ddth-cache-adapter-core/src/main/java/com/github/ddth/cacheadapter/cacheimpl/redis/ClusteredRedisCache.java
@Override
    public long getSize() {
        switch (keyMode) {
        case HASH:
            try {
                return getJedis().hlen(getName());
            } catch (Exception e) {
                throw e instanceof CacheException ? (CacheException) e : new CacheException(e);
            }
        default:
            return -1;
        }
    }
@Override
    public long getSize() {
        switch (keyMode) {
        case HASH:
            try {
                return getJedis().hlen(getName());
            } catch (Exception e) {
                throw e instanceof CacheException ? (CacheException) e : new CacheException(e);
            }
        default:
            return -1;
        }
    }
{@inheritDoc}

<p>
Only {@link KeyMode#HASH} is supported. This method returns {@code -1}
for other key modes.
</p>