PhabricatorCursorPagedPolicyAwareQuery.php
d1842929afaastable

PhabricatorCursorPagedPolicyAwareQuery.php
View Options

			<?php

			/**
			* A query class which uses cursor-based paging. This paging is much more
			* performant than offset-based paging in the presence of policy filtering.
			*
			* @task clauses Building Query Clauses
			* @task appsearch Integration with ApplicationSearch
			* @task customfield Integration with CustomField
			* @task paging Paging
			* @task order Result Ordering
			* @task edgelogic Working with Edge Logic
			* @task spaces Working with Spaces
			*/
			abstract class PhabricatorCursorPagedPolicyAwareQuery
			extends PhabricatorPolicyAwareQuery {

			private $afterID;
			private $beforeID;
			private $applicationSearchConstraints = array();
			private $internalPaging;
			private $orderVector;
			private $groupVector;
			private $builtinOrder;
			private $edgeLogicConstraints = array();
			private $edgeLogicConstraintsAreValid = false;
			private $spacePHIDs;
			private $spaceIsArchived;
			private $ngrams = array();

			protected function getPageCursors(array $page) {
			return array(
			$this->getResultCursor(head($page)),
			$this->getResultCursor(last($page)),
			);
			}

			protected function getResultCursor($object) {
			if (!is_object($object)) {
			throw new Exception(
			pht(
			'Expected object, got "%s".',
			gettype($object)));
			}

			return $object->getID();
			}

			protected function nextPage(array $page) {
			// See getPagingViewer() for a description of this flag.
			$this->internalPaging = true;

			if ($this->beforeID !== null) {
			$page = array_reverse($page, $preserve_keys = true);
			list($before, $after) = $this->getPageCursors($page);
			$this->beforeID = $before;
			} else {
			list($before, $after) = $this->getPageCursors($page);
			$this->afterID = $after;
			}
			}

			final public function setAfterID($object_id) {
			$this->afterID = $object_id;
			return $this;
			}

			final protected function getAfterID() {
			return $this->afterID;
			}

			final public function setBeforeID($object_id) {
			$this->beforeID = $object_id;
			return $this;
			}

			final protected function getBeforeID() {
			return $this->beforeID;
			}

			protected function loadStandardPage(PhabricatorLiskDAO $table) {
			$rows = $this->loadStandardPageRows($table);
			return $table->loadAllFromArray($rows);
			}

			protected function loadStandardPageRows(PhabricatorLiskDAO $table) {
			$conn = $table->establishConnection('r');
			return $this->loadStandardPageRowsWithConnection(
			$conn,
			$table->getTableName());
			}

			protected function loadStandardPageRowsWithConnection(
			AphrontDatabaseConnection $conn,
			$table_name) {

			$rows = queryfx_all(
			$conn,
			'%Q FROM %T %Q %Q %Q %Q %Q %Q %Q',
			$this->buildSelectClause($conn),
			$table_name,
			(string)$this->getPrimaryTableAlias(),
			$this->buildJoinClause($conn),
			$this->buildWhereClause($conn),
			$this->buildGroupClause($conn),
			$this->buildHavingClause($conn),
			$this->buildOrderClause($conn),
			$this->buildLimitClause($conn));

			return $rows;
			}

			/**
			* Get the viewer for making cursor paging queries.
			*
			* NOTE: You should ONLY use this viewer to load cursor objects while
			* building paging queries.
			*
			* Cursor paging can happen in two ways. First, the user can request a page
			* like `/stuff/?after=33`, which explicitly causes paging. Otherwise, we
			* can fall back to implicit paging if we filter some results out of a
			* result list because the user can't see them and need to go fetch some more
			* results to generate a large enough result list.
			*
			* In the first case, want to use the viewer's policies to load the object.
			* This prevents an attacker from figuring out information about an object
			* they can't see by executing queries like `/stuff/?after=33&order=name`,
			* which would otherwise give them a hint about the name of the object.
			* Generally, if a user can't see an object, they can't use it to page.
			*
			* In the second case, we need to load the object whether the user can see
			* it or not, because we need to examine new results. For example, if a user
			* loads `/stuff/` and we run a query for the first 100 items that they can
			* see, but the first 100 rows in the database aren't visible, we need to
			* be able to issue a query for the next 100 results. If we can't load the
			* cursor object, we'll fail or issue the same query over and over again.
			* So, generally, internal paging must bypass policy controls.
			*
			* This method returns the appropriate viewer, based on the context in which
			* the paging is occuring.
			*
			* @return PhabricatorUser Viewer for executing paging queries.
			*/
			final protected function getPagingViewer() {
			if ($this->internalPaging) {
			return PhabricatorUser::getOmnipotentUser();
			} else {
			return $this->getViewer();
			}
			}

			final protected function buildLimitClause(AphrontDatabaseConnection $conn_r) {
			if ($this->shouldLimitResults()) {
			$limit = $this->getRawResultLimit();
			if ($limit) {
			return qsprintf($conn_r, 'LIMIT %d', $limit);
			}
			}

			return '';
			}

			protected function shouldLimitResults() {
			return true;
			}

			final protected function didLoadResults(array $results) {
			if ($this->beforeID) {
			$results = array_reverse($results, $preserve_keys = true);
			}
			return $results;
			}

			final public function executeWithCursorPager(AphrontCursorPagerView $pager) {
			$limit = $pager->getPageSize();

			$this->setLimit($limit + 1);

			if ($pager->getAfterID()) {
			$this->setAfterID($pager->getAfterID());
			} else if ($pager->getBeforeID()) {
			$this->setBeforeID($pager->getBeforeID());
			}

			$results = $this->execute();
			$count = count($results);

			$sliced_results = $pager->sliceResults($results);
			if ($sliced_results) {
			list($before, $after) = $this->getPageCursors($sliced_results);

			if ($pager->getBeforeID() \|\| ($count > $limit)) {
			$pager->setNextPageID($after);
			}

			if ($pager->getAfterID() \|\|
			($pager->getBeforeID() && ($count > $limit))) {
			$pager->setPrevPageID($before);
			}
			}

			return $sliced_results;
			}


			/**
			* Return the alias this query uses to identify the primary table.
			*
			* Some automatic query constructions may need to be qualified with a table
			* alias if the query performs joins which make column names ambiguous. If
			* this is the case, return the alias for the primary table the query
			* uses; generally the object table which has `id` and `phid` columns.
			*
			* @return string Alias for the primary table.
			*/
			protected function getPrimaryTableAlias() {
			return null;
			}

			public function newResultObject() {
			return null;
			}


			/* -( Building Query Clauses )--------------------------------------------- */


			/**
			* @task clauses
			*/
			protected function buildSelectClause(AphrontDatabaseConnection $conn) {
			$parts = $this->buildSelectClauseParts($conn);
			return $this->formatSelectClause($parts);
			}


			/**
			* @task clauses
			*/
			protected function buildSelectClauseParts(AphrontDatabaseConnection $conn) {
			$select = array();

			$alias = $this->getPrimaryTableAlias();
			if ($alias) {
			$select[] = qsprintf($conn, '%T.*', $alias);
			} else {
			$select[] = '*';
			}

			$select[] = $this->buildEdgeLogicSelectClause($conn);

			return $select;
			}


			/**
			* @task clauses
			*/
			protected function buildJoinClause(AphrontDatabaseConnection $conn) {
			$joins = $this->buildJoinClauseParts($conn);
			return $this->formatJoinClause($joins);
			}


			/**
			* @task clauses
			*/
			protected function buildJoinClauseParts(AphrontDatabaseConnection $conn) {
			$joins = array();
			$joins[] = $this->buildEdgeLogicJoinClause($conn);
			$joins[] = $this->buildApplicationSearchJoinClause($conn);
			$joins[] = $this->buildNgramsJoinClause($conn);
			return $joins;
			}


			/**
			* @task clauses
			*/
			protected function buildWhereClause(AphrontDatabaseConnection $conn) {
			$where = $this->buildWhereClauseParts($conn);
			return $this->formatWhereClause($where);
			}


			/**
			* @task clauses
			*/
			protected function buildWhereClauseParts(AphrontDatabaseConnection $conn) {
			$where = array();
			$where[] = $this->buildPagingClause($conn);
			$where[] = $this->buildEdgeLogicWhereClause($conn);
			$where[] = $this->buildSpacesWhereClause($conn);
			$where[] = $this->buildNgramsWhereClause($conn);
			return $where;
			}


			/**
			* @task clauses
			*/
			protected function buildHavingClause(AphrontDatabaseConnection $conn) {
			$having = $this->buildHavingClauseParts($conn);
			return $this->formatHavingClause($having);
			}


			/**
			* @task clauses
			*/
			protected function buildHavingClauseParts(AphrontDatabaseConnection $conn) {
			$having = array();
			$having[] = $this->buildEdgeLogicHavingClause($conn);
			return $having;
			}


			/**
			* @task clauses
			*/
			protected function buildGroupClause(AphrontDatabaseConnection $conn) {
			if (!$this->shouldGroupQueryResultRows()) {
			return '';
			}

			return qsprintf(
			$conn,
			'GROUP BY %Q',
			$this->getApplicationSearchObjectPHIDColumn());
			}


			/**
			* @task clauses
			*/
			protected function shouldGroupQueryResultRows() {
			if ($this->shouldGroupEdgeLogicResultRows()) {
			return true;
			}

			if ($this->getApplicationSearchMayJoinMultipleRows()) {
			return true;
			}

			if ($this->shouldGroupNgramResultRows()) {
			return true;
			}

			return false;
			}



			/* -( Paging )------------------------------------------------------------- */


			/**
			* @task paging
			*/
			protected function buildPagingClause(AphrontDatabaseConnection $conn) {
			$orderable = $this->getOrderableColumns();
			$vector = $this->getOrderVector();

			if ($this->beforeID !== null) {
			$cursor = $this->beforeID;
			$reversed = true;
			} else if ($this->afterID !== null) {
			$cursor = $this->afterID;
			$reversed = false;
			} else {
			// No paging is being applied to this query so we do not need to
			// construct a paging clause.
			return '';
			}

			$keys = array();
			foreach ($vector as $order) {
			$keys[] = $order->getOrderKey();
			}

			$value_map = $this->getPagingValueMap($cursor, $keys);

			$columns = array();
			foreach ($vector as $order) {
			$key = $order->getOrderKey();

			if (!array_key_exists($key, $value_map)) {
			throw new Exception(
			pht(
			'Query "%s" failed to return a value from getPagingValueMap() '.
			'for column "%s".',
			get_class($this),
			$key));
			}

			$column = $orderable[$key];
			$column['value'] = $value_map[$key];

			// If the vector component is reversed, we need to reverse whatever the
			// order of the column is.
			if ($order->getIsReversed()) {
			$column['reverse'] = !idx($column, 'reverse', false);
			}

			$columns[] = $column;
			}

			return $this->buildPagingClauseFromMultipleColumns(
			$conn,
			$columns,
			array(
			'reversed' => $reversed,
			));
			}


			/**
			* @task paging
			*/
			protected function getPagingValueMap($cursor, array $keys) {
			return array(
			'id' => $cursor,
			);
			}


			/**
			* @task paging
			*/
			protected function loadCursorObject($cursor) {
			$query = newv(get_class($this), array())
			->setViewer($this->getPagingViewer())
			->withIDs(array((int)$cursor));

			$this->willExecuteCursorQuery($query);

			$object = $query->executeOne();
			if (!$object) {
			throw new Exception(
			pht(
			'Cursor "%s" does not identify a valid object in query "%s".',
			$cursor,
			get_class($this)));
			}

			return $object;
			}


			/**
			* @task paging
			*/
			protected function willExecuteCursorQuery(
			PhabricatorCursorPagedPolicyAwareQuery $query) {
			return;
			}


			/**
			* Simplifies the task of constructing a paging clause across multiple
			* columns. In the general case, this looks like:
			*
			* A > a OR (A = a AND B > b) OR (A = a AND B = b AND C > c)
			*
			* To build a clause, specify the name, type, and value of each column
			* to include:
			*
			* $this->buildPagingClauseFromMultipleColumns(
			* $conn_r,
			* array(
			* array(
			* 'table' => 't',
			* 'column' => 'title',
			* 'type' => 'string',
			* 'value' => $cursor->getTitle(),
			* 'reverse' => true,
			* ),
			* array(
			* 'table' => 't',
			* 'column' => 'id',
			* 'type' => 'int',
			* 'value' => $cursor->getID(),
			* ),
			* ),
			* array(
			* 'reversed' => $is_reversed,
			* ));
			*
			* This method will then return a composable clause for inclusion in WHERE.
			*
			* @param AphrontDatabaseConnection Connection query will execute on.
			* @param list<map> Column description dictionaries.
			* @param map Additional constuction options.
			* @return string Query clause.
			* @task paging
			*/
			final protected function buildPagingClauseFromMultipleColumns(
			AphrontDatabaseConnection $conn,
			array $columns,
			array $options) {

			foreach ($columns as $column) {
			PhutilTypeSpec::checkMap(
			$column,
			array(
			'table' => 'optional string\|null',
			'column' => 'string',
			'value' => 'wild',
			'type' => 'string',
			'reverse' => 'optional bool',
			'unique' => 'optional bool',
			'null' => 'optional string\|null',
			));
			}

			PhutilTypeSpec::checkMap(
			$options,
			array(
			'reversed' => 'optional bool',
			));

			$is_query_reversed = idx($options, 'reversed', false);

			$clauses = array();
			$accumulated = array();
			$last_key = last_key($columns);
			foreach ($columns as $key => $column) {
			$type = $column['type'];

			$null = idx($column, 'null');
			if ($column['value'] === null) {
			if ($null) {
			$value = null;
			} else {
			throw new Exception(
			pht(
			'Column "%s" has null value, but does not specify a null '.
			'behavior.',
			$key));
			}
			} else {
			switch ($type) {
			case 'int':
			$value = qsprintf($conn, '%d', $column['value']);
			break;
			case 'float':
			$value = qsprintf($conn, '%f', $column['value']);
			break;
			case 'string':
			$value = qsprintf($conn, '%s', $column['value']);
			break;
			default:
			throw new Exception(
			pht(
			'Column "%s" has unknown column type "%s".',
			$column['column'],
			$type));
			}
			}

			$is_column_reversed = idx($column, 'reverse', false);
			$reverse = ($is_query_reversed xor $is_column_reversed);

			$clause = $accumulated;

			$table_name = idx($column, 'table');
			$column_name = $column['column'];
			if ($table_name !== null) {
			$field = qsprintf($conn, '%T.%T', $table_name, $column_name);
			} else {
			$field = qsprintf($conn, '%T', $column_name);
			}

			$parts = array();
			if ($null) {
			$can_page_if_null = ($null === 'head');
			$can_page_if_nonnull = ($null === 'tail');

			if ($reverse) {
			$can_page_if_null = !$can_page_if_null;
			$can_page_if_nonnull = !$can_page_if_nonnull;
			}

			$subclause = null;
			if ($can_page_if_null && $value === null) {
			$parts[] = qsprintf(
			$conn,
			'(%Q IS NOT NULL)',
			$field);
			} else if ($can_page_if_nonnull && $value !== null) {
			$parts[] = qsprintf(
			$conn,
			'(%Q IS NULL)',
			$field);
			}
			}

			if ($value !== null) {
			$parts[] = qsprintf(
			$conn,
			'%Q %Q %Q',
			$field,
			$reverse ? '>' : '<',
			$value);
			}

			if ($parts) {
			if (count($parts) > 1) {
			$clause[] = '('.implode(') OR (', $parts).')';
			} else {
			$clause[] = head($parts);
			}
			}

			if ($clause) {
			if (count($clause) > 1) {
			$clauses[] = '('.implode(') AND (', $clause).')';
			} else {
			$clauses[] = head($clause);
			}
			}

			if ($value === null) {
			$accumulated[] = qsprintf(
			$conn,
			'%Q IS NULL',
			$field);
			} else {
			$accumulated[] = qsprintf(
			$conn,
			'%Q = %Q',
			$field,
			$value);
			}
			}

			return '('.implode(') OR (', $clauses).')';
			}


			/* -( Result Ordering )---------------------------------------------------- */


			/**
			* Select a result ordering.
			*
			* This is a high-level method which selects an ordering from a predefined
			* list of builtin orders, as provided by @{method:getBuiltinOrders}. These
			* options are user-facing and not exhaustive, but are generally convenient
			* and meaningful.
			*
			* You can also use @{method:setOrderVector} to specify a low-level ordering
			* across individual orderable columns. This offers greater control but is
			* also more involved.
			*
			* @param string Key of a builtin order supported by this query.
			* @return this
			* @task order
			*/
			public function setOrder($order) {
			$aliases = $this->getBuiltinOrderAliasMap();

			if (empty($aliases[$order])) {
			throw new Exception(
			pht(
			'Query "%s" does not support a builtin order "%s". Supported orders '.
			'are: %s.',
			get_class($this),
			$order,
			implode(', ', array_keys($aliases))));
			}

			$this->builtinOrder = $aliases[$order];
			$this->orderVector = null;

			return $this;
			}


			/**
			* Set a grouping order to apply before primary result ordering.
			*
			* This allows you to preface the query order vector with additional orders,
			* so you can effect "group by" queries while still respecting "order by".
			*
			* This is a high-level method which works alongside @{method:setOrder}. For
			* lower-level control over order vectors, use @{method:setOrderVector}.
			*
			* @param PhabricatorQueryOrderVector\|list<string> List of order keys.
			* @return this
			* @task order
			*/
			public function setGroupVector($vector) {
			$this->groupVector = $vector;
			$this->orderVector = null;

			return $this;
			}


			/**
			* Get builtin orders for this class.
			*
			* In application UIs, we want to be able to present users with a small
			* selection of meaningful order options (like "Order by Title") rather than
			* an exhaustive set of column ordering options.
			*
			* Meaningful user-facing orders are often really orders across multiple
			* columns: for example, a "title" ordering is usually implemented as a
			* "title, id" ordering under the hood.
			*
			* Builtin orders provide a mapping from convenient, understandable
			* user-facing orders to implementations.
			*
			* A builtin order should provide these keys:
			*
			* - `vector` (`list<string>`): The actual order vector to use.
			* - `name` (`string`): Human-readable order name.
			*
			* @return map<string, wild> Map from builtin order keys to specification.
			* @task order
			*/
			public function getBuiltinOrders() {
			$orders = array(
			'newest' => array(
			'vector' => array('id'),
			'name' => pht('Creation (Newest First)'),
			'aliases' => array('created'),
			),
			'oldest' => array(
			'vector' => array('-id'),
			'name' => pht('Creation (Oldest First)'),
			),
			);

			$object = $this->newResultObject();
			if ($object instanceof PhabricatorCustomFieldInterface) {
			$list = PhabricatorCustomField::getObjectFields(
			$object,
			PhabricatorCustomField::ROLE_APPLICATIONSEARCH);
			foreach ($list->getFields() as $field) {
			$index = $field->buildOrderIndex();
			if (!$index) {
			continue;
			}

			$legacy_key = 'custom:'.$field->getFieldKey();
			$modern_key = $field->getModernFieldKey();

			$orders[$modern_key] = array(
			'vector' => array($modern_key, 'id'),
			'name' => $field->getFieldName(),
			'aliases' => array($legacy_key),
			);

			$orders['-'.$modern_key] = array(
			'vector' => array('-'.$modern_key, '-id'),
			'name' => pht('%s (Reversed)', $field->getFieldName()),
			);
			}
			}

			return $orders;
			}

			public function getBuiltinOrderAliasMap() {
			$orders = $this->getBuiltinOrders();

			$map = array();
			foreach ($orders as $key => $order) {
			$keys = array();
			$keys[] = $key;
			foreach (idx($order, 'aliases', array()) as $alias) {
			$keys[] = $alias;
			}

			foreach ($keys as $alias) {
			if (isset($map[$alias])) {
			throw new Exception(
			pht(
			'Two builtin orders ("%s" and "%s") define the same key or '.
			'alias ("%s"). Each order alias and key must be unique and '.
			'identify a single order.',
			$key,
			$map[$alias],
			$alias));
			}
			$map[$alias] = $key;
			}
			}

			return $map;
			}


			/**
			* Set a low-level column ordering.
			*
			* This is a low-level method which offers granular control over column
			* ordering. In most cases, applications can more easily use
			* @{method:setOrder} to choose a high-level builtin order.
			*
			* To set an order vector, specify a list of order keys as provided by
			* @{method:getOrderableColumns}.
			*
			* @param PhabricatorQueryOrderVector\|list<string> List of order keys.
			* @return this
			* @task order
			*/
			public function setOrderVector($vector) {
			$vector = PhabricatorQueryOrderVector::newFromVector($vector);

			$orderable = $this->getOrderableColumns();

			// Make sure that all the components identify valid columns.
			$unique = array();
			foreach ($vector as $order) {
			$key = $order->getOrderKey();
			if (empty($orderable[$key])) {
			$valid = implode(', ', array_keys($orderable));
			throw new Exception(
			pht(
			'This query ("%s") does not support sorting by order key "%s". '.
			'Supported orders are: %s.',
			get_class($this),
			$key,
			$valid));
			}

			$unique[$key] = idx($orderable[$key], 'unique', false);
			}

			// Make sure that the last column is unique so that this is a strong
			// ordering which can be used for paging.
			$last = last($unique);
			if ($last !== true) {
			throw new Exception(
			pht(
			'Order vector "%s" is invalid: the last column in an order must '.
			'be a column with unique values, but "%s" is not unique.',
			$vector->getAsString(),
			last_key($unique)));
			}

			// Make sure that other columns are not unique; an ordering like "id, name"
			// does not make sense because only "id" can ever have an effect.
			array_pop($unique);
			foreach ($unique as $key => $is_unique) {
			if ($is_unique) {
			throw new Exception(
			pht(
			'Order vector "%s" is invalid: only the last column in an order '.
			'may be unique, but "%s" is a unique column and not the last '.
			'column in the order.',
			$vector->getAsString(),
			$key));
			}
			}

			$this->orderVector = $vector;
			return $this;
			}


			/**
			* Get the effective order vector.
			*
			* @return PhabricatorQueryOrderVector Effective vector.
			* @task order
			*/
			protected function getOrderVector() {
			if (!$this->orderVector) {
			if ($this->builtinOrder !== null) {
			$builtin_order = idx($this->getBuiltinOrders(), $this->builtinOrder);
			$vector = $builtin_order['vector'];
			} else {
			$vector = $this->getDefaultOrderVector();
			}

			if ($this->groupVector) {
			$group = PhabricatorQueryOrderVector::newFromVector($this->groupVector);
			$group->appendVector($vector);
			$vector = $group;
			}

			$vector = PhabricatorQueryOrderVector::newFromVector($vector);

			// We call setOrderVector() here to apply checks to the default vector.
			// This catches any errors in the implementation.
			$this->setOrderVector($vector);
			}

			return $this->orderVector;
			}


			/**
			* @task order
			*/
			protected function getDefaultOrderVector() {
			return array('id');
			}


			/**
			* @task order
			*/
			public function getOrderableColumns() {
			$cache = PhabricatorCaches::getRequestCache();
			$class = get_class($this);
			$cache_key = 'query.orderablecolumns.'.$class;

			$columns = $cache->getKey($cache_key);
			if ($columns !== null) {
			return $columns;
			}

			$columns = array(
			'id' => array(
			'table' => $this->getPrimaryTableAlias(),
			'column' => 'id',
			'reverse' => false,
			'type' => 'int',
			'unique' => true,
			),
			);

			$object = $this->newResultObject();
			if ($object instanceof PhabricatorCustomFieldInterface) {
			$list = PhabricatorCustomField::getObjectFields(
			$object,
			PhabricatorCustomField::ROLE_APPLICATIONSEARCH);
			foreach ($list->getFields() as $field) {
			$index = $field->buildOrderIndex();
			if (!$index) {
			continue;
			}

			$digest = $field->getFieldIndex();

			$key = $field->getModernFieldKey();

			$columns[$key] = array(
			'table' => 'appsearch_order_'.$digest,
			'column' => 'indexValue',
			'type' => $index->getIndexValueType(),
			'null' => 'tail',
			'customfield' => true,
			'customfield.index.table' => $index->getTableName(),
			'customfield.index.key' => $digest,
			);
			}
			}

			$cache->setKey($cache_key, $columns);

			return $columns;
			}


			/**
			* @task order
			*/
			final protected function buildOrderClause(AphrontDatabaseConnection $conn) {
			$orderable = $this->getOrderableColumns();
			$vector = $this->getOrderVector();

			$parts = array();
			foreach ($vector as $order) {
			$part = $orderable[$order->getOrderKey()];
			if ($order->getIsReversed()) {
			$part['reverse'] = !idx($part, 'reverse', false);
			}
			$parts[] = $part;
			}

			return $this->formatOrderClause($conn, $parts);
			}


			/**
			* @task order
			*/
			protected function formatOrderClause(
			AphrontDatabaseConnection $conn,
			array $parts) {

			$is_query_reversed = false;
			if ($this->getBeforeID()) {
			$is_query_reversed = !$is_query_reversed;
			}

			$sql = array();
			foreach ($parts as $key => $part) {
			$is_column_reversed = !empty($part['reverse']);

			$descending = true;
			if ($is_query_reversed) {
			$descending = !$descending;
			}

			if ($is_column_reversed) {
			$descending = !$descending;
			}

			$table = idx($part, 'table');
			$column = $part['column'];

			if ($table !== null) {
			$field = qsprintf($conn, '%T.%T', $table, $column);
			} else {
			$field = qsprintf($conn, '%T', $column);
			}

			$null = idx($part, 'null');
			if ($null) {
			switch ($null) {
			case 'head':
			$null_field = qsprintf($conn, '(%Q IS NULL)', $field);
			break;
			case 'tail':
			$null_field = qsprintf($conn, '(%Q IS NOT NULL)', $field);
			break;
			default:
			throw new Exception(
			pht(
			'NULL value "%s" is invalid. Valid values are "head" and '.
			'"tail".',
			$null));
			}

			if ($descending) {
			$sql[] = qsprintf($conn, '%Q DESC', $null_field);
			} else {
			$sql[] = qsprintf($conn, '%Q ASC', $null_field);
			}
			}

			if ($descending) {
			$sql[] = qsprintf($conn, '%Q DESC', $field);
			} else {
			$sql[] = qsprintf($conn, '%Q ASC', $field);
			}
			}

			return qsprintf($conn, 'ORDER BY %Q', implode(', ', $sql));
			}


			/* -( Application Search )------------------------------------------------- */


			/**
			* Constrain the query with an ApplicationSearch index, requiring field values
			* contain at least one of the values in a set.
			*
			* This constraint can build the most common types of queries, like:
			*
			* - Find users with shirt sizes "X" or "XL".
			* - Find shoes with size "13".
			*
			* @param PhabricatorCustomFieldIndexStorage Table where the index is stored.
			* @param string\|list<string> One or more values to filter by.
			* @return this
			* @task appsearch
			*/
			public function withApplicationSearchContainsConstraint(
			PhabricatorCustomFieldIndexStorage $index,
			$value) {

			$this->applicationSearchConstraints[] = array(
			'type' => $index->getIndexValueType(),
			'cond' => '=',
			'table' => $index->getTableName(),
			'index' => $index->getIndexKey(),
			'value' => $value,
			);

			return $this;
			}


			/**
			* Constrain the query with an ApplicationSearch index, requiring values
			* exist in a given range.
			*
			* This constraint is useful for expressing date ranges:
			*
			* - Find events between July 1st and July 7th.
			*
			* The ends of the range are inclusive, so a `$min` of `3` and a `$max` of
			* `5` will match fields with values `3`, `4`, or `5`. Providing `null` for
			* either end of the range will leave that end of the constraint open.
			*
			* @param PhabricatorCustomFieldIndexStorage Table where the index is stored.
			* @param int\|null Minimum permissible value, inclusive.
			* @param int\|null Maximum permissible value, inclusive.
			* @return this
			* @task appsearch
			*/
			public function withApplicationSearchRangeConstraint(
			PhabricatorCustomFieldIndexStorage $index,
			$min,
			$max) {

			$index_type = $index->getIndexValueType();
			if ($index_type != 'int') {
			throw new Exception(
			pht(
			'Attempting to apply a range constraint to a field with index type '.
			'"%s", expected type "%s".',
			$index_type,
			'int'));
			}

			$this->applicationSearchConstraints[] = array(
			'type' => $index->getIndexValueType(),
			'cond' => 'range',
			'table' => $index->getTableName(),
			'index' => $index->getIndexKey(),
			'value' => array($min, $max),
			);

			return $this;
			}


			/**
			* Get the name of the query's primary object PHID column, for constructing
			* JOIN clauses. Normally (and by default) this is just `"phid"`, but it may
			* be something more exotic.
			*
			* See @{method:getPrimaryTableAlias} if the column needs to be qualified with
			* a table alias.
			*
			* @return string Column name.
			* @task appsearch
			*/
			protected function getApplicationSearchObjectPHIDColumn() {
			if ($this->getPrimaryTableAlias()) {
			$prefix = $this->getPrimaryTableAlias().'.';
			} else {
			$prefix = '';
			}

			return $prefix.'phid';
			}


			/**
			* Determine if the JOINs built by ApplicationSearch might cause each primary
			* object to return multiple result rows. Generally, this means the query
			* needs an extra GROUP BY clause.
			*
			* @return bool True if the query may return multiple rows for each object.
			* @task appsearch
			*/
			protected function getApplicationSearchMayJoinMultipleRows() {
			foreach ($this->applicationSearchConstraints as $constraint) {
			$type = $constraint['type'];
			$value = $constraint['value'];
			$cond = $constraint['cond'];

			switch ($cond) {
			case '=':
			switch ($type) {
			case 'string':
			case 'int':
			if (count((array)$value) > 1) {
			return true;
			}
			break;
			default:
			throw new Exception(pht('Unknown index type "%s"!', $type));
			}
			break;
			case 'range':
			// NOTE: It's possible to write a custom field where multiple rows
			// match a range constraint, but we don't currently ship any in the
			// upstream and I can't immediately come up with cases where this
			// would make sense.
			break;
			default:
			throw new Exception(pht('Unknown constraint condition "%s"!', $cond));
			}
			}

			return false;
			}


			/**
			* Construct a GROUP BY clause appropriate for ApplicationSearch constraints.
			*
			* @param AphrontDatabaseConnection Connection executing the query.
			* @return string Group clause.
			* @task appsearch
			*/
			protected function buildApplicationSearchGroupClause(
			AphrontDatabaseConnection $conn_r) {

			if ($this->getApplicationSearchMayJoinMultipleRows()) {
			return qsprintf(
			$conn_r,
			'GROUP BY %Q',
			$this->getApplicationSearchObjectPHIDColumn());
			} else {
			return '';
			}
			}


			/**
			* Construct a JOIN clause appropriate for applying ApplicationSearch
			* constraints.
			*
			* @param AphrontDatabaseConnection Connection executing the query.
			* @return string Join clause.
			* @task appsearch
			*/
			protected function buildApplicationSearchJoinClause(
			AphrontDatabaseConnection $conn_r) {

			$joins = array();
			foreach ($this->applicationSearchConstraints as $key => $constraint) {
			$table = $constraint['table'];
			$alias = 'appsearch_'.$key;
			$index = $constraint['index'];
			$cond = $constraint['cond'];
			$phid_column = $this->getApplicationSearchObjectPHIDColumn();
			switch ($cond) {
			case '=':
			$type = $constraint['type'];
			switch ($type) {
			case 'string':
			$constraint_clause = qsprintf(
			$conn_r,
			'%T.indexValue IN (%Ls)',
			$alias,
			(array)$constraint['value']);
			break;
			case 'int':
			$constraint_clause = qsprintf(
			$conn_r,
			'%T.indexValue IN (%Ld)',
			$alias,
			(array)$constraint['value']);
			break;
			default:
			throw new Exception(pht('Unknown index type "%s"!', $type));
			}

			$joins[] = qsprintf(
			$conn_r,
			'JOIN %T %T ON %T.objectPHID = %Q
			AND %T.indexKey = %s
			AND (%Q)',
			$table,
			$alias,
			$alias,
			$phid_column,
			$alias,
			$index,
			$constraint_clause);
			break;
			case 'range':
			list($min, $max) = $constraint['value'];
			if (($min === null) && ($max === null)) {
			// If there's no actual range constraint, just move on.
			break;
			}

			if ($min === null) {
			$constraint_clause = qsprintf(
			$conn_r,
			'%T.indexValue <= %d',
			$alias,
			$max);
			} else if ($max === null) {
			$constraint_clause = qsprintf(
			$conn_r,
			'%T.indexValue >= %d',
			$alias,
			$min);
			} else {
			$constraint_clause = qsprintf(
			$conn_r,
			'%T.indexValue BETWEEN %d AND %d',
			$alias,
			$min,
			$max);
			}

			$joins[] = qsprintf(
			$conn_r,
			'JOIN %T %T ON %T.objectPHID = %Q
			AND %T.indexKey = %s
			AND (%Q)',
			$table,
			$alias,
			$alias,
			$phid_column,
			$alias,
			$index,
			$constraint_clause);
			break;
			default:
			throw new Exception(pht('Unknown constraint condition "%s"!', $cond));
			}
			}

			$phid_column = $this->getApplicationSearchObjectPHIDColumn();
			$orderable = $this->getOrderableColumns();

			$vector = $this->getOrderVector();
			foreach ($vector as $order) {
			$spec = $orderable[$order->getOrderKey()];
			if (empty($spec['customfield'])) {
			continue;
			}

			$table = $spec['customfield.index.table'];
			$alias = $spec['table'];
			$key = $spec['customfield.index.key'];

			$joins[] = qsprintf(
			$conn_r,
			'LEFT JOIN %T %T ON %T.objectPHID = %Q
			AND %T.indexKey = %s',
			$table,
			$alias,
			$alias,
			$phid_column,
			$alias,
			$key);
			}

			return implode(' ', $joins);
			}


			/* -( Integration with CustomField )--------------------------------------- */


			/**
			* @task customfield
			*/
			protected function getPagingValueMapForCustomFields(
			PhabricatorCustomFieldInterface $object) {

			// We have to get the current field values on the cursor object.
			$fields = PhabricatorCustomField::getObjectFields(
			$object,
			PhabricatorCustomField::ROLE_APPLICATIONSEARCH);
			$fields->setViewer($this->getViewer());
			$fields->readFieldsFromStorage($object);

			$map = array();
			foreach ($fields->getFields() as $field) {
			$map['custom:'.$field->getFieldKey()] = $field->getValueForStorage();
			}

			return $map;
			}


			/**
			* @task customfield
			*/
			protected function isCustomFieldOrderKey($key) {
			$prefix = 'custom:';
			return !strncmp($key, $prefix, strlen($prefix));
			}


			/* -( Ngrams )------------------------------------------------------------- */


			protected function withNgramsConstraint(
			PhabricatorSearchNgrams $index,
			$value) {

			if (strlen($value)) {
			$this->ngrams[] = array(
			'index' => $index,
			'value' => $value,
			'length' => count(phutil_utf8v($value)),
			);
			}

			return $this;
			}


			protected function buildNgramsJoinClause(AphrontDatabaseConnection $conn) {
			$flat = array();
			foreach ($this->ngrams as $spec) {
			$index = $spec['index'];
			$value = $spec['value'];
			$length = $spec['length'];

			if ($length >= 3) {
			$ngrams = $index->getNgramsFromString($value, 'query');
			$prefix = false;
			} else if ($length == 2) {
			$ngrams = $index->getNgramsFromString($value, 'prefix');
			$prefix = false;
			} else {
			$ngrams = array(' '.$value);
			$prefix = true;
			}

			foreach ($ngrams as $ngram) {
			$flat[] = array(
			'table' => $index->getTableName(),
			'ngram' => $ngram,
			'prefix' => $prefix,
			);
			}
			}

			// MySQL only allows us to join a maximum of 61 tables per query. Each
			// ngram is going to cost us a join toward that limit, so if the user
			// specified a very long query string, just pick 16 of the ngrams
			// at random.
			if (count($flat) > 16) {
			shuffle($flat);
			$flat = array_slice($flat, 0, 16);
			}

			$alias = $this->getPrimaryTableAlias();
			if ($alias) {
			$id_column = qsprintf($conn, '%T.%T', $alias, 'id');
			} else {
			$id_column = qsprintf($conn, '%T', 'id');
			}

			$idx = 1;
			$joins = array();
			foreach ($flat as $spec) {
			$table = $spec['table'];
			$ngram = $spec['ngram'];
			$prefix = $spec['prefix'];

			$alias = 'ngm'.$idx++;

			if ($prefix) {
			$joins[] = qsprintf(
			$conn,
			'JOIN %T %T ON %T.objectID = %Q AND %T.ngram LIKE %>',
			$table,
			$alias,
			$alias,
			$id_column,
			$alias,
			$ngram);
			} else {
			$joins[] = qsprintf(
			$conn,
			'JOIN %T %T ON %T.objectID = %Q AND %T.ngram = %s',
			$table,
			$alias,
			$alias,
			$id_column,
			$alias,
			$ngram);
			}
			}

			return $joins;
			}


			protected function buildNgramsWhereClause(AphrontDatabaseConnection $conn) {
			$where = array();

			foreach ($this->ngrams as $ngram) {
			$index = $ngram['index'];
			$value = $ngram['value'];

			$column = $index->getColumnName();
			$alias = $this->getPrimaryTableAlias();
			if ($alias) {
			$column = qsprintf($conn, '%T.%T', $alias, $column);
			} else {
			$column = qsprintf($conn, '%T', $column);
			}

			$tokens = $index->tokenizeString($value);
			foreach ($tokens as $token) {
			$where[] = qsprintf(
			$conn,
			'%Q LIKE %~',
			$column,
			$token);
			}
			}

			return $where;
			}


			protected function shouldGroupNgramResultRows() {
			return (bool)$this->ngrams;
			}


			/* -( Edge Logic )--------------------------------------------------------- */


			/**
			* Convenience method for specifying edge logic constraints with a list of
			* PHIDs.
			*
			* @param const Edge constant.
			* @param const Constraint operator.
			* @param list<phid> List of PHIDs.
			* @return this
			* @task edgelogic
			*/
			public function withEdgeLogicPHIDs($edge_type, $operator, array $phids) {
			$constraints = array();
			foreach ($phids as $phid) {
			$constraints[] = new PhabricatorQueryConstraint($operator, $phid);
			}

			return $this->withEdgeLogicConstraints($edge_type, $constraints);
			}


			/**
			* @return this
			* @task edgelogic
			*/
			public function withEdgeLogicConstraints($edge_type, array $constraints) {
			assert_instances_of($constraints, 'PhabricatorQueryConstraint');

			$constraints = mgroup($constraints, 'getOperator');
			foreach ($constraints as $operator => $list) {
			foreach ($list as $item) {
			$this->edgeLogicConstraints[$edge_type][$operator][] = $item;
			}
			}

			$this->edgeLogicConstraintsAreValid = false;

			return $this;
			}


			/**
			* @task edgelogic
			*/
			public function buildEdgeLogicSelectClause(AphrontDatabaseConnection $conn) {
			$select = array();

			$this->validateEdgeLogicConstraints();

			foreach ($this->edgeLogicConstraints as $type => $constraints) {
			foreach ($constraints as $operator => $list) {
			$alias = $this->getEdgeLogicTableAlias($operator, $type);
			switch ($operator) {
			case PhabricatorQueryConstraint::OPERATOR_AND:
			if (count($list) > 1) {
			$select[] = qsprintf(
			$conn,
			'COUNT(DISTINCT(%T.dst)) %T',
			$alias,
			$this->buildEdgeLogicTableAliasCount($alias));
			}
			break;
			case PhabricatorQueryConstraint::OPERATOR_ANCESTOR:
			// This is tricky. We have a query which specifies multiple
			// projects, each of which may have an arbitrarily large number
			// of descendants.

			// Suppose the projects are "Engineering" and "Operations", and
			// "Engineering" has subprojects X, Y and Z.

			// We first use `FIELD(dst, X, Y, Z)` to produce a 0 if a row
			// is not part of Engineering at all, or some number other than
			// 0 if it is.

			// Then we use `IF(..., idx, NULL)` to convert the 0 to a NULL and
			// any other value to an index (say, 1) for the ancestor.

			// We build these up for every ancestor, then use `COALESCE(...)`
			// to select the non-null one, giving us an ancestor which this
			// row is a member of.

			// From there, we use `COUNT(DISTINCT(...))` to make sure that
			// each result row is a member of all ancestors.
			if (count($list) > 1) {
			$idx = 1;
			$parts = array();
			foreach ($list as $constraint) {
			$parts[] = qsprintf(
			$conn,
			'IF(FIELD(%T.dst, %Ls) != 0, %d, NULL)',
			$alias,
			(array)$constraint->getValue(),
			$idx++);
			}
			$parts = implode(', ', $parts);

			$select[] = qsprintf(
			$conn,
			'COUNT(DISTINCT(COALESCE(%Q))) %T',
			$parts,
			$this->buildEdgeLogicTableAliasAncestor($alias));
			}
			break;
			default:
			break;
			}
			}
			}

			return $select;
			}


			/**
			* @task edgelogic
			*/
			public function buildEdgeLogicJoinClause(AphrontDatabaseConnection $conn) {
			$edge_table = PhabricatorEdgeConfig::TABLE_NAME_EDGE;
			$phid_column = $this->getApplicationSearchObjectPHIDColumn();

			$joins = array();
			foreach ($this->edgeLogicConstraints as $type => $constraints) {

			$op_null = PhabricatorQueryConstraint::OPERATOR_NULL;
			$has_null = isset($constraints[$op_null]);

			foreach ($constraints as $operator => $list) {
			$alias = $this->getEdgeLogicTableAlias($operator, $type);

			$phids = array();
			foreach ($list as $constraint) {
			$value = (array)$constraint->getValue();
			foreach ($value as $v) {
			$phids[$v] = $v;
			}
			}
			$phids = array_keys($phids);

			switch ($operator) {
			case PhabricatorQueryConstraint::OPERATOR_NOT:
			$joins[] = qsprintf(
			$conn,
			'LEFT JOIN %T %T ON %Q = %T.src AND %T.type = %d
			AND %T.dst IN (%Ls)',
			$edge_table,
			$alias,
			$phid_column,
			$alias,
			$alias,
			$type,
			$alias,
			$phids);
			break;
			case PhabricatorQueryConstraint::OPERATOR_ANCESTOR:
			case PhabricatorQueryConstraint::OPERATOR_AND:
			case PhabricatorQueryConstraint::OPERATOR_OR:
			// If we're including results with no matches, we have to degrade
			// this to a LEFT join. We'll use WHERE to select matching rows
			// later.
			if ($has_null) {
			$join_type = 'LEFT';
			} else {
			$join_type = '';
			}

			$joins[] = qsprintf(
			$conn,
			'%Q JOIN %T %T ON %Q = %T.src AND %T.type = %d
			AND %T.dst IN (%Ls)',
			$join_type,
			$edge_table,
			$alias,
			$phid_column,
			$alias,
			$alias,
			$type,
			$alias,
			$phids);
			break;
			case PhabricatorQueryConstraint::OPERATOR_NULL:
			$joins[] = qsprintf(
			$conn,
			'LEFT JOIN %T %T ON %Q = %T.src AND %T.type = %d',
			$edge_table,
			$alias,
			$phid_column,
			$alias,
			$alias,
			$type);
			break;
			}
			}
			}

			return $joins;
			}


			/**
			* @task edgelogic
			*/
			public function buildEdgeLogicWhereClause(AphrontDatabaseConnection $conn) {
			$where = array();

			foreach ($this->edgeLogicConstraints as $type => $constraints) {

			$full = array();
			$null = array();

			$op_null = PhabricatorQueryConstraint::OPERATOR_NULL;
			$has_null = isset($constraints[$op_null]);

			foreach ($constraints as $operator => $list) {
			$alias = $this->getEdgeLogicTableAlias($operator, $type);
			switch ($operator) {
			case PhabricatorQueryConstraint::OPERATOR_NOT:
			$full[] = qsprintf(
			$conn,
			'%T.dst IS NULL',
			$alias);
			break;
			case PhabricatorQueryConstraint::OPERATOR_AND:
			case PhabricatorQueryConstraint::OPERATOR_OR:
			if ($has_null) {
			$full[] = qsprintf(
			$conn,
			'%T.dst IS NOT NULL',
			$alias);
			}
			break;
			case PhabricatorQueryConstraint::OPERATOR_NULL:
			$null[] = qsprintf(
			$conn,
			'%T.dst IS NULL',
			$alias);
			break;
			}
			}

			if ($full && $null) {
			$full = $this->formatWhereSubclause($full);
			$null = $this->formatWhereSubclause($null);
			$where[] = qsprintf($conn, '(%Q OR %Q)', $full, $null);
			} else if ($full) {
			foreach ($full as $condition) {
			$where[] = $condition;
			}
			} else if ($null) {
			foreach ($null as $condition) {
			$where[] = $condition;
			}
			}
			}

			return $where;
			}


			/**
			* @task edgelogic
			*/
			public function buildEdgeLogicHavingClause(AphrontDatabaseConnection $conn) {
			$having = array();

			foreach ($this->edgeLogicConstraints as $type => $constraints) {
			foreach ($constraints as $operator => $list) {
			$alias = $this->getEdgeLogicTableAlias($operator, $type);
			switch ($operator) {
			case PhabricatorQueryConstraint::OPERATOR_AND:
			if (count($list) > 1) {
			$having[] = qsprintf(
			$conn,
			'%T = %d',
			$this->buildEdgeLogicTableAliasCount($alias),
			count($list));
			}
			break;
			case PhabricatorQueryConstraint::OPERATOR_ANCESTOR:
			if (count($list) > 1) {
			$having[] = qsprintf(
			$conn,
			'%T = %d',
			$this->buildEdgeLogicTableAliasAncestor($alias),
			count($list));
			}
			break;
			}
			}
			}

			return $having;
			}


			/**
			* @task edgelogic
			*/
			public function shouldGroupEdgeLogicResultRows() {
			foreach ($this->edgeLogicConstraints as $type => $constraints) {
			foreach ($constraints as $operator => $list) {
			switch ($operator) {
			case PhabricatorQueryConstraint::OPERATOR_NOT:
			case PhabricatorQueryConstraint::OPERATOR_AND:
			case PhabricatorQueryConstraint::OPERATOR_OR:
			if (count($list) > 1) {
			return true;
			}
			break;
			case PhabricatorQueryConstraint::OPERATOR_ANCESTOR:
			// NOTE: We must always group query results rows when using an
			// "ANCESTOR" operator because a single task may be related to
			// two different descendants of a particular ancestor. For
			// discussion, see T12753.
			return true;
			case PhabricatorQueryConstraint::OPERATOR_NULL:
			return true;
			}
			}
			}

			return false;
			}


			/**
			* @task edgelogic
			*/
			private function getEdgeLogicTableAlias($operator, $type) {
			return 'edgelogic_'.$operator.'_'.$type;
			}


			/**
			* @task edgelogic
			*/
			private function buildEdgeLogicTableAliasCount($alias) {
			return $alias.'_count';
			}

			/**
			* @task edgelogic
			*/
			private function buildEdgeLogicTableAliasAncestor($alias) {
			return $alias.'_ancestor';
			}


			/**
			* Select certain edge logic constraint values.
			*
			* @task edgelogic
			*/
			protected function getEdgeLogicValues(
			array $edge_types,
			array $operators) {

			$values = array();

			$constraint_lists = $this->edgeLogicConstraints;
			if ($edge_types) {
			$constraint_lists = array_select_keys($constraint_lists, $edge_types);
			}

			foreach ($constraint_lists as $type => $constraints) {
			if ($operators) {
			$constraints = array_select_keys($constraints, $operators);
			}
			foreach ($constraints as $operator => $list) {
			foreach ($list as $constraint) {
			$value = (array)$constraint->getValue();
			foreach ($value as $v) {
			$values[] = $v;
			}
			}
			}
			}

			return $values;
			}


			/**
			* Validate edge logic constraints for the query.
			*
			* @return this
			* @task edgelogic
			*/
			private function validateEdgeLogicConstraints() {
			if ($this->edgeLogicConstraintsAreValid) {
			return $this;
			}

			foreach ($this->edgeLogicConstraints as $type => $constraints) {
			foreach ($constraints as $operator => $list) {
			switch ($operator) {
			case PhabricatorQueryConstraint::OPERATOR_EMPTY:
			throw new PhabricatorEmptyQueryException(
			pht('This query specifies an empty constraint.'));
			}
			}
			}

			// This should probably be more modular, eventually, but we only do
			// project-based edge logic today.

			$project_phids = $this->getEdgeLogicValues(
			array(
			PhabricatorProjectObjectHasProjectEdgeType::EDGECONST,
			),
			array(
			PhabricatorQueryConstraint::OPERATOR_AND,
			PhabricatorQueryConstraint::OPERATOR_OR,
			PhabricatorQueryConstraint::OPERATOR_NOT,
			PhabricatorQueryConstraint::OPERATOR_ANCESTOR,
			));
			if ($project_phids) {
			$projects = id(new PhabricatorProjectQuery())
			->setViewer($this->getViewer())
			->setParentQuery($this)
			->withPHIDs($project_phids)
			->execute();
			$projects = mpull($projects, null, 'getPHID');
			foreach ($project_phids as $phid) {
			if (empty($projects[$phid])) {
			throw new PhabricatorEmptyQueryException(
			pht(
			'This query is constrained by a project you do not have '.
			'permission to see.'));
			}
			}
			}

			$this->edgeLogicConstraintsAreValid = true;

			return $this;
			}


			/* -( Spaces )------------------------------------------------------------- */


			/**
			* Constrain the query to return results from only specific Spaces.
			*
			* Pass a list of Space PHIDs, or `null` to represent the default space. Only
			* results in those Spaces will be returned.
			*
			* Queries are always constrained to include only results from spaces the
			* viewer has access to.
			*
			* @param list<phid\|null>
			* @task spaces
			*/
			public function withSpacePHIDs(array $space_phids) {
			$object = $this->newResultObject();

			if (!$object) {
			throw new Exception(
			pht(
			'This query (of class "%s") does not implement newResultObject(), '.
			'but must implement this method to enable support for Spaces.',
			get_class($this)));
			}

			if (!($object instanceof PhabricatorSpacesInterface)) {
			throw new Exception(
			pht(
			'This query (of class "%s") returned an object of class "%s" from '.
			'getNewResultObject(), but it does not implement the required '.
			'interface ("%s"). Objects must implement this interface to enable '.
			'Spaces support.',
			get_class($this),
			get_class($object),
			'PhabricatorSpacesInterface'));
			}

			$this->spacePHIDs = $space_phids;

			return $this;
			}

			public function withSpaceIsArchived($archived) {
			$this->spaceIsArchived = $archived;
			return $this;
			}


			/**
			* Constrain the query to include only results in valid Spaces.
			*
			* This method builds part of a WHERE clause which considers the spaces the
			* viewer has access to see with any explicit constraint on spaces added by
			* @{method:withSpacePHIDs}.
			*
			* @param AphrontDatabaseConnection Database connection.
			* @return string Part of a WHERE clause.
			* @task spaces
			*/
			private function buildSpacesWhereClause(AphrontDatabaseConnection $conn) {
			$object = $this->newResultObject();
			if (!$object) {
			return null;
			}

			if (!($object instanceof PhabricatorSpacesInterface)) {
			return null;
			}

			$viewer = $this->getViewer();

			// If we have an omnipotent viewer and no formal space constraints, don't
			// emit a clause. This primarily enables older migrations to run cleanly,
			// without fataling because they try to match a `spacePHID` column which
			// does not exist yet. See T8743, T8746.
			if ($viewer->isOmnipotent()) {
			if ($this->spaceIsArchived === null && $this->spacePHIDs === null) {
			return null;
			}
			}

			$space_phids = array();
			$include_null = false;

			$all = PhabricatorSpacesNamespaceQuery::getAllSpaces();
			if (!$all) {
			// If there are no spaces at all, implicitly give the viewer access to
			// the default space.
			$include_null = true;
			} else {
			// Otherwise, give them access to the spaces they have permission to
			// see.
			$viewer_spaces = PhabricatorSpacesNamespaceQuery::getViewerSpaces(
			$viewer);
			foreach ($viewer_spaces as $viewer_space) {
			if ($this->spaceIsArchived !== null) {
			if ($viewer_space->getIsArchived() != $this->spaceIsArchived) {
			continue;
			}
			}
			$phid = $viewer_space->getPHID();
			$space_phids[$phid] = $phid;
			if ($viewer_space->getIsDefaultNamespace()) {
			$include_null = true;
			}
			}
			}

			// If we have additional explicit constraints, evaluate them now.
			if ($this->spacePHIDs !== null) {
			$explicit = array();
			$explicit_null = false;
			foreach ($this->spacePHIDs as $phid) {
			if ($phid === null) {
			$space = PhabricatorSpacesNamespaceQuery::getDefaultSpace();
			} else {
			$space = idx($all, $phid);
			}

			if ($space) {
			$phid = $space->getPHID();
			$explicit[$phid] = $phid;
			if ($space->getIsDefaultNamespace()) {
			$explicit_null = true;
			}
			}
			}

			// If the viewer can see the default space but it isn't on the explicit
			// list of spaces to query, don't match it.
			if ($include_null && !$explicit_null) {
			$include_null = false;
			}

			// Include only the spaces common to the viewer and the constraints.
			$space_phids = array_intersect_key($space_phids, $explicit);
			}

			if (!$space_phids && !$include_null) {
			if ($this->spacePHIDs === null) {
			throw new PhabricatorEmptyQueryException(
			pht('You do not have access to any spaces.'));
			} else {
			throw new PhabricatorEmptyQueryException(
			pht(
			'You do not have access to any of the spaces this query '.
			'is constrained to.'));
			}
			}

			$alias = $this->getPrimaryTableAlias();
			if ($alias) {
			$col = qsprintf($conn, '%T.spacePHID', $alias);
			} else {
			$col = 'spacePHID';
			}

			if ($space_phids && $include_null) {
			return qsprintf(
			$conn,
			'(%Q IN (%Ls) OR %Q IS NULL)',
			$col,
			$space_phids,
			$col);
			} else if ($space_phids) {
			return qsprintf(
			$conn,
			'%Q IN (%Ls)',
			$col,
			$space_phids);
			} else {
			return qsprintf(
			$conn,
			'%Q IS NULL',
			$col);
			}
			}

			}

phab/src/infrastructure/query/policy/PhabricatorCursorPagedPolicyAwareQuery.phpd1842929afaastable

PhabricatorCursorPagedPolicyAwareQuery.phpView Options

phab/src/infrastructure/query/policy/PhabricatorCursorPagedPolicyAwareQuery.php
d1842929afaastable

PhabricatorCursorPagedPolicyAwareQuery.php
View Options