Field Detail

• NANOS_PER_SECOND

  public static final long NANOS_PER_SECOND

  See Also:

  Constant Field Values

Constructor Detail

• BlockCacheUtil

  public BlockCacheUtil()

Method Detail

• toString

  public static String toString(CachedBlock cb,
                long now)

  Parameters:

  cb -

  Returns:

  The block content as String.

• toJSON

  public static String toJSON(String filename,
              NavigableSet<CachedBlock> blocks)
                       throws IOException

  Returns:

  A JSON String of filename and counts of blocks

  Throws:

  IOException

• toJSON

  public static String toJSON(BlockCacheUtil.CachedBlocksByFile cbsbf)
                       throws IOException

  Returns:

  JSON string of cbsf aggregated

  Throws:

  IOException

• toJSON

  public static String toJSON(BlockCache bc)
                       throws IOException

  Returns:

  JSON string of bc content.

  Throws:

  IOException

• toStringMinusFileName

  public static String toStringMinusFileName(CachedBlock cb,
                             long now)

  Parameters:

  cb -

  Returns:

  The block content of bc as a String minus the filename.

• getLoadedCachedBlocksByFile

  public static BlockCacheUtil.CachedBlocksByFile getLoadedCachedBlocksByFile(org.apache.hadoop.conf.Configuration conf,
                                                              BlockCache bc)

  Get a BlockCacheUtil.CachedBlocksByFile instance and load it up by iterating content in BlockCache.

  Parameters:

  conf - Used to read configurations

  bc - Block Cache to iterate.

  Returns:

  Laoded up instance of CachedBlocksByFile

• validateBlockAddition

  public static int validateBlockAddition(Cacheable existing,
                          Cacheable newBlock,
                          BlockCacheKey cacheKey)

  Validate that the existing and newBlock are the same without including the nextBlockMetadata, if not, throw an exception. If they are the same without the nextBlockMetadata, return the comparison.

  Parameters:

  existing - block that is existing in the cache.

  newBlock - block that is trying to be cached.

  cacheKey - the cache key of the blocks.

  Returns:

  comparison of the existing block to the newBlock.

• shouldReplaceExistingCacheBlock

  public static boolean shouldReplaceExistingCacheBlock(BlockCache blockCache,
                                        BlockCacheKey cacheKey,
                                        Cacheable newBlock)

  Because of the region splitting, it's possible that the split key locate in the middle of a block. So it's possible that both the daughter regions load the same block from their parent HFile. When pread, we don't force the read to read all of the next block header. So when two threads try to cache the same block, it's possible that one thread read all of the next block header but the other one didn't. if the already cached block hasn't next block header but the new block to cache has, then we can replace the existing block with the new block for better performance.(HBASE-20447)

  Parameters:

  blockCache - BlockCache to check

  cacheKey - the block cache key

  newBlock - the new block which try to put into the block cache.

  Returns:

  true means need to replace existing block with new block for the same block cache key. false means just keep the existing block.