HashRing Class Reference

Convenience class for weighted consistent hash rings. More...

Collaboration diagram for HashRing:

List of all members.

Public Member Functions
	__construct (array $map)
	ejectFromLiveRing ($location, $ttl)
	Remove a location from the "live" hash ring.
	getLiveLocation ($item)
	Get the location of an item on the "live" ring.
	getLiveLocations ($item)
	Get the location of an item on the "live" ring, as well as the next locations.
	getLiveLocationWeights ()
	Get the map of "live" locations to weight (ignores 0-weight items)
	getLiveRing ()
	Get the "live" hash ring (which does not include ejected locations)
	getLocation ($item)
	Get the location of an item on the ring.
	getLocations ($item, $limit)
	Get the location of an item on the ring, as well as the next locations.
	getLocationWeights ()
	Get the map of locations to weight (ignores 0-weight items)
	newWithoutLocation ($location)
	Get a new hash ring with a location removed from the ring.
Public Attributes
const	RING_SIZE = 268435456
Protected Attributes
Array	$ejectionExpiries = array()
	(location => UNIX timestamp) *
integer	$ejectionNextExpiry = INF
	UNIX timestamp *.
Array	$liveRing
	(location => (start, end)) *
Array	$ring = array()
	(location => (start, end)) *
Array	$sourceMap = array()
	(location => weight) *

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Detailed Description

Convenience class for weighted consistent hash rings.

Since:

1.22

Definition at line 29 of file HashRing.php.

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Constructor & Destructor Documentation

HashRing::__construct

(

array $

map

)

Parameters:

array

$map

(location => weight)

Definition at line 42 of file HashRing.php.

References $hashes, array(), as, key, and RING_SIZE.

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Member Function Documentation

HashRing::ejectFromLiveRing	(	$	location,
		$	ttl
	)

Remove a location from the "live" hash ring.

Parameters:

string	$location
integer	$ttl	Seconds

Returns:

bool Whether some non-ejected locations are left

Definition at line 154 of file HashRing.php.

HashRing::getLiveLocation

(

$

item

)

Get the location of an item on the "live" ring.

Parameters:

string

$item

Returns:

string Location

Exceptions:

UnexpectedValueException

Definition at line 209 of file HashRing.php.

HashRing::getLiveLocations

(

$

item

)

Get the location of an item on the "live" ring, as well as the next locations.

Parameters:

string	$item
integer	$limit	Maximum number of locations to return

Returns:

array List of locations

Exceptions:

UnexpectedValueException

Definition at line 221 of file HashRing.php.

HashRing::getLiveLocationWeights

(

)

Get the map of "live" locations to weight (ignores 0-weight items)

Returns:

array

Exceptions:

UnexpectedValueException

Definition at line 231 of file HashRing.php.

HashRing::getLiveRing

(

)

Get the "live" hash ring (which does not include ejected locations)

Returns:

HashRing

Exceptions:

UnexpectedValueException

Definition at line 172 of file HashRing.php.

HashRing::getLocation

(

$

item

)

Get the location of an item on the ring.

Parameters:

string

$item

Returns:

string Location

Definition at line 82 of file HashRing.php.

HashRing::getLocations	(	$	item,
		$	limit
	)

Get the location of an item on the ring, as well as the next locations.

Parameters:

string	$item
integer	$limit	Maximum number of locations to return

Returns:

array List of locations

Definition at line 95 of file HashRing.php.

HashRing::getLocationWeights

(

)

Get the map of locations to weight (ignores 0-weight items)

Returns:

array

Definition at line 130 of file HashRing.php.

HashRing::newWithoutLocation

(

$

location

)

Get a new hash ring with a location removed from the ring.

Parameters:

string

$location

Returns:

HashRing|bool Returns false if no non-zero weighted spots are left

Definition at line 140 of file HashRing.php.

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Member Data Documentation

Array HashRing::$ejectionExpiries = array() [protected]

(location => UNIX timestamp) *

Definition at line 34 of file HashRing.php.

integer HashRing::$ejectionNextExpiry = INF [protected]

UNIX timestamp *.

Definition at line 35 of file HashRing.php.

Array HashRing::$liveRing [protected]

(location => (start, end)) *

Definition at line 33 of file HashRing.php.

Array HashRing::$ring = array() [protected]

(location => (start, end)) *

Definition at line 31 of file HashRing.php.

Array HashRing::$sourceMap = array() [protected]

(location => weight) *

Definition at line 30 of file HashRing.php.

const HashRing::RING_SIZE = 268435456

Definition at line 37 of file HashRing.php.

Referenced by __construct().

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The documentation for this class was generated from the following file:

• includes/libs/HashRing.php