public ElasticLogMeta logMeta() {
        if (logMeta == null) {
            segmentLock.lock();
            try {
                if (logMeta != null) {
                    return logMeta;
                }
                logMeta = generateLogMeta();
            } finally {
                segmentLock.unlock();
            }
        }
        return logMeta;
    }
Calculate trim offset of each stream.

@return stream trim offset map, key is stream name, value is trim offset.
core/src/main/scala/kafka/log/streamaspect/ElasticLogSegmentManager.java