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                         $this->logger->error('DB Error', [
 744                                 'code'      => $this->errorno,
 745                                 'error'     => $this->error,
 746                                 'callstack' => System::callstack(8),
 747                                 'params'    => $this->replaceParameters($sql, $params),
 748                         ]);
 749
 750                         // On a lost connection we simply quit.
 751                         // A reconnect like in $this->p could be dangerous with modifications
 752                         if ($errorno == 2006) {
 753                                 $this->logger->notice('Giving up because of database error', [
 754                                         'code'  => $this->errorno,
 755                                         'error' => $this->error,
 756                                 ]);
 757                                 exit(1);
 758                         }
 759
 760                         $this->error   = $error;
 761                         $this->errorno = $errorno;
 762                 }
 763
 764                 $this->profiler->saveTimestamp($stamp, "database_write", System::callstack());
 765
 766                 return $retval;
 767         }
 768
 769         /**
 770          * Check if data exists
 771          *
 772          * @param string|array $table     Table name or array [schema => table]
 773          * @param array        $condition array of fields for condition
 774          *
 775          * @return boolean Are there rows for that condition?
 776          * @throws \Exception
 777          */
 778         public function exists($table, $condition)
 779         {
 780                 if (empty($table)) {
 781                         return false;
 782                 }
 783
 784                 $fields = [];
 785
 786                 if (empty($condition)) {
 787                         return DBStructure::existsTable($table);
 788                 }
 789
 790                 reset($condition);
 791                 $first_key = key($condition);
 792                 if (!is_int($first_key)) {
 793                         $fields = [$first_key];
 794                 }
 795
 796                 $stmt = $this->select($table, $fields, $condition, ['limit' => 1]);
 797
 798                 if (is_bool($stmt)) {
 799                         $retval = $stmt;
 800                 } else {
 801                         $retval = ($this->numRows($stmt) > 0);
 802                 }
 803
 804                 $this->close($stmt);
 805
 806                 return $retval;
 807         }
 808
 809         /**
 810          * Fetches the first row
 811          *
 812          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 813          *
 814          * Fetches the first row
 815          *
 816          * @param string $sql SQL statement
 817          *
 818          * @return array first row of query
 819          * @throws \Exception
 820          */
 821         public function fetchFirst($sql)
 822         {
 823                 $params = DBA::getParam(func_get_args());
 824
 825                 $stmt = $this->p($sql, $params);
 826
 827                 if (is_bool($stmt)) {
 828                         $retval = $stmt;
 829                 } else {
 830                         $retval = $this->fetch($stmt);
 831                 }
 832
 833                 $this->close($stmt);
 834
 835                 return $retval;
 836         }
 837
 838         /**
 839          * Returns the number of affected rows of the last statement
 840          *
 841          * @return int Number of rows
 842          */
 843         public function affectedRows()
 844         {
 845                 return $this->affected_rows;
 846         }
 847
 848         /**
 849          * Returns the number of columns of a statement
 850          *
 851          * @param object Statement object
 852          *
 853          * @return int Number of columns
 854          */
 855         public function columnCount($stmt)
 856         {
 857                 if (!is_object($stmt)) {
 858                         return 0;
 859                 }
 860                 switch ($this->driver) {
 861                         case 'pdo':
 862                                 return $stmt->columnCount();
 863                         case 'mysqli':
 864                                 return $stmt->field_count;
 865                 }
 866                 return 0;
 867         }
 868
 869         /**
 870          * Returns the number of rows of a statement
 871          *
 872          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 873          *
 874          * @return int Number of rows
 875          */
 876         public function numRows($stmt)
 877         {
 878                 if (!is_object($stmt)) {
 879                         return 0;
 880                 }
 881                 switch ($this->driver) {
 882                         case 'pdo':
 883                                 return $stmt->rowCount();
 884                         case 'mysqli':
 885                                 return $stmt->num_rows;
 886                 }
 887                 return 0;
 888         }
 889
 890         /**
 891          * Fetch a single row
 892          *
 893          * @param mixed $stmt statement object
 894          *
 895          * @return array current row
 896          */
 897         public function fetch($stmt)
 898         {
 899
 900                 $stamp1 = microtime(true);
 901
 902                 $columns = [];
 903
 904                 if (!is_object($stmt)) {
 905                         return false;
 906                 }
 907
 908                 switch ($this->driver) {
 909                         case 'pdo':
 910                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 911                                 break;
 912                         case 'mysqli':
 913                                 if (get_class($stmt) == 'mysqli_result') {
 914                                         $columns = $stmt->fetch_assoc();
 915                                         break;
 916                                 }
 917
 918                                 // This code works, but is slow
 919
 920                                 // Bind the result to a result array
 921                                 $cols = [];
 922
 923                                 $cols_num = [];
 924                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 925                                         $cols[] = &$cols_num[$x];
 926                                 }
 927
 928                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 929
 930                                 if (!$stmt->fetch()) {
 931                                         return false;
 932                                 }
 933
 934                                 // The slow part:
 935                                 // We need to get the field names for the array keys
 936                                 // It seems that there is no better way to do this.
 937                                 $result = $stmt->result_metadata();
 938                                 $fields = $result->fetch_fields();
 939
 940                                 foreach ($cols_num AS $param => $col) {
 941                                         $columns[$fields[$param]->name] = $col;
 942                                 }
 943                 }
 944
 945                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
 946
 947                 return $columns;
 948         }
 949
 950         /**
 951          * Insert a row into a table
 952          *
 953          * @param string|array $table               Table name or array [schema => table]
 954          * @param array        $param               parameter array
 955          * @param bool         $on_duplicate_update Do an update on a duplicate entry
 956          *
 957          * @return boolean was the insert successful?
 958          * @throws \Exception
 959          */
 960         public function insert($table, $param, $on_duplicate_update = false)
 961         {
 962                 if (empty($table) || empty($param)) {
 963                         $this->logger->info('Table and fields have to be set');
 964                         return false;
 965                 }
 966
 967                 $table_string = DBA::buildTableString($table);
 968
 969                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 970
 971                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
 972
 973                 $sql = "INSERT INTO " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
 974
 975                 if ($on_duplicate_update) {
 976                         $fields_string = implode(' = ?, ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 977
 978                         $sql .= " ON DUPLICATE KEY UPDATE " . $fields_string . " = ?";
 979
 980                         $values = array_values($param);
 981                         $param  = array_merge_recursive($values, $values);
 982                 }
 983
 984                 return $this->e($sql, $param);
 985         }
 986
 987         /**
 988          * Fetch the id of the last insert command
 989          *
 990          * @return integer Last inserted id
 991          */
 992         public function lastInsertId()
 993         {
 994                 switch ($this->driver) {
 995                         case 'pdo':
 996                                 $id = $this->connection->lastInsertId();
 997                                 break;
 998                         case 'mysqli':
 999                                 $id = $this->connection->insert_id;
1000                                 break;
1001                 }
1002                 return $id;
1003         }
1004
1005         /**
1006          * Locks a table for exclusive write access
1007          *
1008          * This function can be extended in the future to accept a table array as well.
1009          *
1010          * @param string|array $table Table name or array [schema => table]
1011          *
1012          * @return boolean was the lock successful?
1013          * @throws \Exception
1014          */
1015         public function lock($table)
1016         {
1017                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1018                 if ($this->driver == 'pdo') {
1019                         $this->e("SET autocommit=0");
1020                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1021                 } else {
1022                         $this->connection->autocommit(false);
1023                 }
1024
1025                 $success = $this->e("LOCK TABLES " . DBA::buildTableString($table) . " WRITE");
1026
1027                 if ($this->driver == 'pdo') {
1028                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1029                 }
1030
1031                 if (!$success) {
1032                         if ($this->driver == 'pdo') {
1033                                 $this->e("SET autocommit=1");
1034                         } else {
1035                                 $this->connection->autocommit(true);
1036                         }
1037                 } else {
1038                         $this->in_transaction = true;
1039                 }
1040                 return $success;
1041         }
1042
1043         /**
1044          * Unlocks all locked tables
1045          *
1046          * @return boolean was the unlock successful?
1047          * @throws \Exception
1048          */
1049         public function unlock()
1050         {
1051                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1052                 $this->performCommit();
1053
1054                 if ($this->driver == 'pdo') {
1055                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1056                 }
1057
1058                 $success = $this->e("UNLOCK TABLES");
1059
1060                 if ($this->driver == 'pdo') {
1061                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1062                         $this->e("SET autocommit=1");
1063                 } else {
1064                         $this->connection->autocommit(true);
1065                 }
1066
1067                 $this->in_transaction = false;
1068                 return $success;
1069         }
1070
1071         /**
1072          * Starts a transaction
1073          *
1074          * @return boolean Was the command executed successfully?
1075          */
1076         public function transaction()
1077         {
1078                 if (!$this->performCommit()) {
1079                         return false;
1080                 }
1081
1082                 switch ($this->driver) {
1083                         case 'pdo':
1084                                 if (!$this->connection->inTransaction() && !$this->connection->beginTransaction()) {
1085                                         return false;
1086                                 }
1087                                 break;
1088
1089                         case 'mysqli':
1090                                 if (!$this->connection->begin_transaction()) {
1091                                         return false;
1092                                 }
1093                                 break;
1094                 }
1095
1096                 $this->in_transaction = true;
1097                 return true;
1098         }
1099
1100         protected function performCommit()
1101         {
1102                 switch ($this->driver) {
1103                         case 'pdo':
1104                                 if (!$this->connection->inTransaction()) {
1105                                         return true;
1106                                 }
1107
1108                                 return $this->connection->commit();
1109
1110                         case 'mysqli':
1111                                 return $this->connection->commit();
1112                 }
1113
1114                 return true;
1115         }
1116
1117         /**
1118          * Does a commit
1119          *
1120          * @return boolean Was the command executed successfully?
1121          */
1122         public function commit()
1123         {
1124                 if (!$this->performCommit()) {
1125                         return false;
1126                 }
1127                 $this->in_transaction = false;
1128                 return true;
1129         }
1130
1131         /**
1132          * Does a rollback
1133          *
1134          * @return boolean Was the command executed successfully?
1135          */
1136         public function rollback()
1137         {
1138                 $ret = false;
1139
1140                 switch ($this->driver) {
1141                         case 'pdo':
1142                                 if (!$this->connection->inTransaction()) {
1143                                         $ret = true;
1144                                         break;
1145                                 }
1146                                 $ret = $this->connection->rollBack();
1147                                 break;
1148
1149                         case 'mysqli':
1150                                 $ret = $this->connection->rollback();
1151                                 break;
1152                 }
1153                 $this->in_transaction = false;
1154                 return $ret;
1155         }
1156
1157         /**
1158          * Build the array with the table relations
1159          *
1160          * The array is build from the database definitions in DBStructure.php
1161          *
1162          * This process must only be started once, since the value is cached.
1163          */
1164         private function buildRelationData()
1165         {
1166                 $definition = DBStructure::definition($this->configCache->get('system', 'basepath'));
1167
1168                 foreach ($definition AS $table => $structure) {
1169                         foreach ($structure['fields'] AS $field => $field_struct) {
1170                                 if (isset($field_struct['relation'])) {
1171                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1172                                                 $this->relation[$rel_table][$rel_field][$table][] = $field;
1173                                         }
1174                                 }
1175                         }
1176                 }
1177         }
1178
1179         /**
1180          * Delete a row from a table
1181          *
1182          * Note: this methods does NOT accept schema => table arrays because of the complex relation stuff.
1183          *
1184          * @param string $table      Table name
1185          * @param array  $conditions Field condition(s)
1186          * @param array  $options
1187          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1188          *                           relations (default: true)
1189          * @param array  $callstack  Internal use: prevent endless loops
1190          *
1191          * @return boolean was the delete successful?
1192          * @throws \Exception
1193          */
1194         public function delete($table, array $conditions, array $options = [], array &$callstack = [])
1195         {
1196                 if (empty($table) || empty($conditions)) {
1197                         $this->logger->info('Table and conditions have to be set');
1198                         return false;
1199                 }
1200
1201                 $commands = [];
1202
1203                 // Create a key for the loop prevention
1204                 $key = $table . ':' . json_encode($conditions);
1205
1206                 // We quit when this key already exists in the callstack.
1207                 if (isset($callstack[$key])) {
1208                         return true;
1209                 }
1210
1211                 $callstack[$key] = true;
1212
1213                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1214
1215                 // Don't use "defaults" here, since it would set "false" to "true"
1216                 if (isset($options['cascade'])) {
1217                         $cascade = $options['cascade'];
1218                 } else {
1219                         $cascade = true;
1220                 }
1221
1222                 // To speed up the whole process we cache the table relations
1223                 if ($cascade && count($this->relation) == 0) {
1224                         $this->buildRelationData();
1225                 }
1226
1227                 // Is there a relation entry for the table?
1228                 if ($cascade && isset($this->relation[$table])) {
1229                         // We only allow a simple "one field" relation.
1230                         $field   = array_keys($this->relation[$table])[0];
1231                         $rel_def = array_values($this->relation[$table])[0];
1232
1233                         // Create a key for preventing double queries
1234                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1235
1236                         // When the search field is the relation field, we don't need to fetch the rows
1237                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1238                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1239                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1240                                         foreach ($rel_fields AS $rel_field) {
1241                                                 $this->delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1242                                         }
1243                                 }
1244                                 // We quit when this key already exists in the callstack.
1245                         } elseif (!isset($callstack[$qkey])) {
1246                                 $callstack[$qkey] = true;
1247
1248                                 // Fetch all rows that are to be deleted
1249                                 $data = $this->select($table, [$field], $conditions);
1250
1251                                 while ($row = $this->fetch($data)) {
1252                                         $this->delete($table, [$field => $row[$field]], $options, $callstack);
1253                                 }
1254
1255                                 $this->close($data);
1256
1257                                 // Since we had split the delete command we don't need the original command anymore
1258                                 unset($commands[$key]);
1259                         }
1260                 }
1261
1262                 // Now we finalize the process
1263                 $do_transaction = !$this->in_transaction;
1264
1265                 if ($do_transaction) {
1266                         $this->transaction();
1267                 }
1268
1269                 $compacted = [];
1270                 $counter   = [];
1271
1272                 foreach ($commands AS $command) {
1273                         $conditions = $command['conditions'];
1274                         reset($conditions);
1275                         $first_key = key($conditions);
1276
1277                         $condition_string = DBA::buildCondition($conditions);
1278
1279                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1280                                 $sql = "DELETE FROM " . DBA::quoteIdentifier($command['table']) . " " . $condition_string;
1281                                 $this->logger->info($this->replaceParameters($sql, $conditions), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1282
1283                                 if (!$this->e($sql, $conditions)) {
1284                                         if ($do_transaction) {
1285                                                 $this->rollback();
1286                                         }
1287                                         return false;
1288                                 }
1289                         } else {
1290                                 $key_table     = $command['table'];
1291                                 $key_condition = array_keys($command['conditions'])[0];
1292                                 $value         = array_values($command['conditions'])[0];
1293
1294                                 // Split the SQL queries in chunks of 100 values
1295                                 // We do the $i stuff here to make the code better readable
1296                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1297                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1298                                         ++$i;
1299                                 }
1300
1301                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1302                                 $counter[$key_table][$key_condition]               = $i;
1303                         }
1304                 }
1305                 foreach ($compacted AS $table => $values) {
1306                         foreach ($values AS $field => $field_value_list) {
1307                                 foreach ($field_value_list AS $field_values) {
1308                                         $sql = "DELETE FROM " . DBA::quoteIdentifier($table) . " WHERE " . DBA::quoteIdentifier($field) . " IN (" .
1309                                                substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1310
1311                                         $this->logger->info($this->replaceParameters($sql, $field_values), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1312
1313                                         if (!$this->e($sql, $field_values)) {
1314                                                 if ($do_transaction) {
1315                                                         $this->rollback();
1316                                                 }
1317                                                 return false;
1318                                         }
1319                                 }
1320                         }
1321                 }
1322                 if ($do_transaction) {
1323                         $this->commit();
1324                 }
1325                 return true;
1326         }
1327
1328         /**
1329          * Updates rows
1330          *
1331          * Updates rows in the database. When $old_fields is set to an array,
1332          * the system will only do an update if the fields in that array changed.
1333          *
1334          * Attention:
1335          * Only the values in $old_fields are compared.
1336          * This is an intentional behaviour.
1337          *
1338          * Example:
1339          * We include the timestamp field in $fields but not in $old_fields.
1340          * Then the row will only get the new timestamp when the other fields had changed.
1341          *
1342          * When $old_fields is set to a boolean value the system will do this compare itself.
1343          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1344          *
1345          * Attention:
1346          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1347          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1348          *
1349          * @param string|array  $table      Table name or array [schema => table]
1350          * @param array         $fields     contains the fields that are updated
1351          * @param array         $condition  condition array with the key values
1352          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1353          *
1354          * @return boolean was the update successfull?
1355          * @throws \Exception
1356          */
1357         public function update($table, $fields, $condition, $old_fields = [])
1358         {
1359                 if (empty($table) || empty($fields) || empty($condition)) {
1360                         $this->logger->info('Table, fields and condition have to be set');
1361                         return false;
1362                 }
1363
1364                 if (is_bool($old_fields)) {
1365                         $do_insert = $old_fields;
1366
1367                         $old_fields = $this->selectFirst($table, [], $condition);
1368
1369                         if (is_bool($old_fields)) {
1370                                 if ($do_insert) {
1371                                         $values = array_merge($condition, $fields);
1372                                         return $this->insert($table, $values, $do_insert);
1373                                 }
1374                                 $old_fields = [];
1375                         }
1376                 }
1377
1378                 foreach ($old_fields AS $fieldname => $content) {
1379                         if (isset($fields[$fieldname]) && !is_null($content) && ($fields[$fieldname] == $content)) {
1380                                 unset($fields[$fieldname]);
1381                         }
1382                 }
1383
1384                 if (count($fields) == 0) {
1385                         return true;
1386                 }
1387
1388                 $table_string = DBA::buildTableString($table);
1389
1390                 $condition_string = DBA::buildCondition($condition);
1391
1392                 $sql = "UPDATE " . $table_string . " SET "
1393                         . implode(" = ?, ", array_map([DBA::class, 'quoteIdentifier'], array_keys($fields))) . " = ?"
1394                         . $condition_string;
1395
1396                 // Combines the updated fields parameter values with the condition parameter values
1397                 $params  = array_merge(array_values($fields), $condition);
1398
1399                 return $this->e($sql, $params);
1400         }
1401
1402         /**
1403          * Retrieve a single record from a table and returns it in an associative array
1404          *
1405          * @param string|array $table
1406          * @param array        $fields
1407          * @param array        $condition
1408          * @param array        $params
1409          *
1410          * @return bool|array
1411          * @throws \Exception
1412          * @see   $this->select
1413          */
1414         public function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1415         {
1416                 $params['limit'] = 1;
1417                 $result          = $this->select($table, $fields, $condition, $params);
1418
1419                 if (is_bool($result)) {
1420                         return $result;
1421                 } else {
1422                         $row = $this->fetch($result);
1423                         $this->close($result);
1424                         return $row;
1425                 }
1426         }
1427
1428         /**
1429          * Select rows from a table and fills an array with the data
1430          *
1431          * @param string|array $table     Table name or array [schema => table]
1432          * @param array        $fields    Array of selected fields, empty for all
1433          * @param array        $condition Array of fields for condition
1434          * @param array        $params    Array of several parameters
1435          *
1436          * @return array Data array
1437          * @throws \Exception
1438          * @see   self::select
1439          */
1440         public function selectToArray($table, array $fields = [], array $condition = [], array $params = [])
1441         {
1442                 return $this->toArray($this->select($table, $fields, $condition, $params));
1443         }
1444
1445         /**
1446          * Select rows from a table
1447          *
1448          * @param string|array $table     Table name or array [schema => table]
1449          * @param array        $fields    Array of selected fields, empty for all
1450          * @param array        $condition Array of fields for condition
1451          * @param array        $params    Array of several parameters
1452          *
1453          * @return boolean|object
1454          *
1455          * Example:
1456          * $table = "item";
1457          * $fields = array("id", "uri", "uid", "network");
1458          *
1459          * $condition = array("uid" => 1, "network" => 'dspr');
1460          * or:
1461          * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
1462          *
1463          * $params = array("order" => array("id", "received" => true), "limit" => 10);
1464          *
1465          * $data = DBA::select($table, $fields, $condition, $params);
1466          * @throws \Exception
1467          */
1468         public function select($table, array $fields = [], array $condition = [], array $params = [])
1469         {
1470                 if (empty($table)) {
1471                         return false;
1472                 }
1473
1474                 if (count($fields) > 0) {
1475                         $select_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], $fields));
1476                 } else {
1477                         $select_string = '*';
1478                 }
1479
1480                 $table_string = DBA::buildTableString($table);
1481
1482                 $condition_string = DBA::buildCondition($condition);
1483
1484                 $param_string = DBA::buildParameter($params);
1485
1486                 $sql = "SELECT " . $select_string . " FROM " . $table_string . $condition_string . $param_string;
1487
1488                 $result = $this->p($sql, $condition);
1489
1490                 return $result;
1491         }
1492
1493         /**
1494          * Counts the rows from a table satisfying the provided condition
1495          *
1496          * @param string|array $table     Table name or array [schema => table]
1497          * @param array        $condition Array of fields for condition
1498          * @param array        $params    Array of several parameters
1499          *
1500          * @return int
1501          *
1502          * Example:
1503          * $table = "item";
1504          *
1505          * $condition = ["uid" => 1, "network" => 'dspr'];
1506          * or:
1507          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1508          *
1509          * $count = DBA::count($table, $condition);
1510          * @throws \Exception
1511          */
1512         public function count($table, array $condition = [], array $params = [])
1513         {
1514                 if (empty($table)) {
1515                         return false;
1516                 }
1517
1518                 $table_string = DBA::buildTableString($table);
1519
1520                 $condition_string = DBA::buildCondition($condition);
1521
1522                 if (empty($params['expression'])) {
1523                         $expression = '*';
1524                 } elseif (!empty($params['distinct'])) {
1525                         $expression = "DISTINCT " . DBA::quoteIdentifier($params['expression']);
1526                 } else {
1527                         $expression = DBA::quoteIdentifier($params['expression']);
1528                 }
1529
1530                 $sql = "SELECT COUNT(" . $expression . ") AS `count` FROM " . $table_string . $condition_string;
1531
1532                 $row = $this->fetchFirst($sql, $condition);
1533
1534                 return $row['count'];
1535         }
1536
1537         /**
1538          * Fills an array with data from a query
1539          *
1540          * @param object $stmt statement object
1541          * @param bool   $do_close
1542          *
1543          * @return array Data array
1544          */
1545         public function toArray($stmt, $do_close = true)
1546         {
1547                 if (is_bool($stmt)) {
1548                         return [];
1549                 }
1550
1551                 $data = [];
1552                 while ($row = $this->fetch($stmt)) {
1553                         $data[] = $row;
1554                 }
1555
1556                 if ($do_close) {
1557                         $this->close($stmt);
1558                 }
1559
1560                 return $data;
1561         }
1562
1563         /**
1564          * Returns the error number of the last query
1565          *
1566          * @return string Error number (0 if no error)
1567          */
1568         public function errorNo()
1569         {
1570                 return $this->errorno;
1571         }
1572
1573         /**
1574          * Returns the error message of the last query
1575          *
1576          * @return string Error message ('' if no error)
1577          */
1578         public function errorMessage()
1579         {
1580                 return $this->error;
1581         }
1582
1583         /**
1584          * Closes the current statement
1585          *
1586          * @param object $stmt statement object
1587          *
1588          * @return boolean was the close successful?
1589          */
1590         public function close($stmt)
1591         {
1592
1593                 $stamp1 = microtime(true);
1594
1595                 if (!is_object($stmt)) {
1596                         return false;
1597                 }
1598
1599                 switch ($this->driver) {
1600                         case 'pdo':
1601                                 $ret = $stmt->closeCursor();
1602                                 break;
1603                         case 'mysqli':
1604                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1605                                 // We should be careful not to assume the object type of $stmt
1606                                 // because DBA::p() has been able to return both types.
1607                                 if ($stmt instanceof mysqli_stmt) {
1608                                         $stmt->free_result();
1609                                         $ret = $stmt->close();
1610                                 } elseif ($stmt instanceof mysqli_result) {
1611                                         $stmt->free();
1612                                         $ret = true;
1613                                 } else {
1614                                         $ret = false;
1615                                 }
1616                                 break;
1617                 }
1618
1619                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
1620
1621                 return $ret;
1622         }
1623
1624         /**
1625          * Return a list of database processes
1626          *
1627          * @return array
1628          *      'list' => List of processes, separated in their different states
1629          *      'amount' => Number of concurrent database processes
1630          * @throws \Exception
1631          */
1632         public function processlist()
1633         {
1634                 $ret  = $this->p("SHOW PROCESSLIST");
1635                 $data = $this->toArray($ret);
1636
1637                 $processes = 0;
1638                 $states    = [];
1639                 foreach ($data as $process) {
1640                         $state = trim($process["State"]);
1641
1642                         // Filter out all non blocking processes
1643                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1644                                 ++$states[$state];
1645                                 ++$processes;
1646                         }
1647                 }
1648
1649                 $statelist = "";
1650                 foreach ($states as $state => $usage) {
1651                         if ($statelist != "") {
1652                                 $statelist .= ", ";
1653                         }
1654                         $statelist .= $state . ": " . $usage;
1655                 }
1656                 return (["list" => $statelist, "amount" => $processes]);
1657         }
1658
1659         /**
1660          * Fetch a database variable
1661          *
1662          * @param string $name
1663          * @return string content
1664          */
1665         public function getVariable(string $name)
1666         {
1667                 $result = $this->fetchFirst("SHOW GLOBAL VARIABLES WHERE `Variable_name` = ?", $name);
1668                 return $result['Value'] ?? null;
1669         }
1670
1671         /**
1672          * Checks if $array is a filled array with at least one entry.
1673          *
1674          * @param mixed $array A filled array with at least one entry
1675          *
1676          * @return boolean Whether $array is a filled array or an object with rows
1677          */
1678         public function isResult($array)
1679         {
1680                 // It could be a return value from an update statement
1681                 if (is_bool($array)) {
1682                         return $array;
1683                 }
1684
1685                 if (is_object($array)) {
1686                         return $this->numRows($array) > 0;
1687                 }
1688
1689                 return (is_array($array) && (count($array) > 0));
1690         }
1691
1692         /**
1693          * Callback function for "esc_array"
1694          *
1695          * @param mixed   $value         Array value
1696          * @param string  $key           Array key
1697          * @param boolean $add_quotation add quotation marks for string values
1698          *
1699          * @return void
1700          */
1701         private function escapeArrayCallback(&$value, $key, $add_quotation)
1702         {
1703                 if (!$add_quotation) {
1704                         if (is_bool($value)) {
1705                                 $value = ($value ? '1' : '0');
1706                         } else {
1707                                 $value = $this->escape($value);
1708                         }
1709                         return;
1710                 }
1711
1712                 if (is_bool($value)) {
1713                         $value = ($value ? 'true' : 'false');
1714                 } elseif (is_float($value) || is_integer($value)) {
1715                         $value = (string)$value;
1716                 } else {
1717                         $value = "'" . $this->escape($value) . "'";
1718                 }
1719         }
1720
1721         /**
1722          * Escapes a whole array
1723          *
1724          * @param mixed   $arr           Array with values to be escaped
1725          * @param boolean $add_quotation add quotation marks for string values
1726          *
1727          * @return void
1728          */
1729         public function escapeArray(&$arr, $add_quotation = false)
1730         {
1731                 array_walk($arr, [$this, 'escapeArrayCallback'], $add_quotation);
1732         }
1733 }