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uuid: Simplify GlobalIdGenerator by removing QUICK_VOLATILE flag

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Change-Id: I4f504be5d805281eeb9400cd4fd783c50b561b87
This commit is contained in:
Aaron Schulz 2021-03-03 15:12:21 -08:00 committed by Krinkle
parent f2f26a040c
commit bb1fdb91ac
4 changed files with 39 additions and 60 deletions
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6
includes/ServiceWiring.php
View file

@ -509,12 +509,6 @@ return [
return new GlobalIdGenerator(
$mainConfig->get( 'TmpDirectory' ),
// Ignore APC-like caches in CLI mode since there is no meaningful persistence.
// This avoids having counters restart with each script run. The ID generator
// will fallback to using the disk in those cases.
$mainConfig->get( 'CommandLineMode' )
? new EmptyBagOStuff()
: $services->getLocalServerObjectCache(),
static function ( $command ) {
return wfShellExec( $command );
}

6
includes/deferred/CdnCacheUpdate.php
View file

@ -228,9 +228,9 @@ class CdnCacheUpdate implements DeferrableUpdate, MergeableUpdate {
// Get sequential trx IDs for packet loss counting
$idGenerator = MediaWikiServices::getInstance()->getGlobalIdGenerator();
$ids = $idGenerator->newSequentialPerNodeIDs(
'squidhtcppurge', 32,
count( $urls ),
$idGenerator::QUICK_VOLATILE
'squidhtcppurge',
32,
count( $urls )
);
foreach ( $urls as $url ) {

86
includes/libs/uuid/GlobalIdGenerator.php
View file

@ -20,8 +20,6 @@
namespace Wikimedia\UUID;
use BagOStuff;
use EmptyBagOStuff;
use InvalidArgumentException;
use RuntimeException;
use Wikimedia\Assert\Assert;
@ -34,8 +32,6 @@ use Wikimedia\Timestamp\ConvertibleTimestamp;
* @since 1.35
*/
class GlobalIdGenerator {
/** @var BagOStuff Server-local persistent cache instance */
protected $srvCache;
/** @var callable Callback for running shell commands */
protected $shellCallback;
@ -60,7 +56,8 @@ class GlobalIdGenerator {
/** @var array Cached file handles */
protected $fileHandles = []; // cached file handles
public const QUICK_VOLATILE = 1; // use an APC like in-memory counter if available
/** @var int B/C constant (deprecated since 1.36) */
public const QUICK_VOLATILE = 1;
/**
* Avoid using __CLASS__ so namespace separators aren't interpreted
@ -81,10 +78,16 @@ class GlobalIdGenerator {
/**
* @param string $tempDirectory A writable temporary directory
* @param BagOStuff $srvCache A server-local APC-like cache instance
* @param callback $shellCallback A callback that takes a shell command and returns the output
*/
public function __construct( $tempDirectory, BagOStuff $srvCache, callable $shellCallback ) {
public function __construct( $tempDirectory, $shellCallback ) {
if ( func_num_args() >= 3 && !is_callable( $shellCallback ) ) {
trigger_error(
__CLASS__ . ' with a BagOStuff instance was deprecated in MediaWiki 1.37.',
E_USER_DEPRECATED
);
$shellCallback = func_get_arg( 2 );
}
if ( !strlen( $tempDirectory ) ) {
throw new InvalidArgumentException( "No temp directory provided" );
}
@ -96,7 +99,6 @@ class GlobalIdGenerator {
$this->lockFile128 = $tempDirectory . '/' . self::FILE_PREFIX . '-UID-128';
$this->lockFileUUID = $tempDirectory . '/' . self::FILE_PREFIX . '-UUID-128';
$this->srvCache = $srvCache;
$this->shellCallback = $shellCallback;
}
@ -373,55 +375,39 @@ class GlobalIdGenerator {
throw new RuntimeException( "Requested bit size ($bits) is out of range." );
}
$counter = null; // post-increment persistent counter value
// Use APC/etc if requested, available, and not in CLI mode;
// Counter values would not survive across script instances in CLI mode.
if (
( $flags & self::QUICK_VOLATILE ) &&
!( $this->srvCache instanceof EmptyBagOStuff )
) {
$cache = $this->srvCache;
$counter = $cache->incrWithInit( $bucket, $cache::TTL_INDEFINITE, $count, $count );
if ( $counter === false ) {
throw new RuntimeException( 'Unable to set value to ' . get_class( $cache ) );
}
$path = $this->tmpDir . '/' . self::FILE_PREFIX . '-' . rawurlencode( $bucket ) . '-48';
// Get the UID lock file handle
if ( isset( $this->fileHandles[$path] ) ) {
$handle = $this->fileHandles[$path];
} else {
$handle = fopen( $path, 'cb+' );
$this->fileHandles[$path] = $handle ?: null; // cache
}
// Note: use of fmod() avoids "division by zero" on 32 bit machines
if ( $counter === null ) {
$path = $this->tmpDir . '/' . self::FILE_PREFIX . '-' . rawurlencode( $bucket ) . '-48';
// Get the UID lock file handle
if ( isset( $this->fileHandles[$path] ) ) {
$handle = $this->fileHandles[$path];
} else {
$handle = fopen( $path, 'cb+' );
$this->fileHandles[$path] = $handle ?: null; // cache
}
// Acquire the UID lock file
if ( $handle === false ) {
throw new RuntimeException( "Could not open '{$path}'." );
}
if ( !flock( $handle, LOCK_EX ) ) {
fclose( $handle );
throw new RuntimeException( "Could not acquire '{$path}'." );
}
// Fetch the counter value and increment it...
rewind( $handle );
$counter = floor( (float)trim( fgets( $handle ) ) ) + $count; // fetch as float
// Write back the new counter value
ftruncate( $handle, 0 );
rewind( $handle );
fwrite( $handle, fmod( $counter, 2 ** 48 ) ); // warp-around as needed
fflush( $handle );
// Release the UID lock file
flock( $handle, LOCK_UN );
// Acquire the UID lock file
if ( $handle === false ) {
throw new RuntimeException( "Could not open '{$path}'." );
}
if ( !flock( $handle, LOCK_EX ) ) {
fclose( $handle );
throw new RuntimeException( "Could not acquire '{$path}'." );
}
// Fetch the counter value and increment it...
rewind( $handle );
$counter = floor( (float)trim( fgets( $handle ) ) ) + $count; // fetch as float
// Write back the new counter value
ftruncate( $handle, 0 );
rewind( $handle );
// Use fmod() to avoid "division by zero" on 32 bit machines
fwrite( $handle, fmod( $counter, 2 ** 48 ) ); // warp-around as needed
fflush( $handle );
// Release the UID lock file
flock( $handle, LOCK_UN );
$ids = [];
$divisor = 2 ** $bits;
$currentId = floor( $counter - $count ); // pre-increment counter value
for ( $i = 0; $i < $count; ++$i ) {
// Use fmod() to avoid "division by zero" on 32 bit machines
$ids[] = fmod( ++$currentId, $divisor );
}

1
tests/phpunit/unit/includes/libs/uuid/GlobalIdGeneratorTest.php
View file

@ -218,7 +218,6 @@ class GlobalIdGeneratorTest extends PHPUnit\Framework\TestCase {
protected function setUp() : void {
$this->globalIdGenerator = new GlobalIdGenerator(
wfTempDir(),
new HashBagOStuff( [] ),
static function ( $command ) {
return wfShellExec( $command );
}