org.apache.hadoop.hbase.codec.prefixtree

类 PrefixTreeSeeker

java.lang.Object

org.apache.hadoop.hbase.codec.prefixtree.PrefixTreeSeeker

所有已实现的接口:

DataBlockEncoder.EncodedSeeker

@InterfaceAudience.Private
public class PrefixTreeSeeker
extends Object
implements DataBlockEncoder.EncodedSeeker

These methods have the same definition as any implementation of the EncodedSeeker. In the future, the EncodedSeeker could be modified to work with the Cell interface directly. It currently returns a new KeyValue object each time getKeyValue is called. This is not horrible, but in order to create a new KeyValue object, we must first allocate a new byte[] and copy in the data from the PrefixTreeCell. It is somewhat heavyweight right now.

字段概要

字段

限定符和类型	字段和说明
protected ByteBuffer	block
protected boolean	includeMvccVersion
protected PrefixTreeArraySearcher	ptSearcher

构造器概要

构造器

构造器和说明
PrefixTreeSeeker(boolean includeMvccVersion)

方法概要

方法

限定符和类型	方法和说明
boolean	advance()
int	compareKey(KeyValue.KVComparator comparator, byte[] key, int offset, int length)
int	compareKey(KeyValue.KVComparator comparator, Cell key)
Cell	get() Currently unused.
ByteBuffer	getKeyDeepCopy()
Cell	getKeyValue() currently must do deep copy into new array
ByteBuffer	getValueShallowCopy()
boolean	next()
void	releaseCurrentSearcher() Currently unused.
void	rewind()
int	seekToKeyInBlock(byte[] keyOnlyBytes, int offset, int length, boolean forceBeforeOnExactMatch) Seek forward only (should be called reseekToKeyInBlock?).
int	seekToKeyInBlock(Cell key, boolean forceBeforeOnExactMatch)
protected int	seekToOrBeforeUsingPositionAtOrAfter(byte[] keyOnlyBytes, int offset, int length, boolean seekBefore)
protected int	seekToOrBeforeUsingPositionAtOrAfter(Cell kv, boolean seekBefore)
protected int	seekToOrBeforeUsingPositionAtOrBefore(byte[] keyOnlyBytes, int offset, int length, boolean seekBefore)
protected int	seekToOrBeforeUsingPositionAtOrBefore(Cell kv, boolean seekBefore)
void	setCurrentBuffer(ByteBuffer fullBlockBuffer)

从类继承的方法 java.lang.Object

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

字段详细资料

block

protected ByteBuffer block

includeMvccVersion

protected boolean includeMvccVersion

ptSearcher

protected PrefixTreeArraySearcher ptSearcher

构造器详细资料

PrefixTreeSeeker

public PrefixTreeSeeker(boolean includeMvccVersion)

方法详细资料

setCurrentBuffer

public void setCurrentBuffer(ByteBuffer fullBlockBuffer)

指定者:

setCurrentBuffer 在接口中 DataBlockEncoder.EncodedSeeker

releaseCurrentSearcher

public void releaseCurrentSearcher()

Currently unused.

TODO performance leak. should reuse the searchers. hbase does not currently have a hook where this can be called

getKeyDeepCopy

public ByteBuffer getKeyDeepCopy()

指定者:

getKeyDeepCopy 在接口中 DataBlockEncoder.EncodedSeeker

getValueShallowCopy

public ByteBuffer getValueShallowCopy()

指定者:

getValueShallowCopy 在接口中 DataBlockEncoder.EncodedSeeker

getKeyValue

public Cell getKeyValue()

currently must do deep copy into new array

指定者:

getKeyValue 在接口中 DataBlockEncoder.EncodedSeeker

get

public Cell get()

Currently unused.

A nice, lightweight reference, though the underlying cell is transient. This method may return the same reference to the backing PrefixTreeCell repeatedly, while other implementations may return a different reference for each Cell.

The goal will be to transition the upper layers of HBase, like Filters and KeyValueHeap, to use this method instead of the getKeyValue() methods above.

rewind

public void rewind()

指定者:

rewind 在接口中 DataBlockEncoder.EncodedSeeker

next

public boolean next()

指定者:

next 在接口中 DataBlockEncoder.EncodedSeeker

advance

public boolean advance()

seekToKeyInBlock

public int seekToKeyInBlock(byte[] keyOnlyBytes,
                   int offset,
                   int length,
                   boolean forceBeforeOnExactMatch)

Seek forward only (should be called reseekToKeyInBlock?).

If the exact key is found look at the seekBefore variable and:
- if true: go to the previous key if it's true
- if false: stay on the exact key

If the exact key is not found, then go to the previous key *if possible*, but remember to leave the scanner in a valid state if possible.

指定者:

seekToKeyInBlock 在接口中 DataBlockEncoder.EncodedSeeker

参数:

keyOnlyBytes - KeyValue format of a Cell's key at which to position the seeker

offset - offset into the keyOnlyBytes array

length - number of bytes of the keyOnlyBytes array to use

forceBeforeOnExactMatch - if an exact match is found and seekBefore=true, back up 1 Cell

返回:

0 if the seeker is on the exact key
1 if the seeker is not on the key for any reason, including seekBefore being true

seekToOrBeforeUsingPositionAtOrBefore

protected int seekToOrBeforeUsingPositionAtOrBefore(byte[] keyOnlyBytes,
                                        int offset,
                                        int length,
                                        boolean seekBefore)

seekToOrBeforeUsingPositionAtOrBefore

protected int seekToOrBeforeUsingPositionAtOrBefore(Cell kv,
                                        boolean seekBefore)

seekToOrBeforeUsingPositionAtOrAfter

protected int seekToOrBeforeUsingPositionAtOrAfter(byte[] keyOnlyBytes,
                                       int offset,
                                       int length,
                                       boolean seekBefore)

seekToOrBeforeUsingPositionAtOrAfter

protected int seekToOrBeforeUsingPositionAtOrAfter(Cell kv,
                                       boolean seekBefore)

compareKey

public int compareKey(KeyValue.KVComparator comparator,
             byte[] key,
             int offset,
             int length)

指定者:

compareKey 在接口中 DataBlockEncoder.EncodedSeeker

seekToKeyInBlock

public int seekToKeyInBlock(Cell key,
                   boolean forceBeforeOnExactMatch)

指定者:

seekToKeyInBlock 在接口中 DataBlockEncoder.EncodedSeeker

compareKey

public int compareKey(KeyValue.KVComparator comparator,
             Cell key)

指定者:

compareKey 在接口中 DataBlockEncoder.EncodedSeeker