RegionLocations (Apache HBase 1.4.11 API)

java.lang.Object
- org.apache.hadoop.hbase.RegionLocations

```
@InterfaceAudience.Private
public class RegionLocations
extends Object
```
Container for holding a list of HRegionLocation's that correspond to the same range. The list is indexed by the replicaId. This is an immutable list, however mutation operations are provided which returns a new List via copy-on-write (assuming small number of locations)

Constructor Summary

Constructors
Constructor and Description

RegionLocations(Collection<HRegionLocation> locations)

RegionLocations(HRegionLocation... locations)
Constructs the region location list.

Constructors
Constructor and Description
`RegionLocations(Collection<HRegionLocation> locations)`
`RegionLocations(HRegionLocation... locations)` Constructs the region location list.

Method Summary

Methods
Modifier and Type	Method and Description
`HRegionLocation`	`getDefaultRegionLocation()`
`HRegionLocation`	`getRegionLocation()` Returns the first not-null region location in the list
`HRegionLocation`	`getRegionLocation(int replicaId)`
`HRegionLocation`	`getRegionLocationByRegionName(byte[] regionName)` Returns the region location from the list for matching regionName, which can be regionName or encodedRegionName
`HRegionLocation[]`	`getRegionLocations()`
`boolean`	`isEmpty()` Returns whether there are non-null elements in the list
`RegionLocations`	`mergeLocations(RegionLocations other)` Merges this RegionLocations list with the given list assuming same range, and keeping the most up to date version of the HRegionLocation entries from either list according to seqNum.
`int`	`numNonNullElements()` Returns the size of not-null locations
`RegionLocations`	`remove(HRegionLocation location)` Removes the given location from the list
`RegionLocations`	`remove(int replicaId)` Removes location of the given replicaId from the list
`RegionLocations`	`removeByServer(ServerName serverName)` Returns a new RegionLocations with the locations removed (set to null) which have the destination server as given.
`int`	`size()` Returns the size of the list even if some of the elements might be null.
`String`	`toString()`
`RegionLocations`	`updateLocation(HRegionLocation location, boolean checkForEquals, boolean force)` Updates the location with new only if the new location has a higher seqNum than the old one or force is true.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - RegionLocations
```
public RegionLocations(HRegionLocation... locations)
```
    Constructs the region location list. The locations array should contain all the locations for known replicas for the region, and should be sorted in replicaId ascending order, although it can contain nulls indicating replicaIds that the locations of which are not known.
    
    Parameters:
    locations - an array of HRegionLocations for the same region range
  - RegionLocations
```
public RegionLocations(Collection<HRegionLocation> locations)
```
- Method Detail
  - size
```
public int size()
```
    Returns the size of the list even if some of the elements might be null.
    
    Returns:
    the size of the list (corresponding to the max replicaId)
  - numNonNullElements
```
public int numNonNullElements()
```
    Returns the size of not-null locations
    
    Returns:
    the size of not-null locations
  - isEmpty
```
public boolean isEmpty()
```
    Returns whether there are non-null elements in the list
    
    Returns:
    whether there are non-null elements in the list
  - removeByServer
```
public RegionLocations removeByServer(ServerName serverName)
```
    Returns a new RegionLocations with the locations removed (set to null) which have the destination server as given.
    
    Parameters:
    serverName - the serverName to remove locations of
    
    Returns:
    an RegionLocations object with removed locations or the same object if nothing is removed
  - remove
```
public RegionLocations remove(HRegionLocation location)
```
    Removes the given location from the list
    
    Parameters:
    location - the location to remove
    
    Returns:
    an RegionLocations object with removed locations or the same object if nothing is removed
  - remove
```
public RegionLocations remove(int replicaId)
```
    Removes location of the given replicaId from the list
    
    Parameters:
    replicaId - the replicaId of the location to remove
    
    Returns:
    an RegionLocations object with removed locations or the same object if nothing is removed
  - mergeLocations
```
public RegionLocations mergeLocations(RegionLocations other)
```
    Merges this RegionLocations list with the given list assuming same range, and keeping the most up to date version of the HRegionLocation entries from either list according to seqNum. If seqNums are equal, the location from the argument (other) is taken.
    
    Parameters:
    other - the locations to merge with
    
    Returns:
    an RegionLocations object with merged locations or the same object if nothing is merged
  - updateLocation
```
public RegionLocations updateLocation(HRegionLocation location,
                             boolean checkForEquals,
                             boolean force)
```
    Updates the location with new only if the new location has a higher seqNum than the old one or force is true.
    
    Parameters:
    location - the location to add or update
    checkForEquals - whether to update the location if seqNums for the HRegionLocations for the old and new location are the same
    force - whether to force update
    
    Returns:
    an RegionLocations object with updated locations or the same object if nothing is updated
  - getRegionLocation
```
public HRegionLocation getRegionLocation(int replicaId)
```
  - getRegionLocationByRegionName
```
public HRegionLocation getRegionLocationByRegionName(byte[] regionName)
```
    Returns the region location from the list for matching regionName, which can be regionName or encodedRegionName
    
    Parameters:
    regionName - regionName or encodedRegionName
    
    Returns:
    HRegionLocation found or null
  - getRegionLocations
```
public HRegionLocation[] getRegionLocations()
```
  - getDefaultRegionLocation
```
public HRegionLocation getDefaultRegionLocation()
```
  - getRegionLocation
```
public HRegionLocation getRegionLocation()
```
    Returns the first not-null region location in the list
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class RegionLocations

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

RegionLocations

RegionLocations

Method Detail

size

numNonNullElements

isEmpty

removeByServer

remove

remove

mergeLocations

updateLocation

getRegionLocation

getRegionLocationByRegionName

getRegionLocations

getDefaultRegionLocation

getRegionLocation

toString