| 1 | | | import 'package:meta/meta.dart'; |
| 2 | | | |
| 3 | | | import '../_impl/xplat/_internal_logger.dart'; |
| 4 | | | import '../_impl/xplat/_time_stamp.dart'; |
| 5 | | | import '../exceptions/squadron_error.dart'; |
| 6 | | | import '../tokens/_squadron_cancelation_token.dart'; |
| 7 | | | import '../typedefs.dart'; |
| 8 | | | import 'worker.dart'; |
| 9 | | | import 'worker_channel.dart'; |
| 10 | | | import 'worker_message.dart'; |
| 11 | | | |
| 12 | | | /// [WorkerRequest]s are used to communicate from a client to a [Worker]. |
| 13 | | | /// Typically a [WorkerRequest] consists of a command ID and a list of |
| 14 | | | /// arguments. The [command] ID is used by the [Worker] to dispatch the |
| 15 | | | /// [WorkerRequest] to the method responsible for handling it. |
| 16 | | | /// The command's arguments are passed as a list and should only contain |
| 17 | | | /// primitive values or objects that can be transfered across workers. For |
| 18 | | | /// applications running on a VM platform, Dart objects should be safe |
| 19 | | | /// according to Dart's documentation of [SendPort.send]. [WorkerRequestImpl] |
| 20 | | | /// also implements specific requests used for worker startup, stream/token |
| 21 | | | /// cancelation, worker termination... |
| 22 | | | extension type WorkerRequest._(List data) implements WorkerMessage { |
| 23 | | 10 | factory WorkerRequest.from(List data) { |
| 24 | | 20 | if (data.length != 7) { |
| 25 | | 0 | throw SquadronErrorImpl.create('Invalid worker request'); |
| 26 | | | } |
| 27 | | 10 | return WorkerRequest._(data); |
| 28 | | | } |
| 29 | | | |
| 30 | | | /// Creates a new request with the specified [command] ID and optional arguments. |
| 31 | | 10 | factory WorkerRequest.userCommand(PlatformChannel channelInfo, int command, |
| 32 | | | List args, SquadronCancelationToken? token, bool inspectResponse) => |
| 33 | | 20 | WorkerRequest._([ |
| 34 | | 10 | microsecTimeStamp(), // 0 - travel time |
| 35 | | | channelInfo, // 1 - channel |
| 36 | | | command, // 2 - command |
| 37 | | | args, // 3 - args |
| 38 | | | token, // 4 - cancelation token |
| 39 | | | null, // 5 - stream id |
| 40 | | | inspectResponse, // 6 - inspect response |
| 41 | | | ]); |
| 42 | | | |
| 43 | | | /// Creates a new start request. |
| 44 | | 11 | factory WorkerRequest.start(PlatformChannel channelInfo, List args) => |
| 45 | | 22 | WorkerRequest._([ |
| 46 | | 11 | microsecTimeStamp(), // 0 - travel time |
| 47 | | | channelInfo, // 1 - channel |
| 48 | | | _connectCommand, // 2 - command |
| 49 | | | args, // 3 - args |
| 50 | | | null, // 4 - cancelation token |
| 51 | | | null, // 5 - stream id |
| 52 | | | true, // 6 - inspect response |
| 53 | | | ]); |
| 54 | | | |
| 55 | | | /// Creates a new stream cancelation request. |
| 56 | | 12 | factory WorkerRequest.cancelStream(int streamId) => WorkerRequest._([ |
| 57 | | 4 | microsecTimeStamp(), // 0 - travel time |
| 58 | | | null, // 1 - channel |
| 59 | | | _cancelStreamCommand, // 2 - command |
| 60 | | | null, // 3 - args |
| 61 | | | null, // 4 - cancelation token |
| 62 | | | streamId, // 5 - stream id |
| 63 | | | null, // 6 - inspect response |
| 64 | | | ]); |
| 65 | | | |
| 66 | | | /// Creates a new cancelation request. |
| 67 | | 2 | factory WorkerRequest.cancel(SquadronCancelationToken token) => |
| 68 | | 4 | WorkerRequest._([ |
| 69 | | 2 | microsecTimeStamp(), // 0 - travel time |
| 70 | | | null, // 1 - channel |
| 71 | | | _cancelTokenCommand, // 2 - command |
| 72 | | | null, // 3 - args |
| 73 | | | token, // 4 - cancelation token |
| 74 | | | null, // 5 - stream id |
| 75 | | | null, // 6 - inspect response |
| 76 | | | ]); |
| 77 | | | |
| 78 | | | /// Creates a new termination request. |
| 79 | | 30 | factory WorkerRequest.stop() => WorkerRequest._([ |
| 80 | | 10 | microsecTimeStamp(), // 0 - travel time |
| 81 | | | null, // 1 - channel |
| 82 | | | _terminateCommand, // 2 - command |
| 83 | | | null, // 3 - args |
| 84 | | | null, // 4 - cancelation token |
| 85 | | | null, // 5 - stream id |
| 86 | | | null, // 6 - inspect response |
| 87 | | | ]); |
| 88 | | | |
| 89 | | | /// The client's [WorkerChannel]. Only valid on the receiving end. |
| 90 | | 20 | WorkerChannel? get channel => data[_$channel]; |
| 91 | | | |
| 92 | | | /// The channel method to be used for sending data back. |
| 93 | | 10 | void Function(dynamic)? get reply => |
| 94 | | 34 | inspectResponse ? channel?.inspectAndReply : channel?.reply; |
| 95 | | | |
| 96 | | | /// The client's channel info. |
| 97 | | 0 | PlatformChannel? get channelInfo => data[_$channel]; |
| 98 | | | |
| 99 | | | /// Cancelation token. |
| 100 | | 20 | SquadronCancelationToken? get cancelToken => data[_$token]; |
| 101 | | | |
| 102 | | | /// Stream id. |
| 103 | | 8 | int? get streamId => data[_$streamId]; |
| 104 | | | |
| 105 | | | /// The [command]'s ID. |
| 106 | | 20 | int get command => data[_$command]; |
| 107 | | | |
| 108 | | | /// The command's arguments, if any. |
| 109 | | 20 | List get args => data[_$args]; |
| 110 | | | |
| 111 | | | /// Flag indicating whether the Channel should inspect the payload to identify non-base type objects. In |
| 112 | | | /// Web Workers, ownership of these objects must be transfered across threads. |
| 113 | | 20 | bool get inspectResponse => data[_$inspectResponse]; |
| 114 | | | |
| 115 | | | /// flag for start requests. |
| 116 | | 30 | bool get isConnection => (command == _connectCommand); |
| 117 | | | |
| 118 | | | /// flag for stream cancelation requests. |
| 119 | | 30 | bool get isStreamCancelation => (command == _cancelStreamCommand); |
| 120 | | | |
| 121 | | | /// flag for cancelation requests. |
| 122 | | 30 | bool get isTokenCancelation => (command == _cancelTokenCommand); |
| 123 | | | |
| 124 | | | /// flag for termination requests. |
| 125 | | 30 | bool get isTermination => (command == _terminateCommand); |
| 126 | | | |
| 127 | | | /// In-place deserialization of a [WorkerRequest] received by the worker. |
| 128 | | 10 | void unwrapInPlace(InternalLogger? logger) { |
| 129 | | 10 | unwrapTravelTime(); |
| 130 | | 30 | data[_$command] = (data[_$command] as num).toInt(); |
| 131 | | 24 | data[_$streamId] = (data[_$streamId] as num?)?.toInt(); |
| 132 | | 30 | data[_$channel] = WorkerChannel.deserialize(data[_$channel], logger); |
| 133 | | 30 | data[_$token] = SquadronCancelationToken.deserialize(data[_$token]); |
| 134 | | 10 | data[_$inspectResponse] ??= false; |
| 135 | | 10 | data[_$args] ??= const []; |
| 136 | | | } |
| 137 | | | |
| 138 | | | /// In-place serialization of a [WorkerRequest]. |
| 139 | | 11 | void wrapInPlace() { |
| 140 | | 11 | final token = data[_$token]; |
| 141 | | 11 | if (token is SquadronCancelationToken) { |
| 142 | | 4 | data[_$token] = token.serialize(); |
| 143 | | | } |
| 144 | | | } |
| 145 | | | |
| 146 | | | static const int _connectCommand = -1; |
| 147 | | | static const int _cancelStreamCommand = -2; |
| 148 | | | static const int _cancelTokenCommand = -3; |
| 149 | | | static const int _terminateCommand = -4; |
| 150 | | | } |
| 151 | | | |
| 152 | | | // 0 is reserved for travel time |
| 153 | | | const _$channel = 1; |
| 154 | | | const _$command = 2; |
| 155 | | | const _$args = 3; |
| 156 | | | const _$token = 4; |
| 157 | | | const _$streamId = 5; |
| 158 | | | const _$inspectResponse = 6; |
| 159 | | | |
| 160 | | | @internal |
| 161 | | | extension CancelationTokenExt on WorkerRequest { |
| 162 | | 2 | void overrideCancelToken(SquadronCancelationToken token) { |
| 163 | | 10 | if (cancelToken == null || cancelToken!.id != token.id) { |
| 164 | | 0 | throw SquadronErrorImpl.create('Cancelation token mismatch'); |
| 165 | | | } |
| 166 | | 2 | data[_$token] = token; |
| 167 | | | } |
| 168 | | | } |