<?php

/**
 * Wrapper for network stream functionality.
 * 
 * PHP has built in support for various types of network streams, such as HTTP and TCP sockets. One problem that arises with them is the fact that a single fread/fwrite call might not read/write all the data you intended, regardless of whether you're in blocking mode or not. While the PHP manual offers a workaround in the form of a loop with a few variables, using it every single time you want to read/write can be tedious.

This package abstracts this away, so that when you want to get exactly N amount of bytes, you can be sure the upper levels of your app will be dealing with N bytes. Oh, and the functionality is nicely wrapped in an object (but that's just the icing on the cake).
 * 
 * PHP version 5
 * 
 * @category  Net
 * @package   PEAR2_Net_Transmitter
 * @author    Vasil Rangelov <boen.robot@gmail.com>
 * @copyright 2011 Vasil Rangelov
 * @license   http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
 * @version   1.0.0a5
 * @link      http://pear2.php.net/PEAR2_Net_Transmitter
 */
/**
 * The namespace declaration.
 */
namespace PEAR2\Net\Transmitter;

/**
 * Base for this exception.
 */
use RuntimeException;

/**
 * Used to enable any exception in chaining.
 */
use Exception as E;

/**
 * Exception thrown when something goes wrong with the connection.
 * 
 * @category Net
 * @package  PEAR2_Net_Transmitter
 * @author   Vasil Rangelov <boen.robot@gmail.com>
 * @license  http://www.gnu.org/copyleft/lesser.html LGPL License 2.1
 * @link     http://pear2.php.net/PEAR2_Net_Transmitter
 */
class StreamException extends RuntimeException implements Exception
{
    /**
     * @var int|string|resource|null The fragment up until the point of failure.
     *     On failure with sending, this is the number of bytes sent
     *     successfully before the failure.
     *     On failure when receiving, this is a string/stream holding
     *     the contents received successfully before the failure.
     *     NULL if the failure occured before the operation started.
     */
    protected $fragment = null;

    /**
     * Creates a new stream exception.
     * 
     * @param string                   $message  The Exception message to throw.
     * @param int                      $code     The Exception code.
     * @param E|null                   $previous Previous exception thrown,
     *     or NULL if there is none.
     * @param int|string|resource|null $fragment The fragment up until the
     *     point of failure.
     *     On failure with sending, this is the number of bytes sent
     *     successfully before the failure.
     *     On failure when receiving, this is a string/stream holding
     *     the contents received successfully before the failure.
     *     NULL if the failure occured before the operation started.
     */
    public function __construct(
        $message,
        $code,
        E $previous = null,
        $fragment = null
    ) {
        parent::__construct($message, $code, $previous);
        $this->fragment = $fragment;
    }

    /**
     * Gets the stream fragment.
     * 
     * @return int|string|resource|null The fragment up until the
     *     point of failure.
     *     On failure with sending, this is the number of bytes sent
     *     successfully before the failure.
     *     On failure when receiving, this is a string/stream holding
     *     the contents received successfully before the failure.
     *     NULL if the failure occured before the operation started.
     */
    public function getFragment()
    {
        return $this->fragment;
    }

    // @codeCoverageIgnoreStart
    // Unreliable in testing.

    /**
     * Returns a string representation of the exception.
     * 
     * @return string The exception as a string.
     */
    public function __toString()
    {
        $result = parent::__toString();
        if (null !== $this->fragment) {
            $result .= "\nFragment: ";
            if (is_scalar($this->fragment)) {
                $result .= (string)$this->fragment;
            } else {
                $result .= stream_get_contents($this->fragment);
            }
        }
        return $result;
    }
    // @codeCoverageIgnoreEnd
}