GuzzleHttp\Psr7\CachingStream Class Reference

Stream decorator that can cache previously read bytes from a sequentially read stream. More...

Inheritance diagram for GuzzleHttp\Psr7\CachingStream:

Collaboration diagram for GuzzleHttp\Psr7\CachingStream:

Public Member Functions
	__construct (StreamInterface $stream, StreamInterface $target=null)
	We will treat the buffer object as the body of the stream. More...
	getSize ()
	Get the size of the stream if known. More...
	rewind ()
	Seek to the beginning of the stream. More...
	seek ($offset, $whence=SEEK_SET)
	Seek to a position in the stream. More...
	read ($length)
	Read data from the stream. More...
	write ($string)
	Write data to the stream. More...
	eof ()
	Returns true if the stream is at the end of the stream. More...
	close ()
	Close both the remote stream and buffer stream. More...
Public Member Functions inherited from Psr\Http\Message\StreamInterface
	__toString ()
	Reads all data from the stream into a string, from the beginning to end. More...
	detach ()
	Separates any underlying resources from the stream. More...
	tell ()
	Returns the current position of the file read/write pointer. More...
	isSeekable ()
	Returns whether or not the stream is seekable. More...
	isWritable ()
	Returns whether or not the stream is writable. More...
	isReadable ()
	Returns whether or not the stream is readable. More...
	getContents ()
	Returns the remaining contents in a string. More...
	getMetadata ($key=null)
	Get stream metadata as an associative array or retrieve a specific key. More...

Private Member Functions
	cacheEntireStream ()

Private Attributes
	$remoteStream
	$skipReadBytes = 0

Detailed Description

Stream decorator that can cache previously read bytes from a sequentially read stream.

Definition at line 10 of file CachingStream.php.

Constructor & Destructor Documentation

__construct()

GuzzleHttp\Psr7\CachingStream::__construct	(	StreamInterface	$stream,
		StreamInterface	$target = null
	)

We will treat the buffer object as the body of the stream.

Parameters

StreamInterface	$stream	Stream to cache
StreamInterface	$target	Optionally specify where data is cached

Definition at line 26 of file CachingStream.php.

References GuzzleHttp\Psr7\$stream, and $target.

      {
        $this->remoteStream = $stream;
        $this->stream = $target ?: new Stream(fopen('php://temp', 'r+'));
    }

Member Function Documentation

cacheEntireStream()

GuzzleHttp\Psr7\CachingStream::cacheEntireStream ( )

private

Definition at line 131 of file CachingStream.php.

References $target, GuzzleHttp\Psr7\copy_to_stream(), and Psr\Http\Message\StreamInterface\tell().

Referenced by GuzzleHttp\Psr7\CachingStream\seek().

    {
        $target = new FnStream(['write' => 'strlen']);
        copy_to_stream($this, $target);

        return $this->tell();
    }

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close()

GuzzleHttp\Psr7\CachingStream::close

(

)

Close both the remote stream and buffer stream.

Implements Psr\Http\Message\StreamInterface.

Definition at line 126 of file CachingStream.php.

    {
        $this->remoteStream->close() && $this->stream->close();
    }

eof()

GuzzleHttp\Psr7\CachingStream::eof

(

)

Returns true if the stream is at the end of the stream.

Returns

bool

Implements Psr\Http\Message\StreamInterface.

Definition at line 118 of file CachingStream.php.

    {
        return $this->stream->eof() && $this->remoteStream->eof();
    }

getSize()

GuzzleHttp\Psr7\CachingStream::getSize

(

)

Get the size of the stream if known.

Returns

int|null Returns the size in bytes if known, or null if unknown.

Implements Psr\Http\Message\StreamInterface.

Definition at line 34 of file CachingStream.php.

    {
        return max($this->stream->getSize(), $this->remoteStream->getSize());
    }

read()

GuzzleHttp\Psr7\CachingStream::read

(

$length

)

Read data from the stream.

Parameters

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.

Returns

string Returns the data read from the stream, or an empty string if no bytes are available.

Exceptions

Implements Psr\Http\Message\StreamInterface.

Definition at line 75 of file CachingStream.php.

References $data, and $remaining.

Referenced by GuzzleHttp\Psr7\CachingStream\seek().

    {
        // Perform a regular read on any previously read data from the buffer
        $data = $this->stream->read($length);
        $remaining = $length - strlen($data);

        // More data was requested so read from the remote stream
        if ($remaining) {
            // If data was written to the buffer in a position that would have
            // been filled from the remote stream, then we must skip bytes on
            // the remote stream to emulate overwriting bytes from that
            // position. This mimics the behavior of other PHP stream wrappers.
            $remoteData = $this->remoteStream->read(
                $remaining + $this->skipReadBytes
            );

            if ($this->skipReadBytes) {
                $len = strlen($remoteData);
                $remoteData = substr($remoteData, $this->skipReadBytes);
                $this->skipReadBytes = max(0, $this->skipReadBytes - $len);
            }

            $data .= $remoteData;
            $this->stream->write($remoteData);
        }

        return $data;
    }

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rewind()

GuzzleHttp\Psr7\CachingStream::rewind

(

)

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 also

seek() on failure.

Implements Psr\Http\Message\StreamInterface.

Definition at line 39 of file CachingStream.php.

References GuzzleHttp\Psr7\CachingStream\seek().

    {
        $this->seek(0);
    }

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seek()

GuzzleHttp\Psr7\CachingStream::seek	(		$offset,
			$whence = SEEK_SET
	)

Seek to a position in the stream.

int $offset Stream offset 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. on failure.

Implements Psr\Http\Message\StreamInterface.

Definition at line 44 of file CachingStream.php.

References $size, GuzzleHttp\Psr7\CachingStream\cacheEntireStream(), GuzzleHttp\Psr7\CachingStream\read(), and Psr\Http\Message\StreamInterface\tell().

Referenced by GuzzleHttp\Psr7\CachingStream\rewind().

    {
        if ($whence == SEEK_SET) {
            $byte = $offset;
        } elseif ($whence == SEEK_CUR) {
            $byte = $offset + $this->tell();
        } elseif ($whence == SEEK_END) {
            $size = $this->remoteStream->getSize();
            if ($size === null) {
                $size = $this->cacheEntireStream();
            }
            $byte = $size + $offset;
        } else {
            throw new \InvalidArgumentException('Invalid whence');
        }

        $diff = $byte - $this->stream->getSize();

        if ($diff > 0) {
            // Read the remoteStream until we have read in at least the amount
            // of bytes requested, or we reach the end of the file.
            while ($diff > 0 && !$this->remoteStream->eof()) {
                $this->read($diff);
                $diff = $byte - $this->stream->getSize();
            }
        } else {
            // We can just do a normal seek since we've already seen this byte.
            $this->stream->seek($byte);
        }
    }

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write()

GuzzleHttp\Psr7\CachingStream::write

(

$string

)

Write data to the stream.

Parameters

string

$string

The string that is to be written.

Returns

int Returns the number of bytes written to the stream.

Exceptions

Implements Psr\Http\Message\StreamInterface.

Definition at line 104 of file CachingStream.php.

References Psr\Http\Message\StreamInterface\tell().

    {
        // When appending to the end of the currently read stream, you'll want
        // to skip bytes from being read from the remote stream to emulate
        // other stream wrappers. Basically replacing bytes of data of a fixed
        // length.
        $overflow = (strlen($string) + $this->tell()) - $this->remoteStream->tell();
        if ($overflow > 0) {
            $this->skipReadBytes += $overflow;
        }

        return $this->stream->write($string);
    }

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Field Documentation

$remoteStream

GuzzleHttp\Psr7\CachingStream::$remoteStream

private

Definition at line 15 of file CachingStream.php.

$skipReadBytes

GuzzleHttp\Psr7\CachingStream::$skipReadBytes = 0

private

Definition at line 18 of file CachingStream.php.

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The documentation for this class was generated from the following file:

• libs/composer/vendor/guzzlehttp/psr7/src/CachingStream.php