Package org.apache.accumulo.core.dataImpl

Class KeyExtent

java.lang.Object

org.apache.accumulo.core.dataImpl.KeyExtent

All Implemented Interfaces:

Comparable<KeyExtent>

public class KeyExtent
extends Object
implements Comparable<KeyExtent>

keeps track of information needed to identify a tablet

Constructor Summary

Constructors

Constructor	Description
KeyExtent(TableId table, org.apache.hadoop.io.Text endRow, org.apache.hadoop.io.Text prevEndRow)	Create a new KeyExtent from its components.

Method Summary

Modifier and Type	Method	Description
int	compareTo(KeyExtent other)
boolean	contains(KeyExtent oke)	Determine if another KeyExtent is wholly contained within the range of this one.
boolean	contains(org.apache.hadoop.io.BinaryComparable row)	Determine if the provided row is contained within the range of this KeyExtent.
static KeyExtent	copyOf(KeyExtent original)	Create a copy of a provided KeyExtent.
org.apache.hadoop.io.Text	endRow()	Returns this extent's end row
boolean	equals(Object o)
static Set<KeyExtent>	findOverlapping(KeyExtent nke, SortedMap<KeyExtent,?> extents)
static Set<KeyExtent>	findOverlapping(KeyExtent nke, SortedSet<KeyExtent> extents)
static KeyExtent	fromMetaPrevRow(Map.Entry<Key,Value> prevRowEntry)	Create a KeyExtent from a metadata previous end row entry.
static KeyExtent	fromMetaRow(org.apache.hadoop.io.Text encodedMetadataRow)	Create a KeyExtent from the table ID and the end row encoded in the row field of a tablet's metadata entry, with no previous end row.
static KeyExtent	fromMetaRow(org.apache.hadoop.io.Text encodedMetadataRow, org.apache.hadoop.io.Text prevEndRow)	Create a KeyExtent from the table ID and the end row encoded in the row field of a tablet's metadata entry, along with a previous end row.
static KeyExtent	fromTabletId(TabletId tabletId)	Create a KeyExtent from a TabletId.
static KeyExtent	fromThrift(TKeyExtent tke)	Create a KeyExtent from its Thrift form.
UUID	getUUID()	Retrieve a unique identifier for this tablet that is useful for logging, without revealing the contents of the end row and previous end row.
int	hashCode()
boolean	isMeta()
boolean	isPreviousExtent(KeyExtent prevExtent)
boolean	isRootTablet()
String	obscured()
boolean	overlaps(KeyExtent other)
org.apache.hadoop.io.Text	prevEndRow()	Return the previous extent's end row
static KeyExtent	readFrom(DataInput in)	Create a KeyExtent from a serialized form.
TableId	tableId()	Return the extent's table ID.
Range	toDataRange()	Compute a representation of this extent as a Range suitable for scanning this extent's table and retrieving all data between this extent's previous end row (exclusive) and its end row (inclusive) in that table (or another table in the same range, since the returned range does not specify the table to scan).
Range	toMetaRange()	Compute a representation of this extent as a Range suitable for scanning the corresponding metadata table for this extent's table, and retrieving all the metadata for the table's tablets between this extent's previous end row (exclusive) and its end row (inclusive) in that table.
org.apache.hadoop.io.Text	toMetaRow()	Return a serialized form of the table ID and end row for this extent, in a form suitable for use in the row portion of metadata entries for the tablet this extent represents.
String	toString()
TKeyExtent	toThrift()	Convert to Thrift form.
void	writeTo(DataOutput out)	Serialize this KeyExtent.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

KeyExtent

public KeyExtent(TableId table,
                 org.apache.hadoop.io.Text endRow,
                 org.apache.hadoop.io.Text prevEndRow)

Create a new KeyExtent from its components.

Parameters:

table - the ID for the table

endRow - the last row in this tablet, or null if this is the last tablet in this table

prevEndRow - the last row in the immediately preceding tablet for the table, or null if this represents the first tablet in this table

Method Detail

copyOf

public static KeyExtent copyOf(KeyExtent original)

Create a copy of a provided KeyExtent.

Parameters:

original - the KeyExtent to copy

fromThrift

public static KeyExtent fromThrift(TKeyExtent tke)

Create a KeyExtent from its Thrift form.

Parameters:

tke - the KeyExtent in its Thrift object form

toThrift

public TKeyExtent toThrift()

Convert to Thrift form.

fromMetaPrevRow

public static KeyExtent fromMetaPrevRow(Map.Entry<Key,Value> prevRowEntry)

Create a KeyExtent from a metadata previous end row entry.

Parameters:

prevRowEntry - a provided previous end row entry from the metadata table, stored in the "~tab" column family and "~pr" column. If the individual components are needed, consider KeyExtent(TableId, Text, Text) or fromMetaRow(Text, Text) instead.

fromMetaRow

public static KeyExtent fromMetaRow(org.apache.hadoop.io.Text encodedMetadataRow)

Create a KeyExtent from the table ID and the end row encoded in the row field of a tablet's metadata entry, with no previous end row.

Parameters:

encodedMetadataRow - the encoded tableId and endRow from a metadata entry, as in entry.getKey().getRow() or from MetadataSchema.TabletsSection.encodeRow(TableId, Text)

fromMetaRow

public static KeyExtent fromMetaRow(org.apache.hadoop.io.Text encodedMetadataRow,
                                    org.apache.hadoop.io.Text prevEndRow)

Create a KeyExtent from the table ID and the end row encoded in the row field of a tablet's metadata entry, along with a previous end row.

Parameters:

encodedMetadataRow - the encoded tableId and endRow from a metadata entry, as in entry.getKey().getRow() or from MetadataSchema.TabletsSection.encodeRow(TableId, Text)

prevEndRow - the unencoded previous end row (a copy will be made)

fromTabletId

public static KeyExtent fromTabletId(TabletId tabletId)

Create a KeyExtent from a TabletId.

Parameters:

tabletId - the TabletId to convert to a KeyExtent

toMetaRow

public org.apache.hadoop.io.Text toMetaRow()

Return a serialized form of the table ID and end row for this extent, in a form suitable for use in the row portion of metadata entries for the tablet this extent represents.

tableId

public TableId tableId()

Return the extent's table ID.

endRow

public org.apache.hadoop.io.Text endRow()

Returns this extent's end row

prevEndRow

public org.apache.hadoop.io.Text prevEndRow()

Return the previous extent's end row

readFrom

public static KeyExtent readFrom(DataInput in)
                          throws IOException

Create a KeyExtent from a serialized form.

Throws:

IOException

See Also:

writeTo(DataOutput)

writeTo

public void writeTo(DataOutput out)
             throws IOException

Serialize this KeyExtent.

Throws:

IOException

See Also:

readFrom(DataInput)

compareTo

public int compareTo(KeyExtent other)

Specified by:

compareTo in interface Comparable<KeyExtent>

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object o)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object

getUUID

public UUID getUUID()

Retrieve a unique identifier for this tablet that is useful for logging, without revealing the contents of the end row and previous end row.

contains

public boolean contains(KeyExtent oke)

Determine if another KeyExtent is wholly contained within the range of this one. * @param oke

Returns:

true if and only if the provided KeyExtent is contained within the range of this one

contains

public boolean contains(org.apache.hadoop.io.BinaryComparable row)

Determine if the provided row is contained within the range of this KeyExtent.

Returns:

true if and only if the provided row is contained within the range of this one

toDataRange

public Range toDataRange()

Compute a representation of this extent as a Range suitable for scanning this extent's table and retrieving all data between this extent's previous end row (exclusive) and its end row (inclusive) in that table (or another table in the same range, since the returned range does not specify the table to scan).

For example, if this extent represented a range of data from A to Z for table T, the resulting Range could be used to scan table T's data in the exclusive-inclusive range (A,Z], or the same range in another table, T2.

toMetaRange

public Range toMetaRange()

Compute a representation of this extent as a Range suitable for scanning the corresponding metadata table for this extent's table, and retrieving all the metadata for the table's tablets between this extent's previous end row (exclusive) and its end row (inclusive) in that table.

For example, if this extent represented a range of data from A to Z for a user table, T, this would compute the range to scan accumulo.metadata that would include all the the metadata for T's tablets that contain data in the range (A,Z].

findOverlapping

public static Set<KeyExtent> findOverlapping(KeyExtent nke,
                                             SortedSet<KeyExtent> extents)

overlaps

public boolean overlaps(KeyExtent other)

findOverlapping

public static Set<KeyExtent> findOverlapping(KeyExtent nke,
                                             SortedMap<KeyExtent,?> extents)

isPreviousExtent

public boolean isPreviousExtent(KeyExtent prevExtent)

isMeta

public boolean isMeta()

isRootTablet

public boolean isRootTablet()

obscured

public String obscured()