X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FUtil%2FReversedFileReader.php;h=fbd32d51fd4886f25cc165dc65c6ee1d539c55d1;hb=739ca603bc388c97a11a8d6a4843396bf5d52088;hp=eeedc1a5ccba435fe6ecac8f6055677924eb9101;hpb=5b9aeeeca95165203ed2753ba44ce6d8fbdea321;p=friendica.git

diff --git a/src/Util/ReversedFileReader.php b/src/Util/ReversedFileReader.php
index eeedc1a5cc..fbd32d51fd 100644
--- a/src/Util/ReversedFileReader.php
+++ b/src/Util/ReversedFileReader.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * @copyright Copyright (C) 2021, Friendica
+ * @copyright Copyright (C) 2010-2023, 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
  *
@@ -29,87 +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;
+	/** @var int */
+	private $filesize = -1;
 
-    /** @var int */
-    private $pos;
+	/** @var int */
+	private $pos = -1;
 
-    /** @var array */
-    private $buffer;
+	/** @var array */
+	private $buffer = null;
 
-    /** @var int */
-    private $key;
+	/** @var int */
+	private $key = -1;
 
-    /** @var string */
-    private $value;
+	/** @var string */
+	private $value = null;
 
-    public function __construct($filename)
-    {
-        $this->_fh = fopen($filename, 'r');
-		if (!$this->_fh) {
+	/**
+	 * Open $filename for read and reset iterator
+	 *
+	 * @param string $filename	File to open
+	 * @return $this
+	 */
+	public function open(string $filename): ReversedFileReader
+	{
+		$this->fh = fopen($filename, 'r');
+		if (!$this->fh) {
 			// this should use a custom exception.
-			throw \Exception("Unable to open $filename");
+			throw new \Exception("Unable to open $filename");
+		}
+		$this->filesize = filesize($filename);
+		$this->pos      = -1;
+		$this->buffer   = null;
+		$this->key      = -1;
+		$this->value    = null;
+		return $this;
+	}
+
+	/**
+	 * Read $size bytes behind last position
+	 *
+	 * @param int $size
+	 * @return string
+	 */
+	private function _read(int $size): string
+	{
+		$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|null Depending on data being buffered
+	 */
+	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]);
 		}
-        $this->filesize = filesize($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));
-            $this->next();
-        }
-    }
-
-    public function key()
+	}
+
+	/**
+	 * Fetch next line from end and set it as current iterator value.
+	 *
+	 * @see Iterator::next()
+	 * @return void
+	 */
+	public function next()
+	{
+		++$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(): int
 	{
 		return $this->key;
 	}
 
-    public function current()
+	/**
+	 * Return current line
+	 *
+	 * @see Iterator::current()
+	 * @return string
+	 */
+	public function current(): string
 	{
 		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(): bool
 	{
 		return ! is_null($this->value);
 	}