alluxio.master.metastore

Interface BlockMetaStore

All Known Implementing Classes:

HeapBlockMetaStore, RocksBlockMetaStore

@ThreadSafe
public interface BlockMetaStore

The block store keeps track of block sizes and block locations.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	BlockMetaStore.Block Block metadata.
static interface	BlockMetaStore.Factory Factory for creating block stores.

Method Summary

Modifier and Type	Method and Description
void	addLocation(long id, Block.BlockLocation location) Adds a new block location.
void	clear() Removes all metadata from the block store.
void	close() Closes the block store and releases all resources.
Optional<Block.BlockMeta>	getBlock(long id)
CloseableIterator<BlockMetaStore.Block>	getCloseableIterator() Gets a CloseableIterator over the blocks.
List<Block.BlockLocation>	getLocations(long id) Gets locations for a block.
void	putBlock(long id, Block.BlockMeta meta) Adds block metadata to the block store.
void	removeBlock(long id) Removes a block, or does nothing if the block does not exist.
void	removeLocation(long blockId, long workerId) Removes a block location.
long	size()

Method Detail

getBlock

Optional<Block.BlockMeta> getBlock(long id)

Parameters:

id - a block id

Returns:

the block's metadata, or empty if the block does not exist

putBlock

void putBlock(long id,
              Block.BlockMeta meta)

Adds block metadata to the block store. If the block already exists, its metadata will be updated to the given metadata.

Parameters:

id - the block id

meta - the block metadata

removeBlock

void removeBlock(long id)

Removes a block, or does nothing if the block does not exist.

Parameters:

id - a block id to remove

clear

void clear()

Removes all metadata from the block store.

getLocations

List<Block.BlockLocation> getLocations(long id)

Gets locations for a block. If the block does not exist or has no locations, an empty list is returned.

Parameters:

id - a block id

Returns:

the locations of the block

addLocation

void addLocation(long id,
                 Block.BlockLocation location)

Adds a new block location. If the location already exists, this method is a no-op.

Parameters:

id - a block id

location - a block location

removeLocation

void removeLocation(long blockId,
                    long workerId)

Removes a block location. If the location doesn't exist, this method is a no-op.

Parameters:

blockId - a block id

workerId - a worker id

close

void close()

Closes the block store and releases all resources.

size

long size()

Returns:

size of the block store

getCloseableIterator

CloseableIterator<BlockMetaStore.Block> getCloseableIterator()

Gets a CloseableIterator over the blocks. The iterator must be closed properly. One option is to follow the below idiom:

   try (CloseableIterator<Block> iter =
       mBlockStore.getCloseableIterator()) {
     while (iter.hasNext()) {
       // take the element and perform operations
     }
   }
 

If the iterator must be passed to other methods, it must be closed at the end of operation or on exceptions. Otherwise there can be a leak!

Returns:

a CloseableIterator over the blocks