Function DecodeGeoInvertedKey

pkg/util/encoding/encoding.go:1089–1132

DecodeGeoInvertedKey decodes the bounding box from the geo inverted key. The cellid is skipped in the decoding.

(b []byte)

// DecodeGeoInvertedKey decodes the bounding box from the geo inverted key.
// The cellid is skipped in the decoding.
func DecodeGeoInvertedKey(b []byte) (loX, loY, hiX, hiY float64, remaining []byte, err error) {
	// Minimum: 1 byte marker + 1 byte cell length +
	//          1 byte bbox encoding kind + 16 bytes for 2 floats
	if len(b) < 3+2*uint64AscendingEncodedLength {
		return 0, 0, 0, 0, b,
			errors.Errorf("inverted key length %d too small", len(b))
	}
	if b[0] != geoInvertedIndexMarker {
		return 0, 0, 0, 0, b, errors.Errorf("marker is not geoInvertedIndexMarker")
	}
	b = b[1:]
	var cellLen int
	if cellLen, err = getVarintLen(b); err != nil {
		return 0, 0, 0, 0, b, err
	}
	if len(b) < cellLen+17 {
		return 0, 0, 0, 0, b,
			errors.Errorf("insufficient length for encoded bbox in inverted key: %d", len(b)-cellLen)
	}
	encodingKind := geoInvertedBBoxEncodingKind(b[cellLen])
	if encodingKind != geoInvertedTwoFloats && encodingKind != geoInvertedFourFloats {
		return 0, 0, 0, 0, b,
			errors.Errorf("unknown encoding kind for bbox in inverted key: %d", encodingKind)
	}
	b = b[cellLen+1:]
	if b, loX, err = DecodeUntaggedFloatValue(b); err != nil {
		return 0, 0, 0, 0, b, err
	}
	if b, loY, err = DecodeUntaggedFloatValue(b); err != nil {
		return 0, 0, 0, 0, b, err
	}
	if encodingKind == geoInvertedFourFloats {
		if b, hiX, err = DecodeUntaggedFloatValue(b); err != nil {
			return 0, 0, 0, 0, b, err
		}
		if b, hiY, err = DecodeUntaggedFloatValue(b); err != nil {
			return 0, 0, 0, 0, b, err
		}
	} else {
		hiX = loX
		hiY = loY
	}
	return loX, loY, hiX, hiY, b, nil
}

// EncodeNullDescending is the descending equivalent of EncodeNullAscending.
func EncodeNullDescending(b []byte) []byte {