Method decodeBitmap

structure/bitmap_1.go:419–457

decodeBitmap decodes the value format: [type][length][value] length: the number of bits to save value: bitmap data

(value []byte)

// length: the number of bits to save
// value: bitmap data
func (b *BitMapStructure) decodeBitmap(value []byte) ([]byte, uint, error) {
	// Check the length of the value
	if len(value) < 2 {
		return nil, 0, ErrInvalidValue
	}

	// Check the type of the value
	if value[0] != Bitmap {
		return nil, 0, ErrInvalidType
	}

	valueLen := len(value)

	nowIndex := 1

	length, lenOfLen := binary.Varint(value[nowIndex:])

	// Check the number of bytes read
	if lenOfLen <= 0 {
		return nil, 0, ErrInvalidValue
	}

	nowIndex += lenOfLen

	// Actual size
	dataSize := len2Size(uint(length))

	// Either data or length is invalid
	if int(dataSize) > valueLen-nowIndex {
		return nil, 0, ErrInvalidValue
	}

	// Create an array to store the bitmap result
	result := make([]byte, dataSize)

	copy(result, value[nowIndex:])

	return result, uint(length), nil
}

func len2Size(len uint) uint {