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                 $is_error            = false;
 508                 $this->error         = '';
 509                 $this->errorno       = 0;
 510                 $this->affected_rows = 0;
 511
 512                 // We have to make some things different if this function is called from "e"
 513                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 514
 515                 if (isset($trace[1])) {
 516                         $called_from = $trace[1];
 517                 } else {
 518                         // We use just something that is defined to avoid warnings
 519                         $called_from = $trace[0];
 520                 }
 521                 // We are having an own error logging in the function "e"
 522                 $called_from_e = ($called_from['function'] == 'e');
 523
 524                 if (!isset($this->connection)) {
 525                         throw new InternalServerErrorException('The Connection is empty, although connected is set true.');
 526                 }
 527
 528                 switch ($this->driver) {
 529                         case 'pdo':
 530                                 // If there are no arguments we use "query"
 531                                 if ($this->emulate_prepares || count($args) == 0) {
 532                                         if (!$retval = $this->connection->query($this->replaceParameters($sql, $args))) {
 533                                                 $errorInfo     = $this->connection->errorInfo();
 534                                                 $this->error   = $errorInfo[2];
 535                                                 $this->errorno = $errorInfo[1];
 536                                                 $retval        = false;
 537                                                 $is_error      = true;
 538                                                 break;
 539                                         }
 540                                         $this->affected_rows = $retval->rowCount();
 541                                         break;
 542                                 }
 543
 544                                 /** @var $stmt mysqli_stmt|PDOStatement */
 545                                 if (!$stmt = $this->connection->prepare($sql)) {
 546                                         $errorInfo     = $this->connection->errorInfo();
 547                                         $this->error   = $errorInfo[2];
 548                                         $this->errorno = $errorInfo[1];
 549                                         $retval        = false;
 550                                         $is_error      = true;
 551                                         break;
 552                                 }
 553
 554                                 foreach ($args AS $param => $value) {
 555                                         if (is_int($args[$param])) {
 556                                                 $data_type = PDO::PARAM_INT;
 557                                         } else {
 558                                                 $data_type = PDO::PARAM_STR;
 559                                         }
 560                                         $stmt->bindParam($param, $args[$param], $data_type);
 561                                 }
 562
 563                                 if (!$stmt->execute()) {
 564                                         $errorInfo     = $stmt->errorInfo();
 565                                         $this->error   = $errorInfo[2];
 566                                         $this->errorno = $errorInfo[1];
 567                                         $retval        = false;
 568                                         $is_error      = true;
 569                                 } else {
 570                                         $retval              = $stmt;
 571                                         $this->affected_rows = $retval->rowCount();
 572                                 }
 573                                 break;
 574                         case 'mysqli':
 575                                 // There are SQL statements that cannot be executed with a prepared statement
 576                                 $parts           = explode(' ', $orig_sql);
 577                                 $command         = strtolower($parts[0]);
 578                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
 579
 580                                 // The fallback routine is called as well when there are no arguments
 581                                 if ($this->emulate_prepares || !$can_be_prepared || (count($args) == 0)) {
 582                                         $retval = $this->connection->query($this->replaceParameters($sql, $args));
 583                                         if ($this->connection->errno) {
 584                                                 $this->error   = $this->connection->error;
 585                                                 $this->errorno = $this->connection->errno;
 586                                                 $retval        = false;
 587                                                 $is_error      = true;
 588                                         } else {
 589                                                 if (isset($retval->num_rows)) {
 590                                                         $this->affected_rows = $retval->num_rows;
 591                                                 } else {
 592                                                         $this->affected_rows = $this->connection->affected_rows;
 593                                                 }
 594                                         }
 595                                         break;
 596                                 }
 597
 598                                 $stmt = $this->connection->stmt_init();
 599
 600                                 if (!$stmt->prepare($sql)) {
 601                                         $this->error   = $stmt->error;
 602                                         $this->errorno = $stmt->errno;
 603                                         $retval        = false;
 604                                         $is_error      = true;
 605                                         break;
 606                                 }
 607
 608                                 $param_types = '';
 609                                 $values      = [];
 610                                 foreach ($args AS $param => $value) {
 611                                         if (is_int($args[$param])) {
 612                                                 $param_types .= 'i';
 613                                         } elseif (is_float($args[$param])) {
 614                                                 $param_types .= 'd';
 615                                         } elseif (is_string($args[$param])) {
 616                                                 $param_types .= 's';
 617                                         } else {
 618                                                 $param_types .= 'b';
 619                                         }
 620                                         $values[] = &$args[$param];
 621                                 }
 622
 623                                 if (count($values) > 0) {
 624                                         array_unshift($values, $param_types);
 625                                         call_user_func_array([$stmt, 'bind_param'], $values);
 626                                 }
 627
 628                                 if (!$stmt->execute()) {
 629                                         $this->error   = $this->connection->error;
 630                                         $this->errorno = $this->connection->errno;
 631                                         $retval        = false;
 632                                         $is_error      = true;
 633                                 } else {
 634                                         $stmt->store_result();
 635                                         $retval              = $stmt;
 636                                         $this->affected_rows = $retval->affected_rows;
 637                                 }
 638                                 break;
 639                 }
 640
 641                 // See issue https://github.com/friendica/friendica/issues/8572
 642                 // Ensure that we always get an error message on an error.
 643                 if ($is_error && empty($this->errorno)) {
 644                         $this->errorno = -1;
 645                 }
 646
 647                 if ($is_error && empty($this->error)) {
 648                         $this->error = 'Unknown database error';
 649                 }
 650
 651                 // We are having an own error logging in the function "e"
 652                 if (($this->errorno != 0) && !$called_from_e) {
 653                         // We have to preserve the error code, somewhere in the logging it get lost
 654                         $error   = $this->error;
 655                         $errorno = $this->errorno;
 656
 657                         if ($this->testmode) {
 658                                 throw new Exception(DI::l10n()->t('Database error %d "%s" at "%s"', $errorno, $error, $this->replaceParameters($sql, $args)));
 659                         }
 660
 661                         $this->logger->error('DB Error', [
 662                                 'code'      => $errorno,
 663                                 'error'     => $error,
 664                                 'callstack' => System::callstack(8),
 665                                 'params'    => $this->replaceParameters($sql, $args),
 666                         ]);
 667
 668                         // On a lost connection we try to reconnect - but only once.
 669                         if ($errorno == 2006) {
 670                                 if ($this->in_retrial || !$this->reconnect()) {
 671                                         // It doesn't make sense to continue when the database connection was lost
 672                                         if ($this->in_retrial) {
 673                                                 $this->logger->notice('Giving up retrial because of database error', [
 674                                                         'code'  => $errorno,
 675                                                         'error' => $error,
 676                                                 ]);
 677                                         } else {
 678                                                 $this->logger->notice('Couldn\'t reconnect after database error', [
 679                                                         'code'  => $errorno,
 680                                                         'error' => $error,
 681                                                 ]);
 682                                         }
 683                                         exit(1);
 684                                 } else {
 685                                         // We try it again
 686                                         $this->logger->notice('Reconnected after database error', [
 687                                                 'code'  => $errorno,
 688                                                 'error' => $error,
 689                                         ]);
 690                                         $this->in_retrial = true;
 691                                         $ret              = $this->p($sql, $args);
 692                                         $this->in_retrial = false;
 693                                         return $ret;
 694                                 }
 695                         }
 696
 697                         $this->error   = $error;
 698                         $this->errorno = $errorno;
 699                 }
 700
 701                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
 702
 703                 if ($this->configCache->get('system', 'db_log')) {
 704                         $stamp2   = microtime(true);
 705                         $duration = (float)($stamp2 - $stamp1);
 706
 707                         if (($duration > $this->configCache->get('system', 'db_loglimit'))) {
 708                                 $duration  = round($duration, 3);
 709                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 710
 711                                 @file_put_contents($this->configCache->get('system', 'db_log'), DateTimeFormat::utcNow() . "\t" . $duration . "\t" .
 712                                                                                                 basename($backtrace[1]["file"]) . "\t" .
 713                                                                                                 $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
 714                                                                                                 substr($this->replaceParameters($sql, $args), 0, 2000) . "\n", FILE_APPEND);
 715                         }
 716                 }
 717                 return $retval;
 718         }
 719
 720         /**
 721          * Executes a prepared statement like UPDATE or INSERT that doesn't return data
 722          *
 723          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
 724          *
 725          * @param string $sql SQL statement
 726          *
 727          * @return boolean Was the query successfull? False is returned only if an error occurred
 728          * @throws \Exception
 729          */
 730         public function e($sql)
 731         {
 732
 733                 $stamp = microtime(true);
 734
 735                 $params = DBA::getParam(func_get_args());
 736
 737                 // In a case of a deadlock we are repeating the query 20 times
 738                 $timeout = 20;
 739
 740                 do {
 741                         $stmt = $this->p($sql, $params);
 742
 743                         if (is_bool($stmt)) {
 744                                 $retval = $stmt;
 745                         } elseif (is_object($stmt)) {
 746                                 $retval = true;
 747                         } else {
 748                                 $retval = false;
 749                         }
 750
 751                         $this->close($stmt);
 752
 753                 } while (($this->errorno == 1213) && (--$timeout > 0));
 754
 755                 if ($this->errorno != 0) {
 756                         // We have to preserve the error code, somewhere in the logging it get lost
 757                         $error   = $this->error;
 758                         $errorno = $this->errorno;
 759
 760                         if ($this->testmode) {
 761                                 throw new Exception(DI::l10n()->t('Database error %d "%s" at "%s"', $errorno, $error, $this->replaceParameters($sql, $params)));
 762                         }
 763
 764                         $this->logger->error('DB Error', [
 765                                 'code'      => $errorno,
 766                                 'error'     => $error,
 767                                 'callstack' => System::callstack(8),
 768                                 'params'    => $this->replaceParameters($sql, $params),
 769                         ]);
 770
 771                         // On a lost connection we simply quit.
 772                         // A reconnect like in $this->p could be dangerous with modifications
 773                         if ($errorno == 2006) {
 774                                 $this->logger->notice('Giving up because of database error', [
 775                                         'code'  => $errorno,
 776                                         'error' => $error,
 777                                 ]);
 778                                 exit(1);
 779                         }
 780
 781                         $this->error   = $error;
 782                         $this->errorno = $errorno;
 783                 }
 784
 785                 $this->profiler->saveTimestamp($stamp, "database_write", System::callstack());
 786
 787                 return $retval;
 788         }
 789
 790         /**
 791          * Check if data exists
 792          *
 793          * @param string|array $table     Table name or array [schema => table]
 794          * @param array        $condition array of fields for condition
 795          *
 796          * @return boolean Are there rows for that condition?
 797          * @throws \Exception
 798          */
 799         public function exists($table, $condition)
 800         {
 801                 if (empty($table)) {
 802                         return false;
 803                 }
 804
 805                 $fields = [];
 806
 807                 if (empty($condition)) {
 808                         return DBStructure::existsTable($table);
 809                 }
 810
 811                 reset($condition);
 812                 $first_key = key($condition);
 813                 if (!is_int($first_key)) {
 814                         $fields = [$first_key];
 815                 }
 816
 817                 $stmt = $this->select($table, $fields, $condition, ['limit' => 1]);
 818
 819                 if (is_bool($stmt)) {
 820                         $retval = $stmt;
 821                 } else {
 822                         $retval = ($this->numRows($stmt) > 0);
 823                 }
 824
 825                 $this->close($stmt);
 826
 827                 return $retval;
 828         }
 829
 830         /**
 831          * Fetches the first row
 832          *
 833          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 834          *
 835          * Fetches the first row
 836          *
 837          * @param string $sql SQL statement
 838          *
 839          * @return array first row of query
 840          * @throws \Exception
 841          */
 842         public function fetchFirst($sql)
 843         {
 844                 $params = DBA::getParam(func_get_args());
 845
 846                 $stmt = $this->p($sql, $params);
 847
 848                 if (is_bool($stmt)) {
 849                         $retval = $stmt;
 850                 } else {
 851                         $retval = $this->fetch($stmt);
 852                 }
 853
 854                 $this->close($stmt);
 855
 856                 return $retval;
 857         }
 858
 859         /**
 860          * Returns the number of affected rows of the last statement
 861          *
 862          * @return int Number of rows
 863          */
 864         public function affectedRows()
 865         {
 866                 return $this->affected_rows;
 867         }
 868
 869         /**
 870          * Returns the number of columns of a statement
 871          *
 872          * @param object Statement object
 873          *
 874          * @return int Number of columns
 875          */
 876         public function columnCount($stmt)
 877         {
 878                 if (!is_object($stmt)) {
 879                         return 0;
 880                 }
 881                 switch ($this->driver) {
 882                         case 'pdo':
 883                                 return $stmt->columnCount();
 884                         case 'mysqli':
 885                                 return $stmt->field_count;
 886                 }
 887                 return 0;
 888         }
 889
 890         /**
 891          * Returns the number of rows of a statement
 892          *
 893          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 894          *
 895          * @return int Number of rows
 896          */
 897         public function numRows($stmt)
 898         {
 899                 if (!is_object($stmt)) {
 900                         return 0;
 901                 }
 902                 switch ($this->driver) {
 903                         case 'pdo':
 904                                 return $stmt->rowCount();
 905                         case 'mysqli':
 906                                 return $stmt->num_rows;
 907                 }
 908                 return 0;
 909         }
 910
 911         /**
 912          * Fetch a single row
 913          *
 914          * @param mixed $stmt statement object
 915          *
 916          * @return array current row
 917          */
 918         public function fetch($stmt)
 919         {
 920
 921                 $stamp1 = microtime(true);
 922
 923                 $columns = [];
 924
 925                 if (!is_object($stmt)) {
 926                         return false;
 927                 }
 928
 929                 switch ($this->driver) {
 930                         case 'pdo':
 931                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 932                                 break;
 933                         case 'mysqli':
 934                                 if (get_class($stmt) == 'mysqli_result') {
 935                                         $columns = $stmt->fetch_assoc();
 936                                         break;
 937                                 }
 938
 939                                 // This code works, but is slow
 940
 941                                 // Bind the result to a result array
 942                                 $cols = [];
 943
 944                                 $cols_num = [];
 945                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 946                                         $cols[] = &$cols_num[$x];
 947                                 }
 948
 949                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 950
 951                                 if (!$stmt->fetch()) {
 952                                         return false;
 953                                 }
 954
 955                                 // The slow part:
 956                                 // We need to get the field names for the array keys
 957                                 // It seems that there is no better way to do this.
 958                                 $result = $stmt->result_metadata();
 959                                 $fields = $result->fetch_fields();
 960
 961                                 foreach ($cols_num AS $param => $col) {
 962                                         $columns[$fields[$param]->name] = $col;
 963                                 }
 964                 }
 965
 966                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
 967
 968                 return $columns;
 969         }
 970
 971         /**
 972          * Insert a row into a table
 973          *
 974          * @param string|array $table               Table name or array [schema => table]
 975          * @param array        $param               parameter array
 976          * @param bool         $on_duplicate_update Do an update on a duplicate entry
 977          *
 978          * @return boolean was the insert successful?
 979          * @throws \Exception
 980          */
 981         public function insert($table, $param, $on_duplicate_update = false)
 982         {
 983                 if (empty($table) || empty($param)) {
 984                         $this->logger->info('Table and fields have to be set');
 985                         return false;
 986                 }
 987
 988                 $table_string = DBA::buildTableString($table);
 989
 990                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 991
 992                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
 993
 994                 $sql = "INSERT INTO " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
 995
 996                 if ($on_duplicate_update) {
 997                         $fields_string = implode(' = ?, ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 998
 999                         $sql .= " ON DUPLICATE KEY UPDATE " . $fields_string . " = ?";
1000
1001                         $values = array_values($param);
1002                         $param  = array_merge_recursive($values, $values);
1003                 }
1004
1005                 return $this->e($sql, $param);
1006         }
1007
1008         /**
1009          * Fetch the id of the last insert command
1010          *
1011          * @return integer Last inserted id
1012          */
1013         public function lastInsertId()
1014         {
1015                 switch ($this->driver) {
1016                         case 'pdo':
1017                                 $id = $this->connection->lastInsertId();
1018                                 break;
1019                         case 'mysqli':
1020                                 $id = $this->connection->insert_id;
1021                                 break;
1022                 }
1023                 return $id;
1024         }
1025
1026         /**
1027          * Locks a table for exclusive write access
1028          *
1029          * This function can be extended in the future to accept a table array as well.
1030          *
1031          * @param string|array $table Table name or array [schema => table]
1032          *
1033          * @return boolean was the lock successful?
1034          * @throws \Exception
1035          */
1036         public function lock($table)
1037         {
1038                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1039                 if ($this->driver == 'pdo') {
1040                         $this->e("SET autocommit=0");
1041                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1042                 } else {
1043                         $this->connection->autocommit(false);
1044                 }
1045
1046                 $success = $this->e("LOCK TABLES " . DBA::buildTableString($table) . " WRITE");
1047
1048                 if ($this->driver == 'pdo') {
1049                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1050                 }
1051
1052                 if (!$success) {
1053                         if ($this->driver == 'pdo') {
1054                                 $this->e("SET autocommit=1");
1055                         } else {
1056                                 $this->connection->autocommit(true);
1057                         }
1058                 } else {
1059                         $this->in_transaction = true;
1060                 }
1061                 return $success;
1062         }
1063
1064         /**
1065          * Unlocks all locked tables
1066          *
1067          * @return boolean was the unlock successful?
1068          * @throws \Exception
1069          */
1070         public function unlock()
1071         {
1072                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1073                 $this->performCommit();
1074
1075                 if ($this->driver == 'pdo') {
1076                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1077                 }
1078
1079                 $success = $this->e("UNLOCK TABLES");
1080
1081                 if ($this->driver == 'pdo') {
1082                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
1083                         $this->e("SET autocommit=1");
1084                 } else {
1085                         $this->connection->autocommit(true);
1086                 }
1087
1088                 $this->in_transaction = false;
1089                 return $success;
1090         }
1091
1092         /**
1093          * Starts a transaction
1094          *
1095          * @return boolean Was the command executed successfully?
1096          */
1097         public function transaction()
1098         {
1099                 if (!$this->performCommit()) {
1100                         return false;
1101                 }
1102
1103                 switch ($this->driver) {
1104                         case 'pdo':
1105                                 if (!$this->connection->inTransaction() && !$this->connection->beginTransaction()) {
1106                                         return false;
1107                                 }
1108                                 break;
1109
1110                         case 'mysqli':
1111                                 if (!$this->connection->begin_transaction()) {
1112                                         return false;
1113                                 }
1114                                 break;
1115                 }
1116
1117                 $this->in_transaction = true;
1118                 return true;
1119         }
1120
1121         protected function performCommit()
1122         {
1123                 switch ($this->driver) {
1124                         case 'pdo':
1125                                 if (!$this->connection->inTransaction()) {
1126                                         return true;
1127                                 }
1128
1129                                 return $this->connection->commit();
1130
1131                         case 'mysqli':
1132                                 return $this->connection->commit();
1133                 }
1134
1135                 return true;
1136         }
1137
1138         /**
1139          * Does a commit
1140          *
1141          * @return boolean Was the command executed successfully?
1142          */
1143         public function commit()
1144         {
1145                 if (!$this->performCommit()) {
1146                         return false;
1147                 }
1148                 $this->in_transaction = false;
1149                 return true;
1150         }
1151
1152         /**
1153          * Does a rollback
1154          *
1155          * @return boolean Was the command executed successfully?
1156          */
1157         public function rollback()
1158         {
1159                 $ret = false;
1160
1161                 switch ($this->driver) {
1162                         case 'pdo':
1163                                 if (!$this->connection->inTransaction()) {
1164                                         $ret = true;
1165                                         break;
1166                                 }
1167                                 $ret = $this->connection->rollBack();
1168                                 break;
1169
1170                         case 'mysqli':
1171                                 $ret = $this->connection->rollback();
1172                                 break;
1173                 }
1174                 $this->in_transaction = false;
1175                 return $ret;
1176         }
1177
1178         /**
1179          * Build the array with the table relations
1180          *
1181          * The array is build from the database definitions in DBStructure.php
1182          *
1183          * This process must only be started once, since the value is cached.
1184          */
1185         private function buildRelationData()
1186         {
1187                 $definition = DBStructure::definition($this->configCache->get('system', 'basepath'));
1188
1189                 foreach ($definition AS $table => $structure) {
1190                         foreach ($structure['fields'] AS $field => $field_struct) {
1191                                 if (isset($field_struct['relation'])) {
1192                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1193                                                 $this->relation[$rel_table][$rel_field][$table][] = $field;
1194                                         }
1195                                 }
1196                         }
1197                 }
1198         }
1199
1200         /**
1201          * Delete a row from a table
1202          *
1203          * Note: this methods does NOT accept schema => table arrays because of the complex relation stuff.
1204          *
1205          * @param string $table      Table name
1206          * @param array  $conditions Field condition(s)
1207          * @param array  $options
1208          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1209          *                           relations (default: true)
1210          * @param array  $callstack  Internal use: prevent endless loops
1211          *
1212          * @return boolean was the delete successful?
1213          * @throws \Exception
1214          */
1215         public function delete($table, array $conditions, array $options = [], array &$callstack = [])
1216         {
1217                 if (empty($table) || empty($conditions)) {
1218                         $this->logger->info('Table and conditions have to be set');
1219                         return false;
1220                 }
1221
1222                 $commands = [];
1223
1224                 // Create a key for the loop prevention
1225                 $key = $table . ':' . json_encode($conditions);
1226
1227                 // We quit when this key already exists in the callstack.
1228                 if (isset($callstack[$key])) {
1229                         return true;
1230                 }
1231
1232                 $callstack[$key] = true;
1233
1234                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1235
1236                 // Don't use "defaults" here, since it would set "false" to "true"
1237                 if (isset($options['cascade'])) {
1238                         $cascade = $options['cascade'];
1239                 } else {
1240                         $cascade = true;
1241                 }
1242
1243                 // To speed up the whole process we cache the table relations
1244                 if ($cascade && count($this->relation) == 0) {
1245                         $this->buildRelationData();
1246                 }
1247
1248                 // Is there a relation entry for the table?
1249                 if ($cascade && isset($this->relation[$table])) {
1250                         // We only allow a simple "one field" relation.
1251                         $field   = array_keys($this->relation[$table])[0];
1252                         $rel_def = array_values($this->relation[$table])[0];
1253
1254                         // Create a key for preventing double queries
1255                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1256
1257                         // When the search field is the relation field, we don't need to fetch the rows
1258                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1259                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1260                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1261                                         foreach ($rel_fields AS $rel_field) {
1262                                                 $this->delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1263                                         }
1264                                 }
1265                                 // We quit when this key already exists in the callstack.
1266                         } elseif (!isset($callstack[$qkey])) {
1267                                 $callstack[$qkey] = true;
1268
1269                                 // Fetch all rows that are to be deleted
1270                                 $data = $this->select($table, [$field], $conditions);
1271
1272                                 while ($row = $this->fetch($data)) {
1273                                         $this->delete($table, [$field => $row[$field]], $options, $callstack);
1274                                 }
1275
1276                                 $this->close($data);
1277
1278                                 // Since we had split the delete command we don't need the original command anymore
1279                                 unset($commands[$key]);
1280                         }
1281                 }
1282
1283                 // Now we finalize the process
1284                 $do_transaction = !$this->in_transaction;
1285
1286                 if ($do_transaction) {
1287                         $this->transaction();
1288                 }
1289
1290                 $compacted = [];
1291                 $counter   = [];
1292
1293                 foreach ($commands AS $command) {
1294                         $conditions = $command['conditions'];
1295                         reset($conditions);
1296                         $first_key = key($conditions);
1297
1298                         $condition_string = DBA::buildCondition($conditions);
1299
1300                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1301                                 $sql = "DELETE FROM " . DBA::quoteIdentifier($command['table']) . " " . $condition_string;
1302                                 $this->logger->info($this->replaceParameters($sql, $conditions), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1303
1304                                 if (!$this->e($sql, $conditions)) {
1305                                         if ($do_transaction) {
1306                                                 $this->rollback();
1307                                         }
1308                                         return false;
1309                                 }
1310                         } else {
1311                                 $key_table     = $command['table'];
1312                                 $key_condition = array_keys($command['conditions'])[0];
1313                                 $value         = array_values($command['conditions'])[0];
1314
1315                                 // Split the SQL queries in chunks of 100 values
1316                                 // We do the $i stuff here to make the code better readable
1317                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1318                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1319                                         ++$i;
1320                                 }
1321
1322                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1323                                 $counter[$key_table][$key_condition]               = $i;
1324                         }
1325                 }
1326                 foreach ($compacted AS $table => $values) {
1327                         foreach ($values AS $field => $field_value_list) {
1328                                 foreach ($field_value_list AS $field_values) {
1329                                         $sql = "DELETE FROM " . DBA::quoteIdentifier($table) . " WHERE " . DBA::quoteIdentifier($field) . " IN (" .
1330                                                substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1331
1332                                         $this->logger->info($this->replaceParameters($sql, $field_values), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1333
1334                                         if (!$this->e($sql, $field_values)) {
1335                                                 if ($do_transaction) {
1336                                                         $this->rollback();
1337                                                 }
1338                                                 return false;
1339                                         }
1340                                 }
1341                         }
1342                 }
1343                 if ($do_transaction) {
1344                         $this->commit();
1345                 }
1346                 return true;
1347         }
1348
1349         /**
1350          * Updates rows
1351          *
1352          * Updates rows in the database. When $old_fields is set to an array,
1353          * the system will only do an update if the fields in that array changed.
1354          *
1355          * Attention:
1356          * Only the values in $old_fields are compared.
1357          * This is an intentional behaviour.
1358          *
1359          * Example:
1360          * We include the timestamp field in $fields but not in $old_fields.
1361          * Then the row will only get the new timestamp when the other fields had changed.
1362          *
1363          * When $old_fields is set to a boolean value the system will do this compare itself.
1364          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1365          *
1366          * Attention:
1367          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1368          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1369          *
1370          * @param string|array  $table      Table name or array [schema => table]
1371          * @param array         $fields     contains the fields that are updated
1372          * @param array         $condition  condition array with the key values
1373          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1374          *
1375          * @return boolean was the update successfull?
1376          * @throws \Exception
1377          */
1378         public function update($table, $fields, $condition, $old_fields = [])
1379         {
1380                 if (empty($table) || empty($fields) || empty($condition)) {
1381                         $this->logger->info('Table, fields and condition have to be set');
1382                         return false;
1383                 }
1384
1385                 if (is_bool($old_fields)) {
1386                         $do_insert = $old_fields;
1387
1388                         $old_fields = $this->selectFirst($table, [], $condition);
1389
1390                         if (is_bool($old_fields)) {
1391                                 if ($do_insert) {
1392                                         $values = array_merge($condition, $fields);
1393                                         return $this->insert($table, $values, $do_insert);
1394                                 }
1395                                 $old_fields = [];
1396                         }
1397                 }
1398
1399                 foreach ($old_fields AS $fieldname => $content) {
1400                         if (isset($fields[$fieldname]) && !is_null($content) && ($fields[$fieldname] == $content)) {
1401                                 unset($fields[$fieldname]);
1402                         }
1403                 }
1404
1405                 if (count($fields) == 0) {
1406                         return true;
1407                 }
1408
1409                 $table_string = DBA::buildTableString($table);
1410
1411                 $condition_string = DBA::buildCondition($condition);
1412
1413                 $sql = "UPDATE " . $table_string . " SET "
1414                         . implode(" = ?, ", array_map([DBA::class, 'quoteIdentifier'], array_keys($fields))) . " = ?"
1415                         . $condition_string;
1416
1417                 // Combines the updated fields parameter values with the condition parameter values
1418                 $params  = array_merge(array_values($fields), $condition);
1419
1420                 return $this->e($sql, $params);
1421         }
1422
1423         /**
1424          * Retrieve a single record from a table and returns it in an associative array
1425          *
1426          * @param string|array $table
1427          * @param array        $fields
1428          * @param array        $condition
1429          * @param array        $params
1430          *
1431          * @return bool|array
1432          * @throws \Exception
1433          * @see   $this->select
1434          */
1435         public function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1436         {
1437                 $params['limit'] = 1;
1438                 $result          = $this->select($table, $fields, $condition, $params);
1439
1440                 if (is_bool($result)) {
1441                         return $result;
1442                 } else {
1443                         $row = $this->fetch($result);
1444                         $this->close($result);
1445                         return $row;
1446                 }
1447         }
1448
1449         /**
1450          * Select rows from a table and fills an array with the data
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        $params    Array of several parameters
1456          *
1457          * @return array Data array
1458          * @throws \Exception
1459          * @see   self::select
1460          */
1461         public function selectToArray($table, array $fields = [], array $condition = [], array $params = [])
1462         {
1463                 return $this->toArray($this->select($table, $fields, $condition, $params));
1464         }
1465
1466         /**
1467          * Select rows from a table
1468          *
1469          * @param string|array $table     Table name or array [schema => table]
1470          * @param array        $fields    Array of selected fields, empty for all
1471          * @param array        $condition Array of fields for condition
1472          * @param array        $params    Array of several parameters
1473          *
1474          * @return boolean|object
1475          *
1476          * Example:
1477          * $table = "item";
1478          * $fields = array("id", "uri", "uid", "network");
1479          *
1480          * $condition = array("uid" => 1, "network" => 'dspr');
1481          * or:
1482          * $condition = array("`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr');
1483          *
1484          * $params = array("order" => array("id", "received" => true), "limit" => 10);
1485          *
1486          * $data = DBA::select($table, $fields, $condition, $params);
1487          * @throws \Exception
1488          */
1489         public function select($table, array $fields = [], array $condition = [], array $params = [])
1490         {
1491                 if (empty($table)) {
1492                         return false;
1493                 }
1494
1495                 if (count($fields) > 0) {
1496                         $select_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], $fields));
1497                 } else {
1498                         $select_string = '*';
1499                 }
1500
1501                 $table_string = DBA::buildTableString($table);
1502
1503                 $condition_string = DBA::buildCondition($condition);
1504
1505                 $param_string = DBA::buildParameter($params);
1506
1507                 $sql = "SELECT " . $select_string . " FROM " . $table_string . $condition_string . $param_string;
1508
1509                 $result = $this->p($sql, $condition);
1510
1511                 return $result;
1512         }
1513
1514         /**
1515          * Counts the rows from a table satisfying the provided condition
1516          *
1517          * @param string|array $table     Table name or array [schema => table]
1518          * @param array        $condition Array of fields for condition
1519          * @param array        $params    Array of several parameters
1520          *
1521          * @return int
1522          *
1523          * Example:
1524          * $table = "item";
1525          *
1526          * $condition = ["uid" => 1, "network" => 'dspr'];
1527          * or:
1528          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1529          *
1530          * $count = DBA::count($table, $condition);
1531          * @throws \Exception
1532          */
1533         public function count($table, array $condition = [], array $params = [])
1534         {
1535                 if (empty($table)) {
1536                         return false;
1537                 }
1538
1539                 $table_string = DBA::buildTableString($table);
1540
1541                 $condition_string = DBA::buildCondition($condition);
1542
1543                 if (empty($params['expression'])) {
1544                         $expression = '*';
1545                 } elseif (!empty($params['distinct'])) {
1546                         $expression = "DISTINCT " . DBA::quoteIdentifier($params['expression']);
1547                 } else {
1548                         $expression = DBA::quoteIdentifier($params['expression']);
1549                 }
1550
1551                 $sql = "SELECT COUNT(" . $expression . ") AS `count` FROM " . $table_string . $condition_string;
1552
1553                 $row = $this->fetchFirst($sql, $condition);
1554
1555                 return $row['count'];
1556         }
1557
1558         /**
1559          * Fills an array with data from a query
1560          *
1561          * @param object $stmt statement object
1562          * @param bool   $do_close
1563          *
1564          * @return array Data array
1565          */
1566         public function toArray($stmt, $do_close = true)
1567         {
1568                 if (is_bool($stmt)) {
1569                         return [];
1570                 }
1571
1572                 $data = [];
1573                 while ($row = $this->fetch($stmt)) {
1574                         $data[] = $row;
1575                 }
1576
1577                 if ($do_close) {
1578                         $this->close($stmt);
1579                 }
1580
1581                 return $data;
1582         }
1583
1584         /**
1585          * Returns the error number of the last query
1586          *
1587          * @return string Error number (0 if no error)
1588          */
1589         public function errorNo()
1590         {
1591                 return $this->errorno;
1592         }
1593
1594         /**
1595          * Returns the error message of the last query
1596          *
1597          * @return string Error message ('' if no error)
1598          */
1599         public function errorMessage()
1600         {
1601                 return $this->error;
1602         }
1603
1604         /**
1605          * Closes the current statement
1606          *
1607          * @param object $stmt statement object
1608          *
1609          * @return boolean was the close successful?
1610          */
1611         public function close($stmt)
1612         {
1613
1614                 $stamp1 = microtime(true);
1615
1616                 if (!is_object($stmt)) {
1617                         return false;
1618                 }
1619
1620                 switch ($this->driver) {
1621                         case 'pdo':
1622                                 $ret = $stmt->closeCursor();
1623                                 break;
1624                         case 'mysqli':
1625                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1626                                 // We should be careful not to assume the object type of $stmt
1627                                 // because DBA::p() has been able to return both types.
1628                                 if ($stmt instanceof mysqli_stmt) {
1629                                         $stmt->free_result();
1630                                         $ret = $stmt->close();
1631                                 } elseif ($stmt instanceof mysqli_result) {
1632                                         $stmt->free();
1633                                         $ret = true;
1634                                 } else {
1635                                         $ret = false;
1636                                 }
1637                                 break;
1638                 }
1639
1640                 $this->profiler->saveTimestamp($stamp1, 'database', System::callstack());
1641
1642                 return $ret;
1643         }
1644
1645         /**
1646          * Return a list of database processes
1647          *
1648          * @return array
1649          *      'list' => List of processes, separated in their different states
1650          *      'amount' => Number of concurrent database processes
1651          * @throws \Exception
1652          */
1653         public function processlist()
1654         {
1655                 $ret  = $this->p("SHOW PROCESSLIST");
1656                 $data = $this->toArray($ret);
1657
1658                 $processes = 0;
1659                 $states    = [];
1660                 foreach ($data as $process) {
1661                         $state = trim($process["State"]);
1662
1663                         // Filter out all non blocking processes
1664                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1665                                 ++$states[$state];
1666                                 ++$processes;
1667                         }
1668                 }
1669
1670                 $statelist = "";
1671                 foreach ($states as $state => $usage) {
1672                         if ($statelist != "") {
1673                                 $statelist .= ", ";
1674                         }
1675                         $statelist .= $state . ": " . $usage;
1676                 }
1677                 return (["list" => $statelist, "amount" => $processes]);
1678         }
1679
1680         /**
1681          * Fetch a database variable
1682          *
1683          * @param string $name
1684          * @return string content
1685          */
1686         public function getVariable(string $name)
1687         {
1688                 $result = $this->fetchFirst("SHOW GLOBAL VARIABLES WHERE `Variable_name` = ?", $name);
1689                 return $result['Value'] ?? null;
1690         }
1691
1692         /**
1693          * Checks if $array is a filled array with at least one entry.
1694          *
1695          * @param mixed $array A filled array with at least one entry
1696          *
1697          * @return boolean Whether $array is a filled array or an object with rows
1698          */
1699         public function isResult($array)
1700         {
1701                 // It could be a return value from an update statement
1702                 if (is_bool($array)) {
1703                         return $array;
1704                 }
1705
1706                 if (is_object($array)) {
1707                         return $this->numRows($array) > 0;
1708                 }
1709
1710                 return (is_array($array) && (count($array) > 0));
1711         }
1712
1713         /**
1714          * Callback function for "esc_array"
1715          *
1716          * @param mixed   $value         Array value
1717          * @param string  $key           Array key
1718          * @param boolean $add_quotation add quotation marks for string values
1719          *
1720          * @return void
1721          */
1722         private function escapeArrayCallback(&$value, $key, $add_quotation)
1723         {
1724                 if (!$add_quotation) {
1725                         if (is_bool($value)) {
1726                                 $value = ($value ? '1' : '0');
1727                         } else {
1728                                 $value = $this->escape($value);
1729                         }
1730                         return;
1731                 }
1732
1733                 if (is_bool($value)) {
1734                         $value = ($value ? 'true' : 'false');
1735                 } elseif (is_float($value) || is_integer($value)) {
1736                         $value = (string)$value;
1737                 } else {
1738                         $value = "'" . $this->escape($value) . "'";
1739                 }
1740         }
1741
1742         /**
1743          * Escapes a whole array
1744          *
1745          * @param mixed   $arr           Array with values to be escaped
1746          * @param boolean $add_quotation add quotation marks for string values
1747          *
1748          * @return void
1749          */
1750         public function escapeArray(&$arr, $add_quotation = false)
1751         {
1752                 array_walk($arr, [$this, 'escapeArrayCallback'], $add_quotation);
1753         }
1754 }