Redis Examples

The official runnable project is ss-keel-examples/examples/14-redis-cache.

Cache-aside read

cached, err := s.cache.Get(ctx, cacheKey)
if err != nil {
    s.log.Warn("redis get failed [key=%s]: %v", cacheKey, err)
} else if cached != nil {
    var note Note
    if err := json.Unmarshal(cached, &note); err == nil {
        return &note, "cache", nil
    }
}

Repopulate on cache miss

payload, err := json.Marshal(note)
if err != nil {
    return nil, "", err
}
if err := s.cache.Set(ctx, cacheKey, payload, s.ttl); err != nil {
    s.log.Warn("redis set failed [key=%s]: %v", cacheKey, err)
}

Invalidate on write

if err := s.cache.Delete(ctx, noteCacheKey(saved.ID)); err != nil {
    s.log.Warn("redis delete failed [key=%s]: %v", noteCacheKey(saved.ID), err)
}