Streams

A decoder does not read a string, it reads a Stream. The library ships with StringStream, which reads from a string already in memory:

use CBOR\StringStream;

$stream = StringStream::create($binaryData);
$object = $decoder->decode($stream);

A stream is consumed as the document is read, so one stream decodes one document. Several data items written one after another are read with several decode() calls on the same stream.

Another source

Implement the Stream interface to decode from somewhere else — a file, a socket, a buffer filled as it arrives:

use CBOR\Stream;

class FileStream implements Stream
{
    private $handle;
    private int $position = 0;

    public function __construct(string $filepath)
    {
        $this->handle = fopen($filepath, 'rb');
    }

    public function read(int $length): string
    {
        $data = fread($this->handle, $length);
        $this->position += strlen($data);
        return $data;
    }

    public function getPosition(): int
    {
        return $this->position;
    }

    // … implement the remaining methods
}

// Use it with a decoder
$stream = new FileStream('/path/to/cbor/file.cbor');
$object = $decoder->decode($stream);

read() is asked for an exact number of bytes and is expected to return them. Returning fewer means the document ended in the middle of an item, which the decoder reports as an error: decide there whether to wait for more bytes or to fail.