PHPDaemon\FS\FileSystem::open PHP Method

    public static function open($path, $flags, $cb, $mode = null, $pri = EIO_PRI_DEFAULT)
    {
        $cb = CallbackWrapper::forceWrap($cb);
        if (!FileSystem::$supported) {
            $mode = File::convertFlags($flags, true);
            $fd = fopen($path, $mode);
            if (!$fd) {
                $cb(false);
                return false;
            }
            $file = new File($fd, $path);
            $cb($file);
            return true;
        }
        $fdCacheKey = $path . "" . $flags;
        $noncache = mb_orig_strpos($flags, '!') !== false;
        $flags = File::convertFlags($flags);
        if (!$noncache && ($item = FileSystem::$fdCache->get($fdCacheKey))) {
            // cache hit
            $file = $item->getValue();
            if ($file === null) {
                // operation in progress
                $item->addListener($cb);
            } else {
                // hit
                $cb($file);
            }
            return null;
        } elseif (!$noncache) {
            $item = FileSystem::$fdCache->put($fdCacheKey, null);
            $item->addListener($cb);
        }
        return eio_open($path, $flags, $mode, $pri, function ($path, $fd) use($cb, $flags, $fdCacheKey, $noncache) {
            if ($fd === -1) {
                if ($noncache) {
                    $cb(false);
                } else {
                    FileSystem::$fdCache->put($fdCacheKey, false, self::$badFDttl);
                }
                return;
            }
            $file = new File($fd, $path);
            $file->append = ($flags | EIO_O_APPEND) === $flags;
            if ($file->append) {
                $file->stat(function ($file, $stat) use($cb, $noncache, $fdCacheKey) {
                    $file->offset = $stat['size'];
                    if (!$noncache) {
                        $file->fdCacheKey = $fdCacheKey;
                        FileSystem::$fdCache->put($fdCacheKey, $file);
                    } else {
                        $cb($file);
                    }
                });
            } else {
                if (!$noncache) {
                    $file->fdCacheKey = $fdCacheKey;
                    FileSystem::$fdCache->put($fdCacheKey, $file);
                } else {
                    $cb($file);
                }
            }
        }, $path);
    }

 /**
  * Prepares the request body
  * @return void
  */
 public function postPrepare()
 {
     if (!$this->attrs->server['REQUEST_METHOD_POST']) {
         return;
     }
     if (isset($this->attrs->server['REQUEST_PREPARED_UPLOADS']) && $this->attrs->server['REQUEST_PREPARED_UPLOADS'] === 'nginx') {
         if (isset($this->attrs->server['REQUEST_PREPARED_UPLOADS_URL_PREFIX'])) {
             $URLprefix = $this->attrs->server['REQUEST_PREPARED_UPLOADS_URL_PREFIX'];
             $l = mb_orig_strlen($URLprefix);
             foreach (['PHP_SELF', 'REQUEST_URI', 'SCRIPT_NAME', 'DOCUMENT_URI'] as $k) {
                 if (!isset($this->attrs->server[$k])) {
                     continue;
                 }
                 if (strncmp($this->attrs->server[$k], $URLprefix, $l) === 0) {
                     $this->attrs->server[$k] = substr($this->attrs->server[$k], $l - 1);
                 }
             }
         }
         $prefix = 'file.';
         $prefixlen = mb_orig_strlen($prefix);
         foreach ($this->attrs->post as $k => $v) {
             if (strncmp($k, $prefix, $prefixlen) === 0) {
                 $e = explode('.', substr($k, $prefixlen));
                 if (!isset($e[1])) {
                     $e = ['file', $e[0]];
                 }
                 if (!isset($this->attrs->files[$e[0]])) {
                     $this->attrs->files[$e[0]] = ['error' => UPLOAD_ERR_OK];
                 }
                 $this->attrs->files[$e[0]][$e[1]] = $v;
                 unset($this->attrs->post[$k]);
             }
         }
         $uploadTmp = $this->getUploadTempDir();
         foreach ($this->attrs->files as $k => &$file) {
             if (!isset($file['tmp_name']) || !isset($file['name']) || !ctype_digit(basename($file['tmp_name'])) || mb_orig_strpos(pathinfo($file['tmp_name'], PATHINFO_DIRNAME), $uploadTmp) !== 0) {
                 unset($this->attrs->files[$k]);
                 continue;
             }
             FileSystem::open($file['tmp_name'], 'c+!', function ($fp) use(&$file) {
                 if (!$fp) {
                     return;
                 }
                 $file['fp'] = $fp;
             });
         }
         unset($file);
     }
     if (isset($this->attrs->server['REQUEST_BODY_FILE']) && $this->upstream->pool->config->autoreadbodyfile->value) {
         $this->readBodyFile();
     }
 }