FRpcMessageUtils

FRpcMessageUtils

A MSGKEY used as an RPC interface: send a message that happens to cross the wire, instead of declaring a UFUNCTION per remote call.

Declared in Plugins/GMP/Source/GMP/GMP/GMPRpcUtils.h:17

class GMP_API FRpcMessageUtils
{
    static UPackageMap*      GetPackageMap(APlayerController* PC);
    static const int32       GetMaxBytes();
    static void              PostRPCMsg(APlayerController* PC, const UObject* Sender,
                                        const FString& MessageStr, TArray<uint8>& Buffer,
                                        bool Reliable = true);
    static APlayerController* GetLocalPC(const UObject* Obj);
    static int32             GetPlayerLocalSequence(const APlayerController& PC);

    static bool Z_VerifyRPC(APlayerController* PC, const UObject* Obj,
                            const FMSGKEY& MessageKey, const TArray<FProperty*>& Props);

    template<typename T, typename... TArgs>
    static void Z_PostRPC(bool bReliable, APlayerController* PC, T* Sender,
                          const FMSGKEY& MessageKey, TArgs&... InArgs);
};

How it works

Z_PostRPC turns the argument pack into a FProperty* list via Class2Name/TClass2Prop, serialises through GMPArchive's net writer, and posts the buffer with PostRPCMsg. Because it rides UE's own network serialisation and UPackageMap, object references and replication semantics behave as they normally do — this is not a parallel transport.

Reliable selects the reliable or unreliable channel, as with any UE RPC.

Verification at the boundary

Z_VerifyRPC checks the incoming key and property list against what the endpoint expects.

This is not optional hygiene. An RPC surface addressed by string is reachable with any string a client can construct, so the receiving side has to validate the key and the argument shape before decoding. Treat the verify step as part of the contract, not a debug aid.

Size

GetMaxBytes() bounds the payload. Exceeding it is a caller-side concern — chunking or moving the data out of band is up to you.

See also

GMPArchive · Class2Name · MSGKEY