Protobuf\Binary\StreamWriter::writeVarint PHP Method

    public function writeVarint(Stream $stream, $value)
    {
        // Small values do not need to be encoded
        if ($value >= 0 && $value < 0x80) {
            $this->writeByte($stream, $value);
            return;
        }
        $values = null;
        // Build an array of bytes with the encoded values
        if ($value > 0) {
            $values = [];
            while ($value > 0) {
                $values[] = 0x80 | $value & 0x7f;
                $value = $value >> 7;
            }
        }
        if ($values === null) {
            $values = $this->negativeEncoder->encodeVarint($value);
        }
        // Remove the MSB flag from the last byte
        $values[count($values) - 1] &= 0x7f;
        // Convert the byte sized ints to actual bytes in a string
        $values = array_merge(['C*'], $values);
        $bytes = call_user_func_array('pack', $values);
        $this->writeBytes($stream, $bytes);
    }

 /**
  * @dataProvider varintProvider
  */
 public function testComputeVarintSize($value)
 {
     $stream = Stream::create();
     $this->writer->writeVarint($stream, $value);
     $streamSize = $stream->getSize();
     $actualSize = $this->calculator->computeVarintSize($value);
     $this->assertEquals($streamSize, $actualSize);
 }