MagicBytesSplitter.php

<?php

namespace Clue\React\Foo;

use Evenement\EventEmitter;
use React\Stream\ReadableStreamInterface;
use React\Stream\WritableStreamInterface;
use React\Stream\Util;

class MagicBytesSplitter extends EventEmitter implements ReadableStreamInterface
{
    private $input;
    private $magicBytes;
    private $buffer = '';
    private $closed = false;

    public function __construct(ReadableStreamInterface $input, $magicBytes)
    {
        $this->input = $input;
        $this->magicBytes = $magicBytes;
        if (!$input->isReadable()) {
            $this->close();
            return;
        }

        $this->input->on('data', array($this, 'handleData'));
        $this->input->on('end', array($this, 'handleEnd'));
        $this->input->on('error', array($this, 'handleError'));
        $this->input->on('close', array($this, 'close'));
    }

    public function pause()
    {
        $this->input->pause();
    }

    public function resume()
    {
        $this->input->resume();
    }

    public function isReadable()
    {
        return $this->input->isReadable();
    }

    public function pipe(WritableStreamInterface $dest, array $options = [])
    {
        Util::pipe($this, $dest, $options);

        return $dest;
    }

    public function close()
    {
        if ($this->closed) {
            return;
        }

        $this->closed = true;
        $this->buffer = '';
        $this->input->close();

        $this->emit('close');
        $this->removeAllListeners();
    }

    /** @internal */
    public function handleData($chunk)
    {
        $this->buffer .= $chunk;

        while (($pos = \strpos($this->buffer, $this->magicBytes, 1)) !== false) {
            $chunk = \substr($this->buffer, 0, $pos);
            $this->buffer = (string)\substr($this->buffer, $pos + \strlen($this->magicBytes));

            $this->emit('data', array($chunk));
        }
    }

    /** @internal */
    public function handleEnd()
    {
        if ($this->buffer !== '') {
            $this->emit('data', array($this->buffer));
        }

        if (!$this->closed) {
            $this->emit('end');
            $this->close();
        }
    }

    /** @internal */
    public function handleError(\Exception $e)
    {
        $this->emit('error', array($e));
        $this->close();
    }
}