X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FUtil%2FReversedFileReader.php;h=0566002de29e899e75034972d51f2fa4ad023be1;hb=47a3d8e6ce8461a457dee46d43d5ad14166f8013;hp=8a3083f7d8d14a31489d3cd2263d65af3a29cbce;hpb=9368f5445dda8b63133c6051aa819f641a0ee61d;p=friendica.git

diff --git a/src/Util/ReversedFileReader.php b/src/Util/ReversedFileReader.php
index 8a3083f7d8..0566002de2 100644
--- a/src/Util/ReversedFileReader.php
+++ b/src/Util/ReversedFileReader.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * @copyright Copyright (C) 2021, Friendica
+ * @copyright Copyright (C) 2010-2022, the Friendica project
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -21,7 +21,6 @@
 
 namespace Friendica\Util;
 
-
 /**
  * An iterator which returns lines from file in reversed order
  *
@@ -29,73 +28,142 @@ namespace Friendica\Util;
  */
 class ReversedFileReader implements \Iterator
 {
-    const BUFFER_SIZE = 4096;
-    const SEPARATOR = "\n";
+	const BUFFER_SIZE = 4096;
+	const SEPARATOR   = "\n";
+
+	/** @var resource */
+	private $fh = null;
+
+	/** @var int */
+	private $filesize = -1;
+
+	/** @var int */
+	private $pos = -1;
+
+	/** @var array */
+	private $buffer = null;
+
+	/** @var int */
+	private $key = -1;
 
-    public function __construct($filename)
-    {
-        $this->_fh = fopen($filename, 'r');
-		if (!$this->_fh) {
+	/** @var string */
+	private $value = null;
+
+	/**
+	 * Open $filename for read and reset iterator
+	 *
+	 * @param string $filename	File to open
+	 * @return $this
+	 */
+	public function open(string $filename)
+	{
+		$this->fh = fopen($filename, 'r');
+		if (!$this->fh) {
 			// this should use a custom exception.
 			throw \Exception("Unable to open $filename");
 		}
-        $this->_filesize = filesize($filename);
-        $this->_pos = -1;
-        $this->_buffer = null;
-        $this->_key = -1;
-        $this->_value = null;
-    }
-
-    public function _read($size)
-    {
-        $this->_pos -= $size;
-        fseek($this->_fh, $this->_pos);
-        return fread($this->_fh, $size);
-    }
-
-    public function _readline()
-    {
-        $buffer =& $this->_buffer;
-        while (true) {
-            if ($this->_pos == 0) {
-                return array_pop($buffer);
-            }
-            if (count($buffer) > 1) {
-                return array_pop($buffer);
-            }
-            $buffer = explode(self::SEPARATOR, $this->_read(self::BUFFER_SIZE) . $buffer[0]);
-        }
-    }
-
-    public function next()
-    {
-        ++$this->_key;
-        $this->_value = $this->_readline();
-    }
-
-    public function rewind()
-    {
-        if ($this->_filesize > 0) {
-            $this->_pos = $this->_filesize;
-            $this->_value = null;
-            $this->_key = -1;
-            $this->_buffer = explode(self::SEPARATOR, $this->_read($this->_filesize % self::BUFFER_SIZE ?: self::BUFFER_SIZE));
-            $this->next();
-        }
-    }
-
-    public function key()
+		$this->filesize = filesize($filename);
+		$this->pos      = -1;
+		$this->buffer   = null;
+		$this->key      = -1;
+		$this->value    = null;
+		return $this;
+	}
+
+	/**
+	 * Read $size bytes behind last position
+	 *
+	 * @return string
+	 */
+	private function _read($size)
+	{
+		$this->pos -= $size;
+		fseek($this->fh, $this->pos);
+		return fread($this->fh, $size);
+	}
+
+	/**
+	 * Read next line from end of file
+	 * Return null if no lines are left to read
+	 *
+	 * @return ?string
+	 */
+	private function _readline()
+	{
+		$buffer = & $this->buffer;
+		while (true) {
+			if ($this->pos == 0) {
+				return array_pop($buffer);
+			}
+			if (is_null($buffer)) {
+				return null;
+			}
+			if (count($buffer) > 1) {
+				return array_pop($buffer);
+			}
+			$buffer = explode(self::SEPARATOR, $this->_read(self::BUFFER_SIZE) . $buffer[0]);
+		}
+	}
+
+	/**
+	 * Fetch next line from end and set it as current iterator value.
+	 *
+	 * @see Iterator::next()
+	 * @return void
+	 */
+	public function next()
+	{
+		++$this->key;
+		$this->value = $this->_readline();
+	}
+
+	/**
+	 * Rewind iterator to the first line at the end of file
+	 *
+	 * @see Iterator::rewind()
+	 * @return void
+	 */
+	public function rewind()
+	{
+		if ($this->filesize > 0) {
+			$this->pos    = $this->filesize;
+			$this->value  = null;
+			$this->key    = -1;
+			$this->buffer = explode(self::SEPARATOR, $this->_read($this->filesize % self::BUFFER_SIZE ?: self::BUFFER_SIZE));
+			$this->next();
+		}
+	}
+
+	/**
+	 * Return current line number, starting from zero at the end of file
+	 *
+	 * @see Iterator::key()
+	 * @return int
+	 */
+	public function key()
 	{
-		return $this->_key;
+		return $this->key;
 	}
 
-    public function current()
+	/**
+	 * Return current line
+	 *
+	 * @see Iterator::current()
+	 * @return string
+	 */
+	public function current()
 	{
-		return $this->_value;
+		return $this->value;
 	}
 
-    public function valid()
+	/**
+	 * Checks if current iterator value is valid, that is, we readed all lines in files
+	 *
+	 * @see Iterator::valid()
+	 * @return bool
+	 */
+	public function valid()
 	{
-		return ! is_null($this->_value);
+		return ! is_null($this->value);
 	}
 }