Homec4science
Diffusion Phabricator (stable) Browse

phab/src/infrastructure/daemon/workers/query/PhabricatorWorkerLeaseQuery.php
84ee4cd9f62fstable

Last Change
Raw File

PhabricatorWorkerLeaseQuery.php
View Options

<?php
/*
* Copyright 2012 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* Select and lease tasks from the worker task queue.
*
* @group worker
*/
final class PhabricatorWorkerLeaseQuery extends PhabricatorQuery {
const PHASE_UNLEASED = 'unleased';
const PHASE_EXPIRED = 'expired';
const DEFAULT_LEASE_DURATION = 60; // Seconds
private $ids;
private $limit;
public function withIDs(array $ids) {
$this->ids = $ids;
return $this;
}
public function setLimit($limit) {
$this->limit = $limit;
return $this;
}
public function execute() {
if (!$this->limit) {
throw new Exception("You must setLimit() when leasing tasks.");
}
$task_table = new PhabricatorWorkerActiveTask();
$taskdata_table = new PhabricatorWorkerTaskData();
$lease_ownership_name = $this->getLeaseOwnershipName();
$conn_w = $task_table->establishConnection('w');
// Try to satisfy the request from new, unleased tasks first. If we don't
// find enough tasks, try tasks with expired leases (i.e., tasks which have
// previously failed).
$phases = array(
self::PHASE_UNLEASED,
self::PHASE_EXPIRED,
);
$limit = $this->limit;
$leased = 0;
foreach ($phases as $phase) {
queryfx(
$conn_w,
'UPDATE %T SET leaseOwner = %s, leaseExpires = UNIX_TIMESTAMP() + %d
%Q %Q %Q',
$task_table->getTableName(),
$lease_ownership_name,
self::DEFAULT_LEASE_DURATION,
$this->buildWhereClause($conn_w, $phase),
$this->buildOrderClause($conn_w),
$this->buildLimitClause($conn_w, $limit - $leased));
$leased += $conn_w->getAffectedRows();
if ($leased == $limit) {
break;
}
}
if (!$leased) {
return array();
}
$data = queryfx_all(
$conn_w,
'SELECT task.*, taskdata.data _taskData, UNIX_TIMESTAMP() _serverTime
FROM %T task LEFT JOIN %T taskdata
ON taskdata.id = task.dataID
WHERE leaseOwner = %s AND leaseExpires > UNIX_TIMESTAMP()
%Q %Q',
$task_table->getTableName(),
$taskdata_table->getTableName(),
$lease_ownership_name,
$this->buildOrderClause($conn_w),
$this->buildLimitClause($conn_w, $limit));
$tasks = $task_table->loadAllFromArray($data);
$tasks = mpull($tasks, null, 'getID');
foreach ($data as $row) {
$tasks[$row['id']]->setServerTime($row['_serverTime']);
if ($row['_taskData']) {
$task_data = json_decode($row['_taskData'], true);
} else {
$task_data = null;
}
$tasks[$row['id']]->setData($task_data);
}
return $tasks;
}
private function buildWhereClause(AphrontDatabaseConnection $conn_w, $phase) {
$where = array();
switch ($phase) {
case self::PHASE_UNLEASED:
$where[] = 'leaseOwner IS NULL';
break;
case self::PHASE_EXPIRED:
$where[] = 'leaseExpires < UNIX_TIMESTAMP()';
break;
default:
throw new Exception("Unknown phase '{$phase}'!");
}
if ($this->ids) {
$where[] = qsprintf(
$conn_w,
'id IN (%Ld)',
$this->ids);
}
return $this->formatWhereClause($where);
}
private function buildOrderClause(AphrontDatabaseConnection $conn_w) {
return qsprintf($conn_w, 'ORDER BY id ASC');
}
private function buildLimitClause(AphrontDatabaseConnection $conn_w, $limit) {
return qsprintf($conn_w, 'LIMIT %d', $limit);
}
private function getLeaseOwnershipName() {
static $name = null;
if ($name === null) {
$name = getmypid().':'.time().':'.php_uname('n');
}
return $name;
}
}
c4science · Help