Module component 

IComponent interface from the Open Multiplayer SDK in pure Rust.

The memory layout and vtable indices were derived from the public specification of the Open Multiplayer SDK (https://github.com/openmultiplayer/open.mp-sdk). No SDK code was copied — only signatures and vtable layouts were used as reference for this pure Rust reimplementation.

Platform support

Target	SA-MP	native Open Multiplayer
i686-unknown-linux-gnu	yes	yes (Itanium ABI)
i686-pc-windows-msvc	yes	yes (MSVC ABI)
i686-pc-windows-gnu	yes	no (incompatible ABI)

Multiple inheritance and vtables

IComponent : public IExtensible, public IUIDProvider results in two vtable pointers in the object. The offsets differ between Itanium (Linux GCC) and MSVC because the FlatHashMap (robin_hood::unordered_flat_map) has a different size on the two platforms — confirmed via disasm of omp-server.exe.

Offset  Field (Linux / GCC i686)
------  -----
 0      vtable*      (primary: IExtensible + IComponent)
 4..39  _misc_ext    (robin_hood::unordered_flat_map, 36 bytes)
40      uid_vtable*  (secondary: IUIDProvider)
44      uid          (u64 — plugin's own field)
52      plugin_ptr   (*mut () — plugin's own field)

Offset  Field (Windows / MSVC i686)
------  -----
 0      vtable*      (primary: IExtensible + IComponent)
 4..55  _misc_ext    (52 bytes: padding + robin_hood + trailing padding)
56      uid_vtable*  (secondary: IUIDProvider) — offset hardcoded by the server
60      _uid_pad     (4 bytes to align uid (u64) to 8 bytes)
64      uid          (u64 — plugin's own field)
72      plugin_ptr   (*mut () — plugin's own field)

Primary vtable

Itanium ABI — two destructor slots (D1 complete + D0 deleting):

[0]  getExtension
[1]  addExtension
[2]  removeExtension(ext*)
[3]  removeExtension(uid)
[4]  ~destructor D1 (complete object)
[5]  ~destructor D0 (deleting)
[6]  supportedVersion
[7]  componentName
[8]  componentType
[9]  componentVersion
[10] onLoad
[11] onInit
[12] onReady
[13] onFree
[14] provideConfiguration
[15] free
[16] reset
[17] getUID (the `IUIDProvider` override also lands in the primary vtable)

MSVC ABI — single destructor (scalar deleting) between IExtensible and IComponent:

[0]  getExtension
[1]  addExtension
[2]  removeExtension(uid)   <- MSVC emits an overload set in REVERSE
[3]  removeExtension(ext*)     declaration order
[4]  ~destructor (single scalar deleting — MSVC does not emit D0)
[5]  supportedVersion
[6]  componentName
[7]  componentType
[8]  componentVersion
[9]  onLoad
[10] onInit
[11] onReady
[12] onFree
[13] provideConfiguration
[14] free
[15] reset

The slots were confirmed by runtime + disasm of omp-server.exe (componentVersion calls at [edx+0x20] = slot 8; componentName at [eax+0x18] = slot 6).

Secondary vtable — IUIDProvider

Itanium ABI — a single slot, exactly like MSVC. IUIDProvider declares no virtual destructor, so its secondary vtable holds only the getUID thunk (confirmed in the official Timers.so and Pawn.so: the secondary vtable at offset-to-top -40 has one entry).

[0]  getUID

MSVC ABI — only getUID (IUIDProvider does not declare a virtual destructor):

[0]  getUID

Structs

IComponentList

IComponentList* — list of loaded components. Received in on_init; use to query other components.

IComponentVTable

Primary IComponent vtable for the MSVC ABI (Windows).

ICore

ICore* — opaque pointer to the Open Multiplayer server core. Received in on_load; use only for caching or future queries.

IEarlyConfig

IEarlyConfig* — configuration during initialization.

ILogger

ILogger* — server logging interface.

IUIDProviderVTable

Secondary IUIDProvider vtable for the MSVC ABI (Windows).

OmpComponent

Rust object with a layout compatible with Open Multiplayer’s IComponent*.

Functions

comp_component_type^⚠

Safety

comp_on_free^⚠

Safety

comp_on_init^⚠

Safety

comp_on_ready^⚠

Safety

comp_provide_configuration^⚠

Safety

comp_supported_version^⚠

Safety

ext_add_extension^⚠

Safety

ext_destructor^⚠

Scalar deleting destructor — no-op: cleanup is done via free(). No explicit parameter: this in ECX, no args on the stack (avoids ret 4).

ext_get_extension^⚠

Safety

ext_remove_extension_ptr^⚠

Safety

ext_remove_extension_uid^⚠

Safety

uid_get_uid^⚠

getUID() via the secondary IUIDProvider vtable (MSVC ABI).