public long getIndexStoreSize() {
        long totalSize = 0L;
        if (tubeConfig.isEnableMemStore()) {
            this.writeCacheMutex.readLock().lock();
            try {
                if (this.msgMemStore.getCurMsgCount() > 0) {
                    totalSize += this.msgMemStore.getIndexCacheSize();
                }
                if (this.msgMemStoreBeingFlush.getCurMsgCount() > 0) {
                    totalSize += this.msgMemStoreBeingFlush.getIndexCacheSize();
                }
            } finally {
                this.writeCacheMutex.readLock().unlock();
            }
        }
        totalSize += this.msgFileStore.getIndexSizeInBytes();
        return totalSize;
    }
Get the index total size
If memory cache is enabled, the data in the cache is counted first,
and then the data in the file is counted

@return  the current index total size
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/broker/msgstore/MessageStore.java