<?php
/**
* @see https://github.com/zendframework/zend-diactoros for the canonical source repository
* @copyright Copyright (c) 2015-2017 Zend Technologies USA Inc. (http://www.zend.com)
* @license https://github.com/zendframework/zend-diactoros/blob/master/LICENSE.md New BSD License
*/
namespace Zend\Diactoros;
use InvalidArgumentException;
use Psr\Http\Message\StreamInterface;
use RuntimeException;
use function array_key_exists;
use function fclose;
use function feof;
use function fopen;
use function fread;
use function fseek;
use function fstat;
use function ftell;
use function fwrite;
use function get_resource_type;
use function is_int;
use function is_resource;
use function is_string;
use function restore_error_handler;
use function set_error_handler;
use function stream_get_contents;
use function stream_get_meta_data;
use function strstr;
use const E_WARNING;
use const SEEK_SET;
/**
* Implementation of PSR HTTP streams
*/
class Stream implements StreamInterface
{
/**
* @var resource|null
*/
protected $resource;
/**
* @var string|resource
*/
protected $stream;
/**
* @param string|resource $stream
* @param string $mode Mode with which to open stream
* @throws InvalidArgumentException
*/
public function __construct($stream, $mode = 'r')
{
$this->setStream($stream, $mode);
}
/**
* {@inheritdoc}
*/
public function __toString()
{
if (! $this->isReadable()) {
return '';
}
try {
if ($this->isSeekable()) {
$this->rewind();
}
return $this->getContents();
} catch (RuntimeException $e) {
return '';
}
}
/**
* {@inheritdoc}
*/
public function close()
{
if (! $this->resource) {
return;
}
$resource = $this->detach();
fclose($resource);
}
/**
* {@inheritdoc}
*/
public function detach()
{
$resource = $this->resource;
$this->resource = null;
return $resource;
}
/**
* Attach a new stream/resource to the instance.
*
* @param string|resource $resource
* @param string $mode
* @throws InvalidArgumentException for stream identifier that cannot be
* cast to a resource
* @throws InvalidArgumentException for non-resource stream
*/
public function attach($resource, $mode = 'r')
{
$this->setStream($resource, $mode);
}
/**
* {@inheritdoc}
*/
public function getSize()
{
if (null === $this->resource) {
return null;
}
$stats = fstat($this->resource);
if ($stats !== false) {
return $stats['size'];
}
return null;
}
/**
* {@inheritdoc}
*/
public function tell()
{
if (! $this->resource) {
throw new RuntimeException('No resource available; cannot tell position');
}
$result = ftell($this->resource);
if (! is_int($result)) {
throw new RuntimeException('Error occurred during tell operation');
}
return $result;
}
/**
* {@inheritdoc}
*/
public function eof()
{
if (! $this->resource) {
return true;
}
return feof($this->resource);
}
/**
* {@inheritdoc}
*/
public function isSeekable()
{
if (! $this->resource) {
return false;
}
$meta = stream_get_meta_data($this->resource);
return $meta['seekable'];
}
/**
* {@inheritdoc}
*/
public function seek($offset, $whence = SEEK_SET)
{
if (! $this->resource) {
throw new RuntimeException('No resource available; cannot seek position');
}
if (! $this->isSeekable()) {
throw new RuntimeException('Stream is not seekable');
}
$result = fseek($this->resource, $offset, $whence);
if (0 !== $result) {
throw new RuntimeException('Error seeking within stream');
}
return true;
}
/**
* {@inheritdoc}
*/
public function rewind()
{
return $this->seek(0);
}
/**
* {@inheritdoc}
*/
public function isWritable()
{
if (! $this->resource) {
return false;
}
$meta = stream_get_meta_data($this->resource);
$mode = $meta['mode'];
return (
strstr($mode, 'x')
|| strstr($mode, 'w')
|| strstr($mode, 'c')
|| strstr($mode, 'a')
|| strstr($mode, '+')
);
}
/**
* {@inheritdoc}
*/
public function write($string)
{
if (! $this->resource) {
throw new RuntimeException('No resource available; cannot write');
}
if (! $this->isWritable()) {
throw new RuntimeException('Stream is not writable');
}
$result = fwrite($this->resource, $string);
if (false === $result) {
throw new RuntimeException('Error writing to stream');
}
return $result;
}
/**
* {@inheritdoc}
*/
public function isReadable()
{
if (! $this->resource) {
return false;
}
$meta = stream_get_meta_data($this->resource);
$mode = $meta['mode'];
return (strstr($mode, 'r') || strstr($mode, '+'));
}
/**
* {@inheritdoc}
*/
public function read($length)
{
if (! $this->resource) {
throw new RuntimeException('No resource available; cannot read');
}
if (! $this->isReadable()) {
throw new RuntimeException('Stream is not readable');
}
$result = fread($this->resource, $length);
if (false === $result) {
throw new RuntimeException('Error reading stream');
}
return $result;
}
/**
* {@inheritdoc}
*/
public function getContents()
{
if (! $this->isReadable()) {
throw new RuntimeException('Stream is not readable');
}
$result = stream_get_contents($this->resource);
if (false === $result) {
throw new RuntimeException('Error reading from stream');
}
return $result;
}
/**
* {@inheritdoc}
*/
public function getMetadata($key = null)
{
if (null === $key) {
return stream_get_meta_data($this->resource);
}
$metadata = stream_get_meta_data($this->resource);
if (! array_key_exists($key, $metadata)) {
return null;
}
return $metadata[$key];
}
/**
* Set the internal stream resource.
*
* @param string|resource $stream String stream target or stream resource.
* @param string $mode Resource mode for stream target.
* @throws InvalidArgumentException for invalid streams or resources.
*/
private function setStream($stream, $mode = 'r')
{
$error = null;
$resource = $stream;
if (is_string($stream)) {
set_error_handler(function ($e) use (&$error) {
if ($e !== E_WARNING) {
return;
}
$error = $e;
});
$resource = fopen($stream, $mode);
restore_error_handler();
}
if ($error) {
throw new InvalidArgumentException('Invalid stream reference provided');
}
if (! is_resource($resource) || 'stream' !== get_resource_type($resource)) {
throw new InvalidArgumentException(
'Invalid stream provided; must be a string stream identifier or stream resource'
);
}
if ($stream !== $resource) {
$this->stream = $stream;
}
$this->resource = $resource;
}
}