Function parseUsingFastParser

pkg/util/json/parser.go:20–54

parseUsingFastParser parses string as JSON using fast json parser.

(s string, cfg parseConfig)

// parseUsingFastParser parses string as JSON using fast json parser.
func parseUsingFastParser(s string, cfg parseConfig) (JSON, error) {
	input, err := unsafeGetBytes(s)
	if err != nil {
		return nil, err
	}

	p := fastJSONParser{
		parseConfig: cfg,
		decoder:     tokenizer.MakeDecoder(input),
		state:       (*fastJSONParser).parseTopValue,
	}
	defer p.decoder.Release()

	j, err := p.parse()
	if err != nil {
		if errors.Is(err, io.ErrUnexpectedEOF) && p.decoder.More() {
			// JSON scanner returns nil token if it encounters an invalid input
			// character.  In such cases, decoder returns io.ErrUnexpectedEOF error.
			// However, we know it's not an EOF because decoder has more data.  So,
			// produce a bit nicer error message.
			return nil, jsonDecodeError(decodeErrorContext(errInvalidInputToken, s, p.decoder.Pos()))
		}
		return nil, jsonDecodeError(decodeErrorContext(err, s, p.decoder.Pos()))
	}

	if j == nil {
		return nil, errors.AssertionFailedf("expected parsed JSON value, got nil")
	}

	if p.decoder.More() {
		return nil, jsonDecodeError(decodeErrorContext(errTrailingCharacters, s, p.decoder.Pos()+1))
	}

	return j, nil
}

// fastJSONParser builds JSON given input string. This implementation uses low level
// API provided by fork of github.com/pkg/json package to implement direct