util.go

/*
Copyright 2018 Bitnine Co., Ltd.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package ag

import "fmt"

func readJSONObject(b []byte) ([]byte, error) {
	if b[0] != byte('{') {
		return nil, fmt.Errorf("invalid JSON object: %s", b)
	}
	depth := 1

	for pos, length := 1, len(b); pos < length; pos++ {
		switch b[pos] {
		case byte('"'):
			// Leave pos unchanged if unmatched " were found.
			escape := false
		InString:
			for i := pos + 1; i < length; i++ {
				switch b[i] {
				case byte('\\'):
					escape = !escape
				case byte('"'):
					if escape {
						escape = false
					} else {
						pos = i
						break InString
					}
				default:
					escape = false
				}
			}
		case byte('{'):
			depth++
		case byte('}'):
			depth--
			if depth == 0 {
				return b[:pos+1], nil
			}
		}
	}

	return nil, fmt.Errorf("invalid JSON object: %s", b)
}