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authorSteve Clay <steve@mrclay.org>2012-11-26 01:17:39 -0500
committerSteve Clay <steve@mrclay.org>2012-11-26 16:01:50 -0500
commit33c786c1b7838d38e9797b8731d4e45c9ceb1aac (patch)
tree14d0e21d0ce67939a4483ec1cf0feaccfed09780 /engine/classes/ElggAttributeLoader.php
parent19c6da97ed0178592b9041946f3463f9008dd7ea (diff)
downloadelgg-33c786c1b7838d38e9797b8731d4e45c9ceb1aac.tar.gz
elgg-33c786c1b7838d38e9797b8731d4e45c9ceb1aac.tar.bz2
Fixes #4929: Optimize elgg_get_entities and add attribute loader
Diffstat (limited to 'engine/classes/ElggAttributeLoader.php')
-rw-r--r--engine/classes/ElggAttributeLoader.php199
1 files changed, 199 insertions, 0 deletions
diff --git a/engine/classes/ElggAttributeLoader.php b/engine/classes/ElggAttributeLoader.php
new file mode 100644
index 000000000..602bb8bae
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+++ b/engine/classes/ElggAttributeLoader.php
@@ -0,0 +1,199 @@
+<?php
+
+/**
+ * Loads ElggEntity attributes from DB or validates those passed in via constructor
+ *
+ * @access private
+ */
+class ElggAttributeLoader {
+
+ /**
+ * @var array names of attributes in all entities
+ */
+ protected static $primary_attr_names = array(
+ 'guid',
+ 'type',
+ 'subtype',
+ 'owner_guid',
+ 'container_guid',
+ 'site_guid',
+ 'access_id',
+ 'time_created',
+ 'time_updated',
+ 'last_action',
+ 'enabled'
+ );
+
+ /**
+ * @var array names of secondary attributes required for the entity
+ */
+ protected $secondary_attr_names = array();
+
+ /**
+ * @var string entity type (not class) required for fetched primaries
+ */
+ protected $required_type;
+
+ /**
+ * @var array
+ */
+ protected $initialized_attributes;
+
+ /**
+ * @var string class of object being loaded
+ */
+ protected $class;
+
+ /**
+ * @var bool should access control be considered when fetching entity?
+ */
+ public $requires_access_control = true;
+
+ /**
+ * @var callable function used to load attributes from {prefix}entities table
+ */
+ public $primary_loader = 'get_entity_as_row';
+
+ /**
+ * @var callable function used to load attributes from secondary table
+ */
+ public $secondary_loader = '';
+
+ /**
+ * @var callable function used to load all necessary attributes
+ */
+ public $full_loader = '';
+
+ /**
+ * @param string $class class of object being loaded
+ * @param string $required_type entity type this is being used to populate
+ * @param array $initialized_attrs attributes after initializeAttributes() has been run
+ * @throws InvalidArgumentException
+ */
+ public function __construct($class, $required_type, array $initialized_attrs) {
+ if (!is_string($class)) {
+ throw new InvalidArgumentException('$class must be a class name.');
+ }
+ $this->class = $class;
+
+ if (!is_string($required_type)) {
+ throw new InvalidArgumentException('$requiredType must be a system entity type.');
+ }
+ $this->required_type = $required_type;
+
+ $this->initialized_attributes = $initialized_attrs;
+ unset($initialized_attrs['tables_split'], $initialized_attrs['tables_loaded']);
+ $all_attr_names = array_keys($initialized_attrs);
+ $this->secondary_attr_names = array_diff($all_attr_names, self::$primary_attr_names);
+ }
+
+ protected function isMissingPrimaries($row) {
+ return array_diff(self::$primary_attr_names, array_keys($row)) !== array();
+ }
+
+ protected function isMissingSecondaries($row) {
+ return array_diff($this->secondary_attr_names, array_keys($row)) !== array();
+ }
+
+ protected function checkType($row) {
+ if ($row['type'] !== $this->required_type) {
+ $msg = elgg_echo('InvalidClassException:NotValidElggStar', array($row['guid'], $this->class));
+ throw new InvalidClassException($msg);
+ }
+ }
+
+ /**
+ * Get all required attributes for the entity, validating any that are passed in. Returns empty array
+ * if can't be loaded (Check $failure_reason).
+ *
+ * This function splits loading between "primary" attributes (those in {prefix}entities table) and
+ * "secondary" attributes (e.g. those in {prefix}objects_entity), but can load all at once if a
+ * combined loader is available.
+ *
+ * @param mixed $row a row loaded from DB (array or stdClass) or a GUID
+ * @return array will be empty if failed to load all attributes (access control or entity doesn't exist)
+ *
+ * @throws InvalidArgumentException|LogicException|IncompleteEntityException
+ */
+ public function getRequiredAttributes($row) {
+ if (!is_array($row) && !($row instanceof stdClass)) {
+ // assume row is the GUID
+ $row = array('guid' => $row);
+ }
+ $row = (array) $row;
+ if (empty($row['guid'])) {
+ throw new InvalidArgumentException('$row must be or contain a GUID');
+ }
+
+ // these must be present to support isFullyLoaded()
+ foreach (array('tables_split', 'tables_loaded') as $key) {
+ if (isset($this->initialized_attributes[$key])) {
+ $row[$key] = $this->initialized_attributes[$key];
+ }
+ }
+
+ $was_missing_primaries = $this->isMissingPrimaries($row);
+ $was_missing_secondaries = $this->isMissingSecondaries($row);
+
+ // some types have a function to load all attributes at once, it should be faster
+ if (($was_missing_primaries || $was_missing_secondaries) && is_callable($this->full_loader)) {
+ $fetched = (array) call_user_func($this->full_loader, $row['guid']);
+ if (!$fetched) {
+ return array();
+ }
+ $row = array_merge($row, $fetched);
+ $this->checkType($row);
+ } else {
+ if ($was_missing_primaries) {
+ if (!is_callable($this->primary_loader)) {
+ throw new LogicException('Primary attribute loader must be callable');
+ }
+ if (!$this->requires_access_control) {
+ $ignoring_access = elgg_set_ignore_access();
+ }
+ $fetched = (array) call_user_func($this->primary_loader, $row['guid']);
+ if (!$this->requires_access_control) {
+ elgg_set_ignore_access($ignoring_access);
+ }
+ if (!$fetched) {
+ return array();
+ }
+ $row = array_merge($row, $fetched);
+ }
+
+ // We must test type before trying to load the secondaries so that InvalidClassException
+ // gets thrown. Otherwise the secondary loader will fail and return false.
+ $this->checkType($row);
+
+ if ($was_missing_secondaries) {
+ if (!is_callable($this->secondary_loader)) {
+ throw new LogicException('Secondary attribute loader must be callable');
+ }
+ $fetched = (array) call_user_func($this->secondary_loader, $row['guid']);
+ if (!$fetched) {
+ if ($row['type'] === 'site') {
+ // A special case is needed for sites: When vanilla ElggEntities are created and
+ // saved, these are stored w/ type "site", but with no sites_entity row. These
+ // are probably only created in the unit tests.
+ // @todo Don't save vanilla ElggEntities with type "site"
+ $row['guid'] = (int) $row['guid'];
+ return $row;
+ }
+ throw new IncompleteEntityException("Secondary loader failed to return row for {$row['guid']}");
+ }
+ $row = array_merge($row, $fetched);
+ }
+ }
+
+ // loading complete: re-check missing and check type
+ if (($was_missing_primaries && $this->isMissingPrimaries($row))
+ || ($was_missing_secondaries && $this->isMissingSecondaries($row))) {
+ throw new LogicException('Attribute loaders failed to return proper attributes');
+ }
+
+ // guid needs to be an int http://trac.elgg.org/ticket/4111
+ $row['guid'] = (int) $row['guid'];
+
+ return $row;
+ }
+}