org.apache.hadoop.hbase.io.hfile

Class HFileBlockIndex.CellBasedKeyBlockIndexReader

java.lang.Object

org.apache.hadoop.hbase.io.hfile.HFileBlockIndex.BlockIndexReader

org.apache.hadoop.hbase.io.hfile.HFileBlockIndex.CellBasedKeyBlockIndexReader

All Implemented Interfaces:

HeapSize

Enclosing class:

HFileBlockIndex

static class HFileBlockIndex.CellBasedKeyBlockIndexReader
extends HFileBlockIndex.BlockIndexReader

An implementation of the BlockIndexReader that deals with block keys which are the key part of a cell like the Data block index or the ROW_COL bloom blocks This needs a comparator to work with the Cells

Field Summary

Fields

Modifier and Type	Field and Description
private Cell[]	blockKeys
private CellComparator	comparator Needed doing lookup on blocks.
private AtomicReference<Cell>	midKey Pre-computed mid-key

Fields inherited from class org.apache.hadoop.hbase.io.hfile.HFileBlockIndex.BlockIndexReader

blockDataSizes, blockOffsets, cachingBlockReader, midKeyEntry, midLeafBlockOffset, midLeafBlockOnDiskSize, rootCount, searchTreeLevel

Constructor Summary

Constructors

Constructor and Description
CellBasedKeyBlockIndexReader(CellComparator c, int treeLevel)
CellBasedKeyBlockIndexReader(CellComparator c, int treeLevel, HFile.CachingBlockReader cachingBlockReader)

Method Summary

Modifier and Type	Method and Description
protected void	add(byte[] key, long offset, int dataSize) Adds a new entry in the root block index.
protected long	calculateHeapSizeForBlockKeys(long heapSize)
Cell	getRootBlockKey(int i)
protected void	initialize(int numEntries)
boolean	isEmpty()
BlockWithScanInfo	loadDataBlockWithScanInfo(Cell key, HFileBlock currentBlock, boolean cacheBlocks, boolean pread, boolean isCompaction, DataBlockEncoding expectedDataBlockEncoding) Return the BlockWithScanInfo, a data structure which contains the Data HFileBlock with other scan info such as the key that starts the next HFileBlock.
Cell	midkey() An approximation to the HFile's mid-key.
int	rootBlockContainingKey(byte[] key, int offset, int length, CellComparator comp) Finds the root-level index block containing the given key.
int	rootBlockContainingKey(Cell key) Finds the root-level index block containing the given key.
String	toString()

Methods inherited from class org.apache.hadoop.hbase.io.hfile.HFileBlockIndex.BlockIndexReader

binarySearchNonRootIndex, ensureNonEmpty, getNonRootIndexedKey, getRootBlockCount, getRootBlockDataSize, getRootBlockOffset, heapSize, locateNonRootIndexEntry, readMultiLevelIndexRoot, readRootIndex, readRootIndex, rootBlockContainingKey, seekToDataBlock

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

blockKeys

private Cell[] blockKeys

midKey

private AtomicReference<Cell> midKey

Pre-computed mid-key

comparator

private CellComparator comparator

Needed doing lookup on blocks.

Constructor Detail

CellBasedKeyBlockIndexReader

public CellBasedKeyBlockIndexReader(CellComparator c,
                                    int treeLevel,
                                    HFile.CachingBlockReader cachingBlockReader)

CellBasedKeyBlockIndexReader

public CellBasedKeyBlockIndexReader(CellComparator c,
                                    int treeLevel)

Method Detail

calculateHeapSizeForBlockKeys

protected long calculateHeapSizeForBlockKeys(long heapSize)

Specified by:

calculateHeapSizeForBlockKeys in class HFileBlockIndex.BlockIndexReader

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in class HFileBlockIndex.BlockIndexReader

Returns:

true if the block index is empty.

getRootBlockKey

public Cell getRootBlockKey(int i)

Parameters:

i - from 0 to - 1

loadDataBlockWithScanInfo

public BlockWithScanInfo loadDataBlockWithScanInfo(Cell key,
                                                   HFileBlock currentBlock,
                                                   boolean cacheBlocks,
                                                   boolean pread,
                                                   boolean isCompaction,
                                                   DataBlockEncoding expectedDataBlockEncoding)
                                            throws IOException

Description copied from class: HFileBlockIndex.BlockIndexReader

Return the BlockWithScanInfo, a data structure which contains the Data HFileBlock with other scan info such as the key that starts the next HFileBlock. This function will only be called when the HFile version is larger than 1.

Specified by:

loadDataBlockWithScanInfo in class HFileBlockIndex.BlockIndexReader

Parameters:

key - the key we are looking for

currentBlock - the current block, to avoid re-reading the same block

expectedDataBlockEncoding - the data block encoding the caller is expecting the data block to be in, or null to not perform this check and return the block irrespective of the encoding.

Returns:

the BlockWithScanInfo which contains the DataBlock with other scan info such as nextIndexedKey.

Throws:

IOException

midkey

public Cell midkey()
            throws IOException

Description copied from class: HFileBlockIndex.BlockIndexReader

An approximation to the HFile's mid-key. Operates on block boundaries, and does not go inside blocks. In other words, returns the first key of the middle block of the file.

Specified by:

midkey in class HFileBlockIndex.BlockIndexReader

Returns:

the first key of the middle block

Throws:

IOException

initialize

protected void initialize(int numEntries)

Specified by:

initialize in class HFileBlockIndex.BlockIndexReader

add

protected void add(byte[] key,
                   long offset,
                   int dataSize)

Adds a new entry in the root block index. Only used when reading.

Specified by:

add in class HFileBlockIndex.BlockIndexReader

Parameters:

key - Last key in the block

offset - file offset where the block is stored

dataSize - the uncompressed data size

rootBlockContainingKey

public int rootBlockContainingKey(byte[] key,
                                  int offset,
                                  int length,
                                  CellComparator comp)

Description copied from class: HFileBlockIndex.BlockIndexReader

Finds the root-level index block containing the given key.

Specified by:

rootBlockContainingKey in class HFileBlockIndex.BlockIndexReader

Parameters:

key - Key to find

comp - the comparator to be used

Returns:

Offset of block containing key (between 0 and the number of blocks - 1) or -1 if this file does not contain the request.

rootBlockContainingKey

public int rootBlockContainingKey(Cell key)

Description copied from class: HFileBlockIndex.BlockIndexReader

Finds the root-level index block containing the given key.

Specified by:

rootBlockContainingKey in class HFileBlockIndex.BlockIndexReader

Parameters:

key - Key to find

toString

public String toString()

Overrides:

toString in class Object