friendica/include/dba.php

<?php

use Friendica\App;
use Friendica\Core\L10n;
use Friendica\Core\System;
use Friendica\Database\DBM;
use Friendica\Database\DBStructure;
use Friendica\Util\DateTimeFormat;

/**
 * @class MySQL database class
 *
 * This class is for the low level database stuff that does driver specific things.
 */

class dba {
	public static $connected = false;

	private static $_server_info = '';
	private static $db;
	private static $driver;
	private static $error = false;
	private static $errorno = 0;
	private static $affected_rows = 0;
	private static $in_transaction = false;
	private static $relation = [];

	public static function connect($serveraddr, $user, $pass, $db) {
		if (!is_null(self::$db)) {
			return true;
		}

		$a = get_app();

		$stamp1 = microtime(true);

		$serveraddr = trim($serveraddr);

		$serverdata = explode(':', $serveraddr);
		$server = $serverdata[0];

		if (count($serverdata) > 1) {
			$port = trim($serverdata[1]);
		}

		$server = trim($server);
		$user = trim($user);
		$pass = trim($pass);
		$db = trim($db);

		if (!(strlen($server) && strlen($user))) {
			return false;
		}

		if (class_exists('\PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
			self::$driver = 'pdo';
			$connect = "mysql:host=".$server.";dbname=".$db;

			if (isset($port)) {
				$connect .= ";port=".$port;
			}

			if (isset($a->config["system"]["db_charset"])) {
				$connect .= ";charset=".$a->config["system"]["db_charset"];
			}
			try {
				self::$db = @new PDO($connect, $user, $pass);
				self::$connected = true;
			} catch (PDOException $e) {
			}
		}

		if (!self::$connected && class_exists('mysqli')) {
			self::$driver = 'mysqli';
			self::$db = @new mysqli($server, $user, $pass, $db, $port);
			if (!mysqli_connect_errno()) {
				self::$connected = true;

				if (isset($a->config["system"]["db_charset"])) {
					self::$db->set_charset($a->config["system"]["db_charset"]);
				}
			}
		}

		// No suitable SQL driver was found.
		if (!self::$connected) {
			self::$driver = null;
			self::$db = null;
		}
		$a->save_timestamp($stamp1, "network");

		return self::$connected;
	}

	/**
	 * Return the database object.
	 * @return PDO|mysqli
	 */
	public static function get_db()
	{
		return self::$db;
	}

	/**
	 * @brief Returns the MySQL server version string
	 *
	 * This function discriminate between the deprecated mysql API and the current
	 * object-oriented mysqli API. Example of returned string: 5.5.46-0+deb8u1
	 *
	 * @return string
	 */
	public static function server_info() {
		if (self::$_server_info == '') {
			switch (self::$driver) {
				case 'pdo':
					self::$_server_info = self::$db->getAttribute(PDO::ATTR_SERVER_VERSION);
					break;
				case 'mysqli':
					self::$_server_info = self::$db->server_info;
					break;
			}
		}
		return self::$_server_info;
	}

	/**
	 * @brief Returns the selected database name
	 *
	 * @return string
	 */
	public static function database_name() {
		$ret = self::p("SELECT DATABASE() AS `db`");
                $data = self::inArray($ret);
		return $data[0]['db'];
	}

	/**
	 * @brief Analyze a database query and log this if some conditions are met.
	 *
	 * @param string $query The database query that will be analyzed
	 */
	private static function logIndex($query) {
		$a = get_app();

		if (empty($a->config["system"]["db_log_index"])) {
			return;
		}

		// Don't explain an explain statement
		if (strtolower(substr($query, 0, 7)) == "explain") {
			return;
		}

		// Only do the explain on "select", "update" and "delete"
		if (!in_array(strtolower(substr($query, 0, 6)), ["select", "update", "delete"])) {
			return;
		}

		$r = self::p("EXPLAIN ".$query);
		if (!DBM::is_result($r)) {
			return;
		}

		$watchlist = explode(',', $a->config["system"]["db_log_index_watch"]);
		$blacklist = explode(',', $a->config["system"]["db_log_index_blacklist"]);

		while ($row = dba::fetch($r)) {
			if ((intval($a->config["system"]["db_loglimit_index"]) > 0)) {
				$log = (in_array($row['key'], $watchlist) &&
					($row['rows'] >= intval($a->config["system"]["db_loglimit_index"])));
			} else {
				$log = false;
			}

			if ((intval($a->config["system"]["db_loglimit_index_high"]) > 0) && ($row['rows'] >= intval($a->config["system"]["db_loglimit_index_high"]))) {
				$log = true;
			}

			if (in_array($row['key'], $blacklist) || ($row['key'] == "")) {
				$log = false;
			}

			if ($log) {
				$backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);
				@file_put_contents($a->config["system"]["db_log_index"], DateTimeFormat::utcNow()."\t".
						$row['key']."\t".$row['rows']."\t".$row['Extra']."\t".
						basename($backtrace[1]["file"])."\t".
						$backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
						substr($query, 0, 2000)."\n", FILE_APPEND);
			}
		}
	}

	public static function escape($str) {
		switch (self::$driver) {
			case 'pdo':
				return substr(@self::$db->quote($str, PDO::PARAM_STR), 1, -1);
			case 'mysqli':
				return @self::$db->real_escape_string($str);
		}
	}

	public static function connected() {
		$connected = false;

		switch (self::$driver) {
			case 'pdo':
				$r = dba::p("SELECT 1");
				if (DBM::is_result($r)) {
					$row = dba::inArray($r);
					$connected = ($row[0]['1'] == '1');
				}
				break;
			case 'mysqli':
				$connected = self::$db->ping();
				break;
		}
		return $connected;
	}

	/**
	 * @brief Replaces ANY_VALUE() function by MIN() function,
	 *  if the database server does not support ANY_VALUE().
	 *
	 * Considerations for Standard SQL, or MySQL with ONLY_FULL_GROUP_BY (default since 5.7.5).
	 * ANY_VALUE() is available from MySQL 5.7.5 https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html
	 * A standard fall-back is to use MIN().
	 *
	 * @param string $sql An SQL string without the values
	 * @return string The input SQL string modified if necessary.
	 */
	public static function any_value_fallback($sql) {
		$server_info = self::server_info();
		if (version_compare($server_info, '5.7.5', '<') ||
			(stripos($server_info, 'MariaDB') !== false)) {
			$sql = str_ireplace('ANY_VALUE(', 'MIN(', $sql);
		}
		return $sql;
	}

	/**
	 * @brief beautifies the query - useful for "SHOW PROCESSLIST"
	 *
	 * This is safe when we bind the parameters later.
	 * The parameter values aren't part of the SQL.
	 *
	 * @param string $sql An SQL string without the values
	 * @return string The input SQL string modified if necessary.
	 */
	public static function clean_query($sql) {
		$search = ["\t", "\n", "\r", "  "];
		$replace = [' ', ' ', ' ', ' '];
		do {
			$oldsql = $sql;
			$sql = str_replace($search, $replace, $sql);
		} while ($oldsql != $sql);

		return $sql;
	}


	/**
	 * @brief Replaces the ? placeholders with the parameters in the $args array
	 *
	 * @param string $sql SQL query
	 * @param array $args The parameters that are to replace the ? placeholders
	 * @return string The replaced SQL query
	 */
	private static function replaceParameters($sql, $args) {
		$offset = 0;
		foreach ($args AS $param => $value) {
			if (is_int($args[$param]) || is_float($args[$param])) {
				$replace = intval($args[$param]);
			} else {
				$replace = "'".self::escape($args[$param])."'";
			}

			$pos = strpos($sql, '?', $offset);
			if ($pos !== false) {
				$sql = substr_replace($sql, $replace, $pos, 1);
			}
			$offset = $pos + strlen($replace);
		}
		return $sql;
	}

	/**
	 * @brief Convert parameter array to an universal form
	 * @param array $args Parameter array
	 * @return array universalized parameter array
	 */
	private static function getParam($args) {
		unset($args[0]);

		// When the second function parameter is an array then use this as the parameter array
		if ((count($args) > 0) && (is_array($args[1]))) {
			return $args[1];
		} else {
			return $args;
		}
	}

	/**
	 * @brief Executes a prepared statement that returns data
	 * @usage Example: $r = p("SELECT * FROM `item` WHERE `guid` = ?", $guid);
	 *
	 * Please only use it with complicated queries.
	 * For all regular queries please use dba::select or dba::exists
	 *
	 * @param string $sql SQL statement
	 * @return bool|object statement object
	 */
	public static function p($sql) {
		$a = get_app();

		$stamp1 = microtime(true);

		$params = self::getParam(func_get_args());

		// Renumber the array keys to be sure that they fit
		$i = 0;
		$args = [];
		foreach ($params AS $param) {
			// Avoid problems with some MySQL servers and boolean values. See issue #3645
			if (is_bool($param)) {
				$param = (int)$param;
			}
			$args[++$i] = $param;
		}

		if (!self::$connected) {
			return false;
		}

		if ((substr_count($sql, '?') != count($args)) && (count($args) > 0)) {
			// Question: Should we continue or stop the query here?
			logger('Parameter mismatch. Query "'.$sql.'" - Parameters '.print_r($args, true), LOGGER_DEBUG);
		}

		$sql = self::clean_query($sql);
		$sql = self::any_value_fallback($sql);

		$orig_sql = $sql;

		if (x($a->config,'system') && x($a->config['system'], 'db_callstack')) {
			$sql = "/*".System::callstack()." */ ".$sql;
		}

		self::$error = '';
		self::$errorno = 0;
		self::$affected_rows = 0;

		// We have to make some things different if this function is called from "e"
		$trace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS, 2);

		if (isset($trace[1])) {
			$called_from = $trace[1];
		} else {
			// We use just something that is defined to avoid warnings
			$called_from = $trace[0];
		}
		// We are having an own error logging in the function "e"
		$called_from_e = ($called_from['function'] == 'e');

		switch (self::$driver) {
			case 'pdo':
				// If there are no arguments we use "query"
				if (count($args) == 0) {
					if (!$retval = self::$db->query($sql)) {
						$errorInfo = self::$db->errorInfo();
						self::$error = $errorInfo[2];
						self::$errorno = $errorInfo[1];
						$retval = false;
						break;
					}
					self::$affected_rows = $retval->rowCount();
					break;
				}

				if (!$stmt = self::$db->prepare($sql)) {
					$errorInfo = self::$db->errorInfo();
					self::$error = $errorInfo[2];
					self::$errorno = $errorInfo[1];
					$retval = false;
					break;
				}

				foreach ($args AS $param => $value) {
					$stmt->bindParam($param, $args[$param]);
				}

				if (!$stmt->execute()) {
					$errorInfo = $stmt->errorInfo();
					self::$error = $errorInfo[2];
					self::$errorno = $errorInfo[1];
					$retval = false;
				} else {
					$retval = $stmt;
					self::$affected_rows = $retval->rowCount();
				}
				break;
			case 'mysqli':
				// There are SQL statements that cannot be executed with a prepared statement
				$parts = explode(' ', $orig_sql);
				$command = strtolower($parts[0]);
				$can_be_prepared = in_array($command, ['select', 'update', 'insert', 'delete']);

				// The fallback routine is called as well when there are no arguments
				if (!$can_be_prepared || (count($args) == 0)) {
					$retval = self::$db->query(self::replaceParameters($sql, $args));
					if (self::$db->errno) {
						self::$error = self::$db->error;
						self::$errorno = self::$db->errno;
						$retval = false;
					} else {
						if (isset($retval->num_rows)) {
							self::$affected_rows = $retval->num_rows;
						} else {
							self::$affected_rows = self::$db->affected_rows;
						}
					}
					break;
				}

				$stmt = self::$db->stmt_init();

				if (!$stmt->prepare($sql)) {
					self::$error = $stmt->error;
					self::$errorno = $stmt->errno;
					$retval = false;
					break;
				}

				$params = '';
				$values = [];
				foreach ($args AS $param => $value) {
					if (is_int($args[$param])) {
						$params .= 'i';
					} elseif (is_float($args[$param])) {
						$params .= 'd';
					} elseif (is_string($args[$param])) {
						$params .= 's';
					} else {
						$params .= 'b';
					}
					$values[] = &$args[$param];
				}

				if (count($values) > 0) {
					array_unshift($values, $params);
					call_user_func_array([$stmt, 'bind_param'], $values);
				}

				if (!$stmt->execute()) {
					self::$error = self::$db->error;
					self::$errorno = self::$db->errno;
					$retval = false;
				} else {
					$stmt->store_result();
					$retval = $stmt;
					self::$affected_rows = $retval->affected_rows;
				}
				break;
		}

		// We are having an own error logging in the function "e"
		if ((self::$errorno != 0) && !$called_from_e) {
			// We have to preserve the error code, somewhere in the logging it get lost
			$error = self::$error;
			$errorno = self::$errorno;

			logger('DB Error '.self::$errorno.': '.self::$error."\n".
				System::callstack(8)."\n".self::replaceParameters($sql, $params));

			self::$error = $error;
			self::$errorno = $errorno;
		}

		$a->save_timestamp($stamp1, 'database');

		if (x($a->config,'system') && x($a->config['system'], 'db_log')) {

			$stamp2 = microtime(true);
			$duration = (float)($stamp2 - $stamp1);

			if (($duration > $a->config["system"]["db_loglimit"])) {
				$duration = round($duration, 3);
				$backtrace = debug_backtrace(DEBUG_BACKTRACE_IGNORE_ARGS);

				@file_put_contents($a->config["system"]["db_log"], DateTimeFormat::utcNow()."\t".$duration."\t".
						basename($backtrace[1]["file"])."\t".
						$backtrace[1]["line"]."\t".$backtrace[2]["function"]."\t".
						substr(self::replaceParameters($sql, $args), 0, 2000)."\n", FILE_APPEND);
			}
		}
		return $retval;
	}

	/**
	 * @brief Executes a prepared statement like UPDATE or INSERT that doesn't return data
	 *
	 * Please use dba::delete, dba::insert, dba::update, ... instead
	 *
	 * @param string $sql SQL statement
	 * @return boolean Was the query successfull? False is returned only if an error occurred
	 */
	public static function e($sql) {
		$a = get_app();

		$stamp = microtime(true);

		$params = self::getParam(func_get_args());

		// In a case of a deadlock we are repeating the query 20 times
		$timeout = 20;

		do {
			$stmt = self::p($sql, $params);

			if (is_bool($stmt)) {
				$retval = $stmt;
			} elseif (is_object($stmt)) {
				$retval = true;
			} else {
				$retval = false;
			}

			self::close($stmt);

		} while ((self::$errorno == 1213) && (--$timeout > 0));

		if (self::$errorno != 0) {
			// We have to preserve the error code, somewhere in the logging it get lost
			$error = self::$error;
			$errorno = self::$errorno;

			logger('DB Error '.self::$errorno.': '.self::$error."\n".
				System::callstack(8)."\n".self::replaceParameters($sql, $params));

			self::$error = $error;
			self::$errorno = $errorno;
		}

		$a->save_timestamp($stamp, "database_write");

		return $retval;
	}

	/**
	 * @brief Check if data exists
	 *
	 * @param string $table Table name
	 * @param array $condition array of fields for condition
	 *
	 * @return boolean Are there rows for that condition?
	 */
	public static function exists($table, $condition) {
		if (empty($table)) {
			return false;
		}

		$fields = [];

		reset($condition);
		$first_key = key($condition);
		if (!is_int($first_key)) {
			$fields = [$first_key];
		}

		$stmt = self::select($table, $fields, $condition, ['limit' => 1]);

		if (is_bool($stmt)) {
			$retval = $stmt;
		} else {
			$retval = (self::num_rows($stmt) > 0);
		}

		self::close($stmt);

		return $retval;
	}

	/**
	 * Fetches the first row
	 *
	 * Please use dba::selectFirst or dba::exists whenever this is possible.
	 *
	 * @brief Fetches the first row
	 * @param string $sql SQL statement
	 * @return array first row of query
	 */
	public static function fetch_first($sql) {
		$params = self::getParam(func_get_args());

		$stmt = self::p($sql, $params);

		if (is_bool($stmt)) {
			$retval = $stmt;
		} else {
			$retval = self::fetch($stmt);
		}

		self::close($stmt);

		return $retval;
	}

	/**
	 * @brief Returns the number of affected rows of the last statement
	 *
	 * @return int Number of rows
	 */
	public static function affected_rows() {
		return self::$affected_rows;
	}

	/**
	 * @brief Returns the number of columns of a statement
	 *
	 * @param object Statement object
	 * @return int Number of columns
	 */
	public static function columnCount($stmt) {
		if (!is_object($stmt)) {
			return 0;
		}
		switch (self::$driver) {
			case 'pdo':
				return $stmt->columnCount();
			case 'mysqli':
				return $stmt->field_count;
		}
		return 0;
	}
	/**
	 * @brief Returns the number of rows of a statement
	 *
	 * @param PDOStatement|mysqli_result|mysqli_stmt Statement object
	 * @return int Number of rows
	 */
	public static function num_rows($stmt) {
		if (!is_object($stmt)) {
			return 0;
		}
		switch (self::$driver) {
			case 'pdo':
				return $stmt->rowCount();
			case 'mysqli':
				return $stmt->num_rows;
		}
		return 0;
	}

	/**
	 * @brief Fetch a single row
	 *
	 * @param mixed $stmt statement object