// Sources/SwiftProtobuf/UnknownStorage.swift - Handling unknown fields

//

// Copyright (c) 2014 - 2016 Apple Inc. and the project authors

// Licensed under Apache License v2.0 with Runtime Library Exception

//

// See LICENSE.txt for license information:

// https://github.com/apple/swift-protobuf/blob/main/LICENSE.txt

//

// -----------------------------------------------------------------------------

///

/// Proto2 binary coding requires storing and recoding of unknown fields.

/// This simple support class handles that requirement.  A property of this type

/// is compiled into every proto2 message.

///

// -----------------------------------------------------------------------------

#if canImport(FoundationEssentials)

import FoundationEssentials

#else

import Foundation

#endif

/// Contains any unknown fields in a decoded message; that is, fields that were

/// sent on the wire but were not recognized by the generated message

/// implementation or were valid field numbers but with mismatching wire

/// formats (for example, a field encoded as a varint when a fixed32 integer

/// was expected).

public struct UnknownStorage: Equatable, Sendable {

    /// The raw protocol buffer binary-encoded bytes that represent the unknown

    /// fields of a decoded message.

    public private(set) var data = Data()

    public init() {}

    package mutating func append(protobufData: Data) {

        data.append(protobufData)

    }

    public func traverse<V: Visitor>(visitor: inout V) throws {

        if !data.isEmpty {

            try visitor.visitUnknown(bytes: data)

        }

    }

}