func noteIDs(db redis.Conn) []int64 {
var ids []int64
rawIDs, err := redis.Values(db.Do("LRANGE", "notable:notes", 0, -1))
check(err)
redis.ScanSlice(rawIDs, &ids)
return ids
}
// zpop pops a value from the ZSET key using WATCH/MULTI/EXEC commands.
func zpop(c redis.Conn, key string) (result string, err error) {
defer func() {
// Return connection to normal state on error.
if err != nil {
c.Do("DISCARD")
}
}()
// Loop until transaction is successful.
for {
if _, err := c.Do("WATCH", key); err != nil {
return "", err
}
members, err := redis.Strings(c.Do("ZRANGE", key, 0, 0))
if err != nil {
return "", err
}
if len(members) != 1 {
return "", redis.ErrNil
}
c.Send("MULTI")
c.Send("ZREM", key, members[0])
queued, err := c.Do("EXEC")
if err != nil {
return "", err
}
if queued != nil {
result = members[0]
break
}
}
return result, nil
}
func fetchNote(db redis.Conn, id int64) Note {
noteAsJSON, err := redis.String(db.Do("GET", noteKey(id)))
check(err)
return deserialize(noteAsJSON)
}