<?php
/**
* Slim Framework (https://slimframework.com)
*
* @license https://github.com/slimphp/Slim-Psr7/blob/master/LICENSE.md (MIT License)
*/
declare(strict_types=1);
namespace Slim\Psr7;
use InvalidArgumentException;
use Psr\Http\Message\StreamInterface;
use RuntimeException;
use function fclose;
use function feof;
use function fread;
use function fseek;
use function fstat;
use function ftell;
use function fwrite;
use function is_array;
use function is_resource;
use function is_string;
use function pclose;
use function rewind;
use function stream_get_contents;
use function stream_get_meta_data;
use function strstr;
use const SEEK_SET;
class Stream implements StreamInterface
{
/**
* Bit mask to determine if the stream is a pipe
*
* This is octal as per header stat.h
*/
public const FSTAT_MODE_S_IFIFO = 0010000;
/**
* The underlying stream resource
*
* @var resource|null
*/
protected $stream;
/**
* @var array|null
*/
protected $meta;
/**
* @var bool|null
*/
protected $readable;
/**
* @var bool|null
*/
protected $writable;
/**
* @var bool|null
*/
protected $seekable;
/**
* @var null|int
*/
protected $size;
/**
* @var bool|null
*/
protected $isPipe;
/**
* @var bool
*/
protected $finished = false;
/**
* @var StreamInterface | null
*/
protected $cache;
/**
* @param resource $stream A PHP resource handle.
* @param StreamInterface $cache A stream to cache $stream (useful for non-seekable streams)
*
* @throws InvalidArgumentException If argument is not a resource.
*/
public function __construct($stream, StreamInterface $cache = null)
{
$this->attach($stream);
if ($cache && (!$cache->isSeekable() || !$cache->isWritable())) {
throw new RuntimeException('Cache stream must be seekable and writable');
}
$this->cache = $cache;
}
/**
* {@inheritdoc}
*/
public function getMetadata($key = null)
{
if (!$this->stream) {
return null;
}
$this->meta = stream_get_meta_data($this->stream);
if (!$key) {
return $this->meta;
}
return isset($this->meta[$key]) ? $this->meta[$key] : null;
}
/**
* Attach new resource to this object.
*
* @internal This method is not part of the PSR-7 standard.
*
* @param resource $stream A PHP resource handle.
*
* @throws InvalidArgumentException If argument is not a valid PHP resource.
*
* @return void
*/
protected function attach($stream): void
{
if (!is_resource($stream)) {
throw new InvalidArgumentException(__METHOD__ . ' argument must be a valid PHP resource');
}
if ($this->stream) {
$this->detach();
}
$this->stream = $stream;
}
/**
* {@inheritdoc}
*/
public function detach()
{
$oldResource = $this->stream;
$this->stream = null;
$this->meta = null;
$this->readable = null;
$this->writable = null;
$this->seekable = null;
$this->size = null;
$this->isPipe = null;
$this->cache = null;
$this->finished = false;
return $oldResource;
}
/**
* {@inheritdoc}
*/
public function __toString(): string
{
if (!$this->stream) {
return '';
}
if ($this->cache && $this->finished) {
$this->cache->rewind();
return $this->cache->getContents();
}
if ($this->isSeekable()) {
$this->rewind();
}
return $this->getContents();
}
/**
* {@inheritdoc}
*/
public function close(): void
{
if ($this->stream) {
if ($this->isPipe()) {
pclose($this->stream);
} else {
fclose($this->stream);
}
}
$this->detach();
}
/**
* {@inheritdoc}
*/
public function getSize(): ?int
{
if ($this->stream && !$this->size) {
$stats = fstat($this->stream);
if ($stats) {
$this->size = isset($stats['size']) && !$this->isPipe() ? $stats['size'] : null;
}
}
return $this->size;
}
/**
* {@inheritdoc}
*/
public function tell(): int
{
$position = false;
if ($this->stream) {
$position = ftell($this->stream);
}
if ($position === false || $this->isPipe()) {
throw new RuntimeException('Could not get the position of the pointer in stream.');
}
return $position;
}
/**
* {@inheritdoc}
*/
public function eof(): bool
{
return $this->stream ? feof($this->stream) : true;
}
/**
* {@inheritdoc}
*/
public function isReadable(): bool
{
if ($this->readable === null) {
if ($this->isPipe()) {
$this->readable = true;
} else {
$this->readable = false;
if ($this->stream) {
$mode = $this->getMetadata('mode');
if (strstr($mode, 'r') !== false || strstr($mode, '+') !== false) {
$this->readable = true;
}
}
}
}
return $this->readable;
}
/**
* {@inheritdoc}
*/
public function isWritable(): bool
{
if ($this->writable === null) {
$this->writable = false;
if ($this->stream) {
$mode = $this->getMetadata('mode');
if (strstr($mode, 'w') !== false || strstr($mode, '+') !== false) {
$this->writable = true;
}
}
}
return $this->writable;
}
/**
* {@inheritdoc}
*/
public function isSeekable(): bool
{
if ($this->seekable === null) {
$this->seekable = false;
if ($this->stream) {
$this->seekable = !$this->isPipe() && $this->getMetadata('seekable');
}
}
return $this->seekable;
}
/**
* {@inheritdoc}
*/
public function seek($offset, $whence = SEEK_SET): void
{
if (!$this->isSeekable() || $this->stream && fseek($this->stream, $offset, $whence) === -1) {
throw new RuntimeException('Could not seek in stream.');
}
}
/**
* {@inheritdoc}
*/
public function rewind(): void
{
if (!$this->isSeekable() || $this->stream && rewind($this->stream) === false) {
throw new RuntimeException('Could not rewind stream.');
}
}
/**
* {@inheritdoc}
*/
public function read($length): string
{
$data = false;
if ($this->isReadable() && $this->stream) {
$data = fread($this->stream, $length);
}
if (is_string($data)) {
if ($this->cache) {
$this->cache->write($data);
}
if ($this->eof()) {
$this->finished = true;
}
return $data;
}
throw new RuntimeException('Could not read from stream.');
}
/**
* {@inheritdoc}
*/
public function write($string)
{
$written = false;
if ($this->isWritable() && $this->stream) {
$written = fwrite($this->stream, $string);
}
if ($written !== false) {
$this->size = null;
return $written;
}
throw new RuntimeException('Could not write to stream.');
}
/**
* {@inheritdoc}
*/
public function getContents(): string
{
if ($this->cache && $this->finished) {
$this->cache->rewind();
return $this->cache->getContents();
}
$contents = false;
if ($this->stream) {
$contents = stream_get_contents($this->stream);
}
if (is_string($contents)) {
if ($this->cache) {
$this->cache->write($contents);
}
if ($this->eof()) {
$this->finished = true;
}
return $contents;
}
throw new RuntimeException('Could not get contents of stream.');
}
/**
* Returns whether or not the stream is a pipe.
*
* @internal This method is not part of the PSR-7 standard.
*
* @return bool
*/
public function isPipe(): bool
{
if ($this->isPipe === null) {
$this->isPipe = false;
if ($this->stream) {
$stats = fstat($this->stream);
if (is_array($stats)) {
$this->isPipe = isset($stats['mode']) && ($stats['mode'] & self::FSTAT_MODE_S_IFIFO) !== 0;
}
}
}
return $this->isPipe;
}
}