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         protected $emulate_prepares = false;
  61         protected $pdo_emulate_prepares = false;
  62         private $error          = false;
  63         private $errorno        = 0;
  64         private $affected_rows  = 0;
  65         protected $in_transaction = false;
  66         protected $in_retrial     = false;
  67         protected $testmode       = false;
  68         private $relation       = [];
  69
  70         public function __construct(Cache $configCache, Profiler $profiler, LoggerInterface $logger)
  71         {
  72                 // We are storing these values for being able to perform a reconnect
  73                 $this->configCache   = $configCache;
  74                 $this->profiler      = $profiler;
  75                 $this->logger        = $logger;
  76
  77                 $this->connect();
  78
  79                 if ($this->isConnected()) {
  80                         // Loads DB_UPDATE_VERSION constant
  81                         DBStructure::definition($configCache->get('system', 'basepath'), false);
  82                 }
  83         }
  84
  85         public function connect()
  86         {
  87                 if (!is_null($this->connection) && $this->connected()) {
  88                         return $this->connected;
  89                 }
  90
  91                 // Reset connected state
  92                 $this->connected = false;
  93
  94                 $port       = 0;
  95                 $serveraddr = trim($this->configCache->get('database', 'hostname'));
  96                 $serverdata = explode(':', $serveraddr);
  97                 $server     = $serverdata[0];
  98                 if (count($serverdata) > 1) {
  99                         $port = trim($serverdata[1]);
 100                 }
 101
 102                 if (!empty(trim($this->configCache->get('database', 'port')))) {
 103                         $port = trim($this->configCache->get('database', 'port'));
 104                 }
 105
 106                 $server  = trim($server);
 107                 $user    = trim($this->configCache->get('database', 'username'));
 108                 $pass    = trim($this->configCache->get('database', 'password'));
 109                 $db      = trim($this->configCache->get('database', 'database'));
 110                 $charset = trim($this->configCache->get('database', 'charset'));
 111
 112                 if (!(strlen($server) && strlen($user))) {
 113                         return false;
 114                 }
 115
 116                 $persistent = (bool)$this->configCache->get('database', 'persistent');
 117
 118                 $this->emulate_prepares = (bool)$this->configCache->get('database', 'emulate_prepares');
 119                 $this->pdo_emulate_prepares = (bool)$this->configCache->get('database', 'pdo_emulate_prepares');
 120
 121                 if (!$this->configCache->get('database', 'disable_pdo') && class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
 122                         $this->driver = 'pdo';
 123                         $connect      = "mysql:host=" . $server . ";dbname=" . $db;
 124
 125                         if ($port > 0) {
 126                                 $connect .= ";port=" . $port;
 127                         }
 128
 129                         if ($charset) {
 130                                 $connect .= ";charset=" . $charset;
 131                         }
 132
 133                         try {
 134                                 $this->connection = @new PDO($connect, $user, $pass, [PDO::ATTR_PERSISTENT => $persistent]);
 135                                 $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
 136                                 $this->connected = true;
 137                         } catch (PDOException $e) {
 138                                 $this->connected = false;
 139                         }
 140                 }
 141
 142                 if (!$this->connected && class_exists('\mysqli')) {
 143                         $this->driver = 'mysqli';
 144
 145                         if ($port > 0) {
 146                                 $this->connection = @new mysqli($server, $user, $pass, $db, $port);
 147                         } else {
 148                                 $this->connection = @new mysqli($server, $user, $pass, $db);
 149                         }
 150
 151                         if (!mysqli_connect_errno()) {
 152                                 $this->connected = true;
 153
 154                                 if ($charset) {
 155                                         $this->connection->set_charset($charset);
 156                                 }
 157                         }
 158                 }
 159
 160                 // No suitable SQL driver was found.
 161                 if (!$this->connected) {
 162                         $this->driver     = null;
 163                         $this->connection = null;
 164                 }
 165
 166                 return $this->connected;
 167         }
 168
 169         public function setTestmode(bool $test)
 170         {
 171                 $this->testmode = $test;
 172         }
 173         /**
 174          * Sets the logger for DBA
 175          *
 176          * @note this is necessary because if we want to load the logger configuration
 177          *       from the DB, but there's an error, we would print out an exception.
 178          *       So the logger gets updated after the logger configuration can be retrieved
 179          *       from the database
 180          *
 181          * @param LoggerInterface $logger
 182          */
 183         public function setLogger(LoggerInterface $logger)
 184         {
 185                 $this->logger = $logger;
 186         }
 187
 188         /**
 189          * Sets the profiler for DBA
 190          *
 191          * @param Profiler $profiler
 192          */
 193         public function setProfiler(Profiler $profiler)
 194         {
 195                 $this->profiler = $profiler;
 196         }
 197         /**
 198          * Disconnects the current database connection
 199          */
 200         public function disconnect()
 201         {
 202                 if (!is_null($this->connection)) {
 203                         switch ($this->driver) {
 204                                 case 'pdo':
 205                                         $this->connection = null;
 206                                         break;
 207                                 case 'mysqli':
 208                                         $this->connection->close();
 209                                         $this->connection = null;
 210                                         break;
 211                         }
 212                 }
 213
 214                 $this->driver    = null;
 215                 $this->connected = false;
 216         }
 217
 218         /**
 219          * Perform a reconnect of an existing database connection
 220          */
 221         public function reconnect()
 222         {
 223                 $this->disconnect();
 224                 return $this->connect();
 225         }
 226
 227         /**
 228          * Return the database object.
 229          *
 230          * @return PDO|mysqli
 231          */
 232         public function getConnection()
 233         {
 234                 return $this->connection;
 235         }
 236
 237         /**
 238          * Returns the MySQL server version string
 239          *
 240          * This function discriminate between the deprecated mysql API and the current
 241          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
 242          *
 243          * @return string
 244          */
 245         public function serverInfo()
 246         {
 247                 if ($this->server_info == '') {
 248                         switch ($this->driver) {
 249                                 case 'pdo':
 250                                         $this->server_info = $this->connection->getAttribute(PDO::ATTR_SERVER_VERSION);
 251                                         break;
 252                                 case 'mysqli':
 253                                         $this->server_info = $this->connection->server_info;
 254                                         break;
 255                         }
 256                 }
 257                 return $this->server_info;
 258         }
 259
 260         /**
 261          * Returns the selected database name
 262          *
 263          * @return string
 264          * @throws \Exception
 265          */
 266         public function databaseName()
 267         {
 268                 $ret  = $this->p("SELECT DATABASE() AS `db`");
 269                 $data = $this->toArray($ret);
 270                 return $data[0]['db'];
 271         }
 272
 273         /**
 274          * Analyze a database query and log this if some conditions are met.
 275          *
 276          * @param string $query The database query that will be analyzed
 277          *
 278          * @throws \Exception
 279          */
 280         private function logIndex($query)
 281         {
 282
 283                 if (!$this->configCache->get('system', 'db_log_index')) {
 284                         return;
 285                 }
 286
 287                 // Don't explain an explain statement
 288                 if (strtolower(substr($query, 0, 7)) == "explain") {
 289                         return;
 290                 }
 291
 292                 // Only do the explain on "select", "update" and "delete"
 293                 if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
 294                         return;
 295                 }
 296
 297                 $r = $this->p("EXPLAIN " . $query);
 298                 if (!$this->isResult($r)) {
 299                         return;
 300                 }
 301
 302                 $watchlist = explode(',', $this->configCache->get('system', 'db_log_index_watch'));
 303                 $denylist = explode(',', $this->configCache->get('system', 'db_log_index_denylist'));
 304
 305                 while ($row = $this->fetch($r)) {
 306                         if ((intval($this->configCache->get('system', 'db_loglimit_index')) > 0)) {
 307                                 $log = (in_array($row['key'], $watchlist) &&
 308                                         ($row['rows'] >= intval($this->configCache->get('system', 'db_loglimit_index'))));
 309                         } else {
 310                                 $log = false;
 311                         }
 312
 313                         if ((intval($this->configCache->get('system', 'db_loglimit_index_high')) > 0) && ($row['rows'] >= intval($this->configCache->get('system', 'db_loglimit_index_high')))) {
 314                                 $log = true;
 315                         }
 316
 317                         if (in_array($row['key'], $denylist) || ($row['key'] == "")) {
 318                                 $log = false;
 319                         }
 320
 321                         if ($log) {
 322                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 323                                 @file_put_contents($this->configCache->get('system', 'db_log_index'), DateTimeFormat::utcNow() . "\t" .
 324                                                                                                       $row['key'] . "\t" . $row['rows'] . "\t" . $row['Extra'] . "\t" .
 325                                                                                                       basename($backtrace[1]["file"]) . "\t" .
 326                                                                                                       $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
 327                                                                                                       substr($query, 0, 4000) . "\n", FILE_APPEND);
 328                         }
 329                 }
 330         }
 331
 332         /**
 333          * Removes every not allowlisted character from the identifier string
 334          *
 335          * @param string $identifier
 336          *
 337          * @return string sanitized identifier
 338          * @throws \Exception
 339          */
 340         private function sanitizeIdentifier($identifier)
 341         {
 342                 return preg_replace('/[^A-Za-z0-9_\-]+/', '', $identifier);
 343         }
 344
 345         public function escape($str)
 346         {
 347                 if ($this->connected) {
 348                         switch ($this->driver) {
 349                                 case 'pdo':
 350                                         return substr(@$this->connection->quote($str, PDO::PARAM_STR), 1, -1);
 351
 352                                 case 'mysqli':
 353                                         return @$this->connection->real_escape_string($str);
 354                         }
 355                 } else {
 356                         return str_replace("'", "\\'", $str);
 357                 }
 358         }
 359
 360         public function isConnected()
 361         {
 362                 return $this->connected;
 363         }
 364
 365         public function connected()
 366         {
 367                 $connected = false;
 368
 369                 if (is_null($this->connection)) {
 370                         return false;
 371                 }
 372
 373                 switch ($this->driver) {
 374                         case 'pdo':
 375                                 $r = $this->p("SELECT 1");
 376                                 if ($this->isResult($r)) {
 377                                         $row       = $this->toArray($r);
 378                                         $connected = ($row[0]['1'] == '1');
 379                                 }
 380                                 break;
 381                         case 'mysqli':
 382                                 $connected = $this->connection->ping();
 383                                 break;
 384                 }
 385
 386                 return $connected;
 387         }
 388
 389         /**
 390          * Replaces ANY_VALUE() function by MIN() function,
 391          * if the database server does not support ANY_VALUE().
 392          *
 393          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
 394          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
 395          * A standard fall-back is to use MIN().
 396          *
 397          * @param string $sql An SQL string without the values
 398          *
 399          * @return string The input SQL string modified if necessary.
 400          */
 401         public function anyValueFallback($sql)
 402         {
 403                 $server_info = $this->serverInfo();
 404                 if (version_compare($server_info, '5.7.5', '<') ||
 405                     (stripos($server_info, 'MariaDB') !== false)) {
 406                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
 407                 }
 408                 return $sql;
 409         }
 410
 411         /**
 412          * Replaces the ? placeholders with the parameters in the $args array
 413          *
 414          * @param string $sql  SQL query
 415          * @param array  $args The parameters that are to replace the ? placeholders
 416          *
 417          * @return string The replaced SQL query
 418          */
 419         private function replaceParameters($sql, $args)
 420         {
 421                 $offset = 0;
 422                 foreach ($args AS $param => $value) {
 423                         if (is_int($args[$param]) || is_float($args[$param]) || is_bool($args[$param])) {
 424                                 $replace = intval($args[$param]);
 425                         } elseif (is_null($args[$param])) {
 426                                 $replace = 'NULL';
 427                         } else {
 428                                 $replace = "'" . $this->escape($args[$param]) . "'";
 429                         }
 430
 431                         $pos = strpos($sql, '?', $offset);
 432                         if ($pos !== false) {
 433                                 $sql = substr_replace($sql, $replace, $pos, 1);
 434                         }
 435                         $offset = $pos + strlen($replace);
 436                 }
 437                 return $sql;
 438         }
 439
 440         /**
 441          * Executes a prepared statement that returns data
 442          *
 443          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
 444          *
 445          * Please only use it with complicated queries.
 446          * For all regular queries please use DBA::select or DBA::exists
 447          *
 448          * @param string $sql SQL statement
 449          *
 450          * @return bool|object statement object or result object
 451          * @throws \Exception
 452          */
 453         public function p($sql)
 454         {
 455
 456                 $stamp1 = microtime(true);
 457
 458                 $params = DBA::getParam(func_get_args());
 459
 460                 // Renumber the array keys to be sure that they fit
 461                 $i    = 0;
 462                 $args = [];
 463                 foreach ($params AS $param) {
 464                         // Avoid problems with some MySQL servers and boolean values. See issue #3645
 465                         if (is_bool($param)) {
 466                                 $param = (int)$param;
 467                         }
 468                         $args[++$i] = $param;
 469                 }
 470
 471                 if (!$this->connected) {
 472                         return false;
 473                 }
 474
 475                 if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
 476                         // Question: Should we continue or stop the query here?
 477                         $this->logger->warning('Query parameters mismatch.', ['query' => $sql, 'args' => $args, 'callstack' => System::callstack()]);
 478                 }
 479
 480                 $sql = DBA::cleanQuery($sql);
 481                 $sql = $this->anyValueFallback($sql);
 482
 483                 $orig_sql = $sql;
 484
 485                 if ($this->configCache->get('system', 'db_callstack') !== null) {
 486                         $sql = "/*" . System::callstack() . " */ " . $sql;
 487                 }
 488
 489                 $is_error            = false;
 490                 $this->error         = '';
 491                 $this->errorno       = 0;
 492                 $this->affected_rows = 0;
 493
 494                 // We have to make some things different if this function is called from "e"
 495                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
 496
 497                 if (isset($trace[1])) {
 498                         $called_from = $trace[1];
 499                 } else {
 500                         // We use just something that is defined to avoid warnings
 501                         $called_from = $trace[0];
 502                 }
 503                 // We are having an own error logging in the function "e"
 504                 $called_from_e = ($called_from['function'] == 'e');
 505
 506                 if (!isset($this->connection)) {
 507                         throw new InternalServerErrorException('The Connection is empty, although connected is set true.');
 508                 }
 509
 510                 switch ($this->driver) {
 511                         case 'pdo':
 512                                 // If there are no arguments we use "query"
 513                                 if ($this->emulate_prepares || count($args) == 0) {
 514                                         if (!$retval = $this->connection->query($this->replaceParameters($sql, $args))) {
 515                                                 $errorInfo     = $this->connection->errorInfo();
 516                                                 $this->error   = $errorInfo[2];
 517                                                 $this->errorno = $errorInfo[1];
 518                                                 $retval        = false;
 519                                                 $is_error      = true;
 520                                                 break;
 521                                         }
 522                                         $this->affected_rows = $retval->rowCount();
 523                                         break;
 524                                 }
 525
 526                                 /** @var $stmt mysqli_stmt|PDOStatement */
 527                                 if (!$stmt = $this->connection->prepare($sql)) {
 528                                         $errorInfo     = $this->connection->errorInfo();
 529                                         $this->error   = $errorInfo[2];
 530                                         $this->errorno = $errorInfo[1];
 531                                         $retval        = false;
 532                                         $is_error      = true;
 533                                         break;
 534                                 }
 535
 536                                 foreach ($args AS $param => $value) {
 537                                         if (is_int($args[$param])) {
 538                                                 $data_type = PDO::PARAM_INT;
 539                                         } else {
 540                                                 $data_type = PDO::PARAM_STR;
 541                                         }
 542                                         $stmt->bindParam($param, $args[$param], $data_type);
 543                                 }
 544
 545                                 if (!$stmt->execute()) {
 546                                         $errorInfo     = $stmt->errorInfo();
 547                                         $this->error   = $errorInfo[2];
 548                                         $this->errorno = $errorInfo[1];
 549                                         $retval        = false;
 550                                         $is_error      = true;
 551                                 } else {
 552                                         $retval              = $stmt;
 553                                         $this->affected_rows = $retval->rowCount();
 554                                 }
 555                                 break;
 556                         case 'mysqli':
 557                                 // There are SQL statements that cannot be executed with a prepared statement
 558                                 $parts           = explode(' ', $orig_sql);
 559                                 $command         = strtolower($parts[0]);
 560                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
 561
 562                                 // The fallback routine is called as well when there are no arguments
 563                                 if ($this->emulate_prepares || !$can_be_prepared || (count($args) == 0)) {
 564                                         $retval = $this->connection->query($this->replaceParameters($sql, $args));
 565                                         if ($this->connection->errno) {
 566                                                 $this->error   = $this->connection->error;
 567                                                 $this->errorno = $this->connection->errno;
 568                                                 $retval        = false;
 569                                                 $is_error      = true;
 570                                         } else {
 571                                                 if (isset($retval->num_rows)) {
 572                                                         $this->affected_rows = $retval->num_rows;
 573                                                 } else {
 574                                                         $this->affected_rows = $this->connection->affected_rows;
 575                                                 }
 576                                         }
 577                                         break;
 578                                 }
 579
 580                                 $stmt = $this->connection->stmt_init();
 581
 582                                 if (!$stmt->prepare($sql)) {
 583                                         $this->error   = $stmt->error;
 584                                         $this->errorno = $stmt->errno;
 585                                         $retval        = false;
 586                                         $is_error      = true;
 587                                         break;
 588                                 }
 589
 590                                 $param_types = '';
 591                                 $values      = [];
 592                                 foreach ($args AS $param => $value) {
 593                                         if (is_int($args[$param])) {
 594                                                 $param_types .= 'i';
 595                                         } elseif (is_float($args[$param])) {
 596                                                 $param_types .= 'd';
 597                                         } elseif (is_string($args[$param])) {
 598                                                 $param_types .= 's';
 599                                         } else {
 600                                                 $param_types .= 'b';
 601                                         }
 602                                         $values[] = &$args[$param];
 603                                 }
 604
 605                                 if (count($values) > 0) {
 606                                         array_unshift($values, $param_types);
 607                                         call_user_func_array([$stmt, 'bind_param'], $values);
 608                                 }
 609
 610                                 if (!$stmt->execute()) {
 611                                         $this->error   = $this->connection->error;
 612                                         $this->errorno = $this->connection->errno;
 613                                         $retval        = false;
 614                                         $is_error      = true;
 615                                 } else {
 616                                         $stmt->store_result();
 617                                         $retval              = $stmt;
 618                                         $this->affected_rows = $retval->affected_rows;
 619                                 }
 620                                 break;
 621                 }
 622
 623                 // See issue https://github.com/friendica/friendica/issues/8572
 624                 // Ensure that we always get an error message on an error.
 625                 if ($is_error && empty($this->errorno)) {
 626                         $this->errorno = -1;
 627                 }
 628
 629                 if ($is_error && empty($this->error)) {
 630                         $this->error = 'Unknown database error';
 631                 }
 632
 633                 // We are having an own error logging in the function "e"
 634                 if (($this->errorno != 0) && !$called_from_e) {
 635                         // We have to preserve the error code, somewhere in the logging it get lost
 636                         $error   = $this->error;
 637                         $errorno = $this->errorno;
 638
 639                         if ($this->testmode) {
 640                                 throw new DatabaseException($error, $errorno, $this->replaceParameters($sql, $args));
 641                         }
 642
 643                         $this->logger->error('DB Error', [
 644                                 'code'      => $errorno,
 645                                 'error'     => $error,
 646                                 'callstack' => System::callstack(8),
 647                                 'params'    => $this->replaceParameters($sql, $args),
 648                         ]);
 649
 650                         // On a lost connection we try to reconnect - but only once.
 651                         if ($errorno == 2006) {
 652                                 if ($this->in_retrial || !$this->reconnect()) {
 653                                         // It doesn't make sense to continue when the database connection was lost
 654                                         if ($this->in_retrial) {
 655                                                 $this->logger->notice('Giving up retrial because of database error', [
 656                                                         'code'  => $errorno,
 657                                                         'error' => $error,
 658                                                 ]);
 659                                         } else {
 660                                                 $this->logger->notice('Couldn\'t reconnect after database error', [
 661                                                         'code'  => $errorno,
 662                                                         'error' => $error,
 663                                                 ]);
 664                                         }
 665                                         exit(1);
 666                                 } else {
 667                                         // We try it again
 668                                         $this->logger->notice('Reconnected after database error', [
 669                                                 'code'  => $errorno,
 670                                                 'error' => $error,
 671                                         ]);
 672                                         $this->in_retrial = true;
 673                                         $ret              = $this->p($sql, $args);
 674                                         $this->in_retrial = false;
 675                                         return $ret;
 676                                 }
 677                         }
 678
 679                         $this->error   = $error;
 680                         $this->errorno = $errorno;
 681                 }
 682
 683                 $this->profiler->saveTimestamp($stamp1, 'database');
 684
 685                 if ($this->configCache->get('system', 'db_log')) {
 686                         $stamp2   = microtime(true);
 687                         $duration = (float)($stamp2 - $stamp1);
 688
 689                         if (($duration > $this->configCache->get('system', 'db_loglimit'))) {
 690                                 $duration  = round($duration, 3);
 691                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 692
 693                                 @file_put_contents($this->configCache->get('system', 'db_log'), DateTimeFormat::utcNow() . "\t" . $duration . "\t" .
 694                                                                                                 basename($backtrace[1]["file"]) . "\t" .
 695                                                                                                 $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
 696                                                                                                 substr($this->replaceParameters($sql, $args), 0, 4000) . "\n", FILE_APPEND);
 697                         }
 698                 }
 699                 return $retval;
 700         }
 701
 702         /**
 703          * Executes a prepared statement like UPDATE or INSERT that doesn't return data
 704          *
 705          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
 706          *
 707          * @param string $sql SQL statement
 708          *
 709          * @return boolean Was the query successfull? False is returned only if an error occurred
 710          * @throws \Exception
 711          */
 712         public function e($sql)
 713         {
 714
 715                 $stamp = microtime(true);
 716
 717                 $params = DBA::getParam(func_get_args());
 718
 719                 // In a case of a deadlock we are repeating the query 20 times
 720                 $timeout = 20;
 721
 722                 do {
 723                         $stmt = $this->p($sql, $params);
 724
 725                         if (is_bool($stmt)) {
 726                                 $retval = $stmt;
 727                         } elseif (is_object($stmt)) {
 728                                 $retval = true;
 729                         } else {
 730                                 $retval = false;
 731                         }
 732
 733                         $this->close($stmt);
 734
 735                 } while (($this->errorno == 1213) && (--$timeout > 0));
 736
 737                 if ($this->errorno != 0) {
 738                         // We have to preserve the error code, somewhere in the logging it get lost
 739                         $error   = $this->error;
 740                         $errorno = $this->errorno;
 741
 742                         if ($this->testmode) {
 743                                 throw new DatabaseException($error, $errorno, $this->replaceParameters($sql, $params));
 744                         }
 745
 746                         $this->logger->error('DB Error', [
 747                                 'code'      => $errorno,
 748                                 'error'     => $error,
 749                                 'callstack' => System::callstack(8),
 750                                 'params'    => $this->replaceParameters($sql, $params),
 751                         ]);
 752
 753                         // On a lost connection we simply quit.
 754                         // A reconnect like in $this->p could be dangerous with modifications
 755                         if ($errorno == 2006) {
 756                                 $this->logger->notice('Giving up because of database error', [
 757                                         'code'  => $errorno,
 758                                         'error' => $error,
 759                                 ]);
 760                                 exit(1);
 761                         }
 762
 763                         $this->error   = $error;
 764                         $this->errorno = $errorno;
 765                 }
 766
 767                 $this->profiler->saveTimestamp($stamp, "database_write");
 768
 769                 return $retval;
 770         }
 771
 772         /**
 773          * Check if data exists
 774          *
 775          * @param string|array $table     Table name or array [schema => table]
 776          * @param array        $condition array of fields for condition
 777          *
 778          * @return boolean Are there rows for that condition?
 779          * @throws \Exception
 780          */
 781         public function exists($table, $condition)
 782         {
 783                 if (empty($table)) {
 784                         return false;
 785                 }
 786
 787                 $fields = [];
 788
 789                 if (empty($condition)) {
 790                         return DBStructure::existsTable($table);
 791                 }
 792
 793                 reset($condition);
 794                 $first_key = key($condition);
 795                 if (!is_int($first_key)) {
 796                         $fields = [$first_key];
 797                 }
 798
 799                 $stmt = $this->select($table, $fields, $condition, ['limit' => 1]);
 800
 801                 if (is_bool($stmt)) {
 802                         $retval = $stmt;
 803                 } else {
 804                         $retval = ($this->numRows($stmt) > 0);
 805                 }
 806
 807                 $this->close($stmt);
 808
 809                 return $retval;
 810         }
 811
 812         /**
 813          * Fetches the first row
 814          *
 815          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
 816          *
 817          * Fetches the first row
 818          *
 819          * @param string $sql SQL statement
 820          *
 821          * @return array first row of query
 822          * @throws \Exception
 823          */
 824         public function fetchFirst($sql)
 825         {
 826                 $params = DBA::getParam(func_get_args());
 827
 828                 $stmt = $this->p($sql, $params);
 829
 830                 if (is_bool($stmt)) {
 831                         $retval = $stmt;
 832                 } else {
 833                         $retval = $this->fetch($stmt);
 834                 }
 835
 836                 $this->close($stmt);
 837
 838                 return $retval;
 839         }
 840
 841         /**
 842          * Returns the number of affected rows of the last statement
 843          *
 844          * @return int Number of rows
 845          */
 846         public function affectedRows()
 847         {
 848                 return $this->affected_rows;
 849         }
 850
 851         /**
 852          * Returns the number of columns of a statement
 853          *
 854          * @param object Statement object
 855          *
 856          * @return int Number of columns
 857          */
 858         public function columnCount($stmt)
 859         {
 860                 if (!is_object($stmt)) {
 861                         return 0;
 862                 }
 863                 switch ($this->driver) {
 864                         case 'pdo':
 865                                 return $stmt->columnCount();
 866                         case 'mysqli':
 867                                 return $stmt->field_count;
 868                 }
 869                 return 0;
 870         }
 871
 872         /**
 873          * Returns the number of rows of a statement
 874          *
 875          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
 876          *
 877          * @return int Number of rows
 878          */
 879         public function numRows($stmt)
 880         {
 881                 if (!is_object($stmt)) {
 882                         return 0;
 883                 }
 884                 switch ($this->driver) {
 885                         case 'pdo':
 886                                 return $stmt->rowCount();
 887                         case 'mysqli':
 888                                 return $stmt->num_rows;
 889                 }
 890                 return 0;
 891         }
 892
 893         /**
 894          * Fetch a single row
 895          *
 896          * @param mixed $stmt statement object
 897          *
 898          * @return array current row
 899          */
 900         public function fetch($stmt)
 901         {
 902
 903                 $stamp1 = microtime(true);
 904
 905                 $columns = [];
 906
 907                 if (!is_object($stmt)) {
 908                         return false;
 909                 }
 910
 911                 switch ($this->driver) {
 912                         case 'pdo':
 913                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
 914                                 break;
 915                         case 'mysqli':
 916                                 if (get_class($stmt) == 'mysqli_result') {
 917                                         $columns = $stmt->fetch_assoc();
 918                                         break;
 919                                 }
 920
 921                                 // This code works, but is slow
 922
 923                                 // Bind the result to a result array
 924                                 $cols = [];
 925
 926                                 $cols_num = [];
 927                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 928                                         $cols[] = &$cols_num[$x];
 929                                 }
 930
 931                                 call_user_func_array([$stmt, 'bind_result'], $cols);
 932
 933                                 if (!$stmt->fetch()) {
 934                                         return false;
 935                                 }
 936
 937                                 // The slow part:
 938                                 // We need to get the field names for the array keys
 939                                 // It seems that there is no better way to do this.
 940                                 $result = $stmt->result_metadata();
 941                                 $fields = $result->fetch_fields();
 942
 943                                 foreach ($cols_num AS $param => $col) {
 944                                         $columns[$fields[$param]->name] = $col;
 945                                 }
 946                 }
 947
 948                 $this->profiler->saveTimestamp($stamp1, 'database');
 949
 950                 return $columns;
 951         }
 952
 953         /**
 954          * Insert a row into a table
 955          *
 956          * @param string|array $table               Table name or array [schema => table]
 957          * @param array        $param               parameter array
 958          * @param bool         $on_duplicate_update Do an update on a duplicate entry
 959          *
 960          * @return boolean was the insert successful?
 961          * @throws \Exception
 962          */
 963         public function insert($table, array $param, bool $on_duplicate_update = false)
 964         {
 965                 if (empty($table) || empty($param)) {
 966                         $this->logger->info('Table and fields have to be set');
 967                         return false;
 968                 }
 969
 970                 $table_string = DBA::buildTableString($table);
 971
 972                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 973
 974                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
 975
 976                 $sql = "INSERT INTO " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
 977
 978                 if ($on_duplicate_update) {
 979                         $fields_string = implode(' = ?, ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
 980
 981                         $sql .= " ON DUPLICATE KEY UPDATE " . $fields_string . " = ?";
 982
 983                         $values = array_values($param);
 984                         $param  = array_merge_recursive($values, $values);
 985                 }
 986
 987                 return $this->e($sql, $param);
 988         }
 989
 990         /**
 991          * Inserts a row with the provided data in the provided table.
 992          * If the data corresponds to an existing row through a UNIQUE or PRIMARY index constraints, it updates the row instead.
 993          *
 994          * @param string|array $table Table name or array [schema => table]
 995          * @param array        $param parameter array
 996          *
 997          * @return boolean was the insert successful?
 998          * @throws \Exception
 999          */
1000         public function replace($table, array $param)
1001         {
1002                 if (empty($table) || empty($param)) {
1003                         $this->logger->info('Table and fields have to be set');
1004                         return false;
1005                 }
1006
1007                 $table_string = DBA::buildTableString($table);
1008
1009                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
1010
1011                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
1012
1013                 $sql = "REPLACE " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
1014
1015                 return $this->e($sql, $param);
1016         }
1017
1018         /**
1019          * Fetch the id of the last insert command
1020          *
1021          * @return integer Last inserted id
1022          */
1023         public function lastInsertId()
1024         {
1025                 switch ($this->driver) {
1026                         case 'pdo':
1027                                 $id = $this->connection->lastInsertId();
1028                                 break;
1029                         case 'mysqli':
1030                                 $id = $this->connection->insert_id;
1031                                 break;
1032                 }
1033                 return (int)$id;
1034         }
1035
1036         /**
1037          * Locks a table for exclusive write access
1038          *
1039          * This function can be extended in the future to accept a table array as well.
1040          *
1041          * @param string|array $table Table name or array [schema => table]
1042          *
1043          * @return boolean was the lock successful?
1044          * @throws \Exception
1045          */
1046         public function lock($table)
1047         {
1048                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1049                 if ($this->driver == 'pdo') {
1050                         $this->e("SET autocommit=0");
1051                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1052                 } else {
1053                         $this->connection->autocommit(false);
1054                 }
1055
1056                 $success = $this->e("LOCK TABLES " . DBA::buildTableString($table) . " WRITE");
1057
1058                 if ($this->driver == 'pdo') {
1059                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
1060                 }
1061
1062                 if (!$success) {
1063                         if ($this->driver == 'pdo') {
1064                                 $this->e("SET autocommit=1");
1065                         } else {
1066                                 $this->connection->autocommit(true);
1067                         }
1068                 } else {
1069                         $this->in_transaction = true;
1070                 }
1071                 return $success;
1072         }
1073
1074         /**
1075          * Unlocks all locked tables
1076          *
1077          * @return boolean was the unlock successful?
1078          * @throws \Exception
1079          */
1080         public function unlock()
1081         {
1082                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1083                 $this->performCommit();
1084
1085                 if ($this->driver == 'pdo') {
1086                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1087                 }
1088
1089                 $success = $this->e("UNLOCK TABLES");
1090
1091                 if ($this->driver == 'pdo') {
1092                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
1093                         $this->e("SET autocommit=1");
1094                 } else {
1095                         $this->connection->autocommit(true);
1096                 }
1097
1098                 $this->in_transaction = false;
1099                 return $success;
1100         }
1101
1102         /**
1103          * Starts a transaction
1104          *
1105          * @return boolean Was the command executed successfully?
1106          */
1107         public function transaction()
1108         {
1109                 if (!$this->performCommit()) {
1110                         return false;
1111                 }
1112
1113                 switch ($this->driver) {
1114                         case 'pdo':
1115                                 if (!$this->connection->inTransaction() && !$this->connection->beginTransaction()) {
1116                                         return false;
1117                                 }
1118                                 break;
1119
1120                         case 'mysqli':
1121                                 if (!$this->connection->begin_transaction()) {
1122                                         return false;
1123                                 }
1124                                 break;
1125                 }
1126
1127                 $this->in_transaction = true;
1128                 return true;
1129         }
1130
1131         protected function performCommit()
1132         {
1133                 switch ($this->driver) {
1134                         case 'pdo':
1135                                 if (!$this->connection->inTransaction()) {
1136                                         return true;
1137                                 }
1138
1139                                 return $this->connection->commit();
1140
1141                         case 'mysqli':
1142                                 return $this->connection->commit();
1143                 }
1144
1145                 return true;
1146         }
1147
1148         /**
1149          * Does a commit
1150          *
1151          * @return boolean Was the command executed successfully?
1152          */
1153         public function commit()
1154         {
1155                 if (!$this->performCommit()) {
1156                         return false;
1157                 }
1158                 $this->in_transaction = false;
1159                 return true;
1160         }
1161
1162         /**
1163          * Does a rollback
1164          *
1165          * @return boolean Was the command executed successfully?
1166          */
1167         public function rollback()
1168         {
1169                 $ret = false;
1170
1171                 switch ($this->driver) {
1172                         case 'pdo':
1173                                 if (!$this->connection->inTransaction()) {
1174                                         $ret = true;
1175                                         break;
1176                                 }
1177                                 $ret = $this->connection->rollBack();
1178                                 break;
1179
1180                         case 'mysqli':
1181                                 $ret = $this->connection->rollback();
1182                                 break;
1183                 }
1184                 $this->in_transaction = false;
1185                 return $ret;
1186         }
1187
1188         /**
1189          * Build the array with the table relations
1190          *
1191          * The array is build from the database definitions in DBStructure.php
1192          *
1193          * This process must only be started once, since the value is cached.
1194          */
1195         private function buildRelationData()
1196         {
1197                 $definition = DBStructure::definition($this->configCache->get('system', 'basepath'));
1198
1199                 foreach ($definition AS $table => $structure) {
1200                         foreach ($structure['fields'] AS $field => $field_struct) {
1201                                 if (isset($field_struct['relation'])) {
1202                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1203                                                 $this->relation[$rel_table][$rel_field][$table][] = $field;
1204                                         }
1205                                 }
1206                         }
1207                 }
1208         }
1209
1210         /**
1211          * Delete a row from a table
1212          *
1213          * Note: this methods does NOT accept schema => table arrays because of the complex relation stuff.
1214          *
1215          * @param string $table      Table name
1216          * @param array  $conditions Field condition(s)
1217          * @param array  $options
1218          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1219          *                           relations (default: true)
1220          * @param array  $callstack  Internal use: prevent endless loops
1221          *
1222          * @return boolean was the delete successful?
1223          * @throws \Exception
1224          */
1225         public function delete($table, array $conditions, array $options = [], array &$callstack = [])
1226         {
1227                 if (empty($table) || empty($conditions)) {
1228                         $this->logger->info('Table and conditions have to be set');
1229                         return false;
1230                 }
1231
1232                 $commands = [];
1233
1234                 // Create a key for the loop prevention
1235                 $key = $table . ':' . json_encode($conditions);
1236
1237                 // We quit when this key already exists in the callstack.
1238                 if (isset($callstack[$key])) {
1239                         return true;
1240                 }
1241
1242                 $callstack[$key] = true;
1243
1244                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1245
1246                 // Don't use "defaults" here, since it would set "false" to "true"
1247                 if (isset($options['cascade'])) {
1248                         $cascade = $options['cascade'];
1249                 } else {
1250                         $cascade = true;
1251                 }
1252
1253                 // To speed up the whole process we cache the table relations
1254                 if ($cascade && count($this->relation) == 0) {
1255                         $this->buildRelationData();
1256                 }
1257
1258                 // Is there a relation entry for the table?
1259                 if ($cascade && isset($this->relation[$table])) {
1260                         // We only allow a simple "one field" relation.
1261                         $field   = array_keys($this->relation[$table])[0];
1262                         $rel_def = array_values($this->relation[$table])[0];
1263
1264                         // Create a key for preventing double queries
1265                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1266
1267                         // When the search field is the relation field, we don't need to fetch the rows
1268                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1269                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1270                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1271                                         foreach ($rel_fields AS $rel_field) {
1272                                                 $this->delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1273                                         }
1274                                 }
1275                                 // We quit when this key already exists in the callstack.
1276                         } elseif (!isset($callstack[$qkey])) {
1277                                 $callstack[$qkey] = true;
1278
1279                                 // Fetch all rows that are to be deleted
1280                                 $data = $this->select($table, [$field], $conditions);
1281
1282                                 while ($row = $this->fetch($data)) {
1283                                         $this->delete($table, [$field => $row[$field]], $options, $callstack);
1284                                 }
1285
1286                                 $this->close($data);
1287
1288                                 // Since we had split the delete command we don't need the original command anymore
1289                                 unset($commands[$key]);
1290                         }
1291                 }
1292
1293                 // Now we finalize the process
1294                 $do_transaction = !$this->in_transaction;
1295
1296                 if ($do_transaction) {
1297                         $this->transaction();
1298                 }
1299
1300                 $compacted = [];
1301                 $counter   = [];
1302
1303                 foreach ($commands AS $command) {
1304                         $conditions = $command['conditions'];
1305                         reset($conditions);
1306                         $first_key = key($conditions);
1307
1308                         $condition_string = DBA::buildCondition($conditions);
1309
1310                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1311                                 $sql = "DELETE FROM " . DBA::quoteIdentifier($command['table']) . " " . $condition_string;
1312                                 $this->logger->info($this->replaceParameters($sql, $conditions), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1313
1314                                 if (!$this->e($sql, $conditions)) {
1315                                         if ($do_transaction) {
1316                                                 $this->rollback();
1317                                         }
1318                                         return false;
1319                                 }
1320                         } else {
1321                                 $key_table     = $command['table'];
1322                                 $key_condition = array_keys($command['conditions'])[0];
1323                                 $value         = array_values($command['conditions'])[0];
1324
1325                                 // Split the SQL queries in chunks of 100 values
1326                                 // We do the $i stuff here to make the code better readable
1327                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1328                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1329                                         ++$i;
1330                                 }
1331
1332                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1333                                 $counter[$key_table][$key_condition]               = $i;
1334                         }
1335                 }
1336                 foreach ($compacted AS $table => $values) {
1337                         foreach ($values AS $field => $field_value_list) {
1338                                 foreach ($field_value_list AS $field_values) {
1339                                         $sql = "DELETE FROM " . DBA::quoteIdentifier($table) . " WHERE " . DBA::quoteIdentifier($field) . " IN (" .
1340                                                substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1341
1342                                         $this->logger->info($this->replaceParameters($sql, $field_values), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1343
1344                                         if (!$this->e($sql, $field_values)) {
1345                                                 if ($do_transaction) {
1346                                                         $this->rollback();
1347                                                 }
1348                                                 return false;
1349                                         }
1350                                 }
1351                         }
1352                 }
1353                 if ($do_transaction) {
1354                         $this->commit();
1355                 }
1356                 return true;
1357         }
1358
1359         /**
1360          * Updates rows
1361          *
1362          * Updates rows in the database. When $old_fields is set to an array,
1363          * the system will only do an update if the fields in that array changed.
1364          *
1365          * Attention:
1366          * Only the values in $old_fields are compared.
1367          * This is an intentional behaviour.
1368          *
1369          * Example:
1370          * We include the timestamp field in $fields but not in $old_fields.
1371          * Then the row will only get the new timestamp when the other fields had changed.
1372          *
1373          * When $old_fields is set to a boolean value the system will do this compare itself.
1374          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1375          *
1376          * Attention:
1377          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1378          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1379          *
1380          * @param string|array  $table      Table name or array [schema => table]
1381          * @param array         $fields     contains the fields that are updated
1382          * @param array         $condition  condition array with the key values
1383          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1384          *
1385          * @return boolean was the update successfull?
1386          * @throws \Exception
1387          */
1388         public function update($table, $fields, $condition, $old_fields = [])
1389         {
1390                 if (empty($table) || empty($fields) || empty($condition)) {
1391                         $this->logger->info('Table, fields and condition have to be set');
1392                         return false;
1393                 }
1394
1395                 if (is_bool($old_fields)) {
1396                         $do_insert = $old_fields;
1397
1398                         $old_fields = $this->selectFirst($table, [], $condition);
1399
1400                         if (is_bool($old_fields)) {
1401                                 if ($do_insert) {
1402                                         $values = array_merge($condition, $fields);
1403                                         return $this->replace($table, $values);
1404                                 }
1405                                 $old_fields = [];
1406                         }
1407                 }
1408
1409                 foreach ($old_fields AS $fieldname => $content) {
1410                         if (isset($fields[$fieldname]) && !is_null($content) && ($fields[$fieldname] == $content)) {
1411                                 unset($fields[$fieldname]);
1412                         }
1413                 }
1414
1415                 if (count($fields) == 0) {
1416                         return true;
1417                 }
1418
1419                 $table_string = DBA::buildTableString($table);
1420
1421                 $condition_string = DBA::buildCondition($condition);
1422
1423                 $sql = "UPDATE " . $table_string . " SET "
1424                         . implode(" = ?, ", array_map([DBA::class, 'quoteIdentifier'], array_keys($fields))) . " = ?"
1425                         . $condition_string;
1426
1427                 // Combines the updated fields parameter values with the condition parameter values
1428                 $params  = array_merge(array_values($fields), $condition);
1429
1430                 return $this->e($sql, $params);
1431         }
1432
1433         /**
1434          * Retrieve a single record from a table and returns it in an associative array
1435          *
1436          * @param string|array $table
1437          * @param array        $fields
1438          * @param array        $condition
1439          * @param array        $params
1440          *
1441          * @return bool|array
1442          * @throws \Exception
1443          * @see   $this->select
1444          */
1445         public function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1446         {
1447                 $params['limit'] = 1;
1448                 $result          = $this->select($table, $fields, $condition, $params);
1449
1450                 if (is_bool($result)) {
1451                         return $result;
1452                 } else {
1453                         $row = $this->fetch($result);
1454                         $this->close($result);
1455                         return $row;
1456                 }
1457         }
1458
1459         /**
1460          * Select rows from a table and fills an array with the data
1461          *
1462          * @param string|array $table     Table name or array [schema => table]
1463          * @param array        $fields    Array of selected fields, empty for all
1464          * @param array        $condition Array of fields for condition
1465          * @param array        $params    Array of several parameters
1466          *
1467          * @return array Data array
1468          * @throws \Exception
1469          * @see   self::select
1470          */
1471         public function selectToArray($table, array $fields = [], array $condition = [], array $params = [])
1472         {
1473                 return $this->toArray($this->select($table, $fields, $condition, $params));
1474         }
1475
1476         /**
1477          * Select rows from a table
1478          *
1479          *
1480          * Example:
1481          * $table = 'item';
1482          * or:
1483          * $table = ['schema' => 'table'];
1484          * @see DBA::buildTableString()
1485          *
1486          * $fields = ['id', 'uri', 'uid', 'network'];
1487          *
1488          * $condition = ['uid' => 1, 'network' => 'dspr', 'blocked' => true];
1489          * or:
1490          * $condition = ['`uid` = ? AND `network` IN (?, ?)', 1, 'dfrn', 'dspr'];
1491          * @see DBA::buildCondition()
1492          *
1493          * $params = ['order' => ['id', 'received' => true, 'created' => 'ASC'), 'limit' => 10];
1494          * @see DBA::buildParameter()
1495          *
1496          * $data = DBA::select($table, $fields, $condition, $params);
1497          *
1498          * @param string|array $table     Table name or array [schema => table]
1499          * @param array        $fields    Array of selected fields, empty for all
1500          * @param array        $condition Array of fields for condition
1501          * @param array        $params    Array of several parameters
1502          * @return boolean|object
1503          * @throws \Exception
1504          */
1505         public function select($table, array $fields = [], array $condition = [], array $params = [])
1506         {
1507                 if (empty($table)) {
1508                         return false;
1509                 }
1510
1511                 if (count($fields) > 0) {
1512                         $select_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], $fields));
1513                 } else {
1514                         $select_string = '*';
1515                 }
1516
1517                 $table_string = DBA::buildTableString($table);
1518
1519                 $condition_string = DBA::buildCondition($condition);
1520
1521                 $param_string = DBA::buildParameter($params);
1522
1523                 $sql = "SELECT " . $select_string . " FROM " . $table_string . $condition_string . $param_string;
1524
1525                 $result = $this->p($sql, $condition);
1526
1527                 return $result;
1528         }
1529
1530         /**
1531          * Counts the rows from a table satisfying the provided condition
1532          *
1533          * @param string|array $table     Table name or array [schema => table]
1534          * @param array        $condition Array of fields for condition
1535          * @param array        $params    Array of several parameters
1536          *
1537          * @return int
1538          *
1539          * Example:
1540          * $table = "item";
1541          *
1542          * $condition = ["uid" => 1, "network" => 'dspr'];
1543          * or:
1544          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1545          *
1546          * $count = DBA::count($table, $condition);
1547          * @throws \Exception
1548          */
1549         public function count($table, array $condition = [], array $params = [])
1550         {
1551                 if (empty($table)) {
1552                         return false;
1553                 }
1554
1555                 $table_string = DBA::buildTableString($table);
1556
1557                 $condition_string = DBA::buildCondition($condition);
1558
1559                 if (empty($params['expression'])) {
1560                         $expression = '*';
1561                 } elseif (!empty($params['distinct'])) {
1562                         $expression = "DISTINCT " . DBA::quoteIdentifier($params['expression']);
1563                 } else {
1564                         $expression = DBA::quoteIdentifier($params['expression']);
1565                 }
1566
1567                 $sql = "SELECT COUNT(" . $expression . ") AS `count` FROM " . $table_string . $condition_string;
1568
1569                 $row = $this->fetchFirst($sql, $condition);
1570
1571                 return $row['count'];
1572         }
1573
1574         /**
1575          * Fills an array with data from a query
1576          *
1577          * @param object $stmt statement object
1578          * @param bool   $do_close
1579          *
1580          * @return array Data array
1581          */
1582         public function toArray($stmt, $do_close = true)
1583         {
1584                 if (is_bool($stmt)) {
1585                         return [];
1586                 }
1587
1588                 $data = [];
1589                 while ($row = $this->fetch($stmt)) {
1590                         $data[] = $row;
1591                 }
1592
1593                 if ($do_close) {
1594                         $this->close($stmt);
1595                 }
1596
1597                 return $data;
1598         }
1599
1600         /**
1601          * Returns the error number of the last query
1602          *
1603          * @return string Error number (0 if no error)
1604          */
1605         public function errorNo()
1606         {
1607                 return $this->errorno;
1608         }
1609
1610         /**
1611          * Returns the error message of the last query
1612          *
1613          * @return string Error message ('' if no error)
1614          */
1615         public function errorMessage()
1616         {
1617                 return $this->error;
1618         }
1619
1620         /**
1621          * Closes the current statement
1622          *
1623          * @param object $stmt statement object
1624          *
1625          * @return boolean was the close successful?
1626          */
1627         public function close($stmt)
1628         {
1629
1630                 $stamp1 = microtime(true);
1631
1632                 if (!is_object($stmt)) {
1633                         return false;
1634                 }
1635
1636                 switch ($this->driver) {
1637                         case 'pdo':
1638                                 $ret = $stmt->closeCursor();
1639                                 break;
1640                         case 'mysqli':
1641                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1642                                 // We should be careful not to assume the object type of $stmt
1643                                 // because DBA::p() has been able to return both types.
1644                                 if ($stmt instanceof mysqli_stmt) {
1645                                         $stmt->free_result();
1646                                         $ret = $stmt->close();
1647                                 } elseif ($stmt instanceof mysqli_result) {
1648                                         $stmt->free();
1649                                         $ret = true;
1650                                 } else {
1651                                         $ret = false;
1652                                 }
1653                                 break;
1654                 }
1655
1656                 $this->profiler->saveTimestamp($stamp1, 'database');
1657
1658                 return $ret;
1659         }
1660
1661         /**
1662          * Return a list of database processes
1663          *
1664          * @return array
1665          *      'list' => List of processes, separated in their different states
1666          *      'amount' => Number of concurrent database processes
1667          * @throws \Exception
1668          */
1669         public function processlist()
1670         {
1671                 $ret  = $this->p("SHOW PROCESSLIST");
1672                 $data = $this->toArray($ret);
1673
1674                 $processes = 0;
1675                 $states    = [];
1676                 foreach ($data as $process) {
1677                         $state = trim($process["State"]);
1678
1679                         // Filter out all non blocking processes
1680                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1681                                 ++$states[$state];
1682                                 ++$processes;
1683                         }
1684                 }
1685
1686                 $statelist = "";
1687                 foreach ($states as $state => $usage) {
1688                         if ($statelist != "") {
1689                                 $statelist .= ", ";
1690                         }
1691                         $statelist .= $state . ": " . $usage;
1692                 }
1693                 return (["list" => $statelist, "amount" => $processes]);
1694         }
1695
1696         /**
1697          * Fetch a database variable
1698          *
1699          * @param string $name
1700          * @return string content
1701          */
1702         public function getVariable(string $name)
1703         {
1704                 $result = $this->fetchFirst("SHOW GLOBAL VARIABLES WHERE `Variable_name` = ?", $name);
1705                 return $result['Value'] ?? null;
1706         }
1707
1708         /**
1709          * Checks if $array is a filled array with at least one entry.
1710          *
1711          * @param mixed $array A filled array with at least one entry
1712          *
1713          * @return boolean Whether $array is a filled array or an object with rows
1714          */
1715         public function isResult($array)
1716         {
1717                 // It could be a return value from an update statement
1718                 if (is_bool($array)) {
1719                         return $array;
1720                 }
1721
1722                 if (is_object($array)) {
1723                         return $this->numRows($array) > 0;
1724                 }
1725
1726                 return (is_array($array) && (count($array) > 0));
1727         }
1728
1729         /**
1730          * Callback function for "esc_array"
1731          *
1732          * @param mixed   $value         Array value
1733          * @param string  $key           Array key
1734          * @param boolean $add_quotation add quotation marks for string values
1735          *
1736          * @return void
1737          */
1738         private function escapeArrayCallback(&$value, $key, $add_quotation)
1739         {
1740                 if (!$add_quotation) {
1741                         if (is_bool($value)) {
1742                                 $value = ($value ? '1' : '0');
1743                         } else {
1744                                 $value = $this->escape($value);
1745                         }
1746                         return;
1747                 }
1748
1749                 if (is_bool($value)) {
1750                         $value = ($value ? 'true' : 'false');
1751                 } elseif (is_float($value) || is_integer($value)) {
1752                         $value = (string)$value;
1753                 } else {
1754                         $value = "'" . $this->escape($value) . "'";
1755                 }
1756         }
1757
1758         /**
1759          * Escapes a whole array
1760          *
1761          * @param mixed   $arr           Array with values to be escaped
1762          * @param boolean $add_quotation add quotation marks for string values
1763          *
1764          * @return void
1765          */
1766         public function escapeArray(&$arr, $add_quotation = false)
1767         {
1768                 array_walk($arr, [$this, 'escapeArrayCallback'], $add_quotation);
1769         }
1770 }