1:   2:   3:   4:   5:   6:   7:   8:   9:  10:  11:  12:  13:  14:  15:  16:  17:  18:  19:  20:  21:  22:  23:  24:  25:  26:  27:  28:  29:  30:  31:  32:  33:  34:  35:  36:  37:  38:  39:  40:  41:  42:  43:  44:  45:  46:  47:  48:  49:  50:  51:  52:  53:  54:  55:  56:  57:  58:  59:  60:  61:  62:  63:  64:  65:  66:  67:  68:  69:  70:  71:  72:  73:  74:  75:  76:  77:  78:  79:  80:  81:  82:  83:  84:  85:  86:  87:  88:  89:  90:  91:  92:  93:  94:  95:  96:  97:  98:  99: 100: 101: 102: 103: 104: 105: 106: 107: 108: 109: 110: 111: 112: 113: 114: 115: 116: 117: 118: 119: 120: 121: 122: 123: 124: 125: 126: 127: 128: 129: 130: 131: 132: 133: 134: 135: 136: 137: 138: 139: 140: 141: 142: 143: 144: 145: 146: 147: 148: 149: 150: 151: 152: 153: 154: 155: 156: 157: 158: 159: 160: 161: 162: 163: 164: 165: 166: 167: 168: 169: 170: 171: 172: 173: 174: 175: 176: 177: 178: 179: 180: 181: 182: 183: 184: 185: 186: 187: 188: 189: 190: 191: 192: 193: 194: 195: 196: 197: 198: 199: 200: 201: 202: 203: 204: 205: 206: 207: 208: 209: 210: 211: 212: 213: 214: 215: 216: 217: 218: 219: 220: 221: 222: 223: 224: 225: 226: 227: 228: 229: 230: 231: 232: 233: 234: 235: 236: 237: 238: 239: 240: 241: 242: 243: 244: 245: 246: 247: 248: 249: 250: 251: 252: 253: 254: 255: 256: 257: 258: 259: 260: 261: 262: 263: 264: 

<?php

/**
 * MvcCore
 *
 * This source file is subject to the BSD 3 License
 * For the full copyright and license information, please view
 * the LICENSE.md file that are distributed with this source code.
 *
 * @copyright   Copyright (c) 2016 Tom Flidr (https://github.com/mvccore)
 * @license  https://mvccore.github.io/docs/mvccore/5.0.0/LICENCE.md
 */

namespace MvcCore\Tool;

trait Helpers {

    /**
     * Platform specific temporary directory.
     * @var string|NULL
     */
    protected static $tmpDir = NULL;

    /**
     * @inheritDocs
     * @return string
     */
    public static function GetSystemTmpDir () {
        if (self::$tmpDir === NULL) {
            $tmpDir = sys_get_temp_dir();
            if (strtolower(substr(PHP_OS, 0, 3)) == 'win') {
                // Windows:
                $sysRoot = getenv('SystemRoot');
                // do not store anything directly in C:\Windows, use C:\windows\Temp instead
                if (!$tmpDir || $tmpDir === $sysRoot) {
                    $tmpDir = !empty($_SERVER['TEMP'])
                        ? $_SERVER['TEMP']
                        : (!empty($_SERVER['TMP'])
                            ? $_SERVER['TMP']
                            : (!empty($_SERVER['WINDIR'])
                                ? $_SERVER['WINDIR'] . '/Temp'
                                : $sysRoot . '/Temp'
                            )
                        );
                }
                $tmpDir = str_replace('\\', '/', $tmpDir);
            } else if (!$tmpDir) {
                // Other systems
                $iniSysTempDir = @ini_get('sys_temp_dir');
                $tmpDir = !empty($_SERVER['TMPDIR'])
                    ? $_SERVER['TMPDIR']
                    : (!empty($_SERVER['TMP'])
                        ? $_SERVER['TMP']
                        : (!empty($iniSysTempDir)
                            ? $iniSysTempDir
                            : '/tmp'
                        )
                    );
            }
            self::$tmpDir = $tmpDir;
        }
        return self::$tmpDir;
    }
    
    /**
     * @inheritDocs
     * @param string $jsonStr
     * @return bool
     */
    public static function IsQueryString ($queryStr) {
        $queryStr = trim($queryStr, '&=');
        $apmsCount = substr_count($queryStr, '&');
        $equalsCount = substr_count($queryStr, '=');
        $firstAndLast = mb_substr($queryStr, 0, 1) . mb_substr($queryStr, -1, 1);
        if ($firstAndLast === '{}' || $firstAndLast === '[]') return FALSE; // most likely a JSON
        if ($apmsCount === 0 && $equalsCount === 0) return FALSE; // there was `nothing`
        if ($equalsCount > 0) $equalsCount -= 1;
        if ($equalsCount === 0) return TRUE; // there was `key=value`
        return $apmsCount / $equalsCount >= 1; // there was `key=&key=value`
    }

    /**
     * @inheritDocs
     * @param string|callable $internalFnOrHandler
     * @param array $args
     * @param callable $onError
     * @return mixed
     */
    public static function Invoke ($internalFnOrHandler, array $args, callable $onError) {
        $prevErrorHandler = NULL;
        $prevErrorHandler = set_error_handler(
            function ($errLevel, $errMessage, $errFile, $errLine, $errContext) use ($onError, & $prevErrorHandler, $internalFnOrHandler) {
                if ($errFile === '' && defined('HHVM_VERSION'))  // https://github.com/facebook/hhvm/issues/4625
                    $errFile = func_get_arg(5)[1]['file'];
                if ($errFile === __FILE__) {
                    $funcNameStr = is_string($internalFnOrHandler)
                        ? $internalFnOrHandler
                        : (is_array($internalFnOrHandler) && count($internalFnOrHandler) === 2
                            ? $internalFnOrHandler[1]
                            : strval($internalFnOrHandler)
                        );
                    $errMessage = preg_replace("#^$funcNameStr\(.*?\): #", '', $errMessage);
                    if ($onError($errMessage, $errLevel, $errFile, $errLine, $errContext) !== FALSE)
                        return TRUE;
                }
                return $prevErrorHandler
                    ? call_user_func_array($prevErrorHandler, func_get_args())
                    : FALSE;
            }
        );
        try {
            return call_user_func_array($internalFnOrHandler, $args);
        } catch (\Exception $e) { // backward compatibility
        } catch (\Throwable $e) {
        } /* finally {
            restore_error_handler();
        }*/
        restore_error_handler();
        return NULL;
    }

    /**
     * @inheritDocs
     * @see http://php.net/manual/en/function.flock.php
     * @see http://php.net/manual/en/function.set-error-handler.php
     * @see http://php.net/manual/en/function.clearstatcache.php
     * @param string $fullPath File full path.
     * @param string $content String content to write.
     * @param string $writeMode PHP `fopen()` second argument flag, could be `w`, `w+`, `a`, `a+` etc...
     * @param int $lockWaitMilliseconds Milliseconds to wait before next lock file existence is checked in `while()` cycle.
     * @param int $maxLockWaitMilliseconds Maximum milliseconds time to wait before thrown an exception about not possible write.
     * @param int $oldLockMillisecondsTolerance Maximum milliseconds time to consider lock file as operative or as old after some died process.
     * @throws \Exception
     * @return bool
     */
    public static function AtomicWrite (
        $fullPath,
        $content,
        $writeMode = 'w',
        $lockWaitMilliseconds = 100,
        $maxLockWaitMilliseconds = 5000,
        $oldLockMillisecondsTolerance = 30000
    ) {
        $waitUTime = $lockWaitMilliseconds * 1000;
        $lockHandle = NULL;

        $tmpDir = self::GetSystemTmpDir();
        $lockFullPath = $tmpDir . '/mvccore_lock_' . sha1($fullPath) . '.tmp';

        // capture E_WARNINGs for `fopen()` and `filemtime()` and do not log them:
        set_error_handler(function ($level, $msg, $file, $line, $args) use (& $fullPath, & $lockFullPath, & $lockHandle) {
            if ($level == E_WARNING) {
                if (
                    mb_strpos($msg, 'fopen(' . $fullPath) === 0 ||
                    mb_strpos($msg, 'filemtime(' . $fullPath) === 0 ||
                    mb_strpos($msg, 'fopen(' . $lockFullPath) === 0 ||
                    mb_strpos($msg, 'filemtime(' . $lockFullPath) === 0
                ) {
                    if ($lockHandle !== NULL) {
                        // unlock before exception
                        @flock($lockHandle, LOCK_UN);
                        fclose($lockHandle);
                        unlink($lockFullPath);
                    }
                    throw new \Exception ($msg);
                }
            }
            return FALSE;
        }, E_WARNING);

        // get last modification time for lock file
        // if exists to prevent old locks in cache
        clearstatcache(TRUE, $lockFullPath);
        if (file_exists($lockFullPath)) {
            $fileModTime = @filemtime($lockFullPath);
            if ($fileModTime !== FALSE) {
                if (time() > $fileModTime + $oldLockMillisecondsTolerance)
                    unlink($lockFullPath);
            }
        }

        // try to create lock file handle
        $waitingTime = 0;
        while (TRUE) {
            clearstatcache(TRUE, $lockFullPath);
            $lockHandle = @fopen($lockFullPath, 'x');
            if ($lockHandle !== FALSE) break;
            $waitingTime += $lockWaitMilliseconds;
            if ($waitingTime > $maxLockWaitMilliseconds) {
                throw new \Exception(
                    'Unable to create lock handle: `' . $lockFullPath
                    . '` for file: `' . $fullPath
                    . '`. Lock creation timeout. Try to clear cache: `'
                    . $tmpDir . '`'
                );
            }
            usleep($waitUTime);
        }
        if (!flock($lockHandle, LOCK_EX)) {
            // unlock before exception
            fclose($lockHandle);
            unlink($lockFullPath);
            throw new \Exception(
                'Unable to create lock handle: `' . $lockFullPath
                . '` for file: `' . $fullPath
                . '`. Lock creation timeout. Try to clear cache: `'
                . $tmpDir . '`'
            );
        }
        fwrite($lockHandle, $fullPath);
        fflush($lockHandle);

        // write or append the file
        clearstatcache(TRUE, $fullPath);
        $handle = @fopen($fullPath, $writeMode);
        if ($handle && !flock($handle, LOCK_EX))
            $handle = FALSE;
        if (!$handle) {
            // unlock before exception
            flock($lockHandle, LOCK_UN);
            fclose($lockHandle);
            unlink($lockFullPath);
            throw new \Exception(
                'Unable to create locked handle for file: `' . $fullPath . '`.'
            );
        }
        fwrite($handle, $content);
        fflush($handle);
        flock($handle, LOCK_UN);

        // unlock
        flock($lockHandle, LOCK_UN);
        fclose($lockHandle);
        $success = unlink($lockFullPath);

        restore_error_handler();

        return $success;
    }

    /**
     * @inheritDocs
     * @see https://www.php.net/manual/en/function.realpath.php
     * @param string $path
     * @return string
     */
    public static function RealPathVirtual ($path) {
        $path = str_replace('\\', '/', $path);
        $rawParts = explode('/', $path);
        $parts = array_filter($rawParts, 'strlen');
        if ($rawParts[0] == '' && mb_substr($path, 0, 1) == '/')
            array_unshift($parts, '');
        $items = [];
        foreach ($parts as $part) {
            if ('.' == $part) continue;
            if ('..' == $part) {
                array_pop($items);
            } else {
                $items[] = $part;
            }
        }
        return implode('/', $items);
    }
}