3 * ================================================================
5 * Copyright (C) 2004-2007 AlliedModders LLC. All rights reserved.
6 * ================================================================
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License,
10 * version 3.0, as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 * As a special exception, AlliedModders LLC gives you permission to
21 * link the code of this program (as well as its derivative works) to
22 * "Half-Life 2," the "Source Engine," the "SourcePawn JIT," and any
23 * Game MODs that run on software by the Valve Corporation. You must
24 * obey the GNU General Public License in all respects for all other
25 * code used. Additionally, AlliedModders LLC grants this exception
26 * to all derivative works. AlliedModders LLC defines further
27 * exceptions, found in LICENSE.txt (as of this writing, version
28 * JULY-31-2007), or <http://www.sourcemod.net/license.php>.
33 #ifndef _INCLUDE_SOURCEMOD_HANDLESYSTEM_INTERFACE_H_
34 #define _INCLUDE_SOURCEMOD_HANDLESYSTEM_INTERFACE_H_
38 * @brief Defines the interface for creating, reading, and removing Handles.
40 * The Handle system abstracts generic pointers into typed objects represented by
41 * 32bit codes. This is extremely useful for verifying data integrity and cross-platform
42 * support in SourcePawn scripts. When a Plugin unloads, all its Handles are freed, ensuring
43 * that no memory leaks are present, They have reference counts and thus can be duplicated,
44 * or cloned, and are safe to pass between Plugins even if one is unloaded.
46 * Handles are created with a given type (custom types may be created). They can have
47 * per-Identity permissions for deletion, reading, and cloning. They also support generic
48 * operations. For example, deleting a Handle will call that type's destructor on the generic
49 * pointer, making cleanup easier for users and eliminating memory leaks.
52 #include <IShareSys.h>
53 #include <sp_vm_types.h>
55 #define SMINTERFACE_HANDLESYSTEM_NAME "IHandleSys"
56 #define SMINTERFACE_HANDLESYSTEM_VERSION 2
58 /** Specifies no Identity */
59 #define DEFAULT_IDENTITY NULL
60 /** Specifies no Type. This is invalid for everything but reading a Handle. */
61 #define NO_HANDLE_TYPE 0
62 /** Specifies an invalid/NULL Handle */
68 * @brief Represents a Handle Type ID.
70 typedef unsigned int HandleType_t;
73 * @brief Represents a Handle ID.
75 typedef unsigned int Handle_t;
79 * About type checking:
80 * Types can be inherited - a Parent type ("Supertype") can have child types.
81 * When accessing handles, type checking is done. This table shows how this is resolved:
83 * HANDLE CHECK -> RESULT
85 * Parent Parent Success
87 * Child Parent Success
92 * @brief Lists the possible handle error codes.
96 HandleError_None = 0, /**< No error */
97 HandleError_Changed, /**< The handle has been freed and reassigned */
98 HandleError_Type, /**< The handle has a different type registered */
99 HandleError_Freed, /**< The handle has been freed */
100 HandleError_Index, /**< generic internal indexing error */
101 HandleError_Access, /**< No access permitted to free this handle */
102 HandleError_Limit, /**< The limited number of handles has been reached */
103 HandleError_Identity, /**< The identity token was not usable */
104 HandleError_Owner, /**< Owners do not match for this operation */
105 HandleError_Version, /**< Unrecognized security structure version */
106 HandleError_Parameter, /**< An invalid parameter was passed */
107 HandleError_NoInherit, /**< This type cannot be inherited */
111 * @brief Lists access rights specific to a type.
113 enum HTypeAccessRight
115 HTypeAccess_Create = 0, /**< Handles of this type can be created (DEFAULT=false) */
116 HTypeAccess_Inherit, /**< Sub-types can inherit this type (DEFAULT=false) */
118 HTypeAccess_TOTAL, /**< Total number of type access rights */
122 * @brief Lists access rights specific to a Handle.
124 * These rights are exclusive. For example, you do not need "read" access to delete or clone.
126 enum HandleAccessRight
128 HandleAccess_Read, /**< Can be read (DEFAULT=ident only) */
129 HandleAccess_Delete, /**< Can be deleted (DEFAULT=owner only) */
130 HandleAccess_Clone, /**< Can be cloned (DEFAULT=any) */
132 HandleAccess_TOTAL, /**< Total number of access rights */
135 /** Access is restricted to the identity */
136 #define HANDLE_RESTRICT_IDENTITY (1<<0)
137 /** Access is restricted to the owner */
138 #define HANDLE_RESTRICT_OWNER (1<<1)
141 * @brief This is used to define per-type access rights.
148 hsVersion = SMINTERFACE_HANDLESYSTEM_VERSION;
150 unsigned int hsVersion; /**< Handle API version */
151 IdentityToken_t *ident; /**< Identity owning this type */
152 bool access[HTypeAccess_TOTAL]; /**< Access array */
156 * @brief This is used to define per-Handle access rights.
163 hsVersion = SMINTERFACE_HANDLESYSTEM_VERSION;
165 unsigned int hsVersion; /**< Handle API version */
166 unsigned int access[HandleAccess_TOTAL]; /**< Access array */
170 * @brief This pair of tokens is used for identification.
172 struct HandleSecurity
177 HandleSecurity(IdentityToken_t *owner, IdentityToken_t *identity)
178 : pOwner(owner), pIdentity(identity)
181 IdentityToken_t *pOwner; /**< Owner of the Handle */
182 IdentityToken_t *pIdentity; /**< Owner of the Type */
186 * @brief Hooks type-specific Handle operations.
188 class IHandleTypeDispatch
191 /** Returns the Handle API version */
192 virtual unsigned int GetDispatchVersion()
194 return SMINTERFACE_HANDLESYSTEM_VERSION;
198 * @brief Called when destroying a handle. Must be implemented.
200 virtual void OnHandleDestroy(HandleType_t type, void *object) =0;
204 * @brief Provides functions for managing Handles.
206 class IHandleSys : public SMInterface
209 virtual unsigned int GetInterfaceVersion()
211 return SMINTERFACE_HANDLESYSTEM_VERSION;
213 virtual const char *GetInterfaceName()
215 return SMINTERFACE_HANDLESYSTEM_NAME;
219 * @brief Creates a new Handle type.
220 * NOTE: Currently, a child type may not have its own children.
221 * NOTE: Handle names must be unique if not private.
223 * @param name Name of handle type (NULL or "" to be anonymous)
224 * @param dispatch Pointer to a valid IHandleTypeDispatch object.
225 * @param parent Parent handle to inherit from, 0 for none.
226 * @param typeAccess Pointer to a TypeAccess object, NULL to use default
227 * or inherited permissions. Pointer can be temporary.
228 * @param hndlAccess Pointer to a HandleAccess object to define default
229 * default permissions on each Handle. NULL to use default
231 * @param ident Security token for any permissions. If typeAccess is NULL, this
232 * becomes the owning identity.
233 * @param err Optional pointer to store an error code.
234 * @return A new HandleType_t unique ID, or 0 on failure.
236 virtual HandleType_t CreateType(const char *name,
237 IHandleTypeDispatch *dispatch,
239 const TypeAccess *typeAccess,
240 const HandleAccess *hndlAccess,
241 IdentityToken_t *ident,
242 HandleError *err) =0;
245 * @brief Removes a handle type.
246 * NOTE: This removes all child types.
248 * @param type Type chain to remove.
249 * @param ident Identity token. Removal fails if the token does not match.
250 * @return True on success, false on failure.
252 virtual bool RemoveType(HandleType_t type, IdentityToken_t *ident) =0;
255 * @brief Finds a handle type by name.
257 * @param name Name of handle type to find (anonymous not allowed).
258 * @param type Address to store found handle in (if not found, undefined).
259 * @return True if found, false otherwise.
261 virtual bool FindHandleType(const char *name, HandleType_t *type) =0;
264 * @brief Creates a new handle.
266 * @param type Type to use on the handle.
267 * @param object Object to bind to the handle.
268 * @param owner Owner of the new Handle (may be NULL).
269 * @param ident Identity for type access if needed (may be NULL).
270 * @param err Optional pointer to store an error code.
271 * @return A new Handle_t, or 0 on failure.
273 virtual Handle_t CreateHandle(HandleType_t type,
275 IdentityToken_t *owner,
276 IdentityToken_t *ident,
277 HandleError *err) =0;
280 * @brief Frees the memory associated with a handle and calls any destructors.
281 * NOTE: This function will decrement the internal reference counter. It will
282 * only perform any further action if the counter hits 0.
284 * @param handle Handle_t identifier to destroy.
285 * @param pSecurity Security information struct (may be NULL).
286 * @return A HandleError error code.
288 virtual HandleError FreeHandle(Handle_t handle, const HandleSecurity *pSecurity) =0;
291 * @brief Clones a handle by adding to its internal reference count. Its data,
292 * type, and security permissions remain the same.
294 * @param handle Handle to duplicate. Any non-free handle target is valid.
295 * @param newhandle Stores the duplicated handle in the pointer (must not be NULL).
296 * @param newOwner New owner of cloned handle.
297 * @param pSecurity Security information struct (may be NULL).
298 * @return A HandleError error code.
300 virtual HandleError CloneHandle(Handle_t handle,
302 IdentityToken_t *newOwner,
303 const HandleSecurity *pSecurity) =0;
306 * @brief Retrieves the contents of a handle.
308 * @param handle Handle_t from which to retrieve contents.
309 * @param type Expected type to read as. 0 ignores typing rules.
310 * @param pSecurity Security information struct (may be NULL).
311 * @param object Optional address to store object in.
312 * @return HandleError error code.
314 virtual HandleError ReadHandle(Handle_t handle,
316 const HandleSecurity *pSecurity,
320 * @brief Sets access permissions on one or more structures.
322 * @param pTypeAccess Optional TypeAccess buffer to initialize with the default values.
323 * @param pHandleAccess Optional HandleAccess buffer to initialize with the default values.
324 * @return True on success, false if version is unsupported.
326 virtual bool InitAccessDefaults(TypeAccess *pTypeAccess, HandleAccess *pHandleAccess) =0;
329 * @brief Creates a new handle.
331 * @param type Type to use on the handle.
332 * @param object Object to bind to the handle.
333 * @param pSec Security pointer; pOwner is written as the owner,
334 * pIdent is used as the parent identity for authorization.
335 * @param pAccess Access right descriptor for the Handle; NULL for type defaults.
336 * @param err Optional pointer to store an error code.
337 * @return A new Handle_t, or 0 on failure.
339 virtual Handle_t CreateHandleEx(HandleType_t type,
341 const HandleSecurity *pSec,
342 const HandleAccess *pAccess,
343 HandleError *err) =0;
347 #endif //_INCLUDE_SOURCEMOD_HANDLESYSTEM_INTERFACE_H_
