src/Database/Database.php

   1 <?php
   2 /**
   3  * @copyright Copyright (C) 2020, Friendica
   4  *
   5  * @license GNU AGPL version 3 or any later version
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  19  *
  20  */
  21
  22 namespace Friendica\Database;
  23
  24 use Exception;
  25 use Friendica\Core\Config\Cache;
  26 use Friendica\Core\System;
  27 use Friendica\DI;
  28 use Friendica\Network\HTTPException\InternalServerErrorException;
  29 use Friendica\Util\DateTimeFormat;
  30 use Friendica\Util\Profiler;
  31 use mysqli;
  32 use mysqli_result;
  33 use mysqli_stmt;
  34 use PDO;
  35 use PDOException;
  36 use PDOStatement;
  37 use Psr\Log\LoggerInterface;
  38
  39 /**
  40  * This class is for the low level database stuff that does driver specific things.
  41  */
  42 class Database
  43 {
  44         protected $connected = false;
  45
  46         /**
  47          * @var Cache
  48          */
  49         protected $configCache;
  50         /**
  51          * @var Profiler
  52          */
  53         protected $profiler;
  54         /**
  55          * @var LoggerInterface
  56          */
  57         protected $logger;
  58         protected $server_info    = '';
  59         /** @var PDO|mysqli */
  60         protected $connection;
  61         protected $driver;
  62         private $emulate_prepares = false;
  63         private $error          = false;
  64         private $errorno        = 0;
  65         private $affected_rows  = 0;
  66         protected $in_transaction = false;
  67         protected $in_retrial     = false;
  68         protected $testmode       = false;
  69         private $relation       = [];
  70
  71         public function __construct(Cache $configCache, Profiler $profiler, LoggerInterface $logger, array $server = [])
  72         {
  73                 // We are storing these values for being able to perform a reconnect
  74                 $this->configCache   = $configCache;
  75                 $this->profiler      = $profiler;
  76                 $this->logger        = $logger;
  77
  78                 $this->readServerVariables($server);
  79                 $this->connect();
  80
  81                 if ($this->isConnected()) {
  82                         // Loads DB_UPDATE_VERSION constant
  83                         DBStructure::definition($configCache->get('system', 'basepath'), false);
  84                 }
  85         }
  86
  87         private function readServerVariables(array $server)
  88         {
  89                 // Use environment variables for mysql if they are set beforehand
  90                 if (!empty($server['MYSQL_HOST'])
  91                     && (!empty($server['MYSQL_USERNAME'] || !empty($server['MYSQL_USER'])))
  92                     && $server['MYSQL_PASSWORD'] !== false
  93                     && !empty($server['MYSQL_DATABASE']))
  94                 {
  95                         $db_host = $server['MYSQL_HOST'];
  96                         if (!empty($server['MYSQL_PORT'])) {
  97                                 $db_host .= ':' . $server['MYSQL_PORT'];
  98                         }
  99                         $this->configCache->set('database', 'hostname', $db_host);
 100                         unset($db_host);
 101                         if (!empty($server['MYSQL_USERNAME'])) {
 102                                 $this->configCache->set('database', 'username', $server['MYSQL_USERNAME']);
 103                         } else {
 104                                 $this->configCache->set('database', 'username', $server['MYSQL_USER']);
 105                         }
 106                         $this->configCache->set('database', 'password', (string) $server['MYSQL_PASSWORD']);
 107                         $this->configCache->set('database', 'database', $server['MYSQL_DATABASE']);
 108                 }
 109         }
 110
 111         public function connect()
 112         {
 113                 if (!is_null($this->connection) && $this->connected()) {
 114                         return $this->connected;
 115                 }
 116
 117                 // Reset connected state
 118                 $this->connected = false;
 119
 120                 $port       = 0;
 121                 $serveraddr = trim($this->configCache->get('database', 'hostname'));
 122                 $serverdata = explode(':', $serveraddr);
 123                 $server     = $serverdata[0];
 124                 if (count($serverdata) > 1) {
 125                         $port = trim($serverdata[1]);
 126                 }
 127                 $server  = trim($server);
 128                 $user    = trim($this->configCache->get('database', 'username'));
 129                 $pass    = trim($this->configCache->get('database', 'password'));
 130                 $db      = trim($this->configCache->get('database', 'database'));
 131                 $charset = trim($this->configCache->get('database', 'charset'));
 132
 133                 if (!(strlen($server) && strlen($user))) {
 134                         return false;
 135                 }
 136
 137                 $this->emulate_prepares = (bool)$this->configCache->get('database', 'emulate_prepares');
 138
 139                 if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
 140                         $this->driver = 'pdo';
 141                         $connect      = "mysql:host=" . $server . ";dbname=" . $db;
 142
 143                         if ($port > 0) {
 144                                 $connect .= ";port=" . $port;
 145                         }
 146
 147                         if ($charset) {
 148                                 $connect .= ";charset=" . $charset;
 149                         }
 150
 151                         try {
 152                                 $this->connection = @new PDO($connect, $user, $pass);
 153                                 $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
 154                                 $this->connected = true;
 155                         } catch (PDOException $e) {
 156                                 $this->connected = false;
 157                         }
 158                 }
 159
 160                 if (!$this->connected && class_exists('\mysqli')) {
 161                         $this->driver = 'mysqli';
 162
 163                         if ($port > 0) {
 164                                 $this->connection = @new mysqli($server, $user, $pass, $db, $port);
 165                         } else {
 166                                 $this->connection = @new mysqli($server, $user, $pass, $db);
 167                         }
 168
 169                         if (!mysqli_connect_errno()) {
 170                                 $this->connected = true;
 171
 172                                 if ($charset) {
 173                                         $this->connection->set_charset($charset);
 174                                 }
 175                         }
 176                 }
 177
 178                 // No suitable SQL driver was found.
 179                 if (!$this->connected) {
 180                         $this->driver     = null;
 181                         $this->connection = null;
 182                 }
 183
 184                 return $this->connected;
 185         }
 186
 187         public function setTestmode(bool $test)
 188         {
 189                 $this->testmode = $test;
 190         }
 191         /**
 192          * Sets the logger for DBA
 193          *
 194          * @note this is necessary because if we want to load the logger configuration
 195          *       from the DB, but there's an error, we would print out an exception.
 196          *       So the logger gets updated after the logger configuration can be retrieved
 197          *       from the database
 198          *
 199          * @param LoggerInterface $logger
 200          */
 201         public function setLogger(LoggerInterface $logger)
 202         {
 203                 $this->logger = $logger;
 204         }
 205
 206         /**
 207          * Sets the profiler for DBA
 208          *
 209          * @param Profiler $profiler
 210          */
 211         public function setProfiler(Profiler $profiler)
 212         {
 213                 $this->profiler = $profiler;
 214         }
 215         /**
 216          * Disconnects the current database connection
 217          */
 218         public function disconnect()
 219         {
 220                 if (!is_null($this->connection)) {
 221                         switch ($this->driver) {
 222                                 case 'pdo':
 223                                         $this->connection = null;
 224                                         break;
 225                                 case 'mysqli':
 226                                         $this->connection->close();
 227                                         $this->connection = null;
 228                                         break;
 229                         }
 230                 }
 231
 232                 $this->driver    = null;
 233                 $this->connected = false;
 234         }
 235
 236         /**
 237          * Perform a reconnect of an existing database connection
 238          */
 239         public function reconnect()
 240         {
 241                 $this->disconnect();
 242                 return $this->connect();
 243         }
 244
 245         /**
 246          * Return the database object.
 247          *
 248          * @return PDO|mysqli
 249          */
 250         public function getConnection()
 251         {
 252                 return $this->connection;
 253         }
 254
 255         /**
 256          * Returns the MySQL server version string
 257          *
 258          * This function discriminate between the deprecated mysql API and the current
 259          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
 260          *
 261          * @return string
 262          */
 263         public function serverInfo()
 264         {
 265                 if ($this->server_info == '') {
 266                         switch ($this->driver) {
 267                                 case 'pdo':
 268                                         $this->server_info = $this->connection->getAttribute(PDO::ATTR_SERVER_VERSION);
 269                                         break;
 270                                 case 'mysqli':
 271                                         $this->server_info = $this->connection->server_info;
 272                                         break;
 273                         }
 274                 }
 275                 return $this->server_info;
 276         }
 277
 278         /**
 279          * Returns the selected database name
 280          *
 281          * @return string
 282          * @throws \Exception
 283          */
 284         public function databaseName()
 285         {
 286                 $ret  = $this->p("SELECT DATABASE() AS `db`");
 287                 $data = $this->toArray($ret);
 288                 return $data[0]['db'];
 289         }
 290
 291         /**
 292          * Analyze a database query and log this if some conditions are met.
 293          *
 294          * @param string $query The database query that will be analyzed
 295          *
 296          * @throws \Exception
 297          */
 298         private function logIndex($query)
 299         {
 300
 301                 if (!$this->configCache->get('system', 'db_log_index')) {
 302                         return;
 303                 }
 304
 305                 // Don't explain an explain statement
 306                 if (strtolower(substr($query, 0, 7)) == "explain") {
 307                         return;
 308                 }
 309
 310                 // Only do the explain on "select", "update" and "delete"
 311                 if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
 312                         return;
 313                 }
 314
 315                 $r = $this->p("EXPLAIN " . $query);
 316                 if (!$this->isResult($r)) {
 317                         return;
 318                 }
 319
 320                 $watchlist = explode(',', $this->configCache->get('system', 'db_log_index_watch'));
 321                 $blacklist = explode(',', $this->configCache->get('system', 'db_log_index_blacklist'));
 322
 323                 while ($row = $this->fetch($r)) {
 324                         if ((intval($this->configCache->get('system', 'db_loglimit_index')) > 0)) {
 325                                 $log = (in_array($row['key'], $watchlist) &&
 326                                         ($row['rows'] >= intval($this->configCache->get('system', 'db_loglimit_index'))));
 327                         } else {
 328                                 $log = false;
 329                         }
 330
 331                         if ((intval($this->configCache->get('system', 'db_loglimit_index_high')) > 0) && ($row['rows'] >= intval($this->configCache->get('system', 'db_loglimit_index_high')))) {
 332                                 $log = true;
 333                         }
 334
 335                         if (in_array($row['key'], $blacklist) || ($row['key'] == "")) {
 336                                 $log = false;
 337                         }
 338
 339                         if ($log) {
 340                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 341                                 @file_put_contents($this->configCache->get('system', 'db_log_index'), DateTimeFormat::utcNow() . "\t" .
 342                                                                                                       $row['key'] . "\t" . $row['rows'] . "\t" . $row['Extra'] . "\t" .
 343                                                                                                       basename($backtrace[1]["file"]) . "\t" .
 344                                                                                                       $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
 345                                                                                                       substr($query, 0, 2000) . "\n", FILE_APPEND);
 346                         }
 347                 }
 348         }
 349
 350         /**
 351          * Removes every not whitelisted character from the identifier string
 352          *
 353          * @param string $identifier
 354          *
 355          * @return string sanitized identifier
 356          * @throws \Exception
 357          */
 358         private function sanitizeIdentifier($identifier)
 359         {
 360                 return preg_replace('/[^A-Za-z0-9_\-]+/', '', $identifier);
 361         }
 362
 363         public function escape($str)
 364         {
 365                 if ($this->connected) {
 366                         switch ($this->driver) {
 367                                 case 'pdo':
 368                                         return substr(@$this->connection->quote($str, PDO::PARAM_STR), 1, -1);
 369
 370                                 case 'mysqli':
 371                                         return @$this->connection->real_escape_string($str);
 372                         }
 373                 } else {
 374                         return str_replace("'", "\\'", $str);
 375                 }
 376         }
 377
 378         public function isConnected()
 379         {
 380                 return $this->connected;
 381         }
 382
 383         public function connected()
 384         {
 385                 $connected = false;
 386
 387                 if (is_null($this->connection)) {
 388                         return false;
 389                 }
 390
 391                 switch ($this->driver) {
 392                         case 'pdo':
 393                                 $r = $this->p("SELECT 1");
 394                                 if ($this->isResult($r)) {
 395                                         $row       = $this->toArray($r);
 396                                         $connected = ($row[0]['1'] == '1');
 397                                 }
 398                                 break;
 399                         case 'mysqli':
 400                                 $connected = $this->connection->ping();
 401                                 break;
 402                 }
 403
 404                 return $connected;
 405         }
 406
 407         /**
 408          * Replaces ANY_VALUE() function by MIN() function,
 409          * if the database server does not support ANY_VALUE().
 410          *
 411          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
 412          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
 413          * A standard fall-back is to use MIN().
 414          *
 415          * @param string $sql An SQL string without the values
 416          *
 417          * @return string The input SQL string modified if necessary.
 418          */
 419         public function anyValueFallback($sql)
 420         {
 421                 $server_info = $this->serverInfo();
 422                 if (version_compare($server_info, '5.7.5', '<') ||
 423                     (stripos($server_info, 'MariaDB') !== false)) {
 424                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
 425                 }
 426                 return $sql;
 427         }
 428
 429         /**
 430          * Replaces the ? placeholders with the parameters in the $args array
 431          *
 432          * @param string $sql  SQL query
 433          * @param array  $args The parameters that are to replace the ? placeholders
 434          *
 435          * @return string The replaced SQL query
 436          */
 437         private function replaceParameters($sql, $args)
 438         {
 439                 $offset = 0;
 440                 foreach ($args AS $param => $value) {
 441                         if (is_int($args[$param]) || is_float($args[$param]) || is_bool($args[$param])) {
 442                                 $replace = intval($args[$param]);
 443                         } elseif (is_null($args[$param])) {
 444                                 $replace = 'NULL';
 445                         } else {
 446                                 $replace = "'" . $this->escape($args[$param]) . "'";
 447                         }
 448
 449                         $pos = strpos($sql, '?', $offset);
 450                         if ($pos !== false) {
 451                                 $sql = substr_replace($sql, $replace, $pos, 1);
 452                         }
 453                         $offset = $pos + strlen($replace);
 454                 }
 455                 return $sql;
 456         }
 457
 458         /**
 459          * Executes a prepared statement that returns data
 460          *
 461          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
 462          *
 463          * Please only use it with complicated queries.
 464          * For all regular queries please use DBA::select or DBA::exists
 465          *
 466          * @param string $sql SQL statement
 467          *
 468          * @return bool|object statement object or result object
 469          * @throws \Exception
 470          */
 471         public function p($sql)
 472         {
 473
 474                 $stamp1 = microtime(true);
 475
 476                 $params = DBA::getParam(func_get_args());
 477
 478                 // Renumber the array keys to be sure that they fit
 479                 $i    = 0;
 480                 $args = [];
 481                 foreach ($params AS $param) {
 482                         // Avoid problems with some MySQL servers and boolean values. See issue #3645
 483                         if (is_bool($param)) {
 484                                 $param = (int)$param;
 485                         }
 486                         $args[++$i] = $param;
 487                 }
 488
 489                 if (!$this->connected) {
 490                         return false;
 491                 }
 492
 493                 if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
 494                         // Question: Should we continue or stop the query here?
 495                         $this->logger->warning('Query parameters mismatch.', ['query' => $sql, 'args' => $args, 'callstack' => System::callstack()]);
 496                 }
 497
 498                 $sql = DBA::cleanQuery($sql);
 499                 $sql = $this->anyValueFallback($sql);
 500
 501                 $orig_sql = $sql;
 502
 503                 if ($this->configCache->get('system', 'db_callstack') !== null) {
 504                         $sql = "/*" . System::callstack() . " */ " . $sql;
 505                 }
 506
 507                 $this->error         = '';
 508                 $this->errorno       = 0;
 509                 $this->affected_rows = 0;
 510
 511                 // We have to make some things different if this function is called from "e"
 512                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 513
 514                 if (isset($trace[1])) {
 515                         $called_from = $trace[1];
 516                 } else {
 517                         // We use just something that is defined to avoid warnings
 518                         $called_from = $trace[0];
 519                 }
 520                 // We are having an own error logging in the function "e"
 521                 $called_from_e = ($called_from['function'] == 'e');
 522
 523                 if (!isset($this->connection)) {
 524                         throw new InternalServerErrorException('The Connection is empty, although connected is set true.');
 525                 }
 526
 527                 switch ($this->driver) {
 528                         case 'pdo':
 529                                 // If there are no arguments we use "query"
 530                                 if ($this->emulate_prepares || count($args) == 0) {
 531                                         if (!$retval = $this->connection->query($this->replaceParameters($sql, $args))) {
 532                                                 $errorInfo     = $this->connection->errorInfo();
 533                                                 $this->error   = $errorInfo[2];
 534                                                 $this->errorno = $errorInfo[1];
 535                                                 $retval        = false;
 536                                                 break;
 537                                         }
 538                                         $this->affected_rows = $retval->rowCount();
 539                                         break;
 540                                 }
 541
 542                                 /** @var $stmt mysqli_stmt|PDOStatement */
 543                                 if (!$stmt = $this->connection->prepare($sql)) {
 544                                         $errorInfo     = $this->connection->errorInfo();
 545                                         $this->error   = $errorInfo[2];
 546                                         $this->errorno = $errorInfo[1];
 547                                         $retval        = false;
 548                                         break;
 549                                 }
 550
 551                                 foreach ($args AS $param => $value) {
 552                                         if (is_int($args[$param])) {
 553                                                 $data_type = PDO::PARAM_INT;
 554                                         } else {
 555                                                 $data_type = PDO::PARAM_STR;
 556                                         }
 557                                         $stmt->bindParam($param, $args[$param], $data_type);
 558                                 }
 559
 560                                 if (!$stmt->execute()) {
 561                                         $errorInfo     = $stmt->errorInfo();
 562                                         $this->error   = $errorInfo[2];
 563                                         $this->errorno = $errorInfo[1];
 564                                         $retval        = false;
 565                                 } else {
 566                                         $retval              = $stmt;
 567                                         $this->affected_rows = $retval->rowCount();
 568                                 }
 569                                 break;
 570                         case 'mysqli':
 571                                 // There are SQL statements that cannot be executed with a prepared statement
 572                                 $parts           = explode(' ', $orig_sql);
 573                                 $command         = strtolower($parts[0]);
 574                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
 575
 576                                 // The fallback routine is called as well when there are no arguments
 577                                 if ($this->emulate_prepares || !$can_be_prepared || (count($args) == 0)) {
 578                                         $retval = $this->connection->query($this->replaceParameters($sql, $args));
 579                                         if ($this->connection->errno) {
 580                                                 $this->error   = $this->connection->error;
 581                                                 $this->errorno = $this->connection->errno;
 582                                                 $retval        = false;
 583                                         } else {
 584                                                 if (isset($retval->num_rows)) {
 585                                                         $this->affected_rows = $retval->num_rows;
 586                                                 } else {
 587                                                         $this->affected_rows = $this->connection->affected_rows;
 588                                                 }
 589                                         }
 590                                         break;
 591                                 }
 592
 593                                 $stmt = $this->connection->stmt_init();
 594
 595                                 if (!$stmt->prepare($sql)) {
 596                                         $this->error   = $stmt->error;
 597                                         $this->errorno = $stmt->errno;
 598                                         $retval        = false;
 599                                         break;
 600                                 }
 601
 602                                 $param_types = '';
 603                                 $values      = [];
 604                                 foreach ($args AS $param => $value) {
 605                                         if (is_int($args[$param])) {
 606                                                 $param_types .= 'i';
 607                                         } elseif (is_float($args[$param])) {
 608                                                 $param_types .= 'd';
 609                                         } elseif (is_string($args[$param])) {
 610                                                 $param_types .= 's';
 611                                         } else {
 612                                                 $param_types .= 'b';
 613                                         }
 614                                         $values[] = &$args[$param];
 615                                 }
 616
 617                                 if (count($values) > 0) {
 618                                         array_unshift($values, $param_types);
 619                                         call_user_func_array([$stmt, 'bind_param'], $values);
 620                                 }
 621
 622                                 if (!$stmt->execute()) {
 623                                         $this->error   = $this->connection->error;
 624                                         $this->errorno = $this->connection->errno;
 625                                         $retval        = false;
 626                                 } else {
 627                                         $stmt->store_result();
 628                                         $retval              = $stmt;
 629                                         $this->affected_rows = $retval->affected_rows;
 630                                 }
 631                                 break;
 632                 }
 633
 634                 // We are having an own error logging in the function "e"
 635                 if (($this->errorno != 0) && !$called_from_e) {
 636                         // We have to preserve the error code, somewhere in the logging it get lost
 637                         $error   = $this->error;
 638                         $errorno = $this->errorno;
 639
 640                         if ($this->testmode) {
 641                                 throw new Exception(DI::l10n()->t('Database error %d "%s" at "%s"', $errorno, $error, $this->replaceParameters($sql, $args)));
 642                         }
 643
 644                         $this->logger->error('DB Error', [
 645                                 'code'      => $this->errorno,
 646                                 'error'     => $this->error,
 647                                 'callstack' => System::callstack(8),
 648                                 'params'    => $this->replaceParameters($sql, $args),
 649                         ]);
 650
 651                         // On a lost connection we try to reconnect - but only once.
 652                         if ($errorno == 2006) {
 653                                 if ($this->in_retrial || !$this->reconnect()) {
 654                                         // It doesn't make sense to continue when the database connection was lost
 655                                         if ($this->in_retrial) {
 656                                                 $this->logger->notice('Giving up retrial because of database error', [
 657                                                         'code'  => $this->errorno,
 658                                                         'error' => $this->error,
 659                                                 ]);
 660                                         } else {
 661                                                 $this->logger->notice('Couldn\'t reconnect after database error', [
 662                                                         'code'  => $this->errorno,
 663                                                         'error' => $this->error,
 664                                                 ]);
 665                                         }
 666                                         exit(1);
 667                                 } else {
 668                                         // We try it again
 669                                         $this->logger->notice('Reconnected after database error', [
 670                                                 'code'  => $this->errorno,
 671                                                 'error' => $this->error,
 672                                         ]);
 673                                         $this->in_retrial = true;
 674                                         $ret              = $this->p($sql, $args);
 675                                         $this->in_retrial = false;
 676                                         return $ret;
 677                                 }
 678                         }
 679
 680                         $this->error   = $error;
 681                         $this->errorno = $errorno;
 682                 }
 683
 684                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
 685
 686                 if ($this->configCache->get('system', 'db_log')) {
 687                         $stamp2   = microtime(true);
 688                         $duration = (float)($stamp2 - $stamp1);
 689
 690                         if (($duration > $this->configCache->get('system', 'db_loglimit'))) {
 691                                 $duration  = round($duration, 3);
 692                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 693
 694                                 @file_put_contents($this->configCache->get('system', 'db_log'), DateTimeFormat::utcNow() . "\t" . $duration . "\t" .
 695                                                                                                 basename($backtrace[1]["file"]) . "\t" .
 696                                                                                                 $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
 697                                                                                                 substr($this->replaceParameters($sql, $args), 0, 2000) . "\n", FILE_APPEND);
 698                         }
 699                 }
 700                 return $retval;
 701         }
 702
 703         /**
 704          * Executes a prepared statement like UPDATE or INSERT that doesn't return data
 705          *
 706          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
 707          *
 708          * @param string $sql SQL statement
 709          *
 710          * @return boolean Was the query successfull? False is returned only if an error occurred
 711          * @throws \Exception
 712          */
 713         public function e($sql)
 714         {
 715
 716                 $stamp = microtime(true);
 717
 718                 $params = DBA::getParam(func_get_args());
 719
 720                 // In a case of a deadlock we are repeating the query 20 times
 721                 $timeout = 20;
 722
 723                 do {
 724                         $stmt = $this->p($sql, $params);
 725
 726                         if (is_bool($stmt)) {
 727                                 $retval = $stmt;
 728                         } elseif (is_object($stmt)) {
 729                                 $retval = true;
 730                         } else {
 731                                 $retval = false;
 732                         }
 733
 734                         $this->close($stmt);
 735
 736                 } while (($this->errorno == 1213) && (--$timeout > 0));
 737
 738                 if ($this->errorno != 0) {
 739                         // We have to preserve the error code, somewhere in the logging it get lost
 740                         $error   = $this->error;
 741                         $errorno = $this->errorno;
 742
 743                         if ($this->testmode) {
 744                                 throw new Exception(DI::l10n()->t('Database error %d "%s" at "%s"', $errorno, $error, $this->replaceParameters($sql, $params)));
 745                         }
 746
 747                         $this->logger->error('DB Error', [
 748                                 'code'      => $this->errorno,
 749                                 'error'     => $this->error,
 750                                 'callstack' => System::callstack(8),
 751                                 'params'    => $this->replaceParameters($sql, $params),
 752                         ]);
 753
 754                         // On a lost connection we simply quit.
 755                         // A reconnect like in $this->p could be dangerous with modifications
 756                         if ($errorno == 2006) {
 757                                 $this->logger->notice('Giving up because of database error', [
 758                                         'code'  => $this->errorno,
 759                                         'error' => $this->error,
 760                                 ]);
 761                                 exit(1);
 762                         }
 763
 764                         $this->error   = $error;
 765                         $this->errorno = $errorno;
 766                 }
 767
 768                 $this->profiler->saveTimestamp($stamp, "database_write", System::callstack());
 769
 770                 return $retval;
 771         }
 772
 773         /**
 774          * Check if data exists
 775          *
 776          * @param string|array $table     Table name or array [schema => table]
 777          * @param array        $condition array of fields for condition
 778          *
 779          * @return boolean Are there rows for that condition?
 780          * @throws \Exception
 781          */
 782         public function exists($table, $condition)
 783         {
 784                 if (empty($table)) {
 785                         return false;
 786                 }
 787
 788                 $fields = [];
 789
 790                 if (empty($condition)) {
 791                         return DBStructure::existsTable($table);
 792                 }
 793
 794                 reset($condition);
 795                 $first_key = key($condition);
 796                 if (!is_int($first_key)) {
 797                         $fields = [$first_key];
 798                 }
 799
 800                 $stmt = $this->select($table, $fields, $condition, ['limit' => 1]);
 801
 802                 if (is_bool($stmt)) {
 803                         $retval = $stmt;
 804                 } else {
 805                         $retval = ($this->numRows($stmt) > 0);
 806                 }
 807
 808                 $this->close($stmt);
 809
 810                 return $retval;
 811         }
 812
 813         /**
 814          * Fetches the first row
 815          *
 816          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 817          *
 818          * Fetches the first row
 819          *
 820          * @param string $sql SQL statement
 821          *
 822          * @return array first row of query
 823          * @throws \Exception
 824          */
 825         public function fetchFirst($sql)
 826         {
 827                 $params = DBA::getParam(func_get_args());
 828
 829                 $stmt = $this->p($sql, $params);
 830
 831                 if (is_bool($stmt)) {
 832                         $retval = $stmt;
 833                 } else {
 834                         $retval = $this->fetch($stmt);
 835                 }
 836
 837                 $this->close($stmt);
 838
 839                 return $retval;
 840         }
 841
 842         /**
 843          * Returns the number of affected rows of the last statement
 844          *
 845          * @return int Number of rows
 846          */
 847         public function affectedRows()
 848         {
 849                 return $this->affected_rows;
 850         }
 851
 852         /**
 853          * Returns the number of columns of a statement
 854          *
 855          * @param object Statement object
 856          *
 857          * @return int Number of columns
 858          */
 859         public function columnCount($stmt)
 860         {
 861                 if (!is_object($stmt)) {
 862                         return 0;
 863                 }
 864                 switch ($this->driver) {
 865                         case 'pdo':
 866                                 return $stmt->columnCount();
 867                         case 'mysqli':
 868                                 return $stmt->field_count;
 869                 }
 870                 return 0;
 871         }
 872
 873         /**
 874          * Returns the number of rows of a statement
 875          *
 876          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 877          *
 878          * @return int Number of rows
 879          */
 880         public function numRows($stmt)
 881         {
 882                 if (!is_object($stmt)) {
 883                         return 0;
 884                 }
 885                 switch ($this->driver) {
 886                         case 'pdo':
 887                                 return $stmt->rowCount();
 888                         case 'mysqli':
 889                                 return $stmt->num_rows;
 890                 }
 891                 return 0;
 892         }
 893
 894         /**
 895          * Fetch a single row
 896          *
 897          * @param mixed $stmt statement object
 898          *
 899          * @return array current row
 900          */
 901         public function fetch($stmt)
 902         {
 903
 904                 $stamp1 = microtime(true);
 905
 906                 $columns = [];
 907
 908                 if (!is_object($stmt)) {
 909                         return false;
 910                 }
 911
 912                 switch ($this->driver) {
 913                         case 'pdo':
 914                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 915                                 break;
 916                         case 'mysqli':
 917                                 if (get_class($stmt) == 'mysqli_result') {
 918                                         $columns = $stmt->fetch_assoc();
 919                                         break;
 920                                 }
 921
 922                                 // This code works, but is slow
 923
 924                                 // Bind the result to a result array
 925                                 $cols = [];
 926
 927                                 $cols_num = [];
 928                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 929                                         $cols[] = &$cols_num[$x];
 930                                 }
 931
 932                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 933
 934                                 if (!$stmt->fetch()) {
 935                                         return false;
 936                                 }
 937
 938                                 // The slow part:
 939                                 // We need to get the field names for the array keys
 940                                 // It seems that there is no better way to do this.
 941                                 $result = $stmt->result_metadata();
 942                                 $fields = $result->fetch_fields();
 943
 944                                 foreach ($cols_num AS $param => $col) {
 945                                         $columns[$fields[$param]->name] = $col;
 946                                 }
 947                 }
 948
 949                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
 950
 951                 return $columns;
 952         }
 953
 954         /**
 955          * Insert a row into a table
 956          *
 957          * @param string|array $table               Table name or array [schema => table]
 958          * @param array        $param               parameter array
 959          * @param bool         $on_duplicate_update Do an update on a duplicate entry
 960          *
 961          * @return boolean was the insert successful?
 962          * @throws \Exception
 963          */
 964         public function insert($table, $param, $on_duplicate_update = false)
 965         {
 966                 if (empty($table) || empty($param)) {
 967                         $this->logger->info('Table and fields have to be set');
 968                         return false;
 969                 }
 970
 971                 $table_string = DBA::buildTableString($table);
 972
 973                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 974
 975                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
 976
 977                 $sql = "INSERT INTO " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
 978
 979                 if ($on_duplicate_update) {
 980                         $fields_string = implode(' = ?, ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 981
 982                         $sql .= " ON DUPLICATE KEY UPDATE " . $fields_string . " = ?";
 983
 984                         $values = array_values($param);
 985                         $param  = array_merge_recursive($values, $values);
 986                 }
 987
 988                 return $this->e($sql, $param);
 989         }
 990
 991         /**
 992          * Fetch the id of the last insert command
 993          *
 994          * @return integer Last inserted id
 995          */
 996         public function lastInsertId()
 997         {
 998                 switch ($this->driver) {
 999                         case 'pdo':
1000                                 $id = $this->connection->lastInsertId();
1001                                 break;
1002                         case 'mysqli':
1003                                 $id = $this->connection->insert_id;
1004                                 break;
1005                 }
1006                 return $id;
1007         }
1008
1009         /**
1010          * Locks a table for exclusive write access
1011          *
1012          * This function can be extended in the future to accept a table array as well.
1013          *
1014          * @param string|array $table Table name or array [schema => table]
1015          *
1016          * @return boolean was the lock successful?
1017          * @throws \Exception
1018          */
1019         public function lock($table)
1020         {
1021                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1022                 if ($this->driver == 'pdo') {
1023                         $this->e("SET autocommit=0");
1024                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1025                 } else {
1026                         $this->connection->autocommit(false);
1027                 }
1028
1029                 $success = $this->e("LOCK TABLES " . DBA::buildTableString($table) . " WRITE");
1030
1031                 if ($this->driver == 'pdo') {
1032                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1033                 }
1034
1035                 if (!$success) {
1036                         if ($this->driver == 'pdo') {
1037                                 $this->e("SET autocommit=1");
1038                         } else {
1039                                 $this->connection->autocommit(true);
1040                         }
1041                 } else {
1042                         $this->in_transaction = true;
1043                 }
1044                 return $success;
1045         }
1046
1047         /**
1048          * Unlocks all locked tables
1049          *
1050          * @return boolean was the unlock successful?
1051          * @throws \Exception
1052          */
1053         public function unlock()
1054         {
1055                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1056                 $this->performCommit();
1057
1058                 if ($this->driver == 'pdo') {
1059                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1060                 }
1061
1062                 $success = $this->e("UNLOCK TABLES");
1063
1064                 if ($this->driver == 'pdo') {
1065                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1066                         $this->e("SET autocommit=1");
1067                 } else {
1068                         $this->connection->autocommit(true);
1069                 }
1070
1071                 $this->in_transaction = false;
1072                 return $success;
1073         }
1074
1075         /**
1076          * Starts a transaction
1077          *
1078          * @return boolean Was the command executed successfully?
1079          */
1080         public function transaction()
1081         {
1082                 if (!$this->performCommit()) {
1083                         return false;
1084                 }
1085
1086                 switch ($this->driver) {
1087                         case 'pdo':
1088                                 if (!$this->connection->inTransaction() && !$this->connection->beginTransaction()) {
1089                                         return false;
1090                                 }
1091                                 break;
1092
1093                         case 'mysqli':
1094                                 if (!$this->connection->begin_transaction()) {
1095                                         return false;
1096                                 }
1097                                 break;
1098                 }
1099
1100                 $this->in_transaction = true;
1101                 return true;
1102         }
1103
1104         protected function performCommit()
1105         {
1106                 switch ($this->driver) {
1107                         case 'pdo':
1108                                 if (!$this->connection->inTransaction()) {
1109                                         return true;
1110                                 }
1111
1112                                 return $this->connection->commit();
1113
1114                         case 'mysqli':
1115                                 return $this->connection->commit();
1116                 }
1117
1118                 return true;
1119         }
1120
1121         /**
1122          * Does a commit
1123          *
1124          * @return boolean Was the command executed successfully?
1125          */
1126         public function commit()
1127         {
1128                 if (!$this->performCommit()) {
1129                         return false;
1130                 }
1131                 $this->in_transaction = false;
1132                 return true;
1133         }
1134
1135         /**
1136          * Does a rollback
1137          *
1138          * @return boolean Was the command executed successfully?
1139          */
1140         public function rollback()
1141         {
1142                 $ret = false;
1143
1144                 switch ($this->driver) {
1145                         case 'pdo':
1146                                 if (!$this->connection->inTransaction()) {
1147                                         $ret = true;
1148                                         break;
1149                                 }
1150                                 $ret = $this->connection->rollBack();
1151                                 break;
1152
1153                         case 'mysqli':
1154                                 $ret = $this->connection->rollback();
1155                                 break;
1156                 }
1157                 $this->in_transaction = false;
1158                 return $ret;
1159         }
1160
1161         /**
1162          * Build the array with the table relations
1163          *
1164          * The array is build from the database definitions in DBStructure.php
1165          *
1166          * This process must only be started once, since the value is cached.
1167          */
1168         private function buildRelationData()
1169         {
1170                 $definition = DBStructure::definition($this->configCache->get('system', 'basepath'));
1171
1172                 foreach ($definition AS $table => $structure) {
1173                         foreach ($structure['fields'] AS $field => $field_struct) {
1174                                 if (isset($field_struct['relation'])) {
1175                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1176                                                 $this->relation[$rel_table][$rel_field][$table][] = $field;
1177                                         }
1178                                 }
1179                         }
1180                 }
1181         }
1182
1183         /**
1184          * Delete a row from a table
1185          *
1186          * Note: this methods does NOT accept schema => table arrays because of the complex relation stuff.
1187          *
1188          * @param string $table      Table name
1189          * @param array  $conditions Field condition(s)
1190          * @param array  $options
1191          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1192          *                           relations (default: true)
1193          * @param array  $callstack  Internal use: prevent endless loops
1194          *
1195          * @return boolean was the delete successful?
1196          * @throws \Exception
1197          */
1198         public function delete($table, array $conditions, array $options = [], array &$callstack = [])
1199         {
1200                 if (empty($table) || empty($conditions)) {
1201                         $this->logger->info('Table and conditions have to be set');
1202                         return false;
1203                 }
1204
1205                 $commands = [];
1206
1207                 // Create a key for the loop prevention
1208                 $key = $table . ':' . json_encode($conditions);
1209
1210                 // We quit when this key already exists in the callstack.
1211                 if (isset($callstack[$key])) {
1212                         return true;
1213                 }
1214
1215                 $callstack[$key] = true;
1216
1217                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1218
1219                 // Don't use "defaults" here, since it would set "false" to "true"
1220                 if (isset($options['cascade'])) {
1221                         $cascade = $options['cascade'];
1222                 } else {
1223                         $cascade = true;
1224                 }
1225
1226                 // To speed up the whole process we cache the table relations
1227                 if ($cascade && count($this->relation) == 0) {
1228                         $this->buildRelationData();
1229                 }
1230
1231                 // Is there a relation entry for the table?
1232                 if ($cascade && isset($this->relation[$table])) {
1233                         // We only allow a simple "one field" relation.
1234                         $field   = array_keys($this->relation[$table])[0];
1235                         $rel_def = array_values($this->relation[$table])[0];
1236
1237                         // Create a key for preventing double queries
1238                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1239
1240                         // When the search field is the relation field, we don't need to fetch the rows
1241                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1242                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1243                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1244                                         foreach ($rel_fields AS $rel_field) {
1245                                                 $this->delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1246                                         }
1247                                 }
1248                                 // We quit when this key already exists in the callstack.
1249                         } elseif (!isset($callstack[$qkey])) {
1250                                 $callstack[$qkey] = true;
1251
1252                                 // Fetch all rows that are to be deleted
1253                                 $data = $this->select($table, [$field], $conditions);
1254
1255                                 while ($row = $this->fetch($data)) {
1256                                         $this->delete($table, [$field => $row[$field]], $options, $callstack);
1257                                 }
1258
1259                                 $this->close($data);
1260
1261                                 // Since we had split the delete command we don't need the original command anymore
1262                                 unset($commands[$key]);
1263                         }
1264                 }
1265
1266                 // Now we finalize the process
1267                 $do_transaction = !$this->in_transaction;
1268
1269                 if ($do_transaction) {
1270                         $this->transaction();
1271                 }
1272
1273                 $compacted = [];
1274                 $counter   = [];
1275
1276                 foreach ($commands AS $command) {
1277                         $conditions = $command['conditions'];
1278                         reset($conditions);
1279                         $first_key = key($conditions);
1280
1281                         $condition_string = DBA::buildCondition($conditions);
1282
1283                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1284                                 $sql = "DELETE FROM " . DBA::quoteIdentifier($command['table']) . " " . $condition_string;
1285                                 $this->logger->info($this->replaceParameters($sql, $conditions), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1286
1287                                 if (!$this->e($sql, $conditions)) {
1288                                         if ($do_transaction) {
1289                                                 $this->rollback();
1290                                         }
1291                                         return false;
1292                                 }
1293                         } else {
1294                                 $key_table     = $command['table'];
1295                                 $key_condition = array_keys($command['conditions'])[0];
1296                                 $value         = array_values($command['conditions'])[0];
1297
1298                                 // Split the SQL queries in chunks of 100 values
1299                                 // We do the $i stuff here to make the code better readable
1300                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1301                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1302                                         ++$i;
1303                                 }
1304
1305                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1306                                 $counter[$key_table][$key_condition]               = $i;
1307                         }
1308                 }
1309                 foreach ($compacted AS $table => $values) {
1310                         foreach ($values AS $field => $field_value_list) {
1311                                 foreach ($field_value_list AS $field_values) {
1312                                         $sql = "DELETE FROM " . DBA::quoteIdentifier($table) . " WHERE " . DBA::quoteIdentifier($field) . " IN (" .
1313                                                substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1314
1315                                         $this->logger->info($this->replaceParameters($sql, $field_values), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1316
1317                                         if (!$this->e($sql, $field_values)) {
1318                                                 if ($do_transaction) {
1319                                                         $this->rollback();
1320                                                 }
1321                                                 return false;
1322                                         }
1323                                 }
1324                         }
1325                 }
1326                 if ($do_transaction) {
1327                         $this->commit();
1328                 }
1329                 return true;
1330         }
1331
1332         /**
1333          * Updates rows
1334          *
1335          * Updates rows in the database. When $old_fields is set to an array,
1336          * the system will only do an update if the fields in that array changed.
1337          *
1338          * Attention:
1339          * Only the values in $old_fields are compared.
1340          * This is an intentional behaviour.
1341          *
1342          * Example:
1343          * We include the timestamp field in $fields but not in $old_fields.
1344          * Then the row will only get the new timestamp when the other fields had changed.
1345          *
1346          * When $old_fields is set to a boolean value the system will do this compare itself.
1347          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1348          *
1349          * Attention:
1350          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1351          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1352          *
1353          * @param string|array  $table      Table name or array [schema => table]
1354          * @param array         $fields     contains the fields that are updated
1355          * @param array         $condition  condition array with the key values
1356          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1357          *
1358          * @return boolean was the update successfull?
1359          * @throws \Exception
1360          */
1361         public function update($table, $fields, $condition, $old_fields = [])
1362         {
1363                 if (empty($table) || empty($fields) || empty($condition)) {
1364                         $this->logger->info('Table, fields and condition have to be set');
1365                         return false;
1366                 }
1367
1368                 if (is_bool($old_fields)) {
1369                         $do_insert = $old_fields;
1370
1371                         $old_fields = $this->selectFirst($table, [], $condition);
1372
1373                         if (is_bool($old_fields)) {
1374                                 if ($do_insert) {
1375                                         $values = array_merge($condition, $fields);
1376                                         return $this->insert($table, $values, $do_insert);
1377                                 }
1378                                 $old_fields = [];
1379                         }
1380                 }
1381
1382                 foreach ($old_fields AS $fieldname => $content) {
1383                         if (isset($fields[$fieldname]) && !is_null($content) && ($fields[$fieldname] == $content)) {
1384                                 unset($fields[$fieldname]);
1385                         }
1386                 }
1387
1388                 if (count($fields) == 0) {
1389                         return true;
1390                 }
1391
1392                 $table_string = DBA::buildTableString($table);
1393
1394                 $condition_string = DBA::buildCondition($condition);
1395
1396                 $sql = "UPDATE " . $table_string . " SET "
1397                         . implode(" = ?, ", array_map([DBA::class, 'quoteIdentifier'], array_keys($fields))) . " = ?"
1398                         . $condition_string;
1399
1400                 // Combines the updated fields parameter values with the condition parameter values
1401                 $params  = array_merge(array_values($fields), $condition);
1402
1403                 return $this->e($sql, $params);
1404         }
1405
1406         /**
1407          * Retrieve a single record from a table and returns it in an associative array
1408          *
1409          * @param string|array $table
1410          * @param array        $fields
1411          * @param array        $condition
1412          * @param array        $params
1413          *
1414          * @return bool|array
1415          * @throws \Exception
1416          * @see   $this->select
1417          */
1418         public function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1419         {
1420                 $params['limit'] = 1;
1421                 $result          = $this->select($table, $fields, $condition, $params);
1422
1423                 if (is_bool($result)) {
1424                         return $result;
1425                 } else {
1426                         $row = $this->fetch($result);
1427                         $this->close($result);
1428                         return $row;
1429                 }
1430         }
1431
1432         /**
1433          * Select rows from a table and fills an array with the data
1434          *
1435          * @param string|array $table     Table name or array [schema => table]
1436          * @param array        $fields    Array of selected fields, empty for all
1437          * @param array        $condition Array of fields for condition
1438          * @param array        $params    Array of several parameters
1439          *
1440          * @return array Data array
1441          * @throws \Exception
1442          * @see   self::select
1443          */
1444         public function selectToArray($table, array $fields = [], array $condition = [], array $params = [])
1445         {
1446                 return $this->toArray($this->select($table, $fields, $condition, $params));
1447         }
1448
1449         /**
1450          * Select rows from a table
1451          *
1452          * @param string|array $table     Table name or array [schema => table]
1453          * @param array        $fields    Array of selected fields, empty for all
1454          * @param array        $condition Array of fields for condition
1455          * @param array        $params    Array of several parameters
1456          *
1457          * @return boolean|object
1458          *
1459          * Example:
1460          * $table = "item";
1461          * $fields = array("id", "uri", "uid", "network");
1462          *
1463          * $condition = array("uid" => 1, "network" => 'dspr');
1464          * or:
1465          * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
1466          *
1467          * $params = array("order" => array("id", "received" => true), "limit" => 10);
1468          *
1469          * $data = DBA::select($table, $fields, $condition, $params);
1470          * @throws \Exception
1471          */
1472         public function select($table, array $fields = [], array $condition = [], array $params = [])
1473         {
1474                 if (empty($table)) {
1475                         return false;
1476                 }
1477
1478                 if (count($fields) > 0) {
1479                         $select_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], $fields));
1480                 } else {
1481                         $select_string = '*';
1482                 }
1483
1484                 $table_string = DBA::buildTableString($table);
1485
1486                 $condition_string = DBA::buildCondition($condition);
1487
1488                 $param_string = DBA::buildParameter($params);
1489
1490                 $sql = "SELECT " . $select_string . " FROM " . $table_string . $condition_string . $param_string;
1491
1492                 $result = $this->p($sql, $condition);
1493
1494                 return $result;
1495         }
1496
1497         /**
1498          * Counts the rows from a table satisfying the provided condition
1499          *
1500          * @param string|array $table     Table name or array [schema => table]
1501          * @param array        $condition Array of fields for condition
1502          * @param array        $params    Array of several parameters
1503          *
1504          * @return int
1505          *
1506          * Example:
1507          * $table = "item";
1508          *
1509          * $condition = ["uid" => 1, "network" => 'dspr'];
1510          * or:
1511          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1512          *
1513          * $count = DBA::count($table, $condition);
1514          * @throws \Exception
1515          */
1516         public function count($table, array $condition = [], array $params = [])
1517         {
1518                 if (empty($table)) {
1519                         return false;
1520                 }
1521
1522                 $table_string = DBA::buildTableString($table);
1523
1524                 $condition_string = DBA::buildCondition($condition);
1525
1526                 if (empty($params['expression'])) {
1527                         $expression = '*';
1528                 } elseif (!empty($params['distinct'])) {
1529                         $expression = "DISTINCT " . DBA::quoteIdentifier($params['expression']);
1530                 } else {
1531                         $expression = DBA::quoteIdentifier($params['expression']);
1532                 }
1533
1534                 $sql = "SELECT COUNT(" . $expression . ") AS `count` FROM " . $table_string . $condition_string;
1535
1536                 $row = $this->fetchFirst($sql, $condition);
1537
1538                 return $row['count'];
1539         }
1540
1541         /**
1542          * Fills an array with data from a query
1543          *
1544          * @param object $stmt statement object
1545          * @param bool   $do_close
1546          *
1547          * @return array Data array
1548          */
1549         public function toArray($stmt, $do_close = true)
1550         {
1551                 if (is_bool($stmt)) {
1552                         return [];
1553                 }
1554
1555                 $data = [];
1556                 while ($row = $this->fetch($stmt)) {
1557                         $data[] = $row;
1558                 }
1559
1560                 if ($do_close) {
1561                         $this->close($stmt);
1562                 }
1563
1564                 return $data;
1565         }
1566
1567         /**
1568          * Returns the error number of the last query
1569          *
1570          * @return string Error number (0 if no error)
1571          */
1572         public function errorNo()
1573         {
1574                 return $this->errorno;
1575         }
1576
1577         /**
1578          * Returns the error message of the last query
1579          *
1580          * @return string Error message ('' if no error)
1581          */
1582         public function errorMessage()
1583         {
1584                 return $this->error;
1585         }
1586
1587         /**
1588          * Closes the current statement
1589          *
1590          * @param object $stmt statement object
1591          *
1592          * @return boolean was the close successful?
1593          */
1594         public function close($stmt)
1595         {
1596
1597                 $stamp1 = microtime(true);
1598
1599                 if (!is_object($stmt)) {
1600                         return false;
1601                 }
1602
1603                 switch ($this->driver) {
1604                         case 'pdo':
1605                                 $ret = $stmt->closeCursor();
1606                                 break;
1607                         case 'mysqli':
1608                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1609                                 // We should be careful not to assume the object type of $stmt
1610                                 // because DBA::p() has been able to return both types.
1611                                 if ($stmt instanceof mysqli_stmt) {
1612                                         $stmt->free_result();
1613                                         $ret = $stmt->close();
1614                                 } elseif ($stmt instanceof mysqli_result) {
1615                                         $stmt->free();
1616                                         $ret = true;
1617                                 } else {
1618                                         $ret = false;
1619                                 }
1620                                 break;
1621                 }
1622
1623                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
1624
1625                 return $ret;
1626         }
1627
1628         /**
1629          * Return a list of database processes
1630          *
1631          * @return array
1632          *      'list' => List of processes, separated in their different states
1633          *      'amount' => Number of concurrent database processes
1634          * @throws \Exception
1635          */
1636         public function processlist()
1637         {
1638                 $ret  = $this->p("SHOW PROCESSLIST");
1639                 $data = $this->toArray($ret);
1640
1641                 $processes = 0;
1642                 $states    = [];
1643                 foreach ($data as $process) {
1644                         $state = trim($process["State"]);
1645
1646                         // Filter out all non blocking processes
1647                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1648                                 ++$states[$state];
1649                                 ++$processes;
1650                         }
1651                 }
1652
1653                 $statelist = "";
1654                 foreach ($states as $state => $usage) {
1655                         if ($statelist != "") {
1656                                 $statelist .= ", ";
1657                         }
1658                         $statelist .= $state . ": " . $usage;
1659                 }
1660                 return (["list" => $statelist, "amount" => $processes]);
1661         }
1662
1663         /**
1664          * Fetch a database variable
1665          *
1666          * @param string $name
1667          * @return string content
1668          */
1669         public function getVariable(string $name)
1670         {
1671                 $result = $this->fetchFirst("SHOW GLOBAL VARIABLES WHERE `Variable_name` = ?", $name);
1672                 return $result['Value'] ?? null;
1673         }
1674
1675         /**
1676          * Checks if $array is a filled array with at least one entry.
1677          *
1678          * @param mixed $array A filled array with at least one entry
1679          *
1680          * @return boolean Whether $array is a filled array or an object with rows
1681          */
1682         public function isResult($array)
1683         {
1684                 // It could be a return value from an update statement
1685                 if (is_bool($array)) {
1686                         return $array;
1687                 }
1688
1689                 if (is_object($array)) {
1690                         return $this->numRows($array) > 0;
1691                 }
1692
1693                 return (is_array($array) && (count($array) > 0));
1694         }
1695
1696         /**
1697          * Callback function for "esc_array"
1698          *
1699          * @param mixed   $value         Array value
1700          * @param string  $key           Array key
1701          * @param boolean $add_quotation add quotation marks for string values
1702          *
1703          * @return void
1704          */
1705         private function escapeArrayCallback(&$value, $key, $add_quotation)
1706         {
1707                 if (!$add_quotation) {
1708                         if (is_bool($value)) {
1709                                 $value = ($value ? '1' : '0');
1710                         } else {
1711                                 $value = $this->escape($value);
1712                         }
1713                         return;
1714                 }
1715
1716                 if (is_bool($value)) {
1717                         $value = ($value ? 'true' : 'false');
1718                 } elseif (is_float($value) || is_integer($value)) {
1719                         $value = (string)$value;
1720                 } else {
1721                         $value = "'" . $this->escape($value) . "'";
1722                 }
1723         }
1724
1725         /**
1726          * Escapes a whole array
1727          *
1728          * @param mixed   $arr           Array with values to be escaped
1729          * @param boolean $add_quotation add quotation marks for string values
1730          *
1731          * @return void
1732          */
1733         public function escapeArray(&$arr, $add_quotation = false)
1734         {
1735                 array_walk($arr, [$this, 'escapeArrayCallback'], $add_quotation);
1736         }
1737 }