/**
* Performs aggregation using Mongo "group" command.
* @param mixed $keys fields to group by. If an array or non-code object is passed,
* it will be the key used to group results. If instance of [[\MongoCode]] passed,
* it will be treated as a function that returns the key to group by.
* @param array $initial Initial value of the aggregation counter object.
* @param \MongoCode|string $reduce function that takes two arguments (the current
* document and the aggregation to this point) and does the aggregation.
* Argument will be automatically cast to [[\MongoCode]].
* @param array $options optional parameters to the group command. Valid options include:
* - condition - criteria for including a document in the aggregation.
* - finalize - function called once per unique key that takes the final output of the reduce function.
* @return array the result of the aggregation.
* @throws Exception on failure.
* @see http://docs.mongodb.org/manual/reference/command/group/
*/
public function group($keys, $initial, $reduce, $options = [])
{
if (array_key_exists('condition', $options)) {
$options['condition'] = $this->buildCondition($options['condition']);
}
$token = $this->composeLogToken('group', [$keys, $initial, $reduce, $options]);
Yii::info($token, __METHOD__);
try {
Yii::beginProfile($token, __METHOD__);
$operation = new Group($this->dbName, $this->collectionName, $keys, $initial, $reduce, $options);
$readPreference = !empty($options['readPreference']) ? $options['readPreference'] : $this->mongoManager->getReadPreference();
$server = $this->mongoManager->selectServer($readPreference);
$result = $operation->execute($server);
$this->tryResultError($result);
Yii::endProfile($token, __METHOD__);
return isset($result->retval) ? MongoHelper::resultToArray($result->retval) : [];
} catch (\Exception $e) {
Yii::endProfile($token, __METHOD__);
throw new Exception($e->getMessage(), (int) $e->getCode(), $e);
}
}
/**
* @param \MongoDB\Driver\Cursor $cursor Mongo cursor instance to fetch data from.
* @param boolean $all whether to fetch all rows or only first one.
* @param string|callable $indexBy value to index by.
* @return array|boolean result.
* @see Query::fetchRows()
*/
protected function fetchRowsInternal($cursor, $all, $indexBy)
{
if ($all) {
$rows = [];
foreach ($cursor as $row) {
$rows[] = MongoHelper::resultToArray($row);
}
return $rows;
} else {
foreach ($cursor as $row) {
break;
}
return isset($row) ? MongoHelper::resultToArray($row) : false;
}
}
