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better-testing

DrydockAllocatorWorker.php
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			<?php

			/**
			* @task allocate Allocator
			* @task resource Managing Resources
			* @task lease Managing Leases
			*/
			final class DrydockAllocatorWorker extends DrydockWorker {

			protected function doWork() {
			$lease_phid = $this->getTaskDataValue('leasePHID');
			$lease = $this->loadLease($lease_phid);

			$this->allocateAndAcquireLease($lease);
			}


			/* -( Allocator )---------------------------------------------------------- */


			/**
			* Find or build a resource which can satisfy a given lease request, then
			* acquire the lease.
			*
			* @param DrydockLease Requested lease.
			* @return void
			* @task allocator
			*/
			private function allocateAndAcquireLease(DrydockLease $lease) {
			$blueprints = $this->loadBlueprintsForAllocatingLease($lease);

			// If we get nothing back, that means no blueprint is defined which can
			// ever build the requested resource. This is a permanent failure, since
			// we don't expect to succeed no matter how many times we try.
			if (!$blueprints) {
			$lease
			->setStatus(DrydockLeaseStatus::STATUS_BROKEN)
			->save();
			throw new PhabricatorWorkerPermanentFailureException(
			pht(
			'No active Drydock blueprint exists which can ever allocate a '.
			'resource for lease "%s".',
			$lease->getPHID()));
			}

			// First, try to find a suitable open resource which we can acquire a new
			// lease on.
			$resources = $this->loadResourcesForAllocatingLease($blueprints, $lease);

			// If no resources exist yet, see if we can build one.
			if (!$resources) {
			$usable_blueprints = $this->removeOverallocatedBlueprints(
			$blueprints,
			$lease);

			// If we get nothing back here, some blueprint claims it can eventually
			// satisfy the lease, just not right now. This is a temporary failure,
			// and we expect allocation to succeed eventually.
			if (!$blueprints) {
			// TODO: More formal temporary failure here. We should retry this
			// "soon" but not "immediately".
			throw new Exception(
			pht('No blueprints have space to allocate a resource right now.'));
			}

			$usable_blueprints = $this->rankBlueprints($blueprints, $lease);

			$exceptions = array();
			foreach ($usable_blueprints as $blueprint) {
			try {
			$resources[] = $this->allocateResource($blueprint, $lease);

			// Bail after allocating one resource, we don't need any more than
			// this.
			break;
			} catch (Exception $ex) {
			$exceptions[] = $ex;
			}
			}

			if (!$resources) {
			// TODO: We should distinguish between temporary and permament failures
			// here. If any blueprint failed temporarily, retry "soon". If none
			// of these failures were temporary, maybe this should be a permanent
			// failure?
			throw new PhutilAggregateException(
			pht(
			'All blueprints failed to allocate a suitable new resource when '.
			'trying to allocate lease "%s".',
			$lease->getPHID()),
			$exceptions);
			}

			// NOTE: We have not acquired the lease yet, so it is possible that the
			// resource we just built will be snatched up by some other lease before
			// we can. This is not problematic: we'll retry a little later and should
			// suceed eventually.
			}

			$resources = $this->rankResources($resources, $lease);

			$exceptions = array();
			$allocated = false;
			foreach ($resources as $resource) {
			try {
			$this->acquireLease($resource, $lease);
			$allocated = true;
			break;
			} catch (Exception $ex) {
			$exceptions[] = $ex;
			}
			}

			if (!$allocated) {
			// TODO: We should distinguish between temporary and permanent failures
			// here. If any failures were temporary (specifically, failed to acquire
			// locks)

			throw new PhutilAggregateException(
			pht(
			'Unable to acquire lease "%s" on any resouce.',
			$lease->getPHID()),
			$exceptions);
			}
			}


			/**
			* Get all the @{class:DrydockBlueprintImplementation}s which can possibly
			* build a resource to satisfy a lease.
			*
			* This method returns blueprints which might, at some time, be able to
			* build a resource which can satisfy the lease. They may not be able to
			* build that resource right now.
			*
			* @param DrydockLease Requested lease.
			* @return list<DrydockBlueprintImplementation> List of qualifying blueprint
			* implementations.
			* @task allocator
			*/
			private function loadBlueprintImplementationsForAllocatingLease(
			DrydockLease $lease) {

			$impls = DrydockBlueprintImplementation::getAllBlueprintImplementations();

			$keep = array();
			foreach ($impls as $key => $impl) {
			// Don't use disabled blueprint types.
			if (!$impl->isEnabled()) {
			continue;
			}

			// Don't use blueprint types which can't allocate the correct kind of
			// resource.
			if ($impl->getType() != $lease->getResourceType()) {
			continue;
			}

			if (!$impl->canAnyBlueprintEverAllocateResourceForLease($lease)) {
			continue;
			}

			$keep[$key] = $impl;
			}

			return $keep;
			}


			/**
			* Get all the concrete @{class:DrydockBlueprint}s which can possibly
			* build a resource to satisfy a lease.
			*
			* @param DrydockLease Requested lease.
			* @return list<DrydockBlueprint> List of qualifying blueprints.
			* @task allocator
			*/
			private function loadBlueprintsForAllocatingLease(
			DrydockLease $lease) {
			$viewer = $this->getViewer();

			$impls = $this->loadBlueprintImplementationsForAllocatingLease($lease);
			if (!$impls) {
			return array();
			}

			// TODO: When blueprints can be disabled, this query should ignore disabled
			// blueprints.

			$blueprints = id(new DrydockBlueprintQuery())
			->setViewer($viewer)
			->withBlueprintClasses(array_keys($impls))
			->execute();

			$keep = array();
			foreach ($blueprints as $key => $blueprint) {
			if (!$blueprint->canEverAllocateResourceForLease($lease)) {
			continue;
			}

			$keep[$key] = $blueprint;
			}

			return $keep;
			}


			/**
			* Load a list of all resources which a given lease can possibly be
			* allocated against.
			*
			* @param list<DrydockBlueprint> Blueprints which may produce suitable
			* resources.
			* @param DrydockLease Requested lease.
			* @return list<DrydockResource> Resources which may be able to allocate
			* the lease.
			* @task allocator
			*/
			private function loadResourcesForAllocatingLease(
			array $blueprints,
			DrydockLease $lease) {
			assert_instances_of($blueprints, 'DrydockBlueprint');
			$viewer = $this->getViewer();

			$resources = id(new DrydockResourceQuery())
			->setViewer($viewer)
			->withBlueprintPHIDs(mpull($blueprints, 'getPHID'))
			->withTypes(array($lease->getResourceType()))
			->withStatuses(
			array(
			DrydockResourceStatus::STATUS_PENDING,
			DrydockResourceStatus::STATUS_OPEN,
			))
			->execute();

			$keep = array();
			foreach ($resources as $key => $resource) {
			$blueprint = $resource->getBlueprint();

			if (!$blueprint->canAcquireLeaseOnResource($resource, $lease)) {
			continue;
			}

			$keep[$key] = $resource;
			}

			return $keep;
			}


			/**
			* Remove blueprints which are too heavily allocated to build a resource for
			* a lease from a list of blueprints.
			*
			* @param list<DrydockBlueprint> List of blueprints.
			* @return list<DrydockBlueprint> List with blueprints that can not allocate
			* a resource for the lease right now removed.
			* @task allocator
			*/
			private function removeOverallocatedBlueprints(
			array $blueprints,
			DrydockLease $lease) {
			assert_instances_of($blueprints, 'DrydockBlueprint');

			$keep = array();
			foreach ($blueprints as $key => $blueprint) {
			if (!$blueprint->canAllocateResourceForLease($lease)) {
			continue;
			}

			$keep[$key] = $blueprint;
			}

			return $keep;
			}


			/**
			* Rank blueprints by suitability for building a new resource for a
			* particular lease.
			*
			* @param list<DrydockBlueprint> List of blueprints.
			* @param DrydockLease Requested lease.
			* @return list<DrydockBlueprint> Ranked list of blueprints.
			* @task allocator
			*/
			private function rankBlueprints(array $blueprints, DrydockLease $lease) {
			assert_instances_of($blueprints, 'DrydockBlueprint');

			// TODO: Implement improvements to this ranking algorithm if they become
			// available.
			shuffle($blueprints);

			return $blueprints;
			}


			/**
			* Rank resources by suitability for allocating a particular lease.
			*
			* @param list<DrydockResource> List of resources.
			* @param DrydockLease Requested lease.
			* @return list<DrydockResource> Ranked list of resources.
			* @task allocator
			*/
			private function rankResources(array $resources, DrydockLease $lease) {
			assert_instances_of($resources, 'DrydockResource');

			// TODO: Implement improvements to this ranking algorithm if they become
			// available.
			shuffle($resources);

			return $resources;
			}


			/* -( Managing Resources )------------------------------------------------- */


			/**
			* Perform an actual resource allocation with a particular blueprint.
			*
			* @param DrydockBlueprint The blueprint to allocate a resource from.
			* @param DrydockLease Requested lease.
			* @return DrydockResource Allocated resource.
			* @task resource
			*/
			private function allocateResource(
			DrydockBlueprint $blueprint,
			DrydockLease $lease) {
			$resource = $blueprint->allocateResource($lease);
			$this->validateAllocatedResource($blueprint, $resource, $lease);

			// If this resource was allocated as a pending resource, queue a task to
			// activate it.
			if ($resource->getStatus() == DrydockResourceStatus::STATUS_PENDING) {
			PhabricatorWorker::scheduleTask(
			'DrydockResourceWorker',
			array(
			'resourcePHID' => $resource->getPHID(),
			),
			array(
			'objectPHID' => $resource->getPHID(),
			));
			}

			return $resource;
			}


			/**
			* Check that the resource a blueprint allocated is roughly the sort of
			* object we expect.
			*
			* @param DrydockBlueprint Blueprint which built the resource.
			* @param wild Thing which the blueprint claims is a valid resource.
			* @param DrydockLease Lease the resource was allocated for.
			* @return void
			* @task resource
			*/
			private function validateAllocatedResource(
			DrydockBlueprint $blueprint,
			$resource,
			DrydockLease $lease) {

			if (!($resource instanceof DrydockResource)) {
			throw new Exception(
			pht(
			'Blueprint "%s" (of type "%s") is not properly implemented: %s must '.
			'return an object of type %s or throw, but returned something else.',
			$blueprint->getBlueprintName(),
			$blueprint->getClassName(),
			'allocateResource()',
			'DrydockResource'));
			}

			if (!$resource->isAllocatedResource()) {
			throw new Exception(
			pht(
			'Blueprint "%s" (of type "%s") is not properly implemented: %s '.
			'must actually allocate the resource it returns.',
			$blueprint->getBlueprintName(),
			$blueprint->getClassName(),
			'allocateResource()'));
			}

			$resource_type = $resource->getType();
			$lease_type = $lease->getResourceType();

			if ($resource_type !== $lease_type) {
			// TODO: Destroy the resource here?

			throw new Exception(
			pht(
			'Blueprint "%s" (of type "%s") is not properly implemented: it '.
			'built a resource of type "%s" to satisfy a lease requesting a '.
			'resource of type "%s".',
			$blueprint->getBlueprintName(),
			$blueprint->getClassName(),
			$resource_type,
			$lease_type));
			}
			}


			/* -( Managing Leases )---------------------------------------------------- */


			/**
			* Perform an actual lease acquisition on a particular resource.
			*
			* @param DrydockResource Resource to acquire a lease on.
			* @param DrydockLease Lease to acquire.
			* @return void
			* @task lease
			*/
			private function acquireLease(
			DrydockResource $resource,
			DrydockLease $lease) {

			$blueprint = $resource->getBlueprint();
			$blueprint->acquireLease($resource, $lease);

			$this->validateAcquiredLease($blueprint, $resource, $lease);

			// If this lease has been acquired but not activated, queue a task to
			// activate it.
			if ($lease->getStatus() == DrydockLeaseStatus::STATUS_ACQUIRED) {
			PhabricatorWorker::scheduleTask(
			'DrydockLeaseWorker',
			array(
			'leasePHID' => $lease->getPHID(),
			),
			array(
			'objectPHID' => $lease->getPHID(),
			));
			}
			}


			/**
			* Make sure that a lease was really acquired properly.
			*
			* @param DrydockBlueprint Blueprint which created the resource.
			* @param DrydockResource Resource which was acquired.
			* @param DrydockLease The lease which was supposedly acquired.
			* @return void
			* @task lease
			*/
			private function validateAcquiredLease(
			DrydockBlueprint $blueprint,
			DrydockResource $resource,
			DrydockLease $lease) {

			if (!$lease->isAcquiredLease()) {
			throw new Exception(
			pht(
			'Blueprint "%s" (of type "%s") is not properly implemented: it '.
			'returned from "%s" without acquiring a lease.',
			$blueprint->getBlueprintName(),
			$blueprint->getClassName(),
			'acquireLease()'));
			}

			$lease_phid = $lease->getResourcePHID();
			$resource_phid = $resource->getPHID();

			if ($lease_phid !== $resource_phid) {
			// TODO: Destroy the lease?
			throw new Exception(
			pht(
			'Blueprint "%s" (of type "%s") is not properly implemented: it '.
			'returned from "%s" with a lease acquired on the wrong resource.',
			$blueprint->getBlueprintName(),
			$blueprint->getClassName(),
			'acquireLease()'));
			}
			}


			}

phab/src/applications/drydock/worker/DrydockAllocatorWorker.phpc6aade439283feature/better-testing

DrydockAllocatorWorker.phpView Options

phab/src/applications/drydock/worker/DrydockAllocatorWorker.php
c6aade439283feature/better-testing

DrydockAllocatorWorker.php
View Options