PVF Send Helper Contract Reference

PVF Send-Helper Contract Reference

Source-verified 2026-06-21 against master 0139a346. Paths relative to Missions/[55-2hc]warfarev2_073v48co.chernarus/ unless noted. Arma 2 OA 1.64.

This page documents the sender side of the public-variable function (PVF) layer: the four Common_SendTo* helpers that a caller invokes to "address a registered PVF handler" on another machine. Each helper takes a logical command payload, rewrites it into the wire form the receiver expects (SRVFNC<Command> / CLTFNC<Command>), and pushes it over the right public-variable transport (publicVariable, publicVariableServer, or publicVariableClient) — or, on a hosted (listen) server, short-circuits straight into the local dispatcher. The receiver half (Server_HandlePVF / Client_HandlePVF, the Call Compile dispatch surface, and the DR-1/DR-38 allowlist hardening) is documented separately in PVF dispatch implementation playbook; this page is its sender-contract companion and does not restate that hardening.

The helpers are exposed as WFBE_CO_FNC_SendToClient, WFBE_CO_FNC_SendToClients, and WFBE_CO_FNC_SendToServer, compiled in Common/Init/Init_Common.sqf:147-149. There is no public alias for the optimized server variant — it is swapped in behind WFBE_CO_FNC_SendToServer by a build-time branch (see Build-Time Alias Selection).

The Four Send Helpers

Helper file	Compiled alias	Direction	Transport	Payload index rewritten
Common/Functions/Common_SendToClient.sqf	WFBE_CO_FNC_SendToClient	server → one client	publicVariableClient (UID-targeted)	0 (object → UID), 1 (func → CLTFNC%1)
Common/Functions/Common_SendToClients.sqf	WFBE_CO_FNC_SendToClients	any → all machines	publicVariable (broadcast)	1 (func → CLTFNC%1)
Common/Functions/Common_SendToServer.sqf	WFBE_CO_FNC_SendToServer (Vanilla)	client → server	publicVariable	0 (func → SRVFNC%1)
Common/Functions/Common_SendToServerOptimized.sqf	WFBE_CO_FNC_SendToServer (OA)	client → server	publicVariableServer	0 (func → SRVFNC%1)

All four share the same skeleton: read the logical function name out of a fixed payload index, overwrite that index (and for SendToClient, index 0 too) with the wire token, then either fire the public variable or, on a hosted server, Spawn the local handler directly.

Payload shape and the logical-name rewrite

Callers pass an array whose head is the logical command name. The naming convention differs by direction:

• Client-bound payloads carry the command at index 1; index 0 is the targeting object (or nil for SendToClients). The helper rewrites index 1 to Format["CLTFNC%1",_func] so the receiver resolves CLTFNC<Command>. See Common_SendToClient.sqf:10,14 and Common_SendToClients.sqf:10,12.
• Server-bound payloads carry the command at index 0. The helper rewrites index 0 to Format["SRVFNC%1",_func] so the receiver resolves SRVFNC<Command>. See Common_SendToServer.sqf:10,12 and Common_SendToServerOptimized.sqf:10,12.

This rewrite is the contract the dispatcher depends on: legitimate traffic always names SRVFNC* or CLTFNC*, which is exactly the set the DR-1 allowlist fix is designed around (see PVF dispatch implementation playbook). The remaining payload elements are the handler's own parameters, passed through untouched.

Common_SendToClient — single-client UID targeting

Common/Functions/Common_SendToClient.sqf is the only helper that performs true unicast. It captures the machine id of the target before rewriting the payload, then rewrites the targeting slot to a persistent UID and uses publicVariableClient to deliver only to that machine.

Concern	Source	Detail
Inputs	Common_SendToClient.sqf:9-11	_pvf = _this; _func = _pvf select 1; _id = owner (_pvf select 0). Index 0 is the target unit/object; owner resolves it to that client's network id for publicVariableClient.
Targeting rewrite	:13	_pvf set [0, getPlayerUID (_pvf select 0)] — the live object reference is replaced with the player's persistent UID before transmission (the object would not be meaningful or might be objNull on the receiver).
Function rewrite	:14	_pvf set [1, Format["CLTFNC%1",_func]].
Remote path	:16-17	When !isHostedServer: Call Compile Format ["WFBE_PVF_%1 = _pvf; _id publicVariableClient 'WFBE_PVF_%1';", _func] — assigns the per-command channel variable and fires it only to _id.
Hosted path	:18-20	On a hosted (listen) server: _pvf Spawn WFBE_CL_FNC_HandlePVF runs the client dispatcher locally; then if (isMultiplayer) also re-broadcasts via publicVariableClient so remote clients still receive it. A pure single-player host skips the network fire.

Typical current-stable-shaped call sites pass leader X (or leader commanderTeam) as the index-0 target, e.g. Client/GUI/GUI_Menu_Command.sqf:336,344 ("SetTask" on current stable/B69/B74/naval-HVT; docs/source, Miksuu and perf still comment those sends), Client/Module/CoIn/coin_interface.sqf:264,738 ("Available"), and the headless-delegation hand-offs Server/AI/Commander/AI_Commander_Teams.sqf:642 and Server/FSM/server_side_patrols.sqf:141 ("HandleSpecial" to a specific HC unit).

Common_SendToClients — broadcast

Common/Functions/Common_SendToClients.sqf broadcasts the client PVF to every machine. It does no targeting rewrite — index 0 of the payload is left as-is (callers commonly pass nil, a side, or a UID that the handler filters on), and only the function name is rewritten.

Concern	Source	Detail
Inputs	Common_SendToClients.sqf:9-10	_pvf = _this; _func = _pvf select 1. No owner/UID capture.
Function rewrite	:12	_pvf set [1, Format["CLTFNC%1",_func]].
Remote path	:14-15	When !isHostedServer: WFBE_PVF_%1 = _pvf; publicVariable 'WFBE_PVF_%1' — un-targeted broadcast to all clients (and the server).
Hosted path	:16-18	On a hosted server: _pvf Spawn WFBE_CL_FNC_HandlePVF locally, then if (isMultiplayer) re-broadcasts via publicVariable for remote clients.

Note the "UID at index 0" pattern in several callers — e.g. Client/Functions/Client_FNC_Groups.sqf:161,206,244 ("HandleSpecial" group ops) and Client/GUI/GUI_Menu_Team.sqf:99 ("LocalizeMessage" FundsTransfer) pass getPlayerUID(...) as the head. Because SendToClients is a true broadcast, every client receives the message and the receiving handler discards it if the embedded UID is not its own. When genuine unicast is wanted, SendToClient is the cheaper choice; this distinction is also noted in Public variable channel index.

Common_SendToServer / Common_SendToServerOptimized — server-bound

Both server helpers rewrite index 0 to SRVFNC<Command> and differ only in the public-variable command used on the remote path.

Concern	Common_SendToServer.sqf	Common_SendToServerOptimized.sqf
Inputs	:9-10 _pvf = _this; _func = _pvf select 0	:9-10 identical
Function rewrite	:12 _pvf set [0, Format["SRVFNC%1",_func]]	:12 identical
Remote path	:14-15 WFBE_PVF_%1 = _pvf; publicVariable 'WFBE_PVF_%1'	:14-15 WFBE_PVF_%1 = _pvf; publicVariableServer 'WFBE_PVF_%1'
Hosted path	:16-18 _pvf Spawn WFBE_SE_FNC_HandlePVF (no re-fire)	:16-18 identical
Header note	:2 "Send a PVF to the server."	:2 "Send a PVF to the server ([>1.62] needed for publicVariableServer)."

The vanilla variant uses plain publicVariable, which broadcasts the channel variable to everyone (the server's PVEH then consumes it; other clients ignore an unregistered SRVFNC* channel). The optimized variant uses publicVariableServer, which sends the variable only to the server — strictly less traffic, but publicVariableServer requires Arma 2 OA build > 1.62, hence the version gate in the header comment and the build-time branch below. On the hosted path both just Spawn WFBE_SE_FNC_HandlePVF locally with no network re-fire (the server is this machine).

Server-bound calls are the request channel from clients, e.g. Client/Action/Action_GuerVbiedDetonate.sqf:26 ("RequestSpecial"), Client/Action/Action_RepairMHQ.sqf:35 ("RequestMHQRepair"), and Client/Module/Skill/Skill_SpecOps.sqf:52 ("RequestVehicleLock").

Build-Time Alias Selection

The three public aliases are assigned in Common/Init/Init_Common.sqf:157-159. Two of the three carry a WF_A2_Vanilla branch:

Line	Assignment	Behavior
Init_Common.sqf:157	WFBE_CO_FNC_SendToClient = if !(WF_A2_Vanilla) then {Compile preprocessFileLineNumbers "Common\Functions\Common_SendToClient.sqf"} else {{}};	On OA → real SendToClient. On A2 vanilla → compiled to an empty no-op {}. publicVariableClient-style single-client targeting is OA-only here.
Init_Common.sqf:158	WFBE_CO_FNC_SendToClients = Compile preprocessFileLineNumbers "Common\Functions\Common_SendToClients.sqf";	Always the broadcast helper — no branch (broadcast publicVariable works on both A2 and OA).
Init_Common.sqf:159	WFBE_CO_FNC_SendToServer = if (WF_A2_Vanilla) then {Compile preprocessFileLineNumbers "Common\Functions\Common_SendToServer.sqf"} else {Compile preprocessFileLineNumbers "Common\Functions\Common_SendToServerOptimized.sqf"};	On A2 vanilla → plain-publicVariable SendToServer. On OA → the publicVariableServer Optimized variant.

WF_A2_Vanilla is set in initJIPCompatible.sqf:95-98: it defaults to false and is flipped to true only inside an #ifdef VANILLA block, so the optimized OA path is the default build. The same flag gates other OA-only countermeasure helpers nearby (Init_Common.sqf:156,160), so the send-helper swap is one instance of a general "vanilla-safe vs OA-optimized" compile pattern rather than a one-off.

The Hosted-Server Short-Circuit

Every helper branches on isHostedServer, defined in initJIPCompatible.sqf:53:

isHostedServer = if (!isMultiplayer || (isServer && !isDedicated)) then {true} else {false};

So isHostedServer is true for both single-player and listen-server hosts (any machine that is the server but also runs a player). On those machines the send helpers skip the public-variable round-trip for the local consumer and Spawn the matching dispatcher directly — WFBE_CL_FNC_HandlePVF for client-bound, WFBE_SE_FNC_HandlePVF for server-bound. The client-bound helpers additionally guard the network re-fire with if (isMultiplayer) so that a true single-player host (where isMultiplayer is false) does no network I/O at all, while a listen server still reaches its remote clients. The server-bound helpers have no re-fire because there are no other servers to reach.

Continue Reading

• PVF dispatch implementation playbook — the receiver/dispatcher half (Server_HandlePVF / Client_HandlePVF, Call Compile, DR-1/DR-38 allowlist hardening).
• Public variable channel index — the registered WFBE_PVF_* command set and the direct (non-dispatched) channels.
• Networking and public variables — the broader transport/authority model these helpers sit inside.
• LocalizeMessage chat notification router reference — a concrete CLTFNC consumer reached through SendToClients.
• Server authority migration map — why transport direction is not authority, and the DR-55 sender-authentication lane.