参考：

  • https://www.jianshu.com/p/9b5...
  • https://zhuanlan.zhihu.com/p/...

SST File Format

之前在LSM-Tree局部有提过，但过后理解的比拟浅

<beginning_of_file>[data block 1][data block 2]...[data block N][meta block 1: filter block]                  [meta block 2: index block][meta block 3: compression dictionary block]  [meta block 4: range deletion block]          [meta block 5: stats block]                   ...[meta block K: future extended block]  (More meta blocks may be added in the future)[metaindex block][Footer]                               (fixed size; starts at file_size - sizeof(Footer))<end_of_file>

与BlockBasedTableBuilder相干的类有以下几个

  • BlockBasedTable, 该类封装了用于读取磁盘BlockBasedTable类型的SST表的逻辑。
  • BlockBasedTableBuilder, 该类用于在磁盘上构建一个BlockBasedTable类型的SST表。
  • BlockBasedTableFactory, 该类是BlockBasedTable工厂办法的实现，用于创立BlockBasedTable/BlockBasedTableBuilder。

Write Block的程序：

Write meta blocks, metaindex block and footer in the following order.

  1. [meta block: filter]
  2. [meta block: index]
  3. [meta block: compression dictionary]
  4. [meta block: range deletion tombstone]
  5. [meta block: properties]
  6. [metaindex block]
  7. Footer