Differential D12623 Diff 30373 src/applications/multimeter/data/MultimeterControl.php

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src/applications/multimeter/data/MultimeterControl.php

This file was added.

				<?php

				final class MultimeterControl {

				private static $instance;

				private $events = array();
				private $sampleRate;
				private $pauseDepth;

				private $eventViewer;
				private $eventContext;

				private function __construct() {
				// Private.
				}

				public static function newInstance() {
				$instance = new MultimeterControl();

				// NOTE: We don't set the sample rate yet. This allows the multimeter to
				// be initialized and begin recording events, then make a decision about
				// whether the page will be sampled or not later on (once we've loaded
				// enough configuration).

				self::$instance = $instance;
				return self::getInstance();
				}

				public static function getInstance() {
				return self::$instance;
				}

				public function isActive() {
				return ($this->sampleRate !== 0) && ($this->pauseDepth == 0);
				}

				public function setSampleRate($rate) {
				if ($rate && (mt_rand(1, $rate) == $rate)) {
				$sample_rate = $rate;
				} else {
				$sample_rate = 0;
				}

				$this->sampleRate = $sample_rate;

				return;
				}

				public function pauseMultimeter() {
				$this->pauseDepth++;
				return $this;
				}

				public function unpauseMultimeter() {
				if (!$this->pauseDepth) {
				throw new Exception(pht('Trying to unpause an active multimeter!'));
				}
				$this->pauseDepth--;
				return $this;
				}


				public function newEvent($type, $label, $cost) {
				if (!$this->isActive()) {
				return null;
				}

				$event = id(new MultimeterEvent())
				->setEventType($type)
				->setEventLabel($label)
				->setResourceCost($cost)
				->setEpoch(PhabricatorTime::getNow());

				$this->events[] = $event;

				return $event;
				}

				public function saveEvents() {
				if (!$this->isActive()) {
				return;
				}

				$events = $this->events;
				if (!$events) {
				return;
				}

				if ($this->sampleRate === null) {
				throw new Exception(pht('Call setSampleRate() before saving events!'));
				}

				// Don't sample any of this stuff.
				$this->pauseMultimeter();

				$use_scope = AphrontWriteGuard::isGuardActive();
				if ($use_scope) {
				$unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
				} else {
				AphrontWriteGuard::allowDangerousUnguardedWrites(true);
				}

				$caught = null;
				try {
				$this->writeEvents();
				} catch (Exception $ex) {
				$caught = $ex;
				}

				if ($use_scope) {
				unset($unguarded);
				} else {
				AphrontWriteGuard::allowDangerousUnguardedWrites(false);
				}

				$this->unpauseMultimeter();

				if ($caught) {
				throw $caught;
				}
				}

				private function writeEvents() {
				$events = $this->events;

				$random = Filesystem::readRandomBytes(32);
				$request_key = PhabricatorHash::digestForIndex($random);

				$host_id = $this->loadHostID(php_uname('n'));
				$context_id = $this->loadEventContextID($this->eventContext);
				$viewer_id = $this->loadEventViewerID($this->eventViewer);
				$label_map = $this->loadEventLabelIDs(mpull($events, 'getEventLabel'));

				foreach ($events as $event) {
				$event
				->setRequestKey($request_key)
				->setSampleRate($this->sampleRate)
				->setEventHostID($host_id)
				->setEventContextID($context_id)
				->setEventViewerID($viewer_id)
				->setEventLabelID($label_map[$event->getEventLabel()])
				->save();
				}
				}

				public function setEventContext($event_context) {
				$this->eventContext = $event_context;
				return $this;
				}

				public function setEventViewer($viewer) {
				$this->eventViewer = $viewer;
				return $this;
				}

				private function loadHostID($host) {
				$map = $this->loadDimensionMap(new MultimeterHost(), array($host));
				return idx($map, $host);
				}

				private function loadEventViewerID($viewer) {
				$map = $this->loadDimensionMap(new MultimeterViewer(), array($viewer));
				return idx($map, $viewer);
				}

				private function loadEventContextID($context) {
				$map = $this->loadDimensionMap(new MultimeterContext(), array($context));
				return idx($map, $context);
				}

				private function loadEventLabelIDs(array $labels) {
				return $this->loadDimensionMap(new MultimeterLabel(), $labels);
				}

				private function loadDimensionMap(MultimeterDimension $table, array $names) {
				$hashes = array();
				foreach ($names as $name) {
				$hashes[] = PhabricatorHash::digestForIndex($name);
				}

				$objects = $table->loadAllWhere('nameHash IN (%Ls)', $hashes);
				$map = mpull($objects, 'getID', 'getName');

				$need = array();
				foreach ($names as $name) {
				if (isset($map[$name])) {
				continue;
				}
				$need[] = $name;
				}

				foreach ($need as $name) {
				$object = id(clone $table)
				->setName($name)
				->save();
				$map[$name] = $object->getID();
				}

				return $map;
				}

				}