private void append(final long memstoreTS, final byte[] key, final int koffset, final int klength,final byte[] value, final int voffset, final int vlength)throws IOException {boolean dupKey = checkKey(key, koffset, klength);checkValue(value, voffset, vlength);if (!dupKey) {//在写每一个新的KeyValue之间，都要检查，到了BlockSize就重新写一个HFileBlock
      checkBlockBoundary();}//如果当前的fsBlockWriter的状态不对，就重新写一个新块if (!fsBlockWriter.isWriting())newBlock();// 把值写入到ouputStream当中，怎么写入的自己看啊
    {DataOutputStream out = fsBlockWriter.getUserDataStream();out.writeInt(klength);totalKeyLength += klength;out.writeInt(vlength);totalValueLength += vlength;out.write(key, koffset, klength);out.write(value, voffset, vlength);if (this.includeMemstoreTS) {WritableUtils.writeVLong(out, memstoreTS);}}// 记录每个块的第一个key 和 上次写的keyif (firstKeyInBlock == null) {firstKeyInBlock = new byte[klength];System.arraycopy(key, koffset, firstKeyInBlock, 0, klength);}lastKeyBuffer = key;lastKeyOffset = koffset;lastKeyLength = klength;entryCount++;}

public void close() throws IOException {if (outputStream == null) {return;}// 经过编码压缩的，把编码压缩方式写进FileInfo里面blockEncoder.saveMetadata(this);//结束块
    finishBlock();//输出DataBlockIndex索引的非root层信息writeInlineBlocks(true);FixedFileTrailer trailer = new FixedFileTrailer(2,HFileReaderV2.MAX_MINOR_VERSION);// 如果有meta块的存在的话if (!metaNames.isEmpty()) {for (int i = 0; i < metaNames.size(); ++i) {long offset = outputStream.getPos();// 输出meta的内容，它是meta的名字的集合，按照名字排序DataOutputStream dos = fsBlockWriter.startWriting(BlockType.META);metaData.get(i).write(dos);fsBlockWriter.writeHeaderAndData(outputStream);totalUncompressedBytes += fsBlockWriter.getUncompressedSizeWithHeader();// 把meta块的信息加到meta块的索引里
        metaBlockIndexWriter.addEntry(metaNames.get(i), offset,fsBlockWriter.getOnDiskSizeWithHeader());}}//下面这部分是打开文件的时候就加载的部分，是前面部分的索引//HFileBlockIndex的根层次的索引long rootIndexOffset = dataBlockIndexWriter.writeIndexBlocks(outputStream);trailer.setLoadOnOpenOffset(rootIndexOffset);//Meta块的索引
    metaBlockIndexWriter.writeSingleLevelIndex(fsBlockWriter.startWriting(BlockType.ROOT_INDEX), "meta");fsBlockWriter.writeHeaderAndData(outputStream);totalUncompressedBytes += fsBlockWriter.getUncompressedSizeWithHeader();//如果需要写入Memstore的最大时间戳到FileInfo里面if (this.includeMemstoreTS) {appendFileInfo(MAX_MEMSTORE_TS_KEY, Bytes.toBytes(maxMemstoreTS));appendFileInfo(KEY_VALUE_VERSION, Bytes.toBytes(KEY_VALUE_VER_WITH_MEMSTORE));}//把FileInfo的起始位置写入trailer，然后输出
    writeFileInfo(trailer, fsBlockWriter.startWriting(BlockType.FILE_INFO));fsBlockWriter.writeHeaderAndData(outputStream);totalUncompressedBytes += fsBlockWriter.getUncompressedSizeWithHeader();// 输出GENERAL_BLOOM_META、DELETE_FAMILY_BLOOM_META类型的BloomFilter的信息for (BlockWritable w : additionalLoadOnOpenData){fsBlockWriter.writeBlock(w, outputStream);totalUncompressedBytes += fsBlockWriter.getUncompressedSizeWithHeader();}//HFileBlockIndex的二级实体的层次
    trailer.setNumDataIndexLevels(dataBlockIndexWriter.getNumLevels());//压缩前的HFileBlockIndex的大小
    trailer.setUncompressedDataIndexSize(dataBlockIndexWriter.getTotalUncompressedSize());//第一个HFileBlock的起始位置
    trailer.setFirstDataBlockOffset(firstDataBlockOffset);//最后一个HFileBlock的起始位置
    trailer.setLastDataBlockOffset(lastDataBlockOffset);//比较器的类型
    trailer.setComparatorClass(comparator.getClass());//HFileBlockIndex的根实体的数量，应该是和HFileBlock的数量是一样的//它每次都把HFileBlock的第一个key加进去
    trailer.setDataIndexCount(dataBlockIndexWriter.getNumRootEntries());//把Trailer的信息写入硬盘，关闭输出流
    finishClose(trailer);fsBlockWriter.release();}

this.fileStatus = fileStatus;Path p = fileStatus.getPath();if (HFileLink.isHFileLink(p)) {// HFileLink 被判断出来它是HFilethis.reference = null;this.link = new HFileLink(conf, p);} else if (isReference(p)) {this.reference = Reference.read(fs, p);//关联的地址也可能是一个HFileLink，snapshot的时候介绍了Path referencePath = getReferredToFile(p);if (HFileLink.isHFileLink(referencePath)) {// HFileLink Reference 如果它是一个HFileLink型的this.link = new HFileLink(conf, referencePath);} else {// 只是引用this.link = null;}} else if (isHFile(p)) {// HFilethis.reference = null;this.link = null;} else {throw new IOException("path=" + p + " doesn't look like a valid StoreFile");}

for (Path path: fileLink.getLocations()) {if (path.equals(currentPath)) continue;try {in = fs.open(path, bufferSize);in.seek(pos);assert(in.getPos() == pos) : "Link unable to seek to the right position=" + pos;if (LOG.isTraceEnabled()) {if (currentPath != null) {LOG.debug("link open path=" + path);} else {LOG.trace("link switch from path=" + currentPath + " to path=" + path);}}currentPath = path;return(in);} catch (FileNotFoundException e) {// Try another file location
        }
}