Amp\Artax\Parser::dechunk PHP Method

    private function dechunk()
    {
        if ($this->chunkLenRemaining !== null) {
            goto dechunk;
        }
        determine_chunk_size:
        if (false === ($lineEndPos = strpos($this->buffer, "\r\n"))) {
            goto more_data_needed;
        } elseif ($lineEndPos === 0) {
            throw new ParseException($this->getParsedMessageArray(), $msg = 'Invalid new line; hexadecimal chunk size expected', $code = 400, $previousException = null);
        }
        $line = substr($this->buffer, 0, $lineEndPos);
        $hex = strtolower(trim(ltrim($line, '0'))) ?: 0;
        $dec = hexdec($hex);
        if ($hex == dechex($dec)) {
            $this->chunkLenRemaining = $dec;
        } else {
            throw new ParseException($this->getParsedMessageArray(), $msg = 'Invalid hexadecimal chunk size', $code = 400, $previousException = null);
        }
        $this->buffer = substr($this->buffer, $lineEndPos + 2);
        if (!$dec) {
            return true;
        }
        dechunk:
        $bufferLen = strlen($this->buffer);
        // These first two (extreme) edge cases prevent errors where the packet boundary ends after
        // the \r and before the \n at the end of a chunk.
        if ($bufferLen === $this->chunkLenRemaining) {
            goto more_data_needed;
        } elseif ($bufferLen === $this->chunkLenRemaining + 1) {
            goto more_data_needed;
        } elseif ($bufferLen >= $this->chunkLenRemaining + 2) {
            $chunk = substr($this->buffer, 0, $this->chunkLenRemaining);
            $this->buffer = substr($this->buffer, $this->chunkLenRemaining + 2);
            $this->chunkLenRemaining = null;
            $this->addToBody($chunk);
            goto determine_chunk_size;
        } else {
            $this->addToBody($this->buffer);
            $this->buffer = '';
            $this->chunkLenRemaining -= $bufferLen;
            goto more_data_needed;
        }
        more_data_needed:
        return false;
    }