Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Database;
Chris@0: 
Chris@0: /**
Chris@0:  * Database query logger.
Chris@0:  *
Chris@0:  * We log queries in a separate object rather than in the connection object
Chris@0:  * because we want to be able to see all queries sent to a given database, not
Chris@0:  * database target. If we logged the queries in each connection object we
Chris@0:  * would not be able to track what queries went to which target.
Chris@0:  *
Chris@0:  * Every connection has one and only one logging object on it for all targets
Chris@0:  * and logging keys.
Chris@0:  */
Chris@0: class Log {
Chris@0: 
Chris@0:   /**
Chris@0:    * Cache of logged queries. This will only be used if the query logger is enabled.
Chris@0:    *
Chris@0:    * The structure for the logging array is as follows:
Chris@0:    *
Chris@0:    * array(
Chris@0:    *   $logging_key = array(
Chris@0:    *     array('query' => '', 'args' => array(), 'caller' => '', 'target' => '', 'time' => 0),
Chris@0:    *     array('query' => '', 'args' => array(), 'caller' => '', 'target' => '', 'time' => 0),
Chris@0:    *   ),
Chris@0:    * );
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $queryLog = [];
Chris@0: 
Chris@0:   /**
Chris@0:    * The connection key for which this object is logging.
Chris@0:    *
Chris@0:    * @var string
Chris@0:    */
Chris@0:   protected $connectionKey = 'default';
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructor.
Chris@0:    *
Chris@0:    * @param $key
Chris@0:    *   The database connection key for which to enable logging.
Chris@0:    */
Chris@0:   public function __construct($key = 'default') {
Chris@0:     $this->connectionKey = $key;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Begin logging queries to the specified connection and logging key.
Chris@0:    *
Chris@0:    * If the specified logging key is already running this method does nothing.
Chris@0:    *
Chris@0:    * @param $logging_key
Chris@0:    *   The identification key for this log request. By specifying different
Chris@0:    *   logging keys we are able to start and stop multiple logging runs
Chris@0:    *   simultaneously without them colliding.
Chris@0:    */
Chris@0:   public function start($logging_key) {
Chris@0:     if (empty($this->queryLog[$logging_key])) {
Chris@0:       $this->clear($logging_key);
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Retrieve the query log for the specified logging key so far.
Chris@0:    *
Chris@0:    * @param $logging_key
Chris@0:    *   The logging key to fetch.
Chris@0:    * @return
Chris@0:    *   An indexed array of all query records for this logging key.
Chris@0:    */
Chris@0:   public function get($logging_key) {
Chris@0:     return $this->queryLog[$logging_key];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Empty the query log for the specified logging key.
Chris@0:    *
Chris@0:    * This method does not stop logging, it simply clears the log. To stop
Chris@0:    * logging, use the end() method.
Chris@0:    *
Chris@0:    * @param $logging_key
Chris@0:    *   The logging key to empty.
Chris@0:    */
Chris@0:   public function clear($logging_key) {
Chris@0:     $this->queryLog[$logging_key] = [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Stop logging for the specified logging key.
Chris@0:    *
Chris@0:    * @param $logging_key
Chris@0:    *   The logging key to stop.
Chris@0:    */
Chris@0:   public function end($logging_key) {
Chris@0:     unset($this->queryLog[$logging_key]);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Log a query to all active logging keys.
Chris@0:    *
Chris@0:    * @param $statement
Chris@0:    *   The prepared statement object to log.
Chris@0:    * @param $args
Chris@0:    *   The arguments passed to the statement object.
Chris@0:    * @param $time
Chris@0:    *   The time in milliseconds the query took to execute.
Chris@0:    */
Chris@0:   public function log(StatementInterface $statement, $args, $time) {
Chris@0:     foreach (array_keys($this->queryLog) as $key) {
Chris@0:       $this->queryLog[$key][] = [
Chris@0:         'query' => $statement->getQueryString(),
Chris@0:         'args' => $args,
Chris@0:         'target' => $statement->dbh->getTarget(),
Chris@0:         'caller' => $this->findCaller(),
Chris@0:         'time' => $time,
Chris@0:       ];
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Determine the routine that called this query.
Chris@0:    *
Chris@0:    * We define "the routine that called this query" as the first entry in
Chris@0:    * the call stack that is not inside the includes/Drupal/Database directory,
Chris@0:    * does not begin with db_ and does have a file (which excludes
Chris@0:    * call_user_func_array(), anonymous functions and similar). That makes the
Chris@0:    * climbing logic very simple, and handles the variable stack depth caused by
Chris@0:    * the query builders.
Chris@0:    *
Chris@0:    * See the @link http://php.net/debug_backtrace debug_backtrace() @endlink
Chris@0:    * function.
Chris@0:    *
Chris@0:    * @return
Chris@0:    *   This method returns a stack trace entry similar to that generated by
Chris@0:    *   debug_backtrace(). However, it flattens the trace entry and the trace
Chris@0:    *   entry before it so that we get the function and args of the function that
Chris@0:    *   called into the database system, not the function and args of the
Chris@0:    *   database call itself.
Chris@0:    */
Chris@0:   public function findCaller() {
Chris@0:     $stack = debug_backtrace();
Chris@0:     for ($i = 0, $stack_count = count($stack); $i < $stack_count; ++$i) {
Chris@0:       // If the call was made from a function, 'class' will be empty. It's
Chris@0:       // just easier to give it a default value than to try and integrate
Chris@0:       // that into the if statement below.
Chris@0:       if (empty($stack[$i]['class'])) {
Chris@0:         $stack[$i]['class'] = '';
Chris@0:       }
Chris@0:       if (strpos($stack[$i]['class'], __NAMESPACE__) === FALSE && strpos($stack[$i + 1]['function'], 'db_') === FALSE && !empty($stack[$i]['file'])) {
Chris@0:         $stack[$i] += ['file' => '?', 'line' => '?', 'args' => []];
Chris@0:         return [
Chris@0:           'file' => $stack[$i]['file'],
Chris@0:           'line' => $stack[$i]['line'],
Chris@0:           'function' => $stack[$i + 1]['function'],
Chris@0:           'class' => isset($stack[$i + 1]['class']) ? $stack[$i + 1]['class'] : NULL,
Chris@0:           'type' => isset($stack[$i + 1]['type']) ? $stack[$i + 1]['type'] : NULL,
Chris@0:           'args' => $stack[$i + 1]['args'],
Chris@0:         ];
Chris@0:       }
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0: }