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