[UTIL] Add TemporaryFile class, courtesy of Alexei Sorokin from v2, a class that ensures files stored in /tmp are removed, as it doesn't happen in some cases

src/Util/TemporaryFile.php

@@ -0,0 +1,151 @@
+<?php
+
+// {{{ License
+// This file is part of GNU social - https://www.gnu.org/software/social
+//
+// GNU social is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// GNU social is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.
+// }}}
+
+namespace App\Util;
+
+/**
+ * Class oriented at providing automatic temporary file handling.
+ *
+ * @package   GNUsocial
+ *
+ * @author    Alexei Sorokin <sor.alexei@meowr.ru>
+ * @copyright 2020 Free Software Foundation, Inc http://www.fsf.org
+ * @license   https://www.gnu.org/licenses/agpl.html GNU AGPL v3 or later
+ */
+class TemporaryFile extends \SplFileInfo
+{
+    protected $resource;
+
+    /**
+     * @param null|string $prefix The file name will begin with that prefix
+     *                            ("php" by default)
+     * @param null|string $mode   File open mode ("w+b" by default)
+     */
+    public function __construct(
+        ?string $prefix = null,
+        ?string $mode = null
+    ) {
+        $filename = tempnam(sys_get_temp_dir(), $prefix ?? 'gs-php');
+
+        if ($filename === false) {
+            throw new TemporaryFileException('Could not create file: ' . $filename);
+        }
+
+        parent::__construct($filename);
+
+        if (($this->resource = fopen($filename, $mode ?? 'w+b')) === false) {
+            $this->cleanup();
+            throw new TemporaryFileException('Could not open file: ' . $filename);
+        }
+    }
+
+    public function __destruct()
+    {
+        $this->close();
+        $this->cleanup();
+    }
+
+    public function write($data): int
+    {
+        if (!is_null($this->resource)) {
+            return fwrite($this->resource, $data);
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Closes the file descriptor if opened.
+     *
+     * @return bool Whether successful
+     */
+    protected function close(): bool
+    {
+        $ret = true;
+        if (!is_null($this->resource)) {
+            $ret = fclose($this->resource);
+        }
+        if ($ret) {
+            $this->resource = null;
+        }
+        return $ret;
+    }
+
+    /**
+     * Closes the file descriptor and removes the temporary file.
+     *
+     * @return void
+     */
+    protected function cleanup(): void
+    {
+        $path = $this->getRealPath();
+        $this->close();
+        if (file_exists($path)) {
+            unlink($path);
+        }
+    }
+
+    /**
+     * Get the file resource.
+     *
+     * @return resource
+     */
+    public function getResource()
+    {
+        return $this->resource;
+    }
+
+    /**
+     * Release the hold on the temporary file and move it to the desired
+     * location, setting file permissions in the process.
+     *
+     * @param string File destination
+     * @param int    New file permissions (in octal mode)
+     *
+     * @throws TemporaryFileException
+     *
+     * @return void
+     */
+    public function commit(string $destpath, int $umode = 0644): void
+    {
+        $temppath = $this->getRealPath();
+
+        // Might be attempted, and won't end well
+        if ($destpath === $temppath) {
+            throw new TemporaryFileException('Cannot use self as destination');
+        }
+
+        // Memorise if the file was there and see if there is access
+        $exists = file_exists($destpath);
+        if (!touch($destpath)) {
+            throw new TemporaryFileException(
+                'Insufficient permissions for destination: "' . $destpath . '"'
+            );
+        } elseif (!$exists) {
+            // If the file wasn't there, clean it up in case of a later failure
+            unlink($destpath);
+        }
+        if (!$this->close()) {
+            throw new TemporaryFileException('Could not close the resource');
+        }
+
+        rename($temppath, $destpath);
+        chmod($destpath, $umode);
+    }
+}