rfc2813)
+
+## Running the Server
+
+```sh
+$ ./build.sh
+$ bin/ergonomadicdb init
+$ bin/ergonomadic
+```

build.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
 export GOPATH="$PWD"
 go get "code.google.com/p/go.crypto/bcrypt"
-go install ergonomadic genpasswd
+go get "github.com/mattn/go-sqlite3"
+go install ergonomadic genpasswd ergonomadicdb

sql/drop.sql

@@ -0,0 +1,10 @@
+DROP INDEX user_id_channel_id
+DROP TABLE user_channel
+
+DROP INDEX channel_name
+DROP INDEX channel_id
+DROP TABLE channel
+
+DROP INDEX user_nick
+DROP INDEX user_id
+DROP TABLE user

sql/init.sql

@@ -0,0 +1,10 @@
+CREATE TABLE user (id integer not null primary key autoincrement, nick text not null, hash blob not null)
+CREATE UNIQUE INDEX user_id ON user (id)
+CREATE UNIQUE INDEX user_nick ON user (nick)
+
+CREATE TABLE channel (id integer not null primary key autoincrement, name text not  null)
+CREATE UNIQUE INDEX channel_id ON channel (id)
+CREATE UNIQUE INDEX channel_name ON channel (name)
+
+CREATE_TABLE user_channel (id integer not null primary key autoincrement, user_id integer not null, channel_id integer not null)
+CREATE UNIQUE INDEX user_id_channel_id ON user_channel (user_id, channel_id)

src/ergonomadicdb/ergonomadicdb.go

@@ -0,0 +1,22 @@
+package main
+
+import (
+	"flag"
+	"irc"
+)
+
+var (
+	actions = map[string]func(*irc.Database){
+		"init": func(db *irc.Database) {
+			db.InitTables()
+		},
+		"drop": func(db *irc.Database) {
+			db.DropTables()
+		},
+	}
+)
+
+func main() {
+	flag.Parse()
+	actions[flag.Arg(0)](irc.NewDatabase())
+}

src/irc/channel.go

@@ -9,6 +9,7 @@ const (
 )
 
 type Channel struct {
+	id        *RowId
 	server    *Server
 	commands  chan<- ChannelCommand
 	replies   chan<- Reply
@@ -30,6 +31,16 @@ func (set ChannelSet) Remove(channel *Channel) {
 	delete(set, channel)
 }
 
+func (set ChannelSet) Ids() (ids []RowId) {
+	ids = []RowId{}
+	for channel := range set {
+		if channel.id != nil {
+			ids = append(ids, *channel.id)
+		}
+	}
+	return ids
+}
+
 type ChannelCommand interface {
 	Command
 	HandleChannel(channel *Channel)
@@ -52,6 +63,24 @@ func NewChannel(s *Server, name string) *Channel {
 	return channel
 }
 
+func (channel *Channel) Save(q Queryable) bool {
+	if channel.id == nil {
+		if err := InsertChannel(q, channel); err != nil {
+			return false
+		}
+		channelId, err := FindChannelIdByName(q, channel.name)
+		if err != nil {
+			return false
+		}
+		channel.id = &channelId
+	} else {
+		if err := UpdateChannel(q, channel); err != nil {
+			return false
+		}
+	}
+	return true
+}
+
 // Forward `Reply`s to all `User`s of the `Channel`.
 func (channel *Channel) receiveReplies(replies <-chan Reply) {
 	for reply := range replies {

src/irc/commands.go

@@ -53,7 +53,7 @@ func (command *BaseCommand) User() *User {
 }
 
 func (command *BaseCommand) SetClient(c *Client) {
-	command.client = c
+	*command = BaseCommand{c}
 }
 
 func (command *BaseCommand) Source() Identifier {

src/irc/net.go

@@ -8,7 +8,7 @@ import (
 )
 
 const (
-	DEBUG_NET = false
+	DEBUG_NET = true
 )
 
 func readTrimmedLine(reader *bufio.Reader) (string, error) {

src/irc/persistence.go

@@ -0,0 +1,220 @@
+package irc
+
+import (
+	"database/sql"
+	//"fmt"
+	"bufio"
+	_ "github.com/mattn/go-sqlite3"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type Database struct {
+	*sql.DB
+}
+
+type Transaction struct {
+	*sql.Tx
+}
+
+type RowId uint64
+
+type Queryable interface {
+	Exec(string, ...interface{}) (sql.Result, error)
+	Query(string, ...interface{}) (*sql.Rows, error)
+	QueryRow(string, ...interface{}) *sql.Row
+}
+
+type TransactionFunc func(Queryable) bool
+
+//
+// general
+//
+
+func NewDatabase() *Database {
+	db, err := sql.Open("sqlite3", "ergonomadic.db")
+	if err != nil {
+		panic("cannot open database")
+	}
+	return &Database{db}
+}
+
+func NewTransaction(tx *sql.Tx) *Transaction {
+	return &Transaction{tx}
+}
+
+func readLines(filename string) <-chan string {
+	file, err := os.Open(filename)
+	if err != nil {
+		panic(err)
+	}
+	reader := bufio.NewReader(file)
+	lines := make(chan string)
+	go func(lines chan<- string) {
+		defer file.Close()
+		defer close(lines)
+		for {
+			line, err := reader.ReadString('\n')
+			if err != nil {
+				break
+			}
+			line = strings.TrimSpace(line)
+			if line == "" {
+				continue
+			}
+			lines <- line
+		}
+	}(lines)
+	return lines
+}
+
+func (db *Database) execSqlFile(filename string) {
+	db.Transact(func(q Queryable) bool {
+		for line := range readLines(filepath.Join("sql", filename)) {
+			log.Println(line)
+			q.Exec(line)
+		}
+		return true
+	})
+}
+
+func (db *Database) InitTables() {
+	db.execSqlFile("init.sql")
+}
+
+func (db *Database) DropTables() {
+	db.execSqlFile("drop.sql")
+}
+
+func (db *Database) Transact(txf TransactionFunc) {
+	tx, err := db.Begin()
+	if err != nil {
+		panic(err)
+	}
+	if txf(tx) {
+		tx.Commit()
+	} else {
+		tx.Rollback()
+	}
+}
+
+//
+// data
+//
+
+type UserRow struct {
+	id   RowId
+	nick string
+	hash []byte
+}
+
+type ChannelRow struct {
+	id   RowId
+	name string
+}
+
+// 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)
+	if err != nil {
+		ur = nil
+	}
+	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)
+	return
+}
+
+func FindChannelByName(q Queryable, name string) (cr *ChannelRow) {
+	cr = new(ChannelRow)
+	row := q.QueryRow("SELECT * FROM channel LIMIT 1 WHERE name = ?", name)
+	err := row.Scan(&(cr.id), &(cr.name))
+	if err != nil {
+		cr = nil
+	}
+	return
+}
+
+func InsertUser(q Queryable, user *User) (err error) {
+	_, err = q.Exec("INSERT INTO user (nick, hash) VALUES (?, ?)",
+		user.nick, user.hash)
+	return
+}
+
+func UpdateUser(q Queryable, user *User) (err error) {
+	_, err = q.Exec("UPDATE user SET nick = ?, hash = ? WHERE id = ?",
+		user.nick, user.hash, *(user.id))
+	return
+}
+
+// user-channel
+
+func DeleteAllUserChannels(q Queryable, rowId RowId) (err error) {
+	_, err = q.Exec("DELETE FROM user_channel WHERE user_id = ?", rowId)
+	return
+}
+
+func DeleteOtherUserChannels(q Queryable, userId RowId, channelIds []RowId) (err error) {
+	_, err = q.Exec(`DELETE FROM user_channel WHERE
+user_id = ? AND channel_id NOT IN ?`, userId, channelIds)
+	return
+}
+
+func InsertUserChannels(q Queryable, userId RowId, channelIds []RowId) (err error) {
+	ins := "INSERT OR IGNORE INTO user_channel (user_id, channel_id) VALUES "
+	vals := strings.Repeat("(?, ?), ", len(channelIds))
+	vals = vals[0 : len(vals)-2]
+	args := make([]interface{}, 2*len(channelIds))
+	var i = 0
+	for channelId := range channelIds {
+		args[i] = userId
+		args[i+1] = channelId
+		i += 2
+	}
+	_, err = q.Exec(ins+vals, args)
+	return
+}
+
+// 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 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)
+	if err != nil {
+		panic(err)
+	}
+	crs = make([]ChannelRow, 0)
+	for rows.Next() {
+		cr := ChannelRow{}
+		if err := rows.Scan(&(cr.id), &(cr.name)); err != nil {
+			panic(err)
+		}
+		crs = append(crs, cr)
+	}
+	return
+}
+
+func InsertChannel(q Queryable, channel *Channel) (err error) {
+	_, err = q.Exec("INSERT INTO channel (name) VALUES (?)", channel.name)
+	return
+}
+
+func UpdateChannel(q Queryable, channel *Channel) (err error) {
+	_, err = q.Exec("UPDATE channel SET name = ? WHERE id = ?",
+		channel.name, *(channel.id))
+	return
+}

src/irc/user.go

@@ -16,6 +16,7 @@ type UserCommand interface {
 }
 
 type User struct {
+	id       *RowId
 	nick     string
 	hash     []byte
 	server   *Server
@@ -56,12 +57,46 @@ func NewUser(nick string, password string, server *Server) *User {
 		replies:  replies,
 	}
 	user.SetPassword(password)
+
 	go user.receiveCommands(commands)
 	go user.receiveReplies(replies)
 	server.users[nick] = user
+
 	return user
 }
 
+func (user *User) Save(q Queryable) bool {
+	if user.id == nil {
+		if err := InsertUser(q, user); err != nil {
+			return false
+		}
+		userId, err := FindUserIdByNick(q, user.nick)
+		if err != nil {
+			return false
+		}
+		user.id = &userId
+	} else {
+		if err := UpdateUser(q, user); err != nil {
+			return false
+		}
+	}
+
+	channelIds := user.channels.Ids()
+	if len(channelIds) == 0 {
+		if err := DeleteAllUserChannels(q, *(user.id)); err != nil {
+			return false
+		}
+	} else {
+		if err := DeleteOtherUserChannels(q, *(user.id), channelIds); err != nil {
+			return false
+		}
+		if err := InsertUserChannels(q, *(user.id), channelIds); err != nil {
+			return false
+		}
+	}
+	return true
+}
+
 func (user *User) SetPassword(password string) {
 	hash, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)
 	if err != nil {