Function DecodeTSVectorPGBinary

pkg/util/tsearch/encoding.go:128–165

DecodeTSVectorPGBinary decodes a tsvector from the input byte slice which is formatted in Postgres binary protocol.

(b []byte)

// DecodeTSVectorPGBinary decodes a tsvector from the input byte slice which is
// formatted in Postgres binary protocol.
func DecodeTSVectorPGBinary(b []byte) (ret TSVector, err error) {
	var nTerms uint32
	var nPositions, position uint16
	b, nTerms, err = encoding.DecodeUint32Ascending(b)
	if err != nil {
		return nil, err
	}
	ret = make([]tsTerm, nTerms)
	for i := uint32(0); i < nTerms; i++ {
		termIndex := bytes.IndexByte(b, byte(0))
		if termIndex == -1 {
			return nil, pgerror.Newf(pgcode.Syntax, "unterminated string while parsing tsvector: %s", b)
		}
		term := &ret[i]
		term.lexeme = string(b[:termIndex])
		b = b[termIndex+1:]
		b, nPositions, err = encoding.DecodeUint16Ascending(b)
		if err != nil {
			return nil, err
		}
		term.positions = make([]tsPosition, nPositions)
		for j := uint16(0); j < nPositions; j++ {
			b, position, err = encoding.DecodeUint16Ascending(b)
			if err != nil {
				return nil, err
			}
			encodedWeight := position >> 14
			weight, err := tsWeightFromVectorPGEncoding(byte(encodedWeight))
			if err != nil {
				return nil, err
			}
			// Clear the 2 most significant bits (they were used for the weight).
			position = position & (^(uint16(3) << 14))
			term.positions[j] = tsPosition{position: position, weight: weight}
		}
	}
	return ret, nil
}

// EncodeTSQuery encodes a tsquery into a serialized representation for on-disk
// storage.