Add a object oriented FileStream

Author: na2axl

src/FireFS/Streams/FileStream.php

@@ -0,0 +1,300 @@
+<?php
+
+/**
+ * FireFS - Easily manage your filesystem, through PHP
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * @category  Library
+ * @package   FireFS
+ * @author    Axel Nana <[email protected]>
+ * @copyright 2018 Aliens Group, Inc.
+ * @license   MIT <https://github.com/ElementaryFramework/FireFS/blob/master/LICENSE>
+ * @version   GIT: 0.0.1
+ * @link      http://firefs.na2axl.tk
+ */
+
+namespace ElementaryFramework\FireFS\Streams;
+
+use ElementaryFramework\Core\Events\WithEvents;
+use ElementaryFramework\Core\Streams\Events\StreamEvent;
+use ElementaryFramework\Core\Streams\IReadableStream;
+use ElementaryFramework\Core\Streams\ISeekableStream;
+use ElementaryFramework\Core\Streams\IWritableStream;
+use ElementaryFramework\FireFS\Exceptions\FileStreamException;
+
+/**
+ * File Stream
+ *
+ * Class used to read and write files through a stream for
+ * async I/O under FireFS
+ *
+ * @package    FireFS
+ * @subpackage Streams
+ * @author     Axel Nana <[email protected]>
+ */
+class FileStream implements IReadableStream, IWritableStream, ISeekableStream
+{
+    use WithEvents;
+
+    /**
+     * Stream handle.
+     *
+     * @var resource
+     */
+    private $_handle;
+
+    /**
+     * The path to the file handled by this stream.
+     *
+     * @var string
+     */
+    private $_path;
+
+    /**
+     * The list of readable streams piped to this one.
+     *
+     * @var array
+     */
+    private $_pipedStreams = array();
+
+    /**
+     * Defines if the stream is closed or not.
+     *
+     * @var boolean
+     */
+    private $_closed;
+
+    /**
+     * Defines if the stream is paused or not.
+     *
+     * @var boolean
+     */
+    private $_paused;
+
+    /**
+     * Creates a new instance of the FileStream class.
+     *
+     * @param string  $path   The path to the file.
+     * @param boolean $append Defines if the stream cursor start at
+     *                        the end (true) or at the beginning (false)
+     *                        of the file.
+     */
+    public function __construct(string $path, bool $append)
+    {
+        if (($result = fopen($path, $append ? "a+" : "w+")) !== false) {
+            $this->_handle = $result;
+        } else {
+            throw new FileStreamException("Unable to create the file stream.", $path);
+        }
+
+        $this->_path = $path;
+        $this->_closed = false;
+        $this->_paused = false;
+
+        $this->on(
+            StreamEvent::EVENT_PIPE,
+            [$this, "_onPipe"]
+        );
+    }
+
+    private function _onPipe(IReadableStream $source)
+    {
+        $closure = \Closure::bind(function($data) {
+            if (!$this->_paused) {
+                $this->write($data);
+            }
+        }, $this);
+
+        $source->on(
+            StreamEvent::EVENT_DATA,
+            $closure
+        );
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function close() : void
+    {
+        if ($this->_closed)
+            return;
+
+        if ($this->_closed = fclose($this->_handle)) {
+            $this->emit(StreamEvent::EVENT_CLOSE);
+        } else {
+            $this->emit(
+                StreamEvent::EVENT_ERROR,
+                new FileStreamException("Unable to close the stream.", $this->_path)
+            );
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function isReadable() : bool
+    {
+        return !$this->_closed;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function isWritable() : bool
+    {
+        return !$this->_closed;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function pause() : void
+    {
+        if ($this->_paused)
+            return;
+
+        $this->_paused = true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function resume() : void
+    {
+        if (!$this->_paused)
+            return;
+
+        $this->_paused = false;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function pipe(IWritableStream $destination, bool $autoEnd = true) : IReadableStream
+    {
+        if (!$this->isReadable())
+            return null;
+
+        if (!$destination->isWritable())
+            $this->pause();
+
+        if ($autoEnd) {
+            $this->on(
+                StreamEvent::EVENT_END,
+                function ($data) use (&$destination) {
+                    $destination->end($data);
+                }
+            );
+        }
+
+        $destination->emit(
+            StreamEvent::EVENT_PIPE,
+            $this
+        );
+
+        return $this;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function read(int $length) : void
+    {
+        if ($this->isReadable()) {
+            $data = fread($this->_handle, $length);
+
+            if ($data === false) {
+                $this->emit(
+                    StreamEvent::EVENT_ERROR,
+                    new FileStreamException("Unable to read the stream.", $this->_path)
+                );
+            } else {
+                $this->emit(
+                    StreamEvent::EVENT_DATA,
+                    $data
+                );
+            }
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function write($data) : bool
+    {
+        if (!$this->isWritable())
+            return false;
+
+        if (fwrite($this->_handle, $data) === false)
+            return false;
+
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function end($data = null) : void
+    {
+        if ($data !== null)
+            $this->write($data);
+
+        $this->close();
+
+        $this->emit(
+            StreamEvent::EVENT_END,
+            $data
+        );
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function seekTo(int $offset, int $whence = SEEK_SET) : void
+    {
+        if (!$this->_closed) {
+            fseek($this->_handle, $offset, $whence);
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function seekToStart() : void
+    {
+        $this->seekTo(0);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function seekToEnd() : void
+    {
+        $this->seekTo(0, SEEK_END);
+    }
+
+    /**
+     * Closes the stream when the instance is being destructed.
+     */
+    function __destruct()
+    {
+        $this->close();
+    }
+}