private boolean journalRebuildRequired() {
        final int redundantOpCompactThreshold = 2000;
        return redundantOpCount >= redundantOpCompactThreshold //
                && redundantOpCount >= lruEntries.size();
    }
Returns the byte length of the value for {@code index}.
VideoSqlLite/src/main/java/com/yc/videosqllite/disk/DiskLruCache.java