Function parseProtoMessage

apps/en-decode/endecode-lib.js:407–481

(bytes, depth)

        };

        let parseProtoMessage = function (bytes, depth) {
            let fields = [];
            let offset = 0;

            while (offset < bytes.length) {
                let key = readProtoVarint(bytes, offset);
                offset = key.next;
                let fieldNumber = Number(key.value >> 3n);
                let wireType = Number(key.value & 7n);
                if (!fieldNumber) {
                    throw new Error('Protobuf 字段号无效');
                }

                let field = {
                    field: fieldNumber,
                    wireType,
                    offset: key.next - 1
                };

                if (wireType === 0) {
                    let value = readProtoVarint(bytes, offset);
                    offset = value.next;
                    field.type = 'varint';
                    field.value = formatProtoInteger(value.value);
                } else if (wireType === 1) {
                    let value = readLittleEndianHex(bytes, offset, 8);
                    offset = value.next;
                    field.type = 'fixed64';
                    field.rawHex = value.rawHex;
                    field.littleEndianHex = value.littleEndianHex;
                } else if (wireType === 2) {
                    let lengthInfo = readProtoVarint(bytes, offset);
                    let length = Number(lengthInfo.value);
                    offset = lengthInfo.next;
                    if (!Number.isSafeInteger(length) || offset + length > bytes.length) {
                        throw new Error('Protobuf length-delimited 字段长度异常');
                    }
                    let valueBytes = bytes.slice(offset, offset + length);
                    offset += length;
                    field.type = 'length-delimited';
                    field.length = length;
                    field.rawHex = bytesToHex(valueBytes);

                    let text = decodeUtf8Bytes(valueBytes);
                    if (text) {
                        field.valueType = 'string';
                        field.value = text;
                    } else if (depth < 4 && valueBytes.length) {
                        try {
                            let nested = parseProtoMessage(valueBytes, depth + 1);
                            field.valueType = 'message';
                            field.value = nested;
                        } catch (e) {
                            field.valueType = 'bytes';
                            field.value = field.rawHex;
                        }
                    } else {
                        field.valueType = 'bytes';