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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         const PDO = 'pdo';
43         const MYSQLI = 'mysqli';
44
45         const INSERT_DEFAULT = 0;
46         const INSERT_UPDATE = 1;
47         const INSERT_IGNORE = 2;
48
49         protected $connected = false;
50
51         /**
52          * @var Cache
53          */
54         protected $configCache;
55         /**
56          * @var Profiler
57          */
58         protected $profiler;
59         /**
60          * @var LoggerInterface
61          */
62         protected $logger;
63         protected $server_info    = '';
64         /** @var PDO|mysqli */
65         protected $connection;
66         protected $driver;
67         protected $emulate_prepares = false;
68         protected $pdo_emulate_prepares = false;
69         private $error          = false;
70         private $errorno        = 0;
71         private $affected_rows  = 0;
72         protected $in_transaction = false;
73         protected $in_retrial     = false;
74         protected $testmode       = false;
75         private $relation       = [];
76
77         public function __construct(Cache $configCache, Profiler $profiler, LoggerInterface $logger)
78         {
79                 // We are storing these values for being able to perform a reconnect
80                 $this->configCache   = $configCache;
81                 $this->profiler      = $profiler;
82                 $this->logger        = $logger;
83
84                 $this->connect();
85
86                 if ($this->isConnected()) {
87                         // Loads DB_UPDATE_VERSION constant
88                         DBStructure::definition($configCache->get('system', 'basepath'), false);
89                 }
90         }
91
92         public function connect()
93         {
94                 if (!is_null($this->connection) && $this->connected()) {
95                         return $this->connected;
96                 }
97
98                 // Reset connected state
99                 $this->connected = false;
100
101                 $port       = 0;
102                 $serveraddr = trim($this->configCache->get('database', 'hostname'));
103                 $serverdata = explode(':', $serveraddr);
104                 $server     = $serverdata[0];
105                 if (count($serverdata) > 1) {
106                         $port = trim($serverdata[1]);
107                 }
108
109                 if (!empty(trim($this->configCache->get('database', 'port')))) {
110                         $port = trim($this->configCache->get('database', 'port'));
111                 }
112
113                 $server  = trim($server);
114                 $user    = trim($this->configCache->get('database', 'username'));
115                 $pass    = trim($this->configCache->get('database', 'password'));
116                 $db      = trim($this->configCache->get('database', 'database'));
117                 $charset = trim($this->configCache->get('database', 'charset'));
118
119                 if (!(strlen($server) && strlen($user))) {
120                         return false;
121                 }
122
123                 $persistent = (bool)$this->configCache->get('database', 'persistent');
124
125                 $this->emulate_prepares = (bool)$this->configCache->get('database', 'emulate_prepares');
126                 $this->pdo_emulate_prepares = (bool)$this->configCache->get('database', 'pdo_emulate_prepares');
127
128                 if (!$this->configCache->get('database', 'disable_pdo') && class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
129                         $this->driver = self::PDO;
130                         $connect      = "mysql:host=" . $server . ";dbname=" . $db;
131
132                         if ($port > 0) {
133                                 $connect .= ";port=" . $port;
134                         }
135
136                         if ($charset) {
137                                 $connect .= ";charset=" . $charset;
138                         }
139
140                         try {
141                                 $this->connection = @new PDO($connect, $user, $pass, [PDO::ATTR_PERSISTENT => $persistent]);
142                                 $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
143                                 $this->connected = true;
144                         } catch (PDOException $e) {
145                                 $this->connected = false;
146                         }
147                 }
148
149                 if (!$this->connected && class_exists('\mysqli')) {
150                         $this->driver = self::MYSQLI;
151
152                         if ($port > 0) {
153                                 $this->connection = @new mysqli($server, $user, $pass, $db, $port);
154                         } else {
155                                 $this->connection = @new mysqli($server, $user, $pass, $db);
156                         }
157
158                         if (!mysqli_connect_errno()) {
159                                 $this->connected = true;
160
161                                 if ($charset) {
162                                         $this->connection->set_charset($charset);
163                                 }
164                         }
165                 }
166
167                 // No suitable SQL driver was found.
168                 if (!$this->connected) {
169                         $this->driver     = null;
170                         $this->connection = null;
171                 }
172
173                 return $this->connected;
174         }
175
176         public function setTestmode(bool $test)
177         {
178                 $this->testmode = $test;
179         }
180         /**
181          * Sets the logger for DBA
182          *
183          * @note this is necessary because if we want to load the logger configuration
184          *       from the DB, but there's an error, we would print out an exception.
185          *       So the logger gets updated after the logger configuration can be retrieved
186          *       from the database
187          *
188          * @param LoggerInterface $logger
189          */
190         public function setLogger(LoggerInterface $logger)
191         {
192                 $this->logger = $logger;
193         }
194
195         /**
196          * Sets the profiler for DBA
197          *
198          * @param Profiler $profiler
199          */
200         public function setProfiler(Profiler $profiler)
201         {
202                 $this->profiler = $profiler;
203         }
204         /**
205          * Disconnects the current database connection
206          */
207         public function disconnect()
208         {
209                 if (!is_null($this->connection)) {
210                         switch ($this->driver) {
211                                 case self::PDO:
212                                         $this->connection = null;
213                                         break;
214                                 case self::MYSQLI:
215                                         $this->connection->close();
216                                         $this->connection = null;
217                                         break;
218                         }
219                 }
220
221                 $this->driver    = null;
222                 $this->connected = false;
223         }
224
225         /**
226          * Perform a reconnect of an existing database connection
227          */
228         public function reconnect()
229         {
230                 $this->disconnect();
231                 return $this->connect();
232         }
233
234         /**
235          * Return the database object.
236          *
237          * @return PDO|mysqli
238          */
239         public function getConnection()
240         {
241                 return $this->connection;
242         }
243
244         /**
245          * Return the database driver string
246          *
247          * @return string with either "pdo" or "mysqli"
248          */
249         public function getDriver()
250         {
251                 return $this->driver;
252         }
253
254         /**
255          * Returns the MySQL server version string
256          *
257          * This function discriminate between the deprecated mysql API and the current
258          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
259          *
260          * @return string
261          */
262         public function serverInfo()
263         {
264                 if ($this->server_info == '') {
265                         switch ($this->driver) {
266                                 case self::PDO:
267                                         $this->server_info = $this->connection->getAttribute(PDO::ATTR_SERVER_VERSION);
268                                         break;
269                                 case self::MYSQLI:
270                                         $this->server_info = $this->connection->server_info;
271                                         break;
272                         }
273                 }
274                 return $this->server_info;
275         }
276
277         /**
278          * Returns the selected database name
279          *
280          * @return string
281          * @throws \Exception
282          */
283         public function databaseName()
284         {
285                 $ret  = $this->p("SELECT DATABASE() AS `db`");
286                 $data = $this->toArray($ret);
287                 return $data[0]['db'];
288         }
289
290         /**
291          * Analyze a database query and log this if some conditions are met.
292          *
293          * @param string $query The database query that will be analyzed
294          *
295          * @throws \Exception
296          */
297         private function logIndex($query)
298         {
299
300                 if (!$this->configCache->get('system', 'db_log_index')) {
301                         return;
302                 }
303
304                 // Don't explain an explain statement
305                 if (strtolower(substr($query, 0, 7)) == "explain") {
306                         return;
307                 }
308
309                 // Only do the explain on "select", "update" and "delete"
310                 if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
311                         return;
312                 }
313
314                 $r = $this->p("EXPLAIN " . $query);
315                 if (!$this->isResult($r)) {
316                         return;
317                 }
318
319                 $watchlist = explode(',', $this->configCache->get('system', 'db_log_index_watch'));
320                 $denylist = explode(',', $this->configCache->get('system', 'db_log_index_denylist'));
321
322                 while ($row = $this->fetch($r)) {
323                         if ((intval($this->configCache->get('system', 'db_loglimit_index')) > 0)) {
324                                 $log = (in_array($row['key'], $watchlist) &&
325                                         ($row['rows'] >= intval($this->configCache->get('system', 'db_loglimit_index'))));
326                         } else {
327                                 $log = false;
328                         }
329
330                         if ((intval($this->configCache->get('system', 'db_loglimit_index_high')) > 0) && ($row['rows'] >= intval($this->configCache->get('system', 'db_loglimit_index_high')))) {
331                                 $log = true;
332                         }
333
334                         if (in_array($row['key'], $denylist) || ($row['key'] == "")) {
335                                 $log = false;
336                         }
337
338                         if ($log) {
339                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
340                                 @file_put_contents($this->configCache->get('system', 'db_log_index'), DateTimeFormat::utcNow() . "\t" .
341                                                                                                       $row['key'] . "\t" . $row['rows'] . "\t" . $row['Extra'] . "\t" .
342                                                                                                       basename($backtrace[1]["file"]) . "\t" .
343                                                                                                       $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
344                                                                                                       substr($query, 0, 4000) . "\n", FILE_APPEND);
345                         }
346                 }
347         }
348
349         /**
350          * Removes every not allowlisted character from the identifier string
351          *
352          * @param string $identifier
353          *
354          * @return string sanitized identifier
355          * @throws \Exception
356          */
357         private function sanitizeIdentifier($identifier)
358         {
359                 return preg_replace('/[^A-Za-z0-9_\-]+/', '', $identifier);
360         }
361
362         public function escape($str)
363         {
364                 if ($this->connected) {
365                         switch ($this->driver) {
366                                 case self::PDO:
367                                         return substr(@$this->connection->quote($str, PDO::PARAM_STR), 1, -1);
368
369                                 case self::MYSQLI:
370                                         return @$this->connection->real_escape_string($str);
371                         }
372                 } else {
373                         return str_replace("'", "\\'", $str);
374                 }
375         }
376
377         public function isConnected()
378         {
379                 return $this->connected;
380         }
381
382         public function connected()
383         {
384                 $connected = false;
385
386                 if (is_null($this->connection)) {
387                         return false;
388                 }
389
390                 switch ($this->driver) {
391                         case self::PDO:
392                                 $r = $this->p("SELECT 1");
393                                 if ($this->isResult($r)) {
394                                         $row       = $this->toArray($r);
395                                         $connected = ($row[0]['1'] == '1');
396                                 }
397                                 break;
398                         case self::MYSQLI:
399                                 $connected = $this->connection->ping();
400                                 break;
401                 }
402
403                 return $connected;
404         }
405
406         /**
407          * Replaces ANY_VALUE() function by MIN() function,
408          * if the database server does not support ANY_VALUE().
409          *
410          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
411          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
412          * A standard fall-back is to use MIN().
413          *
414          * @param string $sql An SQL string without the values
415          *
416          * @return string The input SQL string modified if necessary.
417          */
418         public function anyValueFallback($sql)
419         {
420                 $server_info = $this->serverInfo();
421                 if (version_compare($server_info, '5.7.5', '<') ||
422                     (stripos($server_info, 'MariaDB') !== false)) {
423                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
424                 }
425                 return $sql;
426         }
427
428         /**
429          * Replaces the ? placeholders with the parameters in the $args array
430          *
431          * @param string $sql  SQL query
432          * @param array  $args The parameters that are to replace the ? placeholders
433          *
434          * @return string The replaced SQL query
435          */
436         private function replaceParameters($sql, $args)
437         {
438                 $offset = 0;
439                 foreach ($args AS $param => $value) {
440                         if (is_int($args[$param]) || is_float($args[$param]) || is_bool($args[$param])) {
441                                 $replace = intval($args[$param]);
442                         } elseif (is_null($args[$param])) {
443                                 $replace = 'NULL';
444                         } else {
445                                 $replace = "'" . $this->escape($args[$param]) . "'";
446                         }
447
448                         $pos = strpos($sql, '?', $offset);
449                         if ($pos !== false) {
450                                 $sql = substr_replace($sql, $replace, $pos, 1);
451                         }
452                         $offset = $pos + strlen($replace);
453                 }
454                 return $sql;
455         }
456
457         /**
458          * Executes a prepared statement that returns data
459          *
460          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
461          *
462          * Please only use it with complicated queries.
463          * For all regular queries please use DBA::select or DBA::exists
464          *
465          * @param string $sql SQL statement
466          *
467          * @return bool|object statement object or result object
468          * @throws \Exception
469          */
470         public function p($sql)
471         {
472
473                 $stamp1 = microtime(true);
474
475                 $params = DBA::getParam(func_get_args());
476
477                 // Renumber the array keys to be sure that they fit
478                 $i    = 0;
479                 $args = [];
480                 foreach ($params AS $param) {
481                         // Avoid problems with some MySQL servers and boolean values. See issue #3645
482                         if (is_bool($param)) {
483                                 $param = (int)$param;
484                         }
485                         $args[++$i] = $param;
486                 }
487
488                 if (!$this->connected) {
489                         return false;
490                 }
491
492                 if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
493                         // Question: Should we continue or stop the query here?
494                         $this->logger->warning('Query parameters mismatch.', ['query' => $sql, 'args' => $args, 'callstack' => System::callstack()]);
495                 }
496
497                 $sql = DBA::cleanQuery($sql);
498                 $sql = $this->anyValueFallback($sql);
499
500                 $orig_sql = $sql;
501
502                 if ($this->configCache->get('system', 'db_callstack') !== null) {
503                         $sql = "/*" . System::callstack() . " */ " . $sql;
504                 }
505
506                 $is_error            = false;
507                 $this->error         = '';
508                 $this->errorno       = 0;
509                 $this->affected_rows = 0;
510
511                 // We have to make some things different if this function is called from "e"
512                 $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);
513
514                 if (isset($trace[1])) {
515                         $called_from = $trace[1];
516                 } else {
517                         // We use just something that is defined to avoid warnings
518                         $called_from = $trace[0];
519                 }
520                 // We are having an own error logging in the function "e"
521                 $called_from_e = ($called_from['function'] == 'e');
522
523                 if (!isset($this->connection)) {
524                         throw new InternalServerErrorException('The Connection is empty, although connected is set true.');
525                 }
526
527                 switch ($this->driver) {
528                         case self::PDO:
529                                 // If there are no arguments we use "query"
530                                 if ($this->emulate_prepares || count($args) == 0) {
531                                         if (!$retval = $this->connection->query($this->replaceParameters($sql, $args))) {
532                                                 $errorInfo     = $this->connection->errorInfo();
533                                                 $this->error   = $errorInfo[2];
534                                                 $this->errorno = $errorInfo[1];
535                                                 $retval        = false;
536                                                 $is_error      = true;
537                                                 break;
538                                         }
539                                         $this->affected_rows = $retval->rowCount();
540                                         break;
541                                 }
542
543                                 /** @var $stmt mysqli_stmt|PDOStatement */
544                                 if (!$stmt = $this->connection->prepare($sql)) {
545                                         $errorInfo     = $this->connection->errorInfo();
546                                         $this->error   = $errorInfo[2];
547                                         $this->errorno = $errorInfo[1];
548                                         $retval        = false;
549                                         $is_error      = true;
550                                         break;
551                                 }
552
553                                 foreach ($args AS $param => $value) {
554                                         if (is_int($args[$param])) {
555                                                 $data_type = PDO::PARAM_INT;
556                                         } else {
557                                                 $data_type = PDO::PARAM_STR;
558                                         }
559                                         $stmt->bindParam($param, $args[$param], $data_type);
560                                 }
561
562                                 if (!$stmt->execute()) {
563                                         $errorInfo     = $stmt->errorInfo();
564                                         $this->error   = $errorInfo[2];
565                                         $this->errorno = $errorInfo[1];
566                                         $retval        = false;
567                                         $is_error      = true;
568                                 } else {
569                                         $retval              = $stmt;
570                                         $this->affected_rows = $retval->rowCount();
571                                 }
572                                 break;
573                         case self::MYSQLI:
574                                 // There are SQL statements that cannot be executed with a prepared statement
575                                 $parts           = explode(' ', $orig_sql);
576                                 $command         = strtolower($parts[0]);
577                                 $can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);
578
579                                 // The fallback routine is called as well when there are no arguments
580                                 if ($this->emulate_prepares || !$can_be_prepared || (count($args) == 0)) {
581                                         $retval = $this->connection->query($this->replaceParameters($sql, $args));
582                                         if ($this->connection->errno) {
583                                                 $this->error   = $this->connection->error;
584                                                 $this->errorno = $this->connection->errno;
585                                                 $retval        = false;
586                                                 $is_error      = true;
587                                         } else {
588                                                 if (isset($retval->num_rows)) {
589                                                         $this->affected_rows = $retval->num_rows;
590                                                 } else {
591                                                         $this->affected_rows = $this->connection->affected_rows;
592                                                 }
593                                         }
594                                         break;
595                                 }
596
597                                 $stmt = $this->connection->stmt_init();
598
599                                 if (!$stmt->prepare($sql)) {
600                                         $this->error   = $stmt->error;
601                                         $this->errorno = $stmt->errno;
602                                         $retval        = false;
603                                         $is_error      = true;
604                                         break;
605                                 }
606
607                                 $param_types = '';
608                                 $values      = [];
609                                 foreach ($args AS $param => $value) {
610                                         if (is_int($args[$param])) {
611                                                 $param_types .= 'i';
612                                         } elseif (is_float($args[$param])) {
613                                                 $param_types .= 'd';
614                                         } elseif (is_string($args[$param])) {
615                                                 $param_types .= 's';
616                                         } else {
617                                                 $param_types .= 'b';
618                                         }
619                                         $values[] = &$args[$param];
620                                 }
621
622                                 if (count($values) > 0) {
623                                         array_unshift($values, $param_types);
624                                         call_user_func_array([$stmt, 'bind_param'], $values);
625                                 }
626
627                                 if (!$stmt->execute()) {
628                                         $this->error   = $this->connection->error;
629                                         $this->errorno = $this->connection->errno;
630                                         $retval        = false;
631                                         $is_error      = true;
632                                 } else {
633                                         $stmt->store_result();
634                                         $retval              = $stmt;
635                                         $this->affected_rows = $retval->affected_rows;
636                                 }
637                                 break;
638                 }
639
640                 // See issue https://github.com/friendica/friendica/issues/8572
641                 // Ensure that we always get an error message on an error.
642                 if ($is_error && empty($this->errorno)) {
643                         $this->errorno = -1;
644                 }
645
646                 if ($is_error && empty($this->error)) {
647                         $this->error = 'Unknown database error';
648                 }
649
650                 // We are having an own error logging in the function "e"
651                 if (($this->errorno != 0) && !$called_from_e) {
652                         // We have to preserve the error code, somewhere in the logging it get lost
653                         $error   = $this->error;
654                         $errorno = $this->errorno;
655
656                         if ($this->testmode) {
657                                 throw new DatabaseException($error, $errorno, $this->replaceParameters($sql, $args));
658                         }
659
660                         $this->logger->error('DB Error', [
661                                 'code'      => $errorno,
662                                 'error'     => $error,
663                                 'callstack' => System::callstack(8),
664                                 'params'    => $this->replaceParameters($sql, $args),
665                         ]);
666
667                         // On a lost connection we try to reconnect - but only once.
668                         if ($errorno == 2006) {
669                                 if ($this->in_retrial || !$this->reconnect()) {
670                                         // It doesn't make sense to continue when the database connection was lost
671                                         if ($this->in_retrial) {
672                                                 $this->logger->notice('Giving up retrial because of database error', [
673                                                         'code'  => $errorno,
674                                                         'error' => $error,
675                                                 ]);
676                                         } else {
677                                                 $this->logger->notice('Couldn\'t reconnect after database error', [
678                                                         'code'  => $errorno,
679                                                         'error' => $error,
680                                                 ]);
681                                         }
682                                         exit(1);
683                                 } else {
684                                         // We try it again
685                                         $this->logger->notice('Reconnected after database error', [
686                                                 'code'  => $errorno,
687                                                 'error' => $error,
688                                         ]);
689                                         $this->in_retrial = true;
690                                         $ret              = $this->p($sql, $args);
691                                         $this->in_retrial = false;
692                                         return $ret;
693                                 }
694                         }
695
696                         $this->error   = $error;
697                         $this->errorno = $errorno;
698                 }
699
700                 $this->profiler->saveTimestamp($stamp1, 'database');
701
702                 if ($this->configCache->get('system', 'db_log')) {
703                         $stamp2   = microtime(true);
704                         $duration = (float)($stamp2 - $stamp1);
705
706                         if (($duration > $this->configCache->get('system', 'db_loglimit'))) {
707                                 $duration  = round($duration, 3);
708                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
709
710                                 @file_put_contents($this->configCache->get('system', 'db_log'), DateTimeFormat::utcNow() . "\t" . $duration . "\t" .
711                                                                                                 basename($backtrace[1]["file"]) . "\t" .
712                                                                                                 $backtrace[1]["line"] . "\t" . $backtrace[2]["function"] . "\t" .
713                                                                                                 substr($this->replaceParameters($sql, $args), 0, 4000) . "\n", FILE_APPEND);
714                         }
715                 }
716                 return $retval;
717         }
718
719         /**
720          * Executes a prepared statement like UPDATE or INSERT that doesn't return data
721          *
722          * Please use DBA::delete, DBA::insert, DBA::update, ... instead
723          *
724          * @param string $sql SQL statement
725          *
726          * @return boolean Was the query successfull? False is returned only if an error occurred
727          * @throws \Exception
728          */
729         public function e($sql)
730         {
731
732                 $stamp = microtime(true);
733
734                 $params = DBA::getParam(func_get_args());
735
736                 // In a case of a deadlock we are repeating the query 20 times
737                 $timeout = 20;
738
739                 do {
740                         $stmt = $this->p($sql, $params);
741
742                         if (is_bool($stmt)) {
743                                 $retval = $stmt;
744                         } elseif (is_object($stmt)) {
745                                 $retval = true;
746                         } else {
747                                 $retval = false;
748                         }
749
750                         $this->close($stmt);
751
752                 } while (($this->errorno == 1213) && (--$timeout > 0));
753
754                 if ($this->errorno != 0) {
755                         // We have to preserve the error code, somewhere in the logging it get lost
756                         $error   = $this->error;
757                         $errorno = $this->errorno;
758
759                         if ($this->testmode) {
760                                 throw new DatabaseException($error, $errorno, $this->replaceParameters($sql, $params));
761                         }
762
763                         $this->logger->error('DB Error', [
764                                 'code'      => $errorno,
765                                 'error'     => $error,
766                                 'callstack' => System::callstack(8),
767                                 'params'    => $this->replaceParameters($sql, $params),
768                         ]);
769
770                         // On a lost connection we simply quit.
771                         // A reconnect like in $this->p could be dangerous with modifications
772                         if ($errorno == 2006) {
773                                 $this->logger->notice('Giving up because of database error', [
774                                         'code'  => $errorno,
775                                         'error' => $error,
776                                 ]);
777                                 exit(1);
778                         }
779
780                         $this->error   = $error;
781                         $this->errorno = $errorno;
782                 }
783
784                 $this->profiler->saveTimestamp($stamp, "database_write");
785
786                 return $retval;
787         }
788
789         /**
790          * Check if data exists
791          *
792          * @param string|array $table     Table name or array [schema => table]
793          * @param array        $condition array of fields for condition
794          *
795          * @return boolean Are there rows for that condition?
796          * @throws \Exception
797          */
798         public function exists($table, $condition)
799         {
800                 if (empty($table)) {
801                         return false;
802                 }
803
804                 $fields = [];
805
806                 if (empty($condition)) {
807                         return DBStructure::existsTable($table);
808                 }
809
810                 reset($condition);
811                 $first_key = key($condition);
812                 if (!is_int($first_key)) {
813                         $fields = [$first_key];
814                 }
815
816                 $stmt = $this->select($table, $fields, $condition, ['limit' => 1]);
817
818                 if (is_bool($stmt)) {
819                         $retval = $stmt;
820                 } else {
821                         $retval = ($this->numRows($stmt) > 0);
822                 }
823
824                 $this->close($stmt);
825
826                 return $retval;
827         }
828
829         /**
830          * Fetches the first row
831          *
832          * Please use DBA::selectFirst or DBA::exists whenever this is possible.
833          *
834          * Fetches the first row
835          *
836          * @param string $sql SQL statement
837          *
838          * @return array first row of query
839          * @throws \Exception
840          */
841         public function fetchFirst($sql)
842         {
843                 $params = DBA::getParam(func_get_args());
844
845                 $stmt = $this->p($sql, $params);
846
847                 if (is_bool($stmt)) {
848                         $retval = $stmt;
849                 } else {
850                         $retval = $this->fetch($stmt);
851                 }
852
853                 $this->close($stmt);
854
855                 return $retval;
856         }
857
858         /**
859          * Returns the number of affected rows of the last statement
860          *
861          * @return int Number of rows
862          */
863         public function affectedRows()
864         {
865                 return $this->affected_rows;
866         }
867
868         /**
869          * Returns the number of columns of a statement
870          *
871          * @param object Statement object
872          *
873          * @return int Number of columns
874          */
875         public function columnCount($stmt)
876         {
877                 if (!is_object($stmt)) {
878                         return 0;
879                 }
880                 switch ($this->driver) {
881                         case self::PDO:
882                                 return $stmt->columnCount();
883                         case self::MYSQLI:
884                                 return $stmt->field_count;
885                 }
886                 return 0;
887         }
888
889         /**
890          * Returns the number of rows of a statement
891          *
892          * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
893          *
894          * @return int Number of rows
895          */
896         public function numRows($stmt)
897         {
898                 if (!is_object($stmt)) {
899                         return 0;
900                 }
901                 switch ($this->driver) {
902                         case self::PDO:
903                                 return $stmt->rowCount();
904                         case self::MYSQLI:
905                                 return $stmt->num_rows;
906                 }
907                 return 0;
908         }
909
910         /**
911          * Fetch a single row
912          *
913          * @param mixed $stmt statement object
914          *
915          * @return array current row
916          */
917         public function fetch($stmt)
918         {
919
920                 $stamp1 = microtime(true);
921
922                 $columns = [];
923
924                 if (!is_object($stmt)) {
925                         return false;
926                 }
927
928                 switch ($this->driver) {
929                         case self::PDO:
930                                 $columns = $stmt->fetch(PDO::FETCH_ASSOC);
931                                 if (!empty($stmt->table) && is_array($columns)) {
932                                         $columns = $this->castFields($stmt->table, $columns);
933                                 }
934                                 break;
935                         case self::MYSQLI:
936                                 if (get_class($stmt) == 'mysqli_result') {
937                                         $columns = $stmt->fetch_assoc();
938                                         break;
939                                 }
940
941                                 // This code works, but is slow
942
943                                 // Bind the result to a result array
944                                 $cols = [];
945
946                                 $cols_num = [];
947                                 for ($x = 0; $x < $stmt->field_count; $x++) {
948                                         $cols[] = &$cols_num[$x];
949                                 }
950
951                                 call_user_func_array([$stmt, 'bind_result'], $cols);
952
953                                 if (!$stmt->fetch()) {
954                                         return false;
955                                 }
956
957                                 // The slow part:
958                                 // We need to get the field names for the array keys
959                                 // It seems that there is no better way to do this.
960                                 $result = $stmt->result_metadata();
961                                 $fields = $result->fetch_fields();
962
963                                 foreach ($cols_num AS $param => $col) {
964                                         $columns[$fields[$param]->name] = $col;
965                                 }
966                 }
967
968                 $this->profiler->saveTimestamp($stamp1, 'database');
969
970                 return $columns;
971         }
972
973         /**
974          * Insert a row into a table
975          *
976          * @param string|array $table          Table name or array [schema => table]
977          * @param array        $param          parameter array
978          * @param int          $duplicate_mode What to do on a duplicated entry
979          *
980          * @return boolean was the insert successful?
981          * @throws \Exception
982          */
983         public function insert($table, array $param, int $duplicate_mode = self::INSERT_DEFAULT)
984         {
985                 if (empty($table) || empty($param)) {
986                         $this->logger->info('Table and fields have to be set');
987                         return false;
988                 }
989
990                 $param = $this->castFields($table, $param);
991
992                 $table_string = DBA::buildTableString($table);
993
994                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
995
996                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
997
998                 $sql = "INSERT ";
999
1000                 if ($duplicate_mode == self::INSERT_IGNORE) {
1001                         $sql .= "IGNORE ";
1002                 }
1003
1004                 $sql .= "INTO " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
1005
1006                 if ($duplicate_mode == self::INSERT_UPDATE) {
1007                         $fields_string = implode(' = ?, ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
1008
1009                         $sql .= " ON DUPLICATE KEY UPDATE " . $fields_string . " = ?";
1010
1011                         $values = array_values($param);
1012                         $param  = array_merge_recursive($values, $values);
1013                 }
1014
1015                 $result = $this->e($sql, $param);
1016                 if (!$result || ($duplicate_mode != self::INSERT_IGNORE)) {
1017                         return $result;
1018                 }
1019
1020                 return $this->affectedRows() != 0;
1021         }
1022
1023         /**
1024          * Inserts a row with the provided data in the provided table.
1025          * If the data corresponds to an existing row through a UNIQUE or PRIMARY index constraints, it updates the row instead.
1026          *
1027          * @param string|array $table Table name or array [schema => table]
1028          * @param array        $param parameter array
1029          *
1030          * @return boolean was the insert successful?
1031          * @throws \Exception
1032          */
1033         public function replace($table, array $param)
1034         {
1035                 if (empty($table) || empty($param)) {
1036                         $this->logger->info('Table and fields have to be set');
1037                         return false;
1038                 }
1039
1040                 $param = $this->castFields($table, $param);
1041
1042                 $table_string = DBA::buildTableString($table);
1043
1044                 $fields_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], array_keys($param)));
1045
1046                 $values_string = substr(str_repeat("?, ", count($param)), 0, -2);
1047
1048                 $sql = "REPLACE " . $table_string . " (" . $fields_string . ") VALUES (" . $values_string . ")";
1049
1050                 return $this->e($sql, $param);
1051         }
1052
1053         /**
1054          * Fetch the id of the last insert command
1055          *
1056          * @return integer Last inserted id
1057          */
1058         public function lastInsertId()
1059         {
1060                 switch ($this->driver) {
1061                         case self::PDO:
1062                                 $id = $this->connection->lastInsertId();
1063                                 break;
1064                         case self::MYSQLI:
1065                                 $id = $this->connection->insert_id;
1066                                 break;
1067                 }
1068                 return (int)$id;
1069         }
1070
1071         /**
1072          * Locks a table for exclusive write access
1073          *
1074          * This function can be extended in the future to accept a table array as well.
1075          *
1076          * @param string|array $table Table name or array [schema => table]
1077          *
1078          * @return boolean was the lock successful?
1079          * @throws \Exception
1080          */
1081         public function lock($table)
1082         {
1083                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1084                 if ($this->driver == self::PDO) {
1085                         $this->e("SET autocommit=0");
1086                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1087                 } else {
1088                         $this->connection->autocommit(false);
1089                 }
1090
1091                 $success = $this->e("LOCK TABLES " . DBA::buildTableString($table) . " WRITE");
1092
1093                 if ($this->driver == self::PDO) {
1094                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
1095                 }
1096
1097                 if (!$success) {
1098                         if ($this->driver == self::PDO) {
1099                                 $this->e("SET autocommit=1");
1100                         } else {
1101                                 $this->connection->autocommit(true);
1102                         }
1103                 } else {
1104                         $this->in_transaction = true;
1105                 }
1106                 return $success;
1107         }
1108
1109         /**
1110          * Unlocks all locked tables
1111          *
1112          * @return boolean was the unlock successful?
1113          * @throws \Exception
1114          */
1115         public function unlock()
1116         {
1117                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
1118                 $this->performCommit();
1119
1120                 if ($this->driver == self::PDO) {
1121                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
1122                 }
1123
1124                 $success = $this->e("UNLOCK TABLES");
1125
1126                 if ($this->driver == self::PDO) {
1127                         $this->connection->setAttribute(PDO::ATTR_EMULATE_PREPARES, $this->pdo_emulate_prepares);
1128                         $this->e("SET autocommit=1");
1129                 } else {
1130                         $this->connection->autocommit(true);
1131                 }
1132
1133                 $this->in_transaction = false;
1134                 return $success;
1135         }
1136
1137         /**
1138          * Starts a transaction
1139          *
1140          * @return boolean Was the command executed successfully?
1141          */
1142         public function transaction()
1143         {
1144                 if (!$this->performCommit()) {
1145                         return false;
1146                 }
1147
1148                 switch ($this->driver) {
1149                         case self::PDO:
1150                                 if (!$this->connection->inTransaction() && !$this->connection->beginTransaction()) {
1151                                         return false;
1152                                 }
1153                                 break;
1154
1155                         case self::MYSQLI:
1156                                 if (!$this->connection->begin_transaction()) {
1157                                         return false;
1158                                 }
1159                                 break;
1160                 }
1161
1162                 $this->in_transaction = true;
1163                 return true;
1164         }
1165
1166         protected function performCommit()
1167         {
1168                 switch ($this->driver) {
1169                         case self::PDO:
1170                                 if (!$this->connection->inTransaction()) {
1171                                         return true;
1172                                 }
1173
1174                                 return $this->connection->commit();
1175
1176                         case self::MYSQLI:
1177                                 return $this->connection->commit();
1178                 }
1179
1180                 return true;
1181         }
1182
1183         /**
1184          * Does a commit
1185          *
1186          * @return boolean Was the command executed successfully?
1187          */
1188         public function commit()
1189         {
1190                 if (!$this->performCommit()) {
1191                         return false;
1192                 }
1193                 $this->in_transaction = false;
1194                 return true;
1195         }
1196
1197         /**
1198          * Does a rollback
1199          *
1200          * @return boolean Was the command executed successfully?
1201          */
1202         public function rollback()
1203         {
1204                 $ret = false;
1205
1206                 switch ($this->driver) {
1207                         case self::PDO:
1208                                 if (!$this->connection->inTransaction()) {
1209                                         $ret = true;
1210                                         break;
1211                                 }
1212                                 $ret = $this->connection->rollBack();
1213                                 break;
1214
1215                         case self::MYSQLI:
1216                                 $ret = $this->connection->rollback();
1217                                 break;
1218                 }
1219                 $this->in_transaction = false;
1220                 return $ret;
1221         }
1222
1223         /**
1224          * Build the array with the table relations
1225          *
1226          * The array is build from the database definitions in DBStructure.php
1227          *
1228          * This process must only be started once, since the value is cached.
1229          */
1230         private function buildRelationData()
1231         {
1232                 $definition = DBStructure::definition($this->configCache->get('system', 'basepath'));
1233
1234                 foreach ($definition AS $table => $structure) {
1235                         foreach ($structure['fields'] AS $field => $field_struct) {
1236                                 if (isset($field_struct['relation'])) {
1237                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
1238                                                 $this->relation[$rel_table][$rel_field][$table][] = $field;
1239                                         }
1240                                 }
1241                         }
1242                 }
1243         }
1244
1245         /**
1246          * Delete a row from a table
1247          *
1248          * Note: this methods does NOT accept schema => table arrays because of the complex relation stuff.
1249          *
1250          * @param string $table      Table name
1251          * @param array  $conditions Field condition(s)
1252          * @param array  $options
1253          *                           - cascade: If true we delete records in other tables that depend on the one we're deleting through
1254          *                           relations (default: true)
1255          * @param array  $callstack  Internal use: prevent endless loops
1256          *
1257          * @return boolean was the delete successful?
1258          * @throws \Exception
1259          */
1260         public function delete($table, array $conditions, array $options = [], array &$callstack = [])
1261         {
1262                 if (empty($table) || empty($conditions)) {
1263                         $this->logger->info('Table and conditions have to be set');
1264                         return false;
1265                 }
1266
1267                 $commands = [];
1268
1269                 // Create a key for the loop prevention
1270                 $key = $table . ':' . json_encode($conditions);
1271
1272                 // We quit when this key already exists in the callstack.
1273                 if (isset($callstack[$key])) {
1274                         return true;
1275                 }
1276
1277                 $callstack[$key] = true;
1278
1279                 $commands[$key] = ['table' => $table, 'conditions' => $conditions];
1280
1281                 // Don't use "defaults" here, since it would set "false" to "true"
1282                 if (isset($options['cascade'])) {
1283                         $cascade = $options['cascade'];
1284                 } else {
1285                         $cascade = true;
1286                 }
1287
1288                 // To speed up the whole process we cache the table relations
1289                 if ($cascade && count($this->relation) == 0) {
1290                         $this->buildRelationData();
1291                 }
1292
1293                 // Is there a relation entry for the table?
1294                 if ($cascade && isset($this->relation[$table])) {
1295                         // We only allow a simple "one field" relation.
1296                         $field   = array_keys($this->relation[$table])[0];
1297                         $rel_def = array_values($this->relation[$table])[0];
1298
1299                         // Create a key for preventing double queries
1300                         $qkey = $field . '-' . $table . ':' . json_encode($conditions);
1301
1302                         // When the search field is the relation field, we don't need to fetch the rows
1303                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1304                         if ((count($conditions) == 1) && ($field == array_keys($conditions)[0])) {
1305                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1306                                         foreach ($rel_fields AS $rel_field) {
1307                                                 $this->delete($rel_table, [$rel_field => array_values($conditions)[0]], $options, $callstack);
1308                                         }
1309                                 }
1310                                 // We quit when this key already exists in the callstack.
1311                         } elseif (!isset($callstack[$qkey])) {
1312                                 $callstack[$qkey] = true;
1313
1314                                 // Fetch all rows that are to be deleted
1315                                 $data = $this->select($table, [$field], $conditions);
1316
1317                                 while ($row = $this->fetch($data)) {
1318                                         $this->delete($table, [$field => $row[$field]], $options, $callstack);
1319                                 }
1320
1321                                 $this->close($data);
1322
1323                                 // Since we had split the delete command we don't need the original command anymore
1324                                 unset($commands[$key]);
1325                         }
1326                 }
1327
1328                 // Now we finalize the process
1329                 $do_transaction = !$this->in_transaction;
1330
1331                 if ($do_transaction) {
1332                         $this->transaction();
1333                 }
1334
1335                 $compacted = [];
1336                 $counter   = [];
1337
1338                 foreach ($commands AS $command) {
1339                         $conditions = $command['conditions'];
1340                         reset($conditions);
1341                         $first_key = key($conditions);
1342
1343                         $condition_string = DBA::buildCondition($conditions);
1344
1345                         if ((count($command['conditions']) > 1) || is_int($first_key)) {
1346                                 $sql = "DELETE FROM " . DBA::quoteIdentifier($command['table']) . " " . $condition_string;
1347                                 $this->logger->info($this->replaceParameters($sql, $conditions), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1348
1349                                 if (!$this->e($sql, $conditions)) {
1350                                         if ($do_transaction) {
1351                                                 $this->rollback();
1352                                         }
1353                                         return false;
1354                                 }
1355                         } else {
1356                                 $key_table     = $command['table'];
1357                                 $key_condition = array_keys($command['conditions'])[0];
1358                                 $value         = array_values($command['conditions'])[0];
1359
1360                                 // Split the SQL queries in chunks of 100 values
1361                                 // We do the $i stuff here to make the code better readable
1362                                 $i = isset($counter[$key_table][$key_condition]) ? $counter[$key_table][$key_condition] : 0;
1363                                 if (isset($compacted[$key_table][$key_condition][$i]) && count($compacted[$key_table][$key_condition][$i]) > 100) {
1364                                         ++$i;
1365                                 }
1366
1367                                 $compacted[$key_table][$key_condition][$i][$value] = $value;
1368                                 $counter[$key_table][$key_condition]               = $i;
1369                         }
1370                 }
1371                 foreach ($compacted AS $table => $values) {
1372                         foreach ($values AS $field => $field_value_list) {
1373                                 foreach ($field_value_list AS $field_values) {
1374                                         $sql = "DELETE FROM " . DBA::quoteIdentifier($table) . " WHERE " . DBA::quoteIdentifier($field) . " IN (" .
1375                                                substr(str_repeat("?, ", count($field_values)), 0, -2) . ");";
1376
1377                                         $this->logger->info($this->replaceParameters($sql, $field_values), ['callstack' => System::callstack(6), 'internal_callstack' => $callstack]);
1378
1379                                         if (!$this->e($sql, $field_values)) {
1380                                                 if ($do_transaction) {
1381                                                         $this->rollback();
1382                                                 }
1383                                                 return false;
1384                                         }
1385                                 }
1386                         }
1387                 }
1388                 if ($do_transaction) {
1389                         $this->commit();
1390                 }
1391                 return true;
1392         }
1393
1394         /**
1395          * Updates rows
1396          *
1397          * Updates rows in the database. When $old_fields is set to an array,
1398          * the system will only do an update if the fields in that array changed.
1399          *
1400          * Attention:
1401          * Only the values in $old_fields are compared.
1402          * This is an intentional behaviour.
1403          *
1404          * Example:
1405          * We include the timestamp field in $fields but not in $old_fields.
1406          * Then the row will only get the new timestamp when the other fields had changed.
1407          *
1408          * When $old_fields is set to a boolean value the system will do this compare itself.
1409          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1410          *
1411          * Attention:
1412          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1413          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1414          *
1415          * @param string|array  $table      Table name or array [schema => table]
1416          * @param array         $fields     contains the fields that are updated
1417          * @param array         $condition  condition array with the key values
1418          * @param array|boolean $old_fields array with the old field values that are about to be replaced (true = update on duplicate)
1419          *
1420          * @return boolean was the update successfull?
1421          * @throws \Exception
1422          */
1423         public function update($table, $fields, $condition, $old_fields = [])
1424         {
1425                 if (empty($table) || empty($fields) || empty($condition)) {
1426                         $this->logger->info('Table, fields and condition have to be set');
1427                         return false;
1428                 }
1429
1430                 if (is_bool($old_fields)) {
1431                         $do_insert = $old_fields;
1432
1433                         $old_fields = $this->selectFirst($table, [], $condition);
1434
1435                         if (is_bool($old_fields)) {
1436                                 if ($do_insert) {
1437                                         $values = array_merge($condition, $fields);
1438                                         return $this->replace($table, $values);
1439                                 }
1440                                 $old_fields = [];
1441                         }
1442                 }
1443
1444                 foreach ($old_fields AS $fieldname => $content) {
1445                         if (isset($fields[$fieldname]) && !is_null($content) && ($fields[$fieldname] == $content)) {
1446                                 unset($fields[$fieldname]);
1447                         }
1448                 }
1449
1450                 if (count($fields) == 0) {
1451                         return true;
1452                 }
1453
1454                 $fields = $this->castFields($table, $fields);
1455
1456                 $table_string = DBA::buildTableString($table);
1457
1458                 $condition_string = DBA::buildCondition($condition);
1459
1460                 $sql = "UPDATE " . $table_string . " SET "
1461                         . implode(" = ?, ", array_map([DBA::class, 'quoteIdentifier'], array_keys($fields))) . " = ?"
1462                         . $condition_string;
1463
1464                 // Combines the updated fields parameter values with the condition parameter values
1465                 $params  = array_merge(array_values($fields), $condition);
1466
1467                 return $this->e($sql, $params);
1468         }
1469
1470         /**
1471          * Retrieve a single record from a table and returns it in an associative array
1472          *
1473          * @param string|array $table
1474          * @param array        $fields
1475          * @param array        $condition
1476          * @param array        $params
1477          *
1478          * @return bool|array
1479          * @throws \Exception
1480          * @see   $this->select
1481          */
1482         public function selectFirst($table, array $fields = [], array $condition = [], $params = [])
1483         {
1484                 $params['limit'] = 1;
1485                 $result          = $this->select($table, $fields, $condition, $params);
1486
1487                 if (is_bool($result)) {
1488                         return $result;
1489                 } else {
1490                         $row = $this->fetch($result);
1491                         $this->close($result);
1492                         return $row;
1493                 }
1494         }
1495
1496         /**
1497          * Select rows from a table and fills an array with the data
1498          *
1499          * @param string|array $table     Table name or array [schema => table]
1500          * @param array        $fields    Array of selected fields, empty for all
1501          * @param array        $condition Array of fields for condition
1502          * @param array        $params    Array of several parameters
1503          *
1504          * @return array Data array
1505          * @throws \Exception
1506          * @see   self::select
1507          */
1508         public function selectToArray($table, array $fields = [], array $condition = [], array $params = [])
1509         {
1510                 return $this->toArray($this->select($table, $fields, $condition, $params));
1511         }
1512
1513         /**
1514          * Select rows from a table
1515          *
1516          *
1517          * Example:
1518          * $table = 'item';
1519          * or:
1520          * $table = ['schema' => 'table'];
1521          * @see DBA::buildTableString()
1522          *
1523          * $fields = ['id', 'uri', 'uid', 'network'];
1524          *
1525          * $condition = ['uid' => 1, 'network' => 'dspr', 'blocked' => true];
1526          * or:
1527          * $condition = ['`uid` = ? AND `network` IN (?, ?)', 1, 'dfrn', 'dspr'];
1528          * @see DBA::buildCondition()
1529          *
1530          * $params = ['order' => ['id', 'received' => true, 'created' => 'ASC'), 'limit' => 10];
1531          * @see DBA::buildParameter()
1532          *
1533          * $data = DBA::select($table, $fields, $condition, $params);
1534          *
1535          * @param string|array $table     Table name or array [schema => table]
1536          * @param array        $fields    Array of selected fields, empty for all
1537          * @param array        $condition Array of fields for condition
1538          * @param array        $params    Array of several parameters
1539          * @return boolean|object
1540          * @throws \Exception
1541          */
1542         public function select($table, array $fields = [], array $condition = [], array $params = [])
1543         {
1544                 if (empty($table)) {
1545                         return false;
1546                 }
1547
1548                 if (count($fields) > 0) {
1549                         $select_string = implode(', ', array_map([DBA::class, 'quoteIdentifier'], $fields));
1550                 } else {
1551                         $select_string = '*';
1552                 }
1553
1554                 $table_string = DBA::buildTableString($table);
1555
1556                 $condition_string = DBA::buildCondition($condition);
1557
1558                 $param_string = DBA::buildParameter($params);
1559
1560                 $sql = "SELECT " . $select_string . " FROM " . $table_string . $condition_string . $param_string;
1561
1562                 $result = $this->p($sql, $condition);
1563
1564                 if (($this->driver == self::PDO) && !empty($result) && is_string($table)) {
1565                         $result->table = $table;
1566                 }
1567
1568                 return $result;
1569         }
1570
1571         /**
1572          * Counts the rows from a table satisfying the provided condition
1573          *
1574          * @param string|array $table     Table name or array [schema => table]
1575          * @param array        $condition Array of fields for condition
1576          * @param array        $params    Array of several parameters
1577          *
1578          * @return int
1579          *
1580          * Example:
1581          * $table = "item";
1582          *
1583          * $condition = ["uid" => 1, "network" => 'dspr'];
1584          * or:
1585          * $condition = ["`uid` = ? AND `network` IN (?, ?)", 1, 'dfrn', 'dspr'];
1586          *
1587          * $count = DBA::count($table, $condition);
1588          * @throws \Exception
1589          */
1590         public function count($table, array $condition = [], array $params = [])
1591         {
1592                 if (empty($table)) {
1593                         return false;
1594                 }
1595
1596                 $table_string = DBA::buildTableString($table);
1597
1598                 $condition_string = DBA::buildCondition($condition);
1599
1600                 if (empty($params['expression'])) {
1601                         $expression = '*';
1602                 } elseif (!empty($params['distinct'])) {
1603                         $expression = "DISTINCT " . DBA::quoteIdentifier($params['expression']);
1604                 } else {
1605                         $expression = DBA::quoteIdentifier($params['expression']);
1606                 }
1607
1608                 $sql = "SELECT COUNT(" . $expression . ") AS `count` FROM " . $table_string . $condition_string;
1609
1610                 $row = $this->fetchFirst($sql, $condition);
1611
1612                 // Ensure to always return either a "null" or a numeric value
1613                 return is_numeric($row['count']) ? (int)$row['count'] : $row['count'];
1614         }
1615
1616         /**
1617          * Fills an array with data from a query
1618          *
1619          * @param object $stmt statement object
1620          * @param bool   $do_close
1621          *
1622          * @return array Data array
1623          */
1624         public function toArray($stmt, $do_close = true)
1625         {
1626                 if (is_bool($stmt)) {
1627                         return [];
1628                 }
1629
1630                 $data = [];
1631                 while ($row = $this->fetch($stmt)) {
1632                         $data[] = $row;
1633                 }
1634
1635                 if ($do_close) {
1636                         $this->close($stmt);
1637                 }
1638
1639                 return $data;
1640         }
1641
1642         /**
1643          * Cast field types according to the table definition
1644          *
1645          * @param string $table
1646          * @param array  $fields
1647          * @return array casted fields
1648          */
1649         public function castFields(string $table, array $fields) {
1650                 // When there is no data, we don't need to do something
1651                 if (empty($fields)) {
1652                         return $fields;
1653                 }
1654
1655                 // We only need to cast fields with PDO
1656                 if ($this->driver != self::PDO) {
1657                         return $fields;
1658                 }
1659
1660                 // We only need to cast when emulating the prepares
1661                 if (!$this->connection->getAttribute(PDO::ATTR_EMULATE_PREPARES)) {
1662                         return $fields;
1663                 }
1664
1665                 $types = [];
1666
1667                 $tables = DBStructure::definition('', false);
1668                 if (empty($tables[$table])) {
1669                         // When a matching table wasn't found we check if it is a view
1670                         $views = View::definition('', false);
1671                         if (empty($views[$table])) {
1672                                 return $fields;
1673                         }
1674
1675                         foreach(array_keys($fields) as $field) {
1676                                 if (!empty($views[$table]['fields'][$field])) {
1677                                         $viewdef = $views[$table]['fields'][$field];
1678                                         if (!empty($tables[$viewdef[0]]['fields'][$viewdef[1]]['type'])) {
1679                                                 $types[$field] = $tables[$viewdef[0]]['fields'][$viewdef[1]]['type'];
1680                                         }
1681                                 }
1682                         }
1683                 } else {
1684                         foreach ($tables[$table]['fields'] as $field => $definition) {
1685                                 $types[$field] = $definition['type'];
1686                         }
1687                 }
1688
1689                 foreach ($fields as $field => $content) {
1690                         if (is_null($content) || empty($types[$field])) {
1691                                 continue;
1692                         }
1693
1694                         if ((substr($types[$field], 0, 7) == 'tinyint') || (substr($types[$field], 0, 8) == 'smallint') ||
1695                                 (substr($types[$field], 0, 9) == 'mediumint') || (substr($types[$field], 0, 3) == 'int') ||
1696                                 (substr($types[$field], 0, 6) == 'bigint') || (substr($types[$field], 0, 7) == 'boolean')) {
1697                                 $fields[$field] = (int)$content;
1698                         }
1699                         if ((substr($types[$field], 0, 5) == 'float') || (substr($types[$field], 0, 6) == 'double')) {
1700                                 $fields[$field] = (float)$content;
1701                         }
1702                 }
1703
1704                 return $fields; 
1705         }
1706         
1707         /**
1708          * Returns the error number of the last query
1709          *
1710          * @return string Error number (0 if no error)
1711          */
1712         public function errorNo()
1713         {
1714                 return $this->errorno;
1715         }
1716
1717         /**
1718          * Returns the error message of the last query
1719          *
1720          * @return string Error message ('' if no error)
1721          */
1722         public function errorMessage()
1723         {
1724                 return $this->error;
1725         }
1726
1727         /**
1728          * Closes the current statement
1729          *
1730          * @param object $stmt statement object
1731          *
1732          * @return boolean was the close successful?
1733          */
1734         public function close($stmt)
1735         {
1736
1737                 $stamp1 = microtime(true);
1738
1739                 if (!is_object($stmt)) {
1740                         return false;
1741                 }
1742
1743                 switch ($this->driver) {
1744                         case self::PDO:
1745                                 $ret = $stmt->closeCursor();
1746                                 break;
1747                         case self::MYSQLI:
1748                                 // MySQLi offers both a mysqli_stmt and a mysqli_result class.
1749                                 // We should be careful not to assume the object type of $stmt
1750                                 // because DBA::p() has been able to return both types.
1751                                 if ($stmt instanceof mysqli_stmt) {
1752                                         $stmt->free_result();
1753                                         $ret = $stmt->close();
1754                                 } elseif ($stmt instanceof mysqli_result) {
1755                                         $stmt->free();
1756                                         $ret = true;
1757                                 } else {
1758                                         $ret = false;
1759                                 }
1760                                 break;
1761                 }
1762
1763                 $this->profiler->saveTimestamp($stamp1, 'database');
1764
1765                 return $ret;
1766         }
1767
1768         /**
1769          * Return a list of database processes
1770          *
1771          * @return array
1772          *      'list' => List of processes, separated in their different states
1773          *      'amount' => Number of concurrent database processes
1774          * @throws \Exception
1775          */
1776         public function processlist()
1777         {
1778                 $ret  = $this->p("SHOW PROCESSLIST");
1779                 $data = $this->toArray($ret);
1780
1781                 $processes = 0;
1782                 $states    = [];
1783                 foreach ($data as $process) {
1784                         $state = trim($process["State"]);
1785
1786                         // Filter out all non blocking processes
1787                         if (!in_array($state, ["", "init", "statistics", "updating"])) {
1788                                 ++$states[$state];
1789                                 ++$processes;
1790                         }
1791                 }
1792
1793                 $statelist = "";
1794                 foreach ($states as $state => $usage) {
1795                         if ($statelist != "") {
1796                                 $statelist .= ", ";
1797                         }
1798                         $statelist .= $state . ": " . $usage;
1799                 }
1800                 return (["list" => $statelist, "amount" => $processes]);
1801         }
1802
1803         /**
1804          * Fetch a database variable
1805          *
1806          * @param string $name
1807          * @return string content
1808          */
1809         public function getVariable(string $name)
1810         {
1811                 $result = $this->fetchFirst("SHOW GLOBAL VARIABLES WHERE `Variable_name` = ?", $name);
1812                 return $result['Value'] ?? null;
1813         }
1814
1815         /**
1816          * Checks if $array is a filled array with at least one entry.
1817          *
1818          * @param mixed $array A filled array with at least one entry
1819          *
1820          * @return boolean Whether $array is a filled array or an object with rows
1821          */
1822         public function isResult($array)
1823         {
1824                 // It could be a return value from an update statement
1825                 if (is_bool($array)) {
1826                         return $array;
1827                 }
1828
1829                 if (is_object($array)) {
1830                         return $this->numRows($array) > 0;
1831                 }
1832
1833                 return (is_array($array) && (count($array) > 0));
1834         }
1835
1836         /**
1837          * Callback function for "esc_array"
1838          *
1839          * @param mixed   $value         Array value
1840          * @param string  $key           Array key
1841          * @param boolean $add_quotation add quotation marks for string values
1842          *
1843          * @return void
1844          */
1845         private function escapeArrayCallback(&$value, $key, $add_quotation)
1846         {
1847                 if (!$add_quotation) {
1848                         if (is_bool($value)) {
1849                                 $value = ($value ? '1' : '0');
1850                         } else {
1851                                 $value = $this->escape($value);
1852                         }
1853                         return;
1854                 }
1855
1856                 if (is_bool($value)) {
1857                         $value = ($value ? 'true' : 'false');
1858                 } elseif (is_float($value) || is_integer($value)) {
1859                         $value = (string)$value;
1860                 } else {
1861                         $value = "'" . $this->escape($value) . "'";
1862                 }
1863         }
1864
1865         /**
1866          * Escapes a whole array
1867          *
1868          * @param mixed   $arr           Array with values to be escaped
1869          * @param boolean $add_quotation add quotation marks for string values
1870          *
1871          * @return void
1872          */
1873         public function escapeArray(&$arr, $add_quotation = false)
1874         {
1875                 array_walk($arr, [$this, 'escapeArrayCallback'], $add_quotation);
1876         }
1877 }