StreamTrait.php
PHP
Path: src/Http/Message/StreamTrait.php
<?php
namespace mini\Http\Message;
use Psr\Http\Message\StreamInterface;
use function rewind, stream_get_meta_data, get_class, fstat, fclose, ftell,
strpos, feof, fseek, stream_get_contents;
/**
* Describes a data stream.
*
* Typically, an instance will wrap a PHP stream; this interface provides
* a wrapper around the most common operations, including serialization of
* the entire stream to a string.
*/
trait StreamTrait {
protected mixed $stream = null;
protected bool $active;
protected int $offset = 0;
/**
* Configure the StreamTrait
*
* @param resource $stream The stream resource to represent
* @param bool $active The underlying stream resource is being written to
*/
protected function StreamTrait($stream) {
if (!is_resource($stream)) {
throw new \RuntimeException("Expecting a valid stream resource.");
}
$this->stream = $stream;
}
/**
* Reads all data from the stream into a string, from the beginning to end.
*
* This method MUST attempt to seek to the beginning of the stream before
* reading data and read the stream until the end is reached.
*
* Warning: This could attempt to load a large amount of data into memory.
*
* This method MUST NOT raise an exception in order to conform with PHP's
* string casting operations.
*
* @see http://php.net/manual/en/language.oop5.magic.php#object.tostring
* @return string
*/
public function __toString() {
try {
$this->assertUsable();
if ($this->isSeekable()) {
fseek($this->stream, 0);
}
return stream_get_contents($this->stream);
} catch (\Throwable $e) {
return get_class($e).': '.$e->getMessage();
}
}
/**
* Returns the remaining contents in a string
*
* @return string
* @throws \RuntimeException if unable to read.
* @throws \RuntimeException if error occurs while reading.
*/
public function getContents(): string {
$this->assertUsable();
$result = stream_get_contents($this->stream);
if ($result === false) {
throw new \RuntimeException("Unable to read from stream");
}
return $result;
}
/**
* Closes the stream and any underlying resources.
*
* @return void
*/
public function close(): void {
if ($this->stream) {
fclose($this->stream);
}
}
/**
* Separates any underlying resources from the stream.
*
* After the stream has been detached, the stream is in an unusable state.
*
* @return resource|null Underlying PHP stream, if any
*/
public function detach() {
$stream = $this->stream;
$this->stream = null;
return $stream;
}
/**
* Get the size of the stream if known.
*
* @return int|null Returns the size in bytes if known, or null if unknown.
*/
public function getSize(): ?int {
if (!$this->stream) {
return null;
}
$stat = fstat($this->stream);
if ($stat === false) {
return null;
}
return $stat['size'] ?? null;
}
/**
* Returns the current position of the file read/write pointer
*
* @return int Position of the file pointer
* @throws \RuntimeException on error.
*/
public function tell(): int {
$this->assertUsable();
if (!$this->stream || false === ($offset = ftell($this->stream))) {
throw new \RuntimeException("Stream is in unusable state");
}
return $offset;
}
/**
* Returns true if the stream is at the end of the stream.
*
* @return bool
*/
public function eof(): bool {
if (!$this->stream || feof($this->stream)) {
return true;
}
return false;
}
/**
* Returns whether or not the stream is seekable.
*
* @return bool
*/
public function isSeekable(): bool {
if (!$this->stream) {
return false;
}
$meta = stream_get_meta_data($this->stream);
return $meta['seekable'];
}
/**
* Seek to a position in the stream.
*
* @see http://www.php.net/manual/en/function.fseek.php
* @param int $offset Stream offset
* @param int $whence Specifies how the cursor position will be calculated
* based on the seek offset. Valid values are identical to the built-in
* PHP $whence values for `fseek()`. SEEK_SET: Set position equal to
* offset bytes SEEK_CUR: Set position to current location plus offset
* SEEK_END: Set position to end-of-stream plus offset.
* @throws \RuntimeException on failure.
*/
public function seek($offset, $whence = \SEEK_SET): void {
$this->assertUsable();
if (-1 === fseek($this->stream, $whence)) {
throw new \RuntimeException("Unable to seek in stream");
}
}
/**
* Seek to the beginning of the stream.
*
* If the stream is not seekable, this method will raise an exception;
* otherwise, it will perform a seek(0).
*
* @see seek()
* @see http://www.php.net/manual/en/function.fseek.php
* @throws \RuntimeException on failure.
*/
public function rewind(): void {
$this->assertUsable();
if (!rewind($this->stream)) {
throw new \RuntimeException("Unable to rewind the stream");
}
}
/**
* Returns whether or not the stream is writable.
*
* @return bool
*/
public function isWritable(): bool {
if (!$this->stream) {
return false;
}
$meta = stream_get_meta_data($this->stream);
return strpos($meta['mode'], 'r') === false || strpos($meta['mode'], '+') !== false;
}
/**
* Write data to the stream.
*
* @param string $string The string that is to be written.
* @return int Returns the number of bytes written to the stream.
* @throws \RuntimeException on failure.
*/
public function write($string): int {
$this->assertUsable();
$res = fwrite($this->stream, $string);
if ($res === false) {
throw new \RuntimeException("Unable to write to stream");
}
return $res;
}
/**
* Returns whether or not the stream is readable.
*
* @return bool
*/
public function isReadable(): bool {
if (!$this->stream) {
return false;
}
$meta = stream_get_meta_data($this->stream);
return strpos($meta['mode'], 'r') !== false || strpos($meta['mode'], '+') !== false;
}
/**
* Read data from the stream.
*
* @param int $length Read up to $length bytes from the object and return
* them. Fewer than $length bytes may be returned if underlying stream
* call returns fewer bytes.
* @return string Returns the data read from the stream, or an empty string
* if no bytes are available.
* @throws \RuntimeException if an error occurs.
*/
public function read(int $length): string {
$this->assertUsable();
$res = fread($this->stream, $length);
if ($res === false) {
throw new \RuntimeException("Unable to read from stream");
}
return $res;
}
/**
* Get stream metadata as an associative array or retrieve a specific key.
*
* The keys returned are identical to the keys returned from PHP's
* stream_get_meta_data() function.
*
* @see http://php.net/manual/en/function.stream-get-meta-data.php
* @param string $key Specific metadata to retrieve.
* @return array|mixed|null Returns an associative array if no key is
* provided. Returns a specific key value if a key is provided and the
* value is found, or null if the key is not found.
*/
public function getMetadata($key = null) {
if (!$this->stream) {
return null;
}
$meta = stream_get_meta_data($this->stream);
if ($key !== null) {
return $meta[$key] ?? null;
}
return $meta;
}
protected function assertUsable(): void {
if (!$this->stream) {
throw new \RuntimeException("Stream is in an unusable state");
}
}
}