include/dba.php

   1 <?php
   2 require_once("dbm.php");
   3 require_once('include/datetime.php');
   4
   5 /**
   6  * @class MySQL database class
   7  *
   8  * For debugging, insert 'dbg(1);' anywhere in the program flow.
   9  * dbg(0); will turn it off. Logging is performed at LOGGER_DATA level.
  10  * When logging, all binary info is converted to text and html entities are escaped so that
  11  * the debugging stream is safe to view within both terminals and web pages.
  12  *
  13  * This class is for the low level database stuff that does driver specific things.
  14  */
  15
  16 class dba {
  17
  18         private $debug = 0;
  19         private $db;
  20         private $result;
  21         private $driver;
  22         public  $connected = false;
  23         public  $error = false;
  24         public  $errorno = 0;
  25         public  $affected_rows = 0;
  26         private $_server_info = '';
  27         private static $in_transaction = false;
  28         private static $dbo;
  29         private static $relation = array();
  30
  31         function __construct($serveraddr, $user, $pass, $db, $install = false) {
  32                 $a = get_app();
  33
  34                 $stamp1 = microtime(true);
  35
  36                 $serveraddr = trim($serveraddr);
  37
  38                 $serverdata = explode(':', $serveraddr);
  39                 $server = $serverdata[0];
  40
  41                 if (count($serverdata) > 1) {
  42                         $port = trim($serverdata[1]);
  43                 }
  44
  45                 $server = trim($server);
  46                 $user = trim($user);
  47                 $pass = trim($pass);
  48                 $db = trim($db);
  49
  50                 if (!(strlen($server) && strlen($user))) {
  51                         $this->connected = false;
  52                         $this->db = null;
  53                         return;
  54                 }
  55
  56                 if ($install) {
  57                         if (strlen($server) && ($server !== 'localhost') && ($server !== '127.0.0.1')) {
  58                                 if (! dns_get_record($server, DNS_A + DNS_CNAME + DNS_PTR)) {
  59                                         $this->error = sprintf(t('Cannot locate DNS info for database server \'%s\''), $server);
  60                                         $this->connected = false;
  61                                         $this->db = null;
  62                                         return;
  63                                 }
  64                         }
  65                 }
  66
  67                 if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
  68                         $this->driver = 'pdo';
  69                         $connect = "mysql:host=".$server.";dbname=".$db;
  70
  71                         if (isset($port)) {
  72                                 $connect .= ";port=".$port;
  73                         }
  74
  75                         if (isset($a->config["system"]["db_charset"])) {
  76                                 $connect .= ";charset=".$a->config["system"]["db_charset"];
  77                         }
  78                         $this->db = @new PDO($connect, $user, $pass);
  79                         if (!$this->db->errorCode()) {
  80                                 $this->connected = true;
  81                         }
  82                 } elseif (class_exists('mysqli')) {
  83                         $this->driver = 'mysqli';
  84                         $this->db = @new mysqli($server, $user, $pass, $db, $port);
  85                         if (!mysqli_connect_errno()) {
  86                                 $this->connected = true;
  87
  88                                 if (isset($a->config["system"]["db_charset"])) {
  89                                         $this->db->set_charset($a->config["system"]["db_charset"]);
  90                                 }
  91                         }
  92                 } elseif (function_exists('mysql_connect')) {
  93                         $this->driver = 'mysql';
  94                         $this->db = mysql_connect($serveraddr, $user, $pass);
  95                         if ($this->db && mysql_select_db($db, $this->db)) {
  96                                 $this->connected = true;
  97
  98                                 if (isset($a->config["system"]["db_charset"])) {
  99                                         mysql_set_charset($a->config["system"]["db_charset"], $this->db);
 100                                 }
 101                         }
 102                 } else {
 103                         // No suitable SQL driver was found.
 104                         if (!$install) {
 105                                 system_unavailable();
 106                         }
 107                 }
 108
 109                 if (!$this->connected) {
 110                         $this->db = null;
 111                         if (!$install) {
 112                                 system_unavailable();
 113                         }
 114                 }
 115                 $a->save_timestamp($stamp1, "network");
 116
 117                 self::$dbo = $this;
 118         }
 119
 120         /**
 121          * @brief Returns the MySQL server version string
 122          *
 123          * This function discriminate between the deprecated mysql API and the current
 124          * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
 125          *
 126          * @return string
 127          */
 128         public function server_info() {
 129                 if ($this->_server_info == '') {
 130                         switch ($this->driver) {
 131                                 case 'pdo':
 132                                         $this->_server_info = $this->db->getAttribute(PDO::ATTR_SERVER_VERSION);
 133                                         break;
 134                                 case 'mysqli':
 135                                         $this->_server_info = $this->db->server_info;
 136                                         break;
 137                                 case 'mysql':
 138                                         $this->_server_info = mysql_get_server_info($this->db);
 139                                         break;
 140                         }
 141                 }
 142                 return $this->_server_info;
 143         }
 144
 145         /**
 146          * @brief Returns the selected database name
 147          *
 148          * @return string
 149          */
 150         public function database_name() {
 151                 $r = $this->q("SELECT DATABASE() AS `db`");
 152
 153                 return $r[0]['db'];
 154         }
 155
 156         /**
 157          * @brief Analyze a database query and log this if some conditions are met.
 158          *
 159          * @param string $query The database query that will be analyzed
 160          */
 161         public function log_index($query) {
 162                 $a = get_app();
 163
 164                 if ($a->config["system"]["db_log_index"] == "") {
 165                         return;
 166                 }
 167
 168                 // Don't explain an explain statement
 169                 if (strtolower(substr($query, 0, 7)) == "explain") {
 170                         return;
 171                 }
 172
 173                 // Only do the explain on "select", "update" and "delete"
 174                 if (!in_array(strtolower(substr($query, 0, 6)), array("select", "update", "delete"))) {
 175                         return;
 176                 }
 177
 178                 $r = $this->q("EXPLAIN ".$query);
 179                 if (!dbm::is_result($r)) {
 180                         return;
 181                 }
 182
 183                 $watchlist = explode(',', $a->config["system"]["db_log_index_watch"]);
 184                 $blacklist = explode(',', $a->config["system"]["db_log_index_blacklist"]);
 185
 186                 foreach ($r AS $row) {
 187                         if ((intval($a->config["system"]["db_loglimit_index"]) > 0)) {
 188                                 $log = (in_array($row['key'], $watchlist) &&
 189                                         ($row['rows'] >= intval($a->config["system"]["db_loglimit_index"])));
 190                         } else {
 191                                 $log = false;
 192                         }
 193
 194                         if ((intval($a->config["system"]["db_loglimit_index_high"]) > 0) && ($row['rows'] >= intval($a->config["system"]["db_loglimit_index_high"]))) {
 195                                 $log = true;
 196                         }
 197
 198                         if (in_array($row['key'], $blacklist) || ($row['key'] == "")) {
 199                                 $log = false;
 200                         }
 201
 202                         if ($log) {
 203                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 204                                 @file_put_contents($a->config["system"]["db_log_index"], datetime_convert()."\t".
 205                                                 $row['key']."\t".$row['rows']."\t".$row['Extra']."\t".
 206                                                 basename($backtrace[1]["file"])."\t".
 207                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 208                                                 substr($query, 0, 2000)."\n", FILE_APPEND);
 209                         }
 210                 }
 211         }
 212
 213         public function q($sql, $onlyquery = false) {
 214                 $a = get_app();
 215
 216                 if (!$this->db || !$this->connected) {
 217                         return false;
 218                 }
 219
 220                 $this->error = '';
 221
 222                 $connstr = ($this->connected() ? "Connected" : "Disonnected");
 223
 224                 $stamp1 = microtime(true);
 225
 226                 $orig_sql = $sql;
 227
 228                 if (x($a->config,'system') && x($a->config['system'], 'db_callstack')) {
 229                         $sql = "/*".$a->callstack()." */ ".$sql;
 230                 }
 231
 232                 $columns = 0;
 233
 234                 switch ($this->driver) {
 235                         case 'pdo':
 236                                 $result = @$this->db->query($sql);
 237                                 // Is used to separate between queries that returning data - or not
 238                                 if (!is_bool($result)) {
 239                                         $columns = $result->columnCount();
 240                                 }
 241                                 break;
 242                         case 'mysqli':
 243                                 $result = @$this->db->query($sql);
 244                                 break;
 245                         case 'mysql':
 246                                 $result = @mysql_query($sql,$this->db);
 247                                 break;
 248                 }
 249                 $stamp2 = microtime(true);
 250                 $duration = (float)($stamp2 - $stamp1);
 251
 252                 $a->save_timestamp($stamp1, "database");
 253
 254                 if (strtolower(substr($orig_sql, 0, 6)) != "select") {
 255                         $a->save_timestamp($stamp1, "database_write");
 256                 }
 257                 if (x($a->config,'system') && x($a->config['system'],'db_log')) {
 258                         if (($duration > $a->config["system"]["db_loglimit"])) {
 259                                 $duration = round($duration, 3);
 260                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 261                                 @file_put_contents($a->config["system"]["db_log"], datetime_convert()."\t".$duration."\t".
 262                                                 basename($backtrace[1]["file"])."\t".
 263                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 264                                                 substr($sql, 0, 2000)."\n", FILE_APPEND);
 265                         }
 266                 }
 267
 268                 switch ($this->driver) {
 269                         case 'pdo':
 270                                 $errorInfo = $this->db->errorInfo();
 271                                 if ($errorInfo) {
 272                                         $this->error = $errorInfo[2];
 273                                         $this->errorno = $errorInfo[1];
 274                                 }
 275                                 break;
 276                         case 'mysqli':
 277                                 if ($this->db->errno) {
 278                                         $this->error = $this->db->error;
 279                                         $this->errorno = $this->db->errno;
 280                                 }
 281                                 break;
 282                         case 'mysql':
 283                                 if (mysql_errno($this->db)) {
 284                                         $this->error = mysql_error($this->db);
 285                                         $this->errorno = mysql_errno($this->db);
 286                                 }
 287                                 break;
 288                 }
 289                 if (strlen($this->error)) {
 290                         logger('DB Error ('.$connstr.') '.$this->errorno.': '.$this->error);
 291                 }
 292
 293                 if ($this->debug) {
 294
 295                         $mesg = '';
 296
 297                         if ($result === false) {
 298                                 $mesg = 'false';
 299                         } elseif ($result === true) {
 300                                 $mesg = 'true';
 301                         } else {
 302                                 switch ($this->driver) {
 303                                         case 'pdo':
 304                                                 $mesg = $result->rowCount().' results'.EOL;
 305                                                 break;
 306                                         case 'mysqli':
 307                                                 $mesg = $result->num_rows.' results'.EOL;
 308                                                 break;
 309                                         case 'mysql':
 310                                                 $mesg = mysql_num_rows($result).' results'.EOL;
 311                                                 break;
 312                                 }
 313                         }
 314
 315                         $str =  'SQL = ' . printable($sql) . EOL . 'SQL returned ' . $mesg
 316                                 . (($this->error) ? ' error: ' . $this->error : '')
 317                                 . EOL;
 318
 319                         logger('dba: ' . $str );
 320                 }
 321
 322                 /**
 323                  * If dbfail.out exists, we will write any failed calls directly to it,
 324                  * regardless of any logging that may or may nor be in effect.
 325                  * These usually indicate SQL syntax errors that need to be resolved.
 326                  */
 327
 328                 if ($result === false) {
 329                         logger('dba: ' . printable($sql) . ' returned false.' . "\n" . $this->error);
 330                         if (file_exists('dbfail.out')) {
 331                                 file_put_contents('dbfail.out', datetime_convert() . "\n" . printable($sql) . ' returned false' . "\n" . $this->error . "\n", FILE_APPEND);
 332                         }
 333                 }
 334
 335                 if (is_bool($result)) {
 336                         return $result;
 337                 }
 338                 if ($onlyquery) {
 339                         $this->result = $result;
 340                         return true;
 341                 }
 342
 343                 $r = array();
 344                 switch ($this->driver) {
 345                         case 'pdo':
 346                                 while ($x = $result->fetch(PDO::FETCH_ASSOC)) {
 347                                         $r[] = $x;
 348                                 }
 349                                 $result->closeCursor();
 350                                 break;
 351                         case 'mysqli':
 352                                 while ($x = $result->fetch_array(MYSQLI_ASSOC)) {
 353                                         $r[] = $x;
 354                                 }
 355                                 $result->free_result();
 356                                 break;
 357                         case 'mysql':
 358                                 while ($x = mysql_fetch_array($result, MYSQL_ASSOC)) {
 359                                         $r[] = $x;
 360                                 }
 361                                 mysql_free_result($result);
 362                                 break;
 363                 }
 364
 365                 // PDO doesn't return "true" on successful operations - like mysqli does
 366                 // Emulate this behaviour by checking if the query returned data and had columns
 367                 // This should be reliable enough
 368                 if (($this->driver == 'pdo') && (count($r) == 0) && ($columns == 0)) {
 369                         return true;
 370                 }
 371
 372                 //$a->save_timestamp($stamp1, "database");
 373
 374                 if ($this->debug) {
 375                         logger('dba: ' . printable(print_r($r, true)));
 376                 }
 377                 return($r);
 378         }
 379
 380         public function dbg($dbg) {
 381                 $this->debug = $dbg;
 382         }
 383
 384         public function escape($str) {
 385                 if ($this->db && $this->connected) {
 386                         switch ($this->driver) {
 387                                 case 'pdo':
 388                                         return substr(@$this->db->quote($str, PDO::PARAM_STR), 1, -1);
 389                                 case 'mysqli':
 390                                         return @$this->db->real_escape_string($str);
 391                                 case 'mysql':
 392                                         return @mysql_real_escape_string($str,$this->db);
 393                         }
 394                 }
 395         }
 396
 397         function connected() {
 398                 switch ($this->driver) {
 399                         case 'pdo':
 400                                 // Not sure if this really is working like expected
 401                                 $connected = ($this->db->getAttribute(PDO::ATTR_CONNECTION_STATUS) != "");
 402                                 break;
 403                         case 'mysqli':
 404                                 $connected = $this->db->ping();
 405                                 break;
 406                         case 'mysql':
 407                                 $connected = mysql_ping($this->db);
 408                                 break;
 409                 }
 410                 return $connected;
 411         }
 412
 413         function insert_id() {
 414                 switch ($this->driver) {
 415                         case 'pdo':
 416                                 $id = $this->db->lastInsertId();
 417                                 break;
 418                         case 'mysqli':
 419                                 $id = $this->db->insert_id;
 420                                 break;
 421                         case 'mysql':
 422                                 $id = mysql_insert_id($this->db);
 423                                 break;
 424                 }
 425                 return $id;
 426         }
 427
 428         function __destruct() {
 429                 if ($this->db) {
 430                         switch ($this->driver) {
 431                                 case 'pdo':
 432                                         $this->db = null;
 433                                         break;
 434                                 case 'mysqli':
 435                                         $this->db->close();
 436                                         break;
 437                                 case 'mysql':
 438                                         mysql_close($this->db);
 439                                         break;
 440                         }
 441                 }
 442         }
 443
 444         /**
 445          * @brief Replaces ANY_VALUE() function by MIN() function,
 446          *  if the database server does not support ANY_VALUE().
 447          *
 448          * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
 449          * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
 450          * A standard fall-back is to use MIN().
 451          *
 452          * @param string $sql An SQL string without the values
 453          * @return string The input SQL string modified if necessary.
 454          */
 455         public function any_value_fallback($sql) {
 456                 $server_info = $this->server_info();
 457                 if (version_compare($server_info, '5.7.5', '<') ||
 458                         (stripos($server_info, 'MariaDB') !== false)) {
 459                         $sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
 460                 }
 461                 return $sql;
 462         }
 463
 464         /**
 465          * @brief beautifies the query - useful for "SHOW PROCESSLIST"
 466          *
 467          * This is safe when we bind the parameters later.
 468          * The parameter values aren't part of the SQL.
 469          *
 470          * @param string $sql An SQL string without the values
 471          * @return string The input SQL string modified if necessary.
 472          */
 473         public function clean_query($sql) {
 474                 $search = array("\t", "\n", "\r", "  ");
 475                 $replace = array(' ', ' ', ' ', ' ');
 476                 do {
 477                         $oldsql = $sql;
 478                         $sql = str_replace($search, $replace, $sql);
 479                 } while ($oldsql != $sql);
 480
 481                 return $sql;
 482         }
 483
 484
 485         /**
 486          * @brief Replaces the ? placeholders with the parameters in the $args array
 487          *
 488          * @param string $sql SQL query
 489          * @param array $args The parameters that are to replace the ? placeholders
 490          * @return string The replaced SQL query
 491          */
 492         static private function replace_parameters($sql, $args) {
 493                 $offset = 0;
 494                 foreach ($args AS $param => $value) {
 495                         if (is_int($args[$param]) || is_float($args[$param])) {
 496                                 $replace = intval($args[$param]);
 497                         } else {
 498                                 $replace = "'".self::$dbo->escape($args[$param])."'";
 499                         }
 500
 501                         $pos = strpos($sql, '?', $offset);
 502                         if ($pos !== false) {
 503                                 $sql = substr_replace($sql, $replace, $pos, 1);
 504                         }
 505                         $offset = $pos + strlen($replace);
 506                 }
 507                 return $sql;
 508         }
 509
 510         /**
 511          * @brief Executes a prepared statement that returns data
 512          * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
 513          * @param string $sql SQL statement
 514          * @return object statement object
 515          */
 516         static public function p($sql) {
 517                 $a = get_app();
 518
 519                 $stamp1 = microtime(true);
 520
 521                 $args = func_get_args();
 522                 unset($args[0]);
 523
 524                 // When the second function parameter is an array then use this as the parameter array
 525                 if ((count($args) > 0) && (is_array($args[1]))) {
 526                         $params = $args[1];
 527                 } else {
 528                         $params = $args;
 529                 }
 530
 531                 // Renumber the array keys to be sure that they fit
 532                 $i = 0;
 533                 $args = array();
 534                 foreach ($params AS $param) {
 535                         $args[++$i] = $param;
 536                 }
 537
 538                 if (!self::$dbo || !self::$dbo->connected) {
 539                         return false;
 540                 }
 541
 542                 if (substr_count($sql, '?') != count($args)) {
 543                         // Question: Should we continue or stop the query here?
 544                         logger('Parameter mismatch. Query "'.$sql.'" - Parameters '.print_r($args, true), LOGGER_DEBUG);
 545                 }
 546
 547                 $sql = self::$dbo->clean_query($sql);
 548                 $sql = self::$dbo->any_value_fallback($sql);
 549
 550                 if (x($a->config,'system') && x($a->config['system'], 'db_callstack')) {
 551                         $sql = "/*".$a->callstack()." */ ".$sql;
 552                 }
 553
 554                 self::$dbo->error = '';
 555                 self::$dbo->errorno = 0;
 556                 self::$dbo->affected_rows = 0;
 557
 558                 switch (self::$dbo->driver) {
 559                         case 'pdo':
 560                                 if (!$stmt = self::$dbo->db->prepare($sql)) {
 561                                         $errorInfo = self::$dbo->db->errorInfo();
 562                                         self::$dbo->error = $errorInfo[2];
 563                                         self::$dbo->errorno = $errorInfo[1];
 564                                         $retval = false;
 565                                         break;
 566                                 }
 567
 568                                 foreach ($args AS $param => $value) {
 569                                         $stmt->bindParam($param, $args[$param]);
 570                                 }
 571
 572                                 if (!$stmt->execute()) {
 573                                         $errorInfo = $stmt->errorInfo();
 574                                         self::$dbo->error = $errorInfo[2];
 575                                         self::$dbo->errorno = $errorInfo[1];
 576                                         $retval = false;
 577                                 } else {
 578                                         $retval = $stmt;
 579                                         self::$dbo->affected_rows = $retval->rowCount();
 580                                 }
 581                                 break;
 582                         case 'mysqli':
 583                                 $stmt = self::$dbo->db->stmt_init();
 584
 585                                 if (!$stmt->prepare($sql)) {
 586                                         self::$dbo->error = $stmt->error;
 587                                         self::$dbo->errorno = $stmt->errno;
 588                                         $retval = false;
 589                                         break;
 590                                 }
 591
 592                                 $params = '';
 593                                 $values = array();
 594                                 foreach ($args AS $param => $value) {
 595                                         if (is_int($args[$param])) {
 596                                                 $params .= 'i';
 597                                         } elseif (is_float($args[$param])) {
 598                                                 $params .= 'd';
 599                                         } elseif (is_string($args[$param])) {
 600                                                 $params .= 's';
 601                                         } else {
 602                                                 $params .= 'b';
 603                                         }
 604                                         $values[] = &$args[$param];
 605                                 }
 606
 607                                 if (count($values) > 0) {
 608                                         array_unshift($values, $params);
 609                                         call_user_func_array(array($stmt, 'bind_param'), $values);
 610                                 }
 611
 612                                 if (!$stmt->execute()) {
 613                                         self::$dbo->error = self::$dbo->db->error;
 614                                         self::$dbo->errorno = self::$dbo->db->errno;
 615                                         $retval = false;
 616                                 } else {
 617                                         $stmt->store_result();
 618                                         $retval = $stmt;
 619                                         self::$dbo->affected_rows = $retval->affected_rows;
 620                                 }
 621                                 break;
 622                         case 'mysql':
 623                                 // For the old "mysql" functions we cannot use prepared statements
 624                                 $retval = mysql_query(self::replace_parameters($sql, $args), self::$dbo->db);
 625                                 if (mysql_errno(self::$dbo->db)) {
 626                                         self::$dbo->error = mysql_error(self::$dbo->db);
 627                                         self::$dbo->errorno = mysql_errno(self::$dbo->db);
 628                                 } else {
 629                                         self::$dbo->affected_rows = mysql_affected_rows($retval);
 630
 631                                         // Due to missing mysql_* support this here wasn't tested at all
 632                                         // See here: http://php.net/manual/en/function.mysql-num-rows.php
 633                                         if (self::$dbo->affected_rows <= 0) {
 634                                                 self::$dbo->affected_rows = mysql_num_rows($retval);
 635                                         }
 636                                 }
 637                                 break;
 638                 }
 639
 640                 if (self::$dbo->errorno != 0) {
 641                         $trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 1);
 642                         $called_from = array_shift($trace);
 643
 644                         // We are having an own error logging in the function "p"
 645                         if ($called_from['function'] != 'p') {
 646                                 // We have to preserve the error code, somewhere in the logging it get lost
 647                                 $error = self::$dbo->error;
 648                                 $errorno = self::$dbo->errorno;
 649
 650                                 logger('DB Error '.self::$dbo->errorno.': '.self::$dbo->error."\n".
 651                                         $a->callstack(8))."\n".self::replace_parameters($sql, $args);
 652
 653                                 self::$dbo->error = $error;
 654                                 self::$dbo->errorno = $errorno;
 655                         }
 656                 }
 657
 658                 $a->save_timestamp($stamp1, 'database');
 659
 660                 if (x($a->config,'system') && x($a->config['system'], 'db_log')) {
 661
 662                         $stamp2 = microtime(true);
 663                         $duration = (float)($stamp2 - $stamp1);
 664
 665                         if (($duration > $a->config["system"]["db_loglimit"])) {
 666                                 $duration = round($duration, 3);
 667                                 $backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
 668
 669                                 @file_put_contents($a->config["system"]["db_log"], datetime_convert()."\t".$duration."\t".
 670                                                 basename($backtrace[1]["file"])."\t".
 671                                                 $backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
 672                                                 substr(self::replace_parameters($sql, $args), 0, 2000)."\n", FILE_APPEND);
 673                         }
 674                 }
 675                 return $retval;
 676         }
 677
 678         /**
 679          * @brief Executes a prepared statement like UPDATE or INSERT that doesn't return data
 680          *
 681          * @param string $sql SQL statement
 682          * @return boolean Was the query successfull? False is returned only if an error occurred
 683          */
 684         static public function e($sql) {
 685                 $a = get_app();
 686
 687                 $stamp = microtime(true);
 688
 689                 $args = func_get_args();
 690
 691                 // In a case of a deadlock we are repeating the query 20 times
 692                 $timeout = 20;
 693
 694                 do {
 695                         $stmt = call_user_func_array('self::p', $args);
 696
 697                         if (is_bool($stmt)) {
 698                                 $retval = $stmt;
 699                         } elseif (is_object($stmt)) {
 700                                 $retval = true;
 701                         } else {
 702                                 $retval = false;
 703                         }
 704
 705                         self::close($stmt);
 706
 707                 } while ((self::$dbo->errorno == 1213) && (--$timeout > 0));
 708
 709                 if (self::$dbo->errorno != 0) {
 710                         // We have to preserve the error code, somewhere in the logging it get lost
 711                         $error = self::$dbo->error;
 712                         $errorno = self::$dbo->errorno;
 713
 714                         logger('DB Error '.self::$dbo->errorno.': '.self::$dbo->error."\n".
 715                                 $a->callstack(8))."\n".self::replace_parameters($sql, $args);
 716
 717                         self::$dbo->error = $error;
 718                         self::$dbo->errorno = $errorno;
 719                 }
 720
 721                 $a->save_timestamp($stamp, "database_write");
 722
 723                 return $retval;
 724         }
 725
 726         /**
 727          * @brief Check if data exists
 728          *
 729          * @param string $sql SQL statement
 730          * @return boolean Are there rows for that query?
 731          */
 732         static public function exists($sql) {
 733                 $args = func_get_args();
 734
 735                 $stmt = call_user_func_array('self::p', $args);
 736
 737                 if (is_bool($stmt)) {
 738                         $retval = $stmt;
 739                 } else {
 740                         $retval = (self::num_rows($stmt) > 0);
 741                 }
 742
 743                 self::close($stmt);
 744
 745                 return $retval;
 746         }
 747
 748         /**
 749          * @brief Fetches the first row
 750          *
 751          * @param string $sql SQL statement
 752          * @return array first row of query
 753          */
 754         static public function fetch_first($sql) {
 755                 $args = func_get_args();
 756
 757                 $stmt = call_user_func_array('self::p', $args);
 758
 759                 if (is_bool($stmt)) {
 760                         $retval = $stmt;
 761                 } else {
 762                         $retval = self::fetch($stmt);
 763                 }
 764
 765                 self::close($stmt);
 766
 767                 return $retval;
 768         }
 769
 770         /**
 771          * @brief Returns the number of affected rows of the last statement
 772          *
 773          * @return int Number of rows
 774          */
 775         static public function affected_rows() {
 776                 return self::$dbo->affected_rows;
 777         }
 778
 779         /**
 780          * @brief Returns the number of rows of a statement
 781          *
 782          * @param object Statement object
 783          * @return int Number of rows
 784          */
 785         static public function num_rows($stmt) {
 786                 if (!is_object($stmt)) {
 787                         return 0;
 788                 }
 789                 switch (self::$dbo->driver) {
 790                         case 'pdo':
 791                                 return $stmt->rowCount();
 792                         case 'mysqli':
 793                                 return $stmt->num_rows;
 794                         case 'mysql':
 795                                 return mysql_num_rows($stmt);
 796                 }
 797                 return 0;
 798         }
 799
 800         /**
 801          * @brief Fetch a single row
 802          *
 803          * @param object $stmt statement object
 804          * @return array current row
 805          */
 806         static public function fetch($stmt) {
 807                 if (!is_object($stmt)) {
 808                         return false;
 809                 }
 810
 811                 switch (self::$dbo->driver) {
 812                         case 'pdo':
 813                                 return $stmt->fetch(PDO::FETCH_ASSOC);
 814                         case 'mysqli':
 815                                 // This code works, but is slow
 816
 817                                 // Bind the result to a result array
 818                                 $cols = array();
 819
 820                                 $cols_num = array();
 821                                 for ($x = 0; $x < $stmt->field_count; $x++) {
 822                                         $cols[] = &$cols_num[$x];
 823                                 }
 824
 825                                 call_user_func_array(array($stmt, 'bind_result'), $cols);
 826
 827                                 if (!$stmt->fetch()) {
 828                                         return false;
 829                                 }
 830
 831                                 // The slow part:
 832                                 // We need to get the field names for the array keys
 833                                 // It seems that there is no better way to do this.
 834                                 $result = $stmt->result_metadata();
 835                                 $fields = $result->fetch_fields();
 836
 837                                 $columns = array();
 838                                 foreach ($cols_num AS $param => $col) {
 839                                         $columns[$fields[$param]->name] = $col;
 840                                 }
 841                                 return $columns;
 842                         case 'mysql':
 843                                 return mysql_fetch_array(self::$dbo->result, MYSQL_ASSOC);
 844                 }
 845         }
 846
 847         /**
 848          * @brief Insert a row into a table
 849          *
 850          * @param string $table Table name
 851          * @param array $param parameter array
 852          *
 853          * @return boolean was the insert successfull?
 854          */
 855         static public function insert($table, $param) {
 856                 $sql = "INSERT INTO `".self::$dbo->escape($table)."` (`".implode("`, `", array_keys($param))."`) VALUES (".
 857                         substr(str_repeat("?, ", count($param)), 0, -2).");";
 858
 859                 return self::e($sql, $param);
 860         }
 861
 862         /**
 863          * @brief Locks a table for exclusive write access
 864          *
 865          * This function can be extended in the future to accept a table array as well.
 866          *
 867          * @param string $table Table name
 868          *
 869          * @return boolean was the lock successful?
 870          */
 871         static public function lock($table) {
 872                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 873                 self::e("SET autocommit=0");
 874                 $success = self::e("LOCK TABLES `".self::$dbo->escape($table)."` WRITE");
 875                 if (!$success) {
 876                         self::e("SET autocommit=1");
 877                 } else {
 878                         self::$in_transaction = true;
 879                 }
 880                 return $success;
 881         }
 882
 883         /**
 884          * @brief Unlocks all locked tables
 885          *
 886          * @return boolean was the unlock successful?
 887          */
 888         static public function unlock() {
 889                 // See here: https://dev.mysql.com/doc/refman/5.7/en/lock-tables-and-transactions.html
 890                 self::e("COMMIT");
 891                 $success = self::e("UNLOCK TABLES");
 892                 self::e("SET autocommit=1");
 893                 self::$in_transaction = false;
 894                 return $success;
 895         }
 896
 897         /**
 898          * @brief Starts a transaction
 899          *
 900          * @return boolean Was the command executed successfully?
 901          */
 902         static public function transaction() {
 903                 if (!self::e('COMMIT')) {
 904                         return false;
 905                 }
 906                 if (!self::e('START TRANSACTION')) {
 907                         return false;
 908                 }
 909                 self::$in_transaction = true;
 910                 return true;
 911         }
 912
 913         /**
 914          * @brief Does a commit
 915          *
 916          * @return boolean Was the command executed successfully?
 917          */
 918         static public function commit() {
 919                 if (!self::e('COMMIT')) {
 920                         return false;
 921                 }
 922                 self::$in_transaction = false;
 923                 return true;
 924         }
 925
 926         /**
 927          * @brief Does a rollback
 928          *
 929          * @return boolean Was the command executed successfully?
 930          */
 931         static public function rollback() {
 932                 if (!self::e('ROLLBACK')) {
 933                         return false;
 934                 }
 935                 self::$in_transaction = false;
 936                 return true;
 937         }
 938
 939         /**
 940          * @brief Build the array with the table relations
 941          *
 942          * The array is build from the database definitions in dbstructure.php
 943          *
 944          * This process must only be started once, since the value is cached.
 945          */
 946         static private function build_relation_data() {
 947                 $definition = db_definition();
 948
 949                 foreach ($definition AS $table => $structure) {
 950                         foreach ($structure['fields'] AS $field => $field_struct) {
 951                                 if (isset($field_struct['relation'])) {
 952                                         foreach ($field_struct['relation'] AS $rel_table => $rel_field) {
 953                                                 self::$relation[$rel_table][$rel_field][$table][] = $field;
 954                                         }
 955                                 }
 956                         }
 957                 }
 958         }
 959
 960         /**
 961          * @brief Delete a row from a table
 962          *
 963          * @param string $table Table name
 964          * @param array $param parameter array
 965          * @param boolean $in_process Internal use: Only do a commit after the last delete
 966          * @param array $callstack Internal use: prevent endless loops
 967          *
 968          * @return boolean|array was the delete successfull? When $in_process is set: deletion data
 969          */
 970         static public function delete($table, $param, $in_process = false, &$callstack = array()) {
 971
 972                 $commands = array();
 973
 974                 // Create a key for the loop prevention
 975                 $key = $table.':'.implode(':', array_keys($param)).':'.implode(':', $param);
 976
 977                 // We quit when this key already exists in the callstack.
 978                 if (isset($callstack[$key])) {
 979                         return $commands;
 980                 }
 981
 982                 $callstack[$key] = true;
 983
 984                 $table = self::$dbo->escape($table);
 985
 986                 $commands[$key] = array('table' => $table, 'param' => $param);
 987
 988                 // To speed up the whole process we cache the table relations
 989                 if (count(self::$relation) == 0) {
 990                         self::build_relation_data();
 991                 }
 992
 993                 // Is there a relation entry for the table?
 994                 if (isset(self::$relation[$table])) {
 995                         // We only allow a simple "one field" relation.
 996                         $field = array_keys(self::$relation[$table])[0];
 997                         $rel_def = array_values(self::$relation[$table])[0];
 998
 999                         // Create a key for preventing double queries
1000                         $qkey = $field.'-'.$table.':'.implode(':', array_keys($param)).':'.implode(':', $param);
1001
1002                         // When the search field is the relation field, we don't need to fetch the rows
1003                         // This is useful when the leading record is already deleted in the frontend but the rest is done in the backend
1004                         if ((count($param) == 1) && ($field == array_keys($param)[0])) {
1005                                 foreach ($rel_def AS $rel_table => $rel_fields) {
1006                                         foreach ($rel_fields AS $rel_field) {
1007                                                 $retval = self::delete($rel_table, array($rel_field => array_values($param)[0]), true, $callstack);
1008                                                 $commands = array_merge($commands, $retval);
1009                                         }
1010                                 }
1011                         // We quit when this key already exists in the callstack.
1012                         } elseif (!isset($callstack[$qkey])) {
1013
1014                                 $callstack[$qkey] = true;
1015
1016                                 // Fetch all rows that are to be deleted
1017                                 $sql = "SELECT ".self::$dbo->escape($field)." FROM `".$table."` WHERE `".
1018                                 implode("` = ? AND `", array_keys($param))."` = ?";
1019
1020                                 $data = self::p($sql, $param);
1021                                 while ($row = self::fetch($data)) {
1022                                         // Now we accumulate the delete commands
1023                                         $retval = self::delete($table, array($field => $row[$field]), true, $callstack);
1024                                         $commands = array_merge($commands, $retval);
1025                                 }
1026
1027                                 // Since we had split the delete command we don't need the original command anymore
1028                                 unset($commands[$key]);
1029                         }
1030                 }
1031
1032                 if (!$in_process) {
1033                         // Now we finalize the process
1034                         $do_transaction = !self::$in_transaction;
1035
1036                         if ($do_transaction) {
1037                                 self::transaction();
1038                         }
1039
1040                         $compacted = array();
1041                         $counter = array();
1042                         foreach ($commands AS $command) {
1043                                 if (count($command['param']) > 1) {
1044                                         $sql = "DELETE FROM `".$command['table']."` WHERE `".
1045                                                 implode("` = ? AND `", array_keys($command['param']))."` = ?";
1046
1047                                         logger(self::replace_parameters($sql, $command['param']), LOGGER_DATA);
1048
1049                                         if (!self::e($sql, $command['param'])) {
1050                                                 if ($do_transaction) {
1051                                                         self::rollback();
1052                                                 }
1053                                                 return false;
1054                                         }
1055                                 } else {
1056                                         $key_table = $command['table'];
1057                                         $key_param = array_keys($command['param'])[0];
1058                                         $value = array_values($command['param'])[0];
1059
1060                                         // Split the SQL queries in chunks of 100 values
1061                                         // We do the $i stuff here to make the code better readable
1062                                         $i = $counter[$key_table][$key_param];
1063                                         if (count($compacted[$key_table][$key_param][$i]) > 100) {
1064                                                 ++$i;
1065                                         }
1066
1067                                         $compacted[$key_table][$key_param][$i][$value] = $value;
1068                                         $counter[$key_table][$key_param] = $i;
1069                                 }
1070                         }
1071                         foreach ($compacted AS $table => $values) {
1072                                 foreach ($values AS $field => $field_value_list) {
1073                                         foreach ($field_value_list AS $field_values) {
1074                                                 $sql = "DELETE FROM `".$table."` WHERE `".$field."` IN (".
1075                                                         substr(str_repeat("?, ", count($field_values)), 0, -2).");";
1076
1077                                                 logger(self::replace_parameters($sql, $field_values), LOGGER_DATA);
1078
1079                                                 if (!self::e($sql, $field_values)) {
1080                                                         if ($do_transaction) {
1081                                                                 self::rollback();
1082                                                         }
1083                                                         return false;
1084                                                 }
1085                                         }
1086                                 }
1087                         }
1088                         if ($do_transaction) {
1089                                 self::commit();
1090                         }
1091                         return true;
1092                 }
1093
1094                 return $commands;
1095         }
1096
1097         /**
1098          * @brief Updates rows
1099          *
1100          * Updates rows in the database. When $old_fields is set to an array,
1101          * the system will only do an update if the fields in that array changed.
1102          *
1103          * Attention:
1104          * Only the values in $old_fields are compared.
1105          * This is an intentional behaviour.
1106          *
1107          * Example:
1108          * We include the timestamp field in $fields but not in $old_fields.
1109          * Then the row will only get the new timestamp when the other fields had changed.
1110          *
1111          * When $old_fields is set to a boolean value the system will do this compare itself.
1112          * When $old_fields is set to "true" the system will do an insert if the row doesn't exists.
1113          *
1114          * Attention:
1115          * Only set $old_fields to a boolean value when you are sure that you will update a single row.
1116          * When you set $old_fields to "true" then $fields must contain all relevant fields!
1117          *
1118          * @param string $table Table name
1119          * @param array $fields contains the fields that are updated
1120          * @param array $condition condition array with the key values
1121          * @param array|boolean $old_fields array with the old field values that are about to be replaced
1122          *
1123          * @return boolean was the update successfull?
1124          */
1125         static public function update($table, $fields, $condition, $old_fields = array()) {
1126
1127                 /** @todo We may use MySQL specific functions here:
1128                  * INSERT INTO `config` (`cat`, `k`, `v`) VALUES ('%s', '%s', '%s') ON DUPLICATE KEY UPDATE `v` = '%s'"
1129                  * But I think that it doesn't make sense here.
1130                 */
1131
1132                 $table = self::$dbo->escape($table);
1133
1134                 if (is_bool($old_fields)) {
1135                         $sql = "SELECT * FROM `".$table."` WHERE `".
1136                         implode("` = ? AND `", array_keys($condition))."` = ? LIMIT 1";
1137
1138                         $params = array();
1139                         foreach ($condition AS $value) {
1140                                 $params[] = $value;
1141                         }
1142
1143                         $do_insert = $old_fields;
1144
1145                         $old_fields = self::fetch_first($sql, $params);
1146                         if (is_bool($old_fields)) {
1147                                 if ($do_insert) {
1148                                         return self::insert($table, $fields);
1149                                 }
1150                                 $old_fields = array();
1151                         }
1152                 }
1153
1154                 $do_update = (count($old_fields) == 0);
1155
1156                 foreach ($old_fields AS $fieldname => $content) {
1157                         if (isset($fields[$fieldname])) {
1158                                 if ($fields[$fieldname] == $content) {
1159                                         unset($fields[$fieldname]);
1160                                 } else {
1161                                         $do_update = true;
1162                                 }
1163                         }
1164                 }
1165
1166                 if (!$do_update || (count($fields) == 0)) {
1167                         return true;
1168                 }
1169
1170                 $sql = "UPDATE `".$table."` SET `".
1171                         implode("` = ?, `", array_keys($fields))."` = ? WHERE `".
1172                         implode("` = ? AND `", array_keys($condition))."` = ?";
1173
1174                 $params = array();
1175                 foreach ($fields AS $value) {
1176                         $params[] = $value;
1177                 }
1178                 foreach ($condition AS $value) {
1179                         $params[] = $value;
1180                 }
1181
1182                 return self::e($sql, $params);
1183         }
1184
1185         /**
1186          * @brief Select rows from a table
1187          *
1188          * @param string $table Table name
1189          * @param array $fields array of selected fields
1190          * @param array $condition array of fields for condition
1191          * @param array $params array of several parameters
1192          *
1193          * @return boolean|object If "limit" is equal "1" only a single row is returned, else a query object is returned
1194          *
1195          * Example:
1196          * $table = "item";
1197          * $fields = array("id", "uri", "uid", "network");
1198          * $condition = array("uid" => 1, "network" => 'dspr');
1199          * $params = array("order" => array("id", "received" => true), "limit" => 1);
1200          *
1201          * $data = dba::select($table, $fields, $condition, $params);
1202          */
1203         static public function select($table, $fields = array(), $condition = array(), $params = array()) {
1204                 if ($table == '') {
1205                         return false;
1206                 }
1207
1208                 if (count($fields) > 0) {
1209                         $select_fields = "`".implode("`, `", array_values($fields))."`";
1210                 } else {
1211                         $select_fields = "*";
1212                 }
1213
1214                 if (count($condition) > 0) {
1215                         $condition_string = " WHERE `".implode("` = ? AND `", array_keys($condition))."` = ?";
1216                 } else {
1217                         $condition_string = "";
1218                 }
1219
1220                 $param_string = '';
1221                 $single_row = false;
1222
1223                 if (isset($params['order'])) {
1224                         $param_string .= " ORDER BY ";
1225                         foreach ($params['order'] AS $fields => $order) {
1226                                 if (!is_int($fields)) {
1227                                         $param_string .= "`".$fields."` ".($order ? "DESC" : "ASC").", ";
1228                                 } else {
1229                                         $param_string .= "`".$order."`, ";
1230                                 }
1231                         }
1232                         $param_string = substr($param_string, 0, -2);
1233                 }
1234
1235                 if (isset($params['limit'])) {
1236                         if (is_int($params['limit'])) {
1237                                 $param_string .= " LIMIT ".$params['limit'];
1238                                 $single_row =($params['limit'] == 1);
1239                         }
1240                 }
1241
1242                 $sql = "SELECT ".$select_fields." FROM `".$table."`".$condition_string.$param_string;
1243
1244                 $result = self::p($sql, $condition);
1245
1246                 if (is_bool($result) || !$single_row) {
1247                         return $result;
1248                 } else {
1249                         $row = self::fetch($result);
1250                         self::close($result);
1251                         return $row;
1252                 }
1253         }
1254
1255         /**
1256          * @brief Closes the current statement
1257          *
1258          * @param object $stmt statement object
1259          * @return boolean was the close successfull?
1260          */
1261         static public function close($stmt) {
1262                 if (!is_object($stmt)) {
1263                         return false;
1264                 }
1265
1266                 switch (self::$dbo->driver) {
1267                         case 'pdo':
1268                                 return $stmt->closeCursor();
1269                         case 'mysqli':
1270                                 return $stmt->free_result();
1271                                 return $stmt->close();
1272                         case 'mysql':
1273                                 return mysql_free_result($stmt);
1274                 }
1275         }
1276 }
1277
1278 function printable($s) {
1279         $s = preg_replace("~([\x01-\x08\x0E-\x0F\x10-\x1F\x7F-\xFF])~",".", $s);
1280         $s = str_replace("\x00",'.',$s);
1281         if (x($_SERVER,'SERVER_NAME')) {
1282                 $s = escape_tags($s);
1283         }
1284         return $s;
1285 }
1286
1287 // Procedural functions
1288 function dbg($state) {
1289         global $db;
1290
1291         if ($db) {
1292                 $db->dbg($state);
1293         }
1294 }
1295
1296 function dbesc($str) {
1297         global $db;
1298
1299         if ($db && $db->connected) {
1300                 return($db->escape($str));
1301         } else {
1302                 return(str_replace("'","\\'",$str));
1303         }
1304 }
1305
1306 // Function: q($sql,$args);
1307 // Description: execute SQL query with printf style args.
1308 // Example: $r = q("SELECT * FROM `%s` WHERE `uid` = %d",
1309 //                   'user', 1);
1310 function q($sql) {
1311         global $db;
1312         $args = func_get_args();
1313         unset($args[0]);
1314
1315         if ($db && $db->connected) {
1316                 $sql = $db->clean_query($sql);
1317                 $sql = $db->any_value_fallback($sql);
1318                 $stmt = @vsprintf($sql,$args); // Disabled warnings
1319                 //logger("dba: q: $stmt", LOGGER_ALL);
1320                 if ($stmt === false)
1321                         logger('dba: vsprintf error: ' . print_r(debug_backtrace(),true), LOGGER_DEBUG);
1322
1323                 $db->log_index($stmt);
1324
1325                 return $db->q($stmt);
1326         }
1327
1328         /**
1329          *
1330          * This will happen occasionally trying to store the
1331          * session data after abnormal program termination
1332          *
1333          */
1334         logger('dba: no database: ' . print_r($args,true));
1335         return false;
1336 }
1337
1338 /**
1339  * @brief Performs a query with "dirty reads"
1340  *
1341  * By doing dirty reads (reading uncommitted data) no locks are performed
1342  * This function can be used to fetch data that doesn't need to be reliable.
1343  *
1344  * @param $args Query parameters (1 to N parameters of different types)
1345  * @return array Query array
1346  */
1347 function qu($sql) {
1348         global $db;
1349
1350         $args = func_get_args();
1351         unset($args[0]);
1352
1353         if ($db && $db->connected) {
1354                 $sql = $db->clean_query($sql);
1355                 $sql = $db->any_value_fallback($sql);
1356                 $stmt = @vsprintf($sql,$args); // Disabled warnings
1357                 if ($stmt === false)
1358                         logger('dba: vsprintf error: ' . print_r(debug_backtrace(),true), LOGGER_DEBUG);
1359
1360                 $db->log_index($stmt);
1361
1362                 $db->q("SET SESSION TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;");
1363                 $retval = $db->q($stmt);
1364                 $db->q("SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ;");
1365                 return $retval;
1366         }
1367
1368         /**
1369          *
1370          * This will happen occasionally trying to store the
1371          * session data after abnormal program termination
1372          *
1373          */
1374         logger('dba: no database: ' . print_r($args,true));
1375         return false;
1376 }
1377
1378 /**
1379  *
1380  * Raw db query, no arguments
1381  *
1382  */
1383 function dbq($sql) {
1384         global $db;
1385
1386         if ($db && $db->connected) {
1387                 $ret = $db->q($sql);
1388         } else {
1389                 $ret = false;
1390         }
1391         return $ret;
1392 }
1393
1394 // Caller is responsible for ensuring that any integer arguments to
1395 // dbesc_array are actually integers and not malformed strings containing
1396 // SQL injection vectors. All integer array elements should be specifically
1397 // cast to int to avoid trouble.
1398 function dbesc_array_cb(&$item, $key) {
1399         if (is_string($item))
1400                 $item = dbesc($item);
1401 }
1402
1403 function dbesc_array(&$arr) {
1404         if (is_array($arr) && count($arr)) {
1405                 array_walk($arr,'dbesc_array_cb');
1406         }
1407 }
1408
1409 function dba_timer() {
1410         return microtime(true);
1411 }