Method Detail

• readBlock

  HFileBlock readBlock(long offset,
                     long onDiskBlockSize,
                     boolean cacheBlock,
                     boolean pread,
                     boolean isCompaction,
                     boolean updateCacheMetrics,
                     BlockType expectedBlockType,
                     DataBlockEncoding expectedDataBlockEncoding)
                       throws IOException

  Read in a file block.

  Parameters:

  offset - offset to read.

  onDiskBlockSize - size of the block

  cacheBlock -

  pread -

  isCompaction - is this block being read as part of a compaction

  expectedBlockType - the block type we are expecting to read with this read operation, or null to read whatever block type is available and avoid checking (that might reduce caching efficiency of encoded data blocks)

  expectedDataBlockEncoding - the data block encoding the caller is expecting data blocks to be in, or null to not perform this check and return the block irrespective of the encoding. This check only applies to data blocks and can be set to null when the caller is expecting to read a non-data block and has set expectedBlockType accordingly.

  Returns:

  Block wrapped in a ByteBuffer.

  Throws:

  IOException