org.apache.hadoop.hbase.regionserver

Enum ScannerContext.LimitScope

java.lang.Object

java.lang.Enum<ScannerContext.LimitScope>

org.apache.hadoop.hbase.regionserver.ScannerContext.LimitScope

All Implemented Interfaces:

Serializable, Comparable<ScannerContext.LimitScope>

Enclosing class:

ScannerContext

public static enum ScannerContext.LimitScope
extends Enum<ScannerContext.LimitScope>

The various scopes where a limit can be enforced. Used to differentiate when a limit should be enforced or not.

Enum Constant Summary

Enum Constants

Enum Constant and Description
BETWEEN_CELLS Enforcing a limit between cells means that the limit will be considered after each full cell has been retrieved
BETWEEN_ROWS Enforcing a limit between rows means that the limit will not be considered until all the cells for a particular row have been retrieved

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int	depth When enforcing a limit, we must check that the scope is appropriate for enforcement.

Method Summary

Modifier and Type	Method and Description
(package private) boolean	canEnforceLimitFromScope(ScannerContext.LimitScope checkerScope)
(package private) int	depth()
static ScannerContext.LimitScope	valueOf(String name) Returns the enum constant of this type with the specified name.
static ScannerContext.LimitScope[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

BETWEEN_ROWS

public static final ScannerContext.LimitScope BETWEEN_ROWS

Enforcing a limit between rows means that the limit will not be considered until all the cells for a particular row have been retrieved

BETWEEN_CELLS

public static final ScannerContext.LimitScope BETWEEN_CELLS

Enforcing a limit between cells means that the limit will be considered after each full cell has been retrieved

Field Detail

depth

final int depth

When enforcing a limit, we must check that the scope is appropriate for enforcement.

To communicate this concept, each scope has a depth. A limit will be enforced if the depth of the checker's scope is less than or equal to the limit's scope. This means that when checking limits, the checker must know their own scope (i.e. are they checking the limits between rows, between cells, etc...)

Method Detail

values

public static ScannerContext.LimitScope[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (ScannerContext.LimitScope c : ScannerContext.LimitScope.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static ScannerContext.LimitScope valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

depth

final int depth()

canEnforceLimitFromScope

boolean canEnforceLimitFromScope(ScannerContext.LimitScope checkerScope)

Parameters:

checkerScope - The scope in which the limit is being checked

Returns:

true when the checker is in a scope that indicates the limit can be enforced. Limits can be enforced from "higher or equal" scopes (i.e. the checker's scope is at a lesser depth than the limit)