org.janusgraph.diskstorage.inmemory

Class SinglePageEntryBuffer

java.lang.Object

org.janusgraph.diskstorage.inmemory.SinglePageEntryBuffer

All Implemented Interfaces:

SharedEntryBuffer

public class SinglePageEntryBuffer
extends Object
implements SharedEntryBuffer

"Single page" implementation of SharedEntryBuffer.

It extends BufferPage and complements it with the methods required to make a page look like a complete buffer. In essence, it just makes a page mutable by reassigning merge results to the same buffer + index refs

This saves a lot of overhead because 90% of stores fit into one page, as we don't have to keep track of a list of pages etc

Field Summary

Fields

Modifier and Type	Field and Description
static byte[]	EMPTY_DATA
static int[]	EMPTY_INDEX

Constructor Summary

Constructors

Constructor and Description
SinglePageEntryBuffer()

Method Summary

Modifier and Type	Method and Description
int	byteSize()
SharedEntryBufferFragmentationReport	createFragmentationReport(int maxPageSize)
void	dumpTo(DataOutputStream out)
Entry	get(int index) Entry is packed into byte array in the following way 1.
int	getIndex(StaticBuffer column)
Entry	getNoCopy(int index)
protected int[]	getOffsetIndex()
protected byte[]	getRawData()
EntryList	getSlice(KeySliceQuery query)
boolean	isEmpty()
boolean	isPaged()
List<org.janusgraph.diskstorage.inmemory.BufferPage>	merge(Entry[] add, int iaddp, int addLimit, Entry[] del, int idelp, int delLimit, int maxPageSize)
static List<org.janusgraph.diskstorage.inmemory.BufferPage>	merge(List<org.janusgraph.diskstorage.inmemory.BufferPage> pagesToMerge, int maxPageSize)
void	mutate(Entry[] add, Entry[] del, int maxPageSize)
int	numEntries()
int	numPages()
void	quickDefragment(int maxPageSize)
protected void	setOffsetIndex(int[] offsetIndex)
protected void	setRawData(byte[] rawData)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.janusgraph.diskstorage.inmemory.SharedEntryBuffer

byteSize, isEmpty, numEntries

Field Detail

EMPTY_INDEX

public static final int[] EMPTY_INDEX

EMPTY_DATA

public static final byte[] EMPTY_DATA

Constructor Detail

SinglePageEntryBuffer

public SinglePageEntryBuffer()

Method Detail

numPages

public int numPages()

Specified by:

numPages in interface SharedEntryBuffer

getSlice

public EntryList getSlice(KeySliceQuery query)

Specified by:

getSlice in interface SharedEntryBuffer

mutate

public void mutate(Entry[] add,
                   Entry[] del,
                   int maxPageSize)

Specified by:

mutate in interface SharedEntryBuffer

isPaged

public boolean isPaged()

Specified by:

isPaged in interface SharedEntryBuffer

createFragmentationReport

public SharedEntryBufferFragmentationReport createFragmentationReport(int maxPageSize)

Specified by:

createFragmentationReport in interface SharedEntryBuffer

quickDefragment

public void quickDefragment(int maxPageSize)

Specified by:

quickDefragment in interface SharedEntryBuffer

dumpTo

public void dumpTo(DataOutputStream out)
            throws IOException

Specified by:

dumpTo in interface SharedEntryBuffer

Throws:

IOException

getOffsetIndex

protected int[] getOffsetIndex()

getRawData

protected byte[] getRawData()

setRawData

protected void setRawData(byte[] rawData)

setOffsetIndex

protected void setOffsetIndex(int[] offsetIndex)

isEmpty

public boolean isEmpty()

getIndex

public int getIndex(StaticBuffer column)

get

public Entry get(int index)

Entry is packed into byte array in the following way 1. "valPos" - offset at which the value data starts (same as size of "column") 2. "column" - N bytes, where N=valPos 3. "value" - everything from the end of column to the end of the array

Parameters:

index -

Returns:

getNoCopy

public Entry getNoCopy(int index)

numEntries

public int numEntries()

byteSize

public int byteSize()

merge

public static List<org.janusgraph.diskstorage.inmemory.BufferPage> merge(List<org.janusgraph.diskstorage.inmemory.BufferPage> pagesToMerge,
                                                                         int maxPageSize)

merge

public List<org.janusgraph.diskstorage.inmemory.BufferPage> merge(Entry[] add,
                                                                  int iaddp,
                                                                  int addLimit,
                                                                  Entry[] del,
                                                                  int idelp,
                                                                  int delLimit,
                                                                  int maxPageSize)