<?php
/**
* This file is part of the PHP Generics package.
*
* @package Generics
*/
namespace Generics\Streams;
use Generics\Util\Interpolator;
/**
* This class provides a memory stream for both input and output
*
* @author Maik Greubel <greubel@nkey.de>
*/
class MemoryStream implements InputOutputStream
{
use Interpolator {
interpolate as tinterpolate;
}
/**
* The local memory buffer
*
* @var string
*/
private $memory;
/**
* Current position in memory buffer
*
* @var int
*/
private $current;
/**
* Whether it is possible to perform reading action
*
* @var boolean
*/
private $ready;
/**
* Whether stream is closed
*
* @var boolean
*/
private $closed;
/**
* Create a new MemoryStream
*
* @param InputStream $in
* optional existing input stream - will be copied
*/
public function __construct(InputStream $in = null)
{
$this->memory = "";
if ($in != null) {
$copy = clone $in;
$copy->reset();
while ($copy->ready()) {
$this->memory .= $copy->read();
}
$copy->close();
}
$this->current = 0;
$this->ready = true;
$this->closed = false;
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\Stream::close()
*/
public function close()
{
unset($this->memory);
$this->current = 0;
$this->ready = false;
$this->closed = true;
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\Stream::ready()
*/
public function ready(): bool
{
return $this->ready;
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\OutputStream::write()
*/
public function write($buffer)
{
if ($this->closed) {
throw new StreamException("Stream is not open");
}
$this->memory .= $buffer;
$this->ready = true;
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\InputStream::read()
*/
public function read($length = 1, $offset = null): string
{
if ($this->closed) {
throw new StreamException("Stream is not open");
}
if ($offset !== null) {
$this->current = intval($offset);
}
if (strlen($this->memory) <= $this->current) {
$this->ready = false;
return "";
}
if (strlen($this->memory) - $this->current < $length) {
$length = strlen($this->memory) - $this->current;
}
$out = substr($this->memory, $this->current, $length);
$this->current += $length;
if ($this->current == strlen($this->memory)) {
$this->ready = false;
}
return $out;
}
/**
*
* {@inheritdoc}
* @see \Countable::count()
*/
public function count(): int
{
if ($this->closed) {
throw new StreamException("Stream is not open");
}
if (! isset($this->memory)) {
return 0;
}
return strlen($this->memory);
}
/**
*
* {@inheritdoc}
* @see \Generics\Resettable::reset()
*/
public function reset()
{
if ($this->closed) {
throw new StreamException("Stream is not open");
}
$this->current = 0;
$this->ready = true;
}
/**
* Write to stream by interpolation of context vars into a string
*
* @param string $string
* The string to interpolate, may contains placeholders in format {placeholder}.
* @param array $context
* The context array containing the associative replacers and its values.
*/
public function interpolate($string, array $context)
{
$this->write($this->tinterpolate($string, $context));
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\OutputStream::isWriteable()
*/
public function isWriteable(): bool
{
return true;
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\OutputStream::flush()
*/
public function flush()
{
if ($this->closed) {
throw new StreamException("Stream is not open");
}
unset($this->memory);
$this->memory = "";
$this->reset();
}
/**
*
* {@inheritdoc}
* @see \Generics\Streams\Stream::isOpen()
*/
public function isOpen(): bool
{
return true;
}
/**
* Retrieve the whole memory string content
*
* @return string
*/
public function slurp(): string
{
$str = "";
while ($this->ready()) {
$str .= $this->read($this->count());
}
return $str;
}
}
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