Function scanContainerLen

parser.go:2255–2463

SYS-REQ-112

(data []byte, offset int, open byte)

// SYS-REQ-112
func scanContainerLen(data []byte, offset int, open byte) (int, error) {
	const (
		scanArrayValue = iota
		scanArrayPrimitive
		scanArrayDelimiter
		scanObjectKey
		scanObjectColon
		scanObjectValue
		scanObjectPrimitive
		scanObjectDelimiter
	)

	close := byte(']')
	malformedErr := MalformedArrayError
	state := scanArrayValue
	if open == '{' {
		close = '}'
		malformedErr = MalformedObjectError
		state = scanObjectKey
	}

	var fixedStack [32]byte
	stack := fixedStack[:1]
	stack[0] = close

	count := 0
	primitiveStart := -1

	for i := offset + 1; i < len(data); i++ {
		c := data[i]

		// Only delimiters at the addressed container's top level affect its
		// length. Strings and nested containers are skipped structurally.
		if len(stack) > 1 {
			switch c {
			case '"':
				stringLength, _ := stringEnd(data[i+1:])
				if stringLength == -1 {
					return 0, malformedErr
				}
				i += stringLength
			case '[':
				stack = append(stack, ']')
			case '{':
				stack = append(stack, '}')
			case ']', '}':
				if c != stack[len(stack)-1] {
					return 0, malformedErr
				}
				stack = stack[:len(stack)-1]
			}
			continue
		}

		switch state {
		case scanArrayValue:
			if isContainerWhitespace(c) {
				continue