UIDGenerator Class Reference

Class for getting statistically unique IDs. More...

Collaboration diagram for UIDGenerator:

List of all members.

Public Member Functions
	__destruct ()
Static Public Member Functions
static	newRawUUIDv4 ($flags=0)
	Return an RFC4122 compliant v4 UUID.
static	newTimestampedUID128 ($base=10)
	Get a statistically unique 128-bit unsigned integer ID string.
static	newTimestampedUID88 ($base=10)
	Get a statistically unique 88-bit unsigned integer ID string.
static	newUUIDv4 ($flags=0)
	Return an RFC4122 compliant v4 UUID.
Public Attributes
const	QUICK_RAND = 1
Protected Member Functions
	__construct ()
	getTimestampAndDelay ($lockFile, $clockSeqSize, $counterSize)
	Get a (time,counter,clock sequence) where (time,counter) is higher than any previous (time,counter) value for the given clock sequence.
	getTimestampedID128 (array $info)
	getTimestampedID88 (array $info)
	millisecondsSinceEpochBinary (array $time)
	timeWaitUntil (array $time)
	Wait till the current timestamp reaches $time and return the current timestamp.
Static Protected Member Functions
static	millitime ()
static	singleton ()
Protected Attributes
Array	$fileHandles = array()
	*
	$lockFile128
	$lockFile88
	$nodeId32
	$nodeId48
Static Protected Attributes
static	$instance = null

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Detailed Description

Class for getting statistically unique IDs.

Since:

1.21

Definition at line 29 of file UIDGenerator.php.

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Constructor & Destructor Documentation

UIDGenerator::__construct

(

)

[protected]

Definition at line 43 of file UIDGenerator.php.

References array(), MWCryptRand\generateHex(), wfBaseConvert(), wfIsWindows(), wfRestoreWarnings(), wfShellExec(), wfSuppressWarnings(), and wfTempDir().

UIDGenerator::__destruct

(

)

Definition at line 333 of file UIDGenerator.php.

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Member Function Documentation

UIDGenerator::getTimestampAndDelay	(	$	lockFile,
		$	clockSeqSize,
		$	counterSize
	)		[protected]

Get a (time,counter,clock sequence) where (time,counter) is higher than any previous (time,counter) value for the given clock sequence.

This is useful for making UIDs sequential on a per-node bases.

Parameters:

string	$lockFile	Name of a local lock file
	$clockSeqSize	integer The number of possible clock sequence values
	$counterSize	integer The number of possible counter values

Returns:

Array (result of UIDGenerator::millitime(), counter, clock sequence)

Exceptions:

MWException

Definition at line 222 of file UIDGenerator.php.

UIDGenerator::getTimestampedID128

(

array $

info

)

[protected]

Parameters:

array

$info

(UIDGenerator::millitime(), counter, clock sequence)

Returns:

string 128 bits

Definition at line 157 of file UIDGenerator.php.

UIDGenerator::getTimestampedID88

(

array $

info

)

[protected]

Parameters:

array

$time

(UIDGenerator::millitime(), clock sequence)

Returns:

string 88 bits

Definition at line 115 of file UIDGenerator.php.

UIDGenerator::millisecondsSinceEpochBinary

(

array $

time

)

[protected]

Parameters:

array

$time

Result of UIDGenerator::millitime()

Returns:

string 46 MSBs of "milliseconds since epoch" in binary (rolls over in 4201)

Definition at line 315 of file UIDGenerator.php.

static UIDGenerator::millitime

(

)

[static, protected]

Returns:

Array (current time in seconds, milliseconds since then)

Definition at line 328 of file UIDGenerator.php.

static UIDGenerator::newRawUUIDv4

(

$

flags = 0

)

[static]

Return an RFC4122 compliant v4 UUID.

Parameters:

$flags

integer Bitfield (supports UIDGenerator::QUICK_RAND)

Returns:

string 32 hex characters with no hyphens

Exceptions:

MWException

Definition at line 207 of file UIDGenerator.php.

Referenced by UIDGeneratorTest\testRawUUIDv4(), and UIDGeneratorTest\testRawUUIDv4QuickRand().

static UIDGenerator::newTimestampedUID128

(

$

base = 10

)

[static]

Get a statistically unique 128-bit unsigned integer ID string.

The bits of the UID are prefixed with the time (down to the millisecond).

These IDs are suitable as globally unique IDs, without any enforced uniqueness. New rows almost always have higher UIDs, which makes B-TREE updates on INSERT fast. They can also be stored as "DECIMAL(39) UNSIGNED" or BINARY(16) in MySQL.

UID generation is serialized on each server (as the node ID is for the whole machine).

Parameters:

$base

integer Specifies a base other than 10

Returns:

string Number

Exceptions:

MWException

Definition at line 144 of file UIDGenerator.php.

Referenced by ExternalStoreMwstore\store().

static UIDGenerator::newTimestampedUID88

(

$

base = 10

)

[static]

Get a statistically unique 88-bit unsigned integer ID string.

The bits of the UID are prefixed with the time (down to the millisecond).

These IDs are suitable as values for the shard key of distributed data. If a column uses these as values, it should be declared UNIQUE to handle collisions. New rows almost always have higher UIDs, which makes B-TREE updates on INSERT fast. They can also be stored "DECIMAL(27) UNSIGNED" or BINARY(11) in MySQL.

UID generation is serialized on each server (as the node ID is for the whole machine).

Parameters:

$base

integer Specifies a base other than 10

Returns:

string Number

Exceptions:

MWException

Definition at line 102 of file UIDGenerator.php.

static UIDGenerator::newUUIDv4

(

$

flags = 0

)

[static]

Return an RFC4122 compliant v4 UUID.

Parameters:

$flags

integer Bitfield (supports UIDGenerator::QUICK_RAND)

Returns:

string

Exceptions:

MWException

Definition at line 181 of file UIDGenerator.php.

Referenced by UIDGeneratorTest\testUUIDv4().

static UIDGenerator::singleton

(

)

[static, protected]

Returns:

UIDGenerator

Definition at line 80 of file UIDGenerator.php.

UIDGenerator::timeWaitUntil

(

array $

time

)

[protected]

Wait till the current timestamp reaches $time and return the current timestamp.

This returns false if it would have to wait more than 10ms.

Parameters:

array

$time

Result of UIDGenerator::millitime()

Returns:

Array|bool UIDGenerator::millitime() result or false

Definition at line 300 of file UIDGenerator.php.

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Member Data Documentation

Array UIDGenerator::$fileHandles = array() [protected]

*

Definition at line 39 of file UIDGenerator.php.

UIDGenerator::$instance = null [static, protected]

Definition at line 31 of file UIDGenerator.php.

UIDGenerator::$lockFile128 [protected]

Definition at line 37 of file UIDGenerator.php.

UIDGenerator::$lockFile88 [protected]

Definition at line 36 of file UIDGenerator.php.

UIDGenerator::$nodeId32 [protected]

Definition at line 33 of file UIDGenerator.php.

UIDGenerator::$nodeId48 [protected]

Definition at line 34 of file UIDGenerator.php.

const UIDGenerator::QUICK_RAND = 1

Definition at line 41 of file UIDGenerator.php.

Referenced by UIDGeneratorTest\testRawUUIDv4QuickRand().

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

• includes/UIDGenerator.php