Up to date
This page is up to date for Godot 4.2.
If you still find outdated information, please open an issue.
ENetConnection¶
Inherits: RefCounted < Object
A wrapper class for an ENetHost.
Description¶
ENet's purpose is to provide a relatively thin, simple and robust network communication layer on top of UDP (User Datagram Protocol).
Tutorials¶
Methods¶
void |
bandwidth_limit ( int in_bandwidth=0, int out_bandwidth=0 ) |
void |
broadcast ( int channel, PackedByteArray packet, int flags ) |
void |
channel_limit ( int limit ) |
void |
compress ( CompressionMode mode ) |
connect_to_host ( String address, int port, int channels=0, int data=0 ) |
|
create_host ( int max_peers=32, int max_channels=0, int in_bandwidth=0, int out_bandwidth=0 ) |
|
create_host_bound ( String bind_address, int bind_port, int max_peers=32, int max_channels=0, int in_bandwidth=0, int out_bandwidth=0 ) |
|
void |
destroy ( ) |
dtls_client_setup ( String hostname, TLSOptions client_options=null ) |
|
dtls_server_setup ( TLSOptions server_options ) |
|
void |
flush ( ) |
get_local_port ( ) const |
|
get_max_channels ( ) const |
|
get_peers ( ) |
|
pop_statistic ( HostStatistic statistic ) |
|
void |
refuse_new_connections ( bool refuse ) |
void |
socket_send ( String destination_address, int destination_port, PackedByteArray packet ) |
Enumerations¶
enum CompressionMode:
CompressionMode COMPRESS_NONE = 0
No compression. This uses the most bandwidth, but has the upside of requiring the fewest CPU resources. This option may also be used to make network debugging using tools like Wireshark easier.
CompressionMode COMPRESS_RANGE_CODER = 1
ENet's built-in range encoding. Works well on small packets, but is not the most efficient algorithm on packets larger than 4 KB.
CompressionMode COMPRESS_FASTLZ = 2
FastLZ compression. This option uses less CPU resources compared to COMPRESS_ZLIB, at the expense of using more bandwidth.
CompressionMode COMPRESS_ZLIB = 3
Zlib compression. This option uses less bandwidth compared to COMPRESS_FASTLZ, at the expense of using more CPU resources.
CompressionMode COMPRESS_ZSTD = 4
Zstandard compression. Note that this algorithm is not very efficient on packets smaller than 4 KB. Therefore, it's recommended to use other compression algorithms in most cases.
enum EventType:
EventType EVENT_ERROR = -1
An error occurred during service. You will likely need to destroy the host and recreate it.
EventType EVENT_NONE = 0
No event occurred within the specified time limit.
EventType EVENT_CONNECT = 1
A connection request initiated by enet_host_connect has completed. The array will contain the peer which successfully connected.
EventType EVENT_DISCONNECT = 2
A peer has disconnected. This event is generated on a successful completion of a disconnect initiated by ENetPacketPeer.peer_disconnect, if a peer has timed out, or if a connection request initialized by connect_to_host has timed out. The array will contain the peer which disconnected. The data field contains user supplied data describing the disconnection, or 0, if none is available.
EventType EVENT_RECEIVE = 3
A packet has been received from a peer. The array will contain the peer which sent the packet and the channel number upon which the packet was received. The received packet will be queued to the associated ENetPacketPeer.
enum HostStatistic:
HostStatistic HOST_TOTAL_SENT_DATA = 0
Total data sent.
HostStatistic HOST_TOTAL_SENT_PACKETS = 1
Total UDP packets sent.
HostStatistic HOST_TOTAL_RECEIVED_DATA = 2
Total data received.
HostStatistic HOST_TOTAL_RECEIVED_PACKETS = 3
Total UDP packets received.
Method Descriptions¶
void bandwidth_limit ( int in_bandwidth=0, int out_bandwidth=0 )
Adjusts the bandwidth limits of a host.
void broadcast ( int channel, PackedByteArray packet, int flags )
Queues a packet to be sent to all peers associated with the host over the specified channel. See ENetPacketPeer FLAG_* constants for available packet flags.
void channel_limit ( int limit )
Limits the maximum allowed channels of future incoming connections.
void compress ( CompressionMode mode )
Sets the compression method used for network packets. These have different tradeoffs of compression speed versus bandwidth, you may need to test which one works best for your use case if you use compression at all.
Note: Most games' network design involve sending many small packets frequently (smaller than 4 KB each). If in doubt, it is recommended to keep the default compression algorithm as it works best on these small packets.
Note: The compression mode must be set to the same value on both the server and all its clients. Clients will fail to connect if the compression mode set on the client differs from the one set on the server.
ENetPacketPeer connect_to_host ( String address, int port, int channels=0, int data=0 )
Initiates a connection to a foreign address using the specified port and allocating the requested channels. Optional data can be passed during connection in the form of a 32 bit integer.
Note: You must call either create_host or create_host_bound before calling this method.
Error create_host ( int max_peers=32, int max_channels=0, int in_bandwidth=0, int out_bandwidth=0 )
Create an ENetHost that will allow up to max_peers connected peers, each allocating up to max_channels channels, optionally limiting bandwidth to in_bandwidth and out_bandwidth.
Error create_host_bound ( String bind_address, int bind_port, int max_peers=32, int max_channels=0, int in_bandwidth=0, int out_bandwidth=0 )
Create an ENetHost like create_host which is also bound to the given bind_address and bind_port.
void destroy ( )
Destroys the host and all resources associated with it.
Error dtls_client_setup ( String hostname, TLSOptions client_options=null )
Configure this ENetHost to use the custom Godot extension allowing DTLS encryption for ENet clients. Call this before connect_to_host to have ENet connect using DTLS validating the server certificate against hostname. You can pass the optional client_options parameter to customize the trusted certification authorities, or disable the common name verification. See TLSOptions.client and TLSOptions.client_unsafe.
Error dtls_server_setup ( TLSOptions server_options )
Configure this ENetHost to use the custom Godot extension allowing DTLS encryption for ENet servers. Call this right after create_host_bound to have ENet expect peers to connect using DTLS. See TLSOptions.server.
void flush ( )
Sends any queued packets on the host specified to its designated peers.
int get_local_port ( ) const
Returns the local port to which this peer is bound.
int get_max_channels ( ) const
Returns the maximum number of channels allowed for connected peers.
ENetPacketPeer[] get_peers ( )
Returns the list of peers associated with this host.
Note: This list might include some peers that are not fully connected or are still being disconnected.
float pop_statistic ( HostStatistic statistic )
Returns and resets host statistics. See HostStatistic for more info.
void refuse_new_connections ( bool refuse )
Configures the DTLS server to automatically drop new connections.
Note: This method is only relevant after calling dtls_server_setup.
Array service ( int timeout=0 )
Waits for events on the host specified and shuttles packets between the host and its peers. The returned Array will have 4 elements. An EventType, the ENetPacketPeer which generated the event, the event associated data (if any), the event associated channel (if any). If the generated event is EVENT_RECEIVE, the received packet will be queued to the associated ENetPacketPeer.
Call this function regularly to handle connections, disconnections, and to receive new packets.
void socket_send ( String destination_address, int destination_port, PackedByteArray packet )
Sends a packet toward a destination from the address and port currently bound by this ENetConnection instance.
This is useful as it serves to establish entries in NAT routing tables on all devices between this bound instance and the public facing internet, allowing a prospective client's connection packets to be routed backward through the NAT device(s) between the public internet and this host.
This requires forward knowledge of a prospective client's address and communication port as seen by the public internet - after any NAT devices have handled their connection request. This information can be obtained by a STUN service, and must be handed off to your host by an entity that is not the prospective client. This will never work for a client behind a Symmetric NAT due to the nature of the Symmetric NAT routing algorithm, as their IP and Port cannot be known beforehand.