org.apache.flink.table.runtime.operators.rank

Class TopNBuffer

java.lang.Object

org.apache.flink.table.runtime.operators.rank.TopNBuffer

All Implemented Interfaces:

Serializable

public class TopNBuffer
extends Object
implements Serializable

TopNBuffer stores mapping from sort key to records list, sortKey is RowData type, each record is RowData type. TopNBuffer could also track rank number of each record.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
TopNBuffer(Comparator<org.apache.flink.table.data.RowData> sortKeyComparator, Supplier<Collection<org.apache.flink.table.data.RowData>> valueSupplier)

Method Summary

Modifier and Type	Method and Description
boolean	checkSortKeyInBufferRange(org.apache.flink.table.data.RowData sortKey, long topNum) Checks whether the record should be put into the buffer.
boolean	containsKey(org.apache.flink.table.data.RowData key) Returns true if the buffer contains a mapping for the specified key.
Set<Map.Entry<org.apache.flink.table.data.RowData,Collection<org.apache.flink.table.data.RowData>>>	entrySet() Returns a Set view of the mappings contained in the buffer.
Collection<org.apache.flink.table.data.RowData>	get(org.apache.flink.table.data.RowData sortKey) Gets the record list from the buffer under the sortKey.
int	getCurrentTopNum() Gets number of total records.
org.apache.flink.table.data.RowData	getElement(int rank) Gets record which rank is given value.
Comparator<org.apache.flink.table.data.RowData>	getSortKeyComparator() Gets sort key comparator used by buffer.
org.apache.flink.table.data.RowData	lastElement() Returns the last record of the last Entry in the buffer.
Map.Entry<org.apache.flink.table.data.RowData,Collection<org.apache.flink.table.data.RowData>>	lastEntry() Returns the last Entry in the buffer.
int	put(org.apache.flink.table.data.RowData sortKey, org.apache.flink.table.data.RowData value) Appends a record into the buffer.
void	putAll(org.apache.flink.table.data.RowData sortKey, Collection<org.apache.flink.table.data.RowData> values) Puts a record list into the buffer under the sortKey.
void	remove(org.apache.flink.table.data.RowData sortKey, org.apache.flink.table.data.RowData value)
void	removeAll(org.apache.flink.table.data.RowData sortKey) Removes all record list from the buffer under the sortKey.
org.apache.flink.table.data.RowData	removeLast() Removes the last record of the last Entry in the buffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

TopNBuffer

public TopNBuffer(Comparator<org.apache.flink.table.data.RowData> sortKeyComparator,
                  Supplier<Collection<org.apache.flink.table.data.RowData>> valueSupplier)

Method Detail

put

public int put(org.apache.flink.table.data.RowData sortKey,
               org.apache.flink.table.data.RowData value)

Appends a record into the buffer.

Parameters:

sortKey - sort key with which the specified value is to be associated

value - record which is to be appended

Returns:

the size of the collection under the sortKey.

putAll

public void putAll(org.apache.flink.table.data.RowData sortKey,
                   Collection<org.apache.flink.table.data.RowData> values)

Puts a record list into the buffer under the sortKey. Note: if buffer already contains sortKey, putAll will overwrite the previous value

Parameters:

sortKey - sort key with which the specified values are to be associated

values - record lists to be associated with the specified key

get

public Collection<org.apache.flink.table.data.RowData> get(org.apache.flink.table.data.RowData sortKey)

Gets the record list from the buffer under the sortKey.

Parameters:

sortKey - key to get

Returns:

the record list from the buffer under the sortKey

remove

public void remove(org.apache.flink.table.data.RowData sortKey,
                   org.apache.flink.table.data.RowData value)

removeAll

public void removeAll(org.apache.flink.table.data.RowData sortKey)

Removes all record list from the buffer under the sortKey.

Parameters:

sortKey - key to remove

removeLast

public org.apache.flink.table.data.RowData removeLast()

Removes the last record of the last Entry in the buffer.

Returns:

removed record

lastElement

public org.apache.flink.table.data.RowData lastElement()

Returns the last record of the last Entry in the buffer.

getElement

public org.apache.flink.table.data.RowData getElement(int rank)

Gets record which rank is given value.

Parameters:

rank - rank value to search

Returns:

the record which rank is given value

entrySet

public Set<Map.Entry<org.apache.flink.table.data.RowData,Collection<org.apache.flink.table.data.RowData>>> entrySet()

Returns a Set view of the mappings contained in the buffer.

lastEntry

public Map.Entry<org.apache.flink.table.data.RowData,Collection<org.apache.flink.table.data.RowData>> lastEntry()

Returns the last Entry in the buffer. Returns null if the TreeMap is empty.

containsKey

public boolean containsKey(org.apache.flink.table.data.RowData key)

Returns true if the buffer contains a mapping for the specified key.

Parameters:

key - key whose presence in the buffer is to be tested

Returns:

true if the buffer contains a mapping for the specified key

getCurrentTopNum

public int getCurrentTopNum()

Gets number of total records.

Returns:

the number of total records.

getSortKeyComparator

public Comparator<org.apache.flink.table.data.RowData> getSortKeyComparator()

Gets sort key comparator used by buffer.

Returns:

sort key comparator used by buffer

checkSortKeyInBufferRange

public boolean checkSortKeyInBufferRange(org.apache.flink.table.data.RowData sortKey,
                                         long topNum)

Checks whether the record should be put into the buffer.

Parameters:

sortKey - sortKey to test

topNum - buffer to add

Returns:

true if the record should be put into the buffer.