{{tag>igde testing remote network}}
<WRAP youarehere>
[[:start|Start Page]] >> [[:gamedev|Game Development with the Drag[en]gine]] >> [[gamedev:remotelaunching|Remote Launching]] >> **Remote Launcher Network Protocol**
</WRAP>

====== Remote Launcher Network Protocol ======

The Remote Launcher Network Protocol uses the [[gamedev:dnp|Drag[en]gine Network Protocol]] as protocol and defines a set of ''messages'' and ''linked states'' supported by IGDE and Remote Launchers. The specification can change with upcoming Drag[en]gine updates but stays backwards compatible. Servers and clients are required to ignore unknown messages and linked states.

To implement this protocol best use [[https://github.com/LordOfDragons/denetwork/releases|Drag[en]gine Network Library]] and add the necessary message and state handling.

====== Messages ======

These are all messages the server and the client can send to each other.

===== Connect Request =====

Upon connecting the client has to send this message to request access to IGDE indicating the kinds of features it supports. The connect request message has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''1'' |
| [[gamedev:dnp#data_types|Byte]][16] | Signature | Identifies the connecting client as a Remote Launcher client. Value has to be ''![DERemLaunchCnt-0]!''. |
| [[gamedev:dnp#data_types|UInt]] | SupportedFeatures | <WRAP>
Features supported by the client. Flags value with these possible values:
  * //No flags defined. Reserved for future expansion//
</WRAP> |
| [[gamedev:dnp#data_types|String8]] | Name | Name describing the remote client connecting. This is a free form name of short length chosen by the developer to distinguish multiple connected clients in the IGDE. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message |

The server will then respond with a [[#connect_accepted|Connect Accepted]] message or disconnect the client if rejected.

===== Connect Accepted =====

Send by the server after a client connects which send [[#connect_request|Connect Request]] message identifying itself as a Remote Launcher client. This is the first message received from the server. The client should not send any messages until it has received this message as this will get him disconnected. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''2'' |
| [[gamedev:dnp#data_types|Byte]][16] | Signature | Identifies the server as a Remote Launcher server. Value is <wrap hi>''![DERemLaunchSrv-0]!''</wrap>. If this value is not matching the client has to disconnect immediately as it is not connecting to a Remote Launcher server. |
| [[gamedev:dnp#data_types|UInt]] | EnabledFeatures | Enabled features supported by both the connecting client and the server. Same possible values as in ''SupportedFeatures'' in [[#connect_request|Connect Request]] message |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message |

===== Request File Layout =====

Send by the server to request the file layout of the client. The client has to scan the entire date storage where the project files are located and record the file parameters. Since this process can be lengthy the client typically stores the file layout in memory and updates it as files are modified. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''3'' |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

Once the file layout is ready a [[#response_file_layout|Response File Layout]] message is send.

===== Response File Layout =====

Send by the client in response to a [[#request_file_layout|Request File Layout]] message containing the scanned file layout. Layout contains the entire file hierarchy as flat list. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code  | Message code. Is value ''4'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files. |
| FileData[FileCount] | Files | ''FileCount'' file data. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

''FileData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|ULong]] | Size | File size in bytes. |
| [[gamedev:dnp#data_types|String8]] | Hash | Hash of file (SHA-256). |

===== Request File Block Hashes =====

Send by the server to request block wise hashes of a file from the client. Block wise hashes are useful for large files to avoid updating the entire file. Since this process can be lengthy the client typically stores the block wise hashes for a file in memory if requested. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''5'' |
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|UInt]] | BlockSize | Size of blocks in bytes. |

Once the block wise hashes are calculated a [[#response_file_block_hashes|Response File Block Hashes]] message is send.

===== Response File Block Hashes =====

Send by the client in response to a [[#request_file_block_hashes|Request File Block Hashes]] message containing the file block hashes. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code  | Message code. Is value ''6'' |
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|UInt]] | BlockCount | Count of blocks. |
| [[gamedev:dnp#data_types|UInt]] | BlockSize | Size of blocks in bytes. |
| [[gamedev:dnp#data_types|String8]][BlockCount] | Blocks | ''BlockCount'' hashes (SHA-256). |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

===== Request Delete Files =====

Send by the server to request the client to delete files. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''7'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files to delete. |
| [[gamedev:dnp#data_types|String16]][FileCount] | Files | ''FileCount'' file path relative to to root of data directory. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

Once the operation finished (either successfully or not) a [[#response_delete_files|Response Delete Files]] message is send.

===== Response Delete Files =====

Send by the client in response to a [[#request_delete_files|Request Delete Files]] message. Indicates if the operation succeeded or not. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code  | Message code. Is value ''8'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files. |
| FileData[FileCount] | Files | ''FileCount'' file data. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

''FileData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|Byte]] | Result | <WRAP>Result of delete operation. Can be one of these values:
  * ''0'': File has been deleted.
  * ''1'': File could not be deleted.
Additional result codes can be added in the future to indicate better what has been the problem. Servers have to consider all values except ''0'' as a failure.</WRAP> |

===== Request Write Files =====

Send by the server to request the client to start writing files. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''9'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files to start write. |
| FileData[FileCount] | Files | ''FileCount'' data to process. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |


''FileData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|ULong]] | Size | File size in bytes. |

The client has to mark the files as in progress for writing. If the file size is shorter than the existing file the file has to be truncated. File writing has to be done in overwrite mode hence the file content is retained. This allows updating only ranges of data inside large files. Data to write is send using unreliable [[#send_file_data|Send File Data]] messages.

Once ready the client has to send back a [[#response_write_file|Response Write Files]].

===== Response Write Files =====

Send by the client in response to a [[#request_write_file|Request Write Files]] message. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''10'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files. |
| FileData[FileCount] | Files | ''FileCount'' file data. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |


''FileData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|Byte]] | Result | <WRAP>Result of operation. Can be one of these values:
  * ''0'': File is ready to be written to.
  * ''1'': File can not be written.
Additional result codes can be added in the future. Servers have to consider all values except ''0'' as a failure.</WRAP> |

===== Send File Data =====

Message send by the server to client with data to write to a file. The message is send unreliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''11'' |
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|ULong]] | Offset | Byte offset in the file to write the data to. |
| [[gamedev:dnp#data_types|Byte]][*] | Data | Remaining bytes in the message is the data to write at ''Offset''. |

Receiving and processing the message (successful or not) requires the client to send a [[#file_data_received|File Data Received]] message. Multiple ''Send File Data'' messages can be acknowledged in the same ''File Data Received'' message.

===== File Data Received =====

Send by the client after receiving one or more [[#send_file_data|Send File Data]] messages. Using this message the server knows which ''Send File Data'' messages have arrive and which have been successfully been written. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code  | Message code. Is value ''12'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files. |
| FileData[FileCount] | Files | ''FileCount'' file data. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

''FileData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|ULong]] | Offset | Byte offset in the file. |
| [[gamedev:dnp#data_types|UInt]] | Length | Length in bytes. |
| [[gamedev:dnp#data_types|Byte]] | Result | <WRAP>Result of write operation. Can be one of these values:
  * ''0'': Writing data has been successful.
  * ''1'': Writing data has failed.
Additional result codes can be added in the future to indicate better what has been the problem. Servers have to consider all values except ''0'' as a failure.</WRAP> |


===== Request Finish Write Files =====

Send by the server to request the client to finish writing files. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''13'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files to finish writing. |
| [[gamedev:dnp#data_types|String16]][FileCount] | Files | ''FileCount'' file path relative to root of data directory to finish writing. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

The client has to mark the files as finished writing and ready to be used.

Once ready the client has to send back a [[#response_finish_write_file|Response Finish Write Files]].

===== Response Finish Write Files =====

Send by the client in response to a [[#request_finish_write_file|Request Finish Write Files]] message. The message is send reliable and has this format:

^  Type ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''14'' |
| [[gamedev:dnp#data_types|UInt]] | FileCount | Count of files. |
| FileData[FileCount] | Files | ''FileCount'' file data. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

''FileData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|String16]] | Path | File path relative to root of data directory. |
| [[gamedev:dnp#data_types|Byte]] | Result | <WRAP>Result of operation. Can be one of these values:
  * ''0'': File has been successfully written.
  * ''1'': Writing file failed.
Additional result codes can be added in the future. Servers have to consider all values except ''0'' as a failure.</WRAP> |

===== Start Application =====

Send by the server to request the client to start application. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''15'' |
| [[gamedev:dnp#data_types|String16]] | GameConfig | Content of ''*.degame'' file used to launch the application. |
| [[gamedev:dnp#data_types|String8]] | ProfileName | Name of profile to use for launching the application. Use default if empty string. |
| [[gamedev:dnp#data_types|String16]] | Arguments | Command line arguments to use. Use none if empty string. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message |


===== Stop Application =====

Send by the server to request the client to stop application. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''16'' |
| [[gamedev:dnp#data_types|Byte]] | Mode | <WRAP>How to stop the application. Can be one of these values:
  * ''0'': Request closing application using system means. This can be for example a close application or close window event.
  * ''1'': Kill application. Used if the application is not responding to closing.
Additional result codes can be added in the future. Clients have to ignore unknown values.</WRAP> |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message |

===== Logs =====

Send by the client to send logs to the server. Logs are send as lines. The message is send reliable and has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''17'' |
| [[gamedev:dnp#data_types|UShort]] | LineCount | Count of lines. |
| LineData[LineCount] | Lines | ''LineCount'' line data. |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message. |

''LineData'' has this format:
^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Level | <WRAP>Log level. Can be one of these values:
  * ''0'': Information.
  * ''1'': Warning.
  * ''2'': Error.
Additional levels can be added in the future. Servers have to consider all unknown values as being ''0''.</WRAP> |
| [[gamedev:dnp#data_types|String8]] | Timestamp | Timestamp in text form. |
| [[gamedev:dnp#data_types|String16]] | Message | Log message. |

====== Linked States ======

These are all linked states the server can request.

===== Record/Playback =====

Send by the server to link the running state. The link message has this format:

^  Type  ^  Name  ^  Description  ^
| [[gamedev:dnp#data_types|Byte]] | Code | Message code. Is value ''1'' |
|  -  | Reserved | Reserved for future expansion. Ignore any additional bytes in the message |

The client has to add these values to the state in this specified order:
^  Index  ^  Type  ^  Name  ^  Description  ^
|  ''0''  | [[gamedev:dnp#state_value_data_types|UInt8]] | Status | <WRAP>
Status of the application. Can be one of these values:
  * ''0'': Stopped.
  * ''1'': Running.
</WRAP> |

===== Revision =====

^ Date      | Changes                                   |