Rework db layer.

Add database checker.
Rename SkinsRepositoryInterface and CapesRepositoryInterface methods.

db/redis/redis.go

@@ -0,0 +1,272 @@
+package redis
+
+import (
+	"bytes"
+	"compress/zlib"
+	"encoding/json"
+	"io"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/mediocregopher/radix.v2/pool"
+	"github.com/mediocregopher/radix.v2/redis"
+	"github.com/mediocregopher/radix.v2/util"
+
+	"github.com/elyby/chrly/model"
+	"github.com/elyby/chrly/mojangtextures"
+)
+
+func New(addr string, poolSize int) (*Redis, error) {
+	conn, err := pool.New("tcp", addr, poolSize)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Redis{
+		pool: conn,
+	}, nil
+}
+
+const accountIdToUsernameKey = "hash:username-to-account-id"
+const mojangUsernameToUuidKey = "hash:mojang-username-to-uuid"
+
+type Redis struct {
+	pool *pool.Pool
+}
+
+func (db *Redis) FindSkinByUsername(username string) (*model.Skin, error) {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return nil, err
+	}
+	defer db.pool.Put(conn)
+
+	return findByUsername(username, conn)
+}
+
+func findByUsername(username string, conn util.Cmder) (*model.Skin, error) {
+	redisKey := buildUsernameKey(username)
+	response := conn.Cmd("GET", redisKey)
+	if response.IsType(redis.Nil) {
+		return nil, nil
+	}
+
+	encodedResult, err := response.Bytes()
+	if err != nil {
+		return nil, err
+	}
+
+	result, err := zlibDecode(encodedResult)
+	if err != nil {
+		return nil, err
+	}
+
+	var skin *model.Skin
+	err = json.Unmarshal(result, &skin)
+	if err != nil {
+		return nil, err
+	}
+
+	skin.OldUsername = skin.Username
+
+	return skin, nil
+}
+
+func (db *Redis) FindSkinByUserId(id int) (*model.Skin, error) {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return nil, err
+	}
+	defer db.pool.Put(conn)
+
+	return findByUserId(id, conn)
+}
+
+func findByUserId(id int, conn util.Cmder) (*model.Skin, error) {
+	response := conn.Cmd("HGET", accountIdToUsernameKey, id)
+	if response.IsType(redis.Nil) {
+		return nil, nil
+	}
+
+	username, err := response.Str()
+	if err != nil {
+		return nil, err
+	}
+
+	return findByUsername(username, conn)
+}
+
+func (db *Redis) SaveSkin(skin *model.Skin) error {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return err
+	}
+	defer db.pool.Put(conn)
+
+	return save(skin, conn)
+}
+
+func save(skin *model.Skin, conn util.Cmder) error {
+	conn.Cmd("MULTI")
+
+	// If user has changed username, then we must delete his old username record
+	if skin.OldUsername != "" && skin.OldUsername != skin.Username {
+		conn.Cmd("DEL", buildUsernameKey(skin.OldUsername))
+	}
+
+	// If this is a new record or if the user has changed username, we set the value in the hash table
+	if skin.OldUsername != "" || skin.OldUsername != skin.Username {
+		conn.Cmd("HSET", accountIdToUsernameKey, skin.UserId, skin.Username)
+	}
+
+	str, _ := json.Marshal(skin)
+	conn.Cmd("SET", buildUsernameKey(skin.Username), zlibEncode(str))
+
+	conn.Cmd("EXEC")
+
+	skin.OldUsername = skin.Username
+
+	return nil
+}
+
+func (db *Redis) RemoveSkinByUserId(id int) error {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return err
+	}
+	defer db.pool.Put(conn)
+
+	return removeByUserId(id, conn)
+}
+
+func removeByUserId(id int, conn util.Cmder) error {
+	record, err := findByUserId(id, conn)
+	if err != nil {
+		return err
+	}
+
+	conn.Cmd("MULTI")
+
+	conn.Cmd("HDEL", accountIdToUsernameKey, id)
+	if record != nil {
+		conn.Cmd("DEL", buildUsernameKey(record.Username))
+	}
+
+	conn.Cmd("EXEC")
+
+	return nil
+}
+
+func (db *Redis) RemoveSkinByUsername(username string) error {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return err
+	}
+	defer db.pool.Put(conn)
+
+	return removeByUsername(username, conn)
+}
+
+func removeByUsername(username string, conn util.Cmder) error {
+	record, err := findByUsername(username, conn)
+	if err != nil {
+		return err
+	}
+
+	if record == nil {
+		return nil
+	}
+
+	conn.Cmd("MULTI")
+
+	conn.Cmd("DEL", buildUsernameKey(record.Username))
+	conn.Cmd("HDEL", accountIdToUsernameKey, record.UserId)
+
+	conn.Cmd("EXEC")
+
+	return nil
+}
+
+func (db *Redis) GetUuid(username string) (string, error) {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return "", err
+	}
+	defer db.pool.Put(conn)
+
+	return findMojangUuidByUsername(username, conn)
+}
+
+func findMojangUuidByUsername(username string, conn util.Cmder) (string, error) {
+	response := conn.Cmd("HGET", mojangUsernameToUuidKey, strings.ToLower(username))
+	if response.IsType(redis.Nil) {
+		return "", &mojangtextures.ValueNotFound{}
+	}
+
+	data, _ := response.Str()
+	parts := strings.Split(data, ":")
+	timestamp, _ := strconv.ParseInt(parts[1], 10, 64)
+	storedAt := time.Unix(timestamp, 0)
+	if storedAt.Add(time.Hour * 24 * 30).Before(time.Now()) {
+		return "", &mojangtextures.ValueNotFound{}
+	}
+
+	return parts[0], nil
+}
+
+func (db *Redis) StoreUuid(username string, uuid string) error {
+	conn, err := db.pool.Get()
+	if err != nil {
+		return err
+	}
+	defer db.pool.Put(conn)
+
+	return storeMojangUuid(username, uuid, conn)
+}
+
+func storeMojangUuid(username string, uuid string, conn util.Cmder) error {
+	value := uuid + ":" + strconv.FormatInt(time.Now().Unix(), 10)
+	res := conn.Cmd("HSET", mojangUsernameToUuidKey, strings.ToLower(username), value)
+	if res.IsType(redis.Err) {
+		return res.Err
+	}
+
+	return nil
+}
+
+func (db *Redis) Ping() error {
+	r := db.pool.Cmd("PING")
+	if r.Err != nil {
+		return r.Err
+	}
+
+	return nil
+}
+
+func buildUsernameKey(username string) string {
+	return "username:" + strings.ToLower(username)
+}
+
+func zlibEncode(str []byte) []byte {
+	var buff bytes.Buffer
+	writer := zlib.NewWriter(&buff)
+	_, _ = writer.Write(str)
+	_ = writer.Close()
+
+	return buff.Bytes()
+}
+
+func zlibDecode(bts []byte) ([]byte, error) {
+	buff := bytes.NewReader(bts)
+	reader, err := zlib.NewReader(buff)
+	if err != nil {
+		return nil, err
+	}
+
+	resultBuffer := new(bytes.Buffer)
+	_, _ = io.Copy(resultBuffer, reader)
+	_ = reader.Close()
+
+	return resultBuffer.Bytes(), nil
+}