// Retrieve a cache item from the cache.
func (fs *Fs) Get(key string, items ...kit.CacheItem) (kit.CacheItem, apperror.Error) {
var item kit.CacheItem = &StrItem{}
if items != nil {
if len(items) != 1 {
return nil, &apperror.Err{
Code: "invalid_item",
Message: "You must specify one item only",
}
}
item = items[0]
}
key = fs.key(key)
if key == "" {
return nil, apperror.New("empty_key")
}
exists, err := utils.FileExists(fs.keyPath(key))
if err != nil {
return nil, err
}
if !exists {
return nil, nil
}
metaContent, err := utils.ReadFile(fs.keyMetaPath(key))
if err != nil {
return nil, err
}
if err := json.Unmarshal(metaContent, &item); err != nil {
return nil, apperror.Wrap(err, "metadata_unmarshal_error")
}
// Reset ExpiresAt if it is zero, since json.Unmarshal produces
// a time.Time which is not exactly equal to the zero value.
if item.GetExpiresAt().IsZero() {
item.SetExpiresAt(time.Time{})
}
content, err := utils.ReadFile(fs.keyPath(key))
if err != nil {
return nil, err
}
if err := item.FromString(string(content)); err != nil {
return nil, apperror.Wrap(err, "cacheitem_fromstring_error")
}
// Return nil if item is expired.
if item.IsExpired() {
return nil, nil
}
return item, nil
}
// Save a new item into the cache.
func (r *Redis) Set(item kit.CacheItem) Error {
key := item.GetKey()
if key == "" {
return kit.AppError{Code: "empty_key"}
}
key = r.key(key)
if item.IsExpired() {
return kit.AppError{Code: "item_expired"}
}
expireSeconds := 0
if expires := item.GetExpiresAt(); !expires.IsZero() {
seconds := expires.Sub(time.Now()).Seconds()
if seconds > 0 && seconds < 1 {
return kit.AppError{Code: "item_expired"}
}
expireSeconds = int(seconds)
}
conn := r.pool.Get()
defer conn.Close()
value, err := item.ToString()
if err != nil {
return kit.AppError{
Code: "cacheitem_tostring_error",
Message: err.Error(),
Errors: []error{err},
}
}
if value == "" {
return kit.AppError{Code: "empty_value"}
}
conn.Send("SET", key, value)
if expireSeconds > 0 {
conn.Send("EXPIRE", key, expireSeconds)
}
if tags := item.GetTags(); tags != nil {
tagKey := r.tagKey(key)
conn.Send("SET", tagKey, strings.Join(tags, ";"))
if expireSeconds > 0 {
conn.Send("EXPIRE", tagKey, expireSeconds)
}
}
if err := conn.Flush(); err != nil {
return redisErr(err)
}
return nil
}