LUMIERA.clone/src/common/interface.h

495 lines
20 KiB
C

/*
interface.h - Lumiera interface macros and structures
Copyright (C) Lumiera.org
2008, Christian Thaeter <ct@pipapo.org>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2 of
the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef LUMIERA_INTERFACE_H
#define LUMIERA_INTERFACE_H
#include "lib/luid.h"
#include "lib/ppmpl.h"
#include "lib/psplay.h"
/* TODO better doxygen formating */
/**
* @file
* Lumiera interface macros and structures.
*
* Instead just simple function/library bindings, Lumiera uses a system of
* versioned interfaces. This interfaces are C-binding compatible and thus
* can be used by any language which can bind to C. This interfaces are versioned
* to provide exceptional forward and backward compatibility for both, source and
* binary deployment of modules. This interfaces play a central role on the Lumiera
* architecture, other facilities, like serializing sessions and distributed computing
* will use them extensively.
*
* Overview
*
* Interfaces are used for two purposes in Lumiera:
* 1. The core uses them internally and exports its functionality though them.
* 2. Plugins (effects,...) extend Lumiera by providing interfaces
*
* We define some macros here which ease the declaration and definition of interfaces.
*
* Declaration of an interface happens in a header and has the form:
* LUMIERA_INTERFACE_DECLARE(name, version,
* LUMIERA_INTERFACE_SLOT(ret, name, params),
* ...
* )
* Any code which want to use this interface must then include its declaration.
*
* Basic definition of an interface is done by mapping functions to slots or giving
* inline definitions for slot functions:
* LUMIERA_INTERFACE_INSTANCE(iname, version, name, descriptor, acquire, release,
* LUMIERA_INTERFACE_MAP (slot, luid, function),
* LUMIERA_INTERFACE_INLINE (slot, luid, ret, params, {body}),
* ...
* )
*
* There are 2 ways to define collections of interfaces:
* LUMIERA_EXPORT(queryfunc,
* LUMIERA_INTERFACE_DEFINE(...),
* ...
* )
* to export interfaces from the core.
*
* LUMIERA_PLUGIN(descriptor, acquire, release, luid,
* LUMIERA_INTERFACE_DEFINE(...),
* ...
* )
* is used to export interfaces from a plugin.
*
* Naming and Versioning
* Interfaces have unique names and a major and minor version. The name and the major version
* is used to construct a C identifier for the interface, the minor version is implicit defined
* by the number of functions a interface. Interface instances are not versioned by the
* interface system, versioning these shall be defined somewhere else.
*
* Slot names are normal C identifiers, how these shall be versioned has to be defined somewhere
* else and is not subject of the interface system. Each function can has its own unique uuid.
*/
/*
Interface declaration macros
*/
/**
* Construct a type identifier for an interface
* @param name name of the interface
* @param version major version of this interface
*/
#define LUMIERA_INTERFACE_INAME(name, version) name##_##version
/**
* Construct a definition identifier for an interface
* @param iname name of the interface
* @param version major version of the interface
* @param dname name for the instance
* @return constructed identifier
*/
#define LUMIERA_INTERFACE_DNAME(iname, version, dname) PPMPL_CAT (LUMIERA_INTERFACE_INAME (iname, version), _##dname)
/**
* Construct a definition string r for an interface
* @param iname name of the interface
* @param version major version of the interface
* @param dname name for the instance
* @return constructed string
*/
#define LUMIERA_INTERFACE_DSTRING(iname, version, dname) PPMPL_STRINGIFY (LUMIERA_INTERFACE_DNAME (iname, version, dname))
/**
* Return a reference (pointer) to an interface implementation
* @param iname name of the interface
* @param version major version of the interface
* @param dname name for the instance
*/
#define LUMIERA_INTERFACE_REF(iname, version, dname) \
(LumieraInterface)&LUMIERA_INTERFACE_DNAME(iname, version, dname)
/**
* Construct the type of the interface
* @param name name of the interface
* @param version major version of this interface
*/
#define LUMIERA_INTERFACE_TYPE(name, version) struct LUMIERA_INTERFACE_INAME(name, version)
/**
* Construct a cast to the target interface type
* Used to cast a generic LumieraInterface to the real type
* @param name name of the interface
* @param version major version of this interface
*/
#define LUMIERA_INTERFACE_CAST(name, version) (LUMIERA_INTERFACE_TYPE(name, version)*)
/**
* Declare an interface.
* @param name name of the interface
* @param version major version of this interface declaration. 0 denotes a experimental interface,
* otherwise this shall be counting from 1 upwards for each new (incompatible) change of an interface.
* The older interface declarations may still be maintained in parallel (backwards compatibility!).
* @param ... Slot declarations for the functions provided by this interface @see LUMIERA_INTERFACE_SLOT
* The number of Slots in an interface defines its 'minor' version.
* New slots must be added at the end. The prototype and order of existing slots must not be changed.
* Slots may be renamed, for example a slot 'foo' can be renamed to 'foo_old' when a new 'foo' slot is
* added. Binary modules will then still use the 'foo_old' slot which was the 'foo' slot at their
* compile time while compiling modules from source will use the new 'foo' slot. This may be
* intentionally used to break compilation and force the update of modules to a new api.
*/
#define LUMIERA_INTERFACE_DECLARE(name, version, ...) \
LUMIERA_INTERFACE_TYPE(name, version) \
{ \
lumiera_interface interface_header_; \
PPMPL_FOREACH(_, __VA_ARGS__) \
}
/**
* Declare function slot inside an interface.
* @param ret return type of the function
* @param name name of this slot
* @param params parentized list of parameters for the function
*/
#define PPMPL_FOREACH_LUMIERA_INTERFACE_SLOT(ret, name, params) \
ret (*name) params; \
lumiera_uid name##_uid;
/*
Interface definition macros
*/
/**
* Define a interface instance.
* @param iname name of the interface to instance
* @param version major version of the interface to instance
* @param name name of the instance
* @param descriptor pointer to an interface instance which provides a description of this interface, might be NULL
* @param acquire a function which is called whenever this interface is opened for using, might be NULL
* @param release a function which is called whenever this interface is closed after use, might be NULL
* @param ... map functions to interface slots @see LUMIERA_INTERFACE_MAP
*/
#define LUMIERA_INTERFACE_INSTANCE(iname, version, name, descriptor, acquire, release, ...) \
PPMPL_FOREACH(_P1_, __VA_ARGS__) \
LUMIERA_INTERFACE_TYPE(iname, version) LUMIERA_INTERFACE_DNAME(iname, version, name) = \
{ \
{ \
#iname, \
version, \
#name, \
sizeof (LUMIERA_INTERFACE_TYPE(iname, version)), \
descriptor, \
acquire, \
release \
}, \
PPMPL_FOREACH(_P2_, __VA_ARGS__) \
}
/**
* Map a function to a interface slot
* @param slot name of the slot to be mapped
* @param luid unique identifier for this function, use the magic word LUIDGEN here and run the
* lumiera uuid generator tool (to be written) over the source file to generate luid's automatically
* @param function name of the function to be mapped on slot
*
* @note C++ requires that all mappings are in the same order than defined in the interface declaration,
* this would be good style for C too anyways
*/
#define PPMPL_FOREACH_P1_LUMIERA_INTERFACE_MAP(slot, luid, function)
#ifdef __cplusplus
#define PPMPL_FOREACH_P2_LUMIERA_INTERFACE_MAP(slot, luid, function) \
function, LUMIERA_UID_INITIALIZER (luid),
#else
#define PPMPL_FOREACH_P2_LUMIERA_INTERFACE_MAP(slot, luid, function) \
.slot = function, .slot##_uid = LUMIERA_UID_INITIALIZER (luid),
#endif
/**
* Map a inline defined function to a interface slot
* @param slot name of the slot to be mapped
* @param luid unique identifier for this function, use the magic word LUIDGEN here and run the
* lumiera uuid generator tool (to be written) over the source file to generate luid's automatically
* @param ret return type of the inline function
* @param params parentized list of parameters given to the function
* @param ... braced function body
*
* @note C++ requires that all mappings are in the same order than defined in the interface declaration,
* this would be good style for C too anyways
*/
#define PPMPL_FOREACH_P1_LUMIERA_INTERFACE_INLINE(slot, luid, ret, params, ...) \
static ret \
LUMIERA_INTERFACE_INLINE_NAME(slot) params \
__VA_ARGS__
#ifdef __cplusplus
#define PPMPL_FOREACH_P2_LUMIERA_INTERFACE_INLINE(slot, luid, ret, params, ...) \
LUMIERA_INTERFACE_INLINE_NAME(slot), LUMIERA_UID_INITIALIZER (luid),
#else
#define PPMPL_FOREACH_P2_LUMIERA_INTERFACE_INLINE(slot, luid, ret, params, ...) \
.slot = LUMIERA_INTERFACE_INLINE_NAME(slot), .slot##_uid = LUMIERA_UID_INITIALIZER (luid),
#endif
#define LUMIERA_INTERFACE_INLINE_NAME(slot) PPMPL_CAT(lumiera_##slot##_l, __LINE__)
#define PPMPL_FOREACH_L1_P1_LUMIERA_INTERFACE_DEFINE(iname, version, name, descriptor, acquire, release, ...) \
LUMIERA_INTERFACE_INSTANCE (iname, version, \
name, \
descriptor, \
acquire, \
release, \
__VA_ARGS__ \
);
#define PPMPL_FOREACH_L1_P2_LUMIERA_INTERFACE_DEFINE(iname, version, name, descriptor, acquire, release, ...) \
&LUMIERA_INTERFACE_DNAME(iname, version, name).interface_header_,
/**
* Generate interface container suitable for enumerating interfaces.
* This takes a list of interface definitions, instantiates them and places pointers to them
* into a zero terminated array which address is returned by a static function named 'lumiera_plugin_interfaces'.
* For interfaces generated by he core, the user is responsible to register these dynamically.
* When LUMIERA_PLUGIN is defined, things change and an additional 'lumieraorg__plugin' interface is generated.
* The plugin loader then uses this to register the provided interfaces automatically.
* @param ... list of LUMIERA_INTERFACE_DEFINE()/LUMIERA_INTERFACE_INLINE() for all interfaces this plugin provides.
*/
#define LUMIERA_EXPORT(...) \
PPMPL_FOREACH_L1(_P1_, __VA_ARGS__) \
static LumieraInterface* \
lumiera_plugin_interfaces (void) \
{ \
static LumieraInterface interfaces[] = \
{ \
PPMPL_FOREACH_L1(_P2_, __VA_ARGS__) \
NULL \
}; \
return interfaces; \
} \
LUMIERA_PLUGININTERFACE
/**
* Create a plugin interface when being compiled as plugin
*/
#ifdef LUMIERA_PLUGIN /* compile as plugin */
#define LUMIERA_PLUGIN_INTERFACEHANDLE static LUMIERA_INTERFACE_HANDLE(lumieraorg_interface, 0) lumiera_interface_handle
#define LUMIERA_PLUGIN_STORE_INTERFACEHANDLE(name) lumiera_interface_handle = LUMIERA_INTERFACE_CAST (lumieraorg_interface, 0) name
#define LUMIERA_PLUGININTERFACE \
LUMIERA_INTERFACE_INSTANCE (lumieraorg__plugin, 0, \
lumieraorg_plugin, \
NULL, \
NULL, \
NULL, \
LUMIERA_INTERFACE_MAP (plugin_interfaces, \
"\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", \
lumiera_plugin_interfaces) \
);
#define LUMIERA_INTERFACE_REGISTEREXPORTED
#define LUMIERA_INTERFACE_UNREGISTEREXPORTED
#define LUMIERA_INTERFACE_OPEN(interface, version, minminor, name) \
LUMIERA_INTERFACE_CAST(interface, version) lumiera_interface_handle->open (#interface, version, minminor, #name)
#define LUMIERA_INTERFACE_CLOSE(handle) \
lumiera_interface_handle->close (&(handle)->interface_header_)
#else /* compile as builtin */
#define LUMIERA_PLUGIN_INTERFACEHANDLE static LUMIERA_INTERFACE_HANDLE(lumieraorg_interface, 0) lumiera_interface_handle
#define LUMIERA_PLUGIN_STORE_INTERFACEHANDLE(name) lumiera_interface_handle = LUMIERA_INTERFACE_CAST (lumieraorg_interface, 0) name
#define LUMIERA_PLUGININTERFACE
/**
* Register all exported interfaces when not a plugin
* This is a no-op when LUMIERA_PLUGIN is defined, since plugins are automatically registered
*/
#define LUMIERA_INTERFACE_REGISTEREXPORTED \
lumiera_interfaceregistry_bulkregister_interfaces (lumiera_plugin_interfaces(), NULL)
/**
* Unregister all exported interfaces when not a plugin
* This is a no-op when LUMIERA_PLUGIN is defined, since plugins are automatically registered
*/
#define LUMIERA_INTERFACE_UNREGISTEREXPORTED \
lumiera_interfaceregistry_bulkremove_interfaces (lumiera_plugin_interfaces())
#define LUMIERA_INTERFACE_OPEN(interface, version, minminor, name) \
LUMIERA_INTERFACE_CAST(interface, version) lumiera_interface_open (#interface, version, minminor, #name)
#define LUMIERA_INTERFACE_CLOSE(handle) \
lumiera_interface_close (&(handle)->interface_header_)
#endif
/**
* create a handle for a interface (WIP)
*/
#define LUMIERA_INTERFACE_HANDLE(interface, version) \
LUMIERA_INTERFACE_TYPE(interface, version)*
typedef struct lumiera_interfaceslot_struct lumiera_interfaceslot;
typedef lumiera_interfaceslot* LumieraInterfaceslot;
typedef struct lumiera_interface_struct lumiera_interface;
typedef lumiera_interface* LumieraInterface;
/**
* This is just a placeholder for an entry in a interface table.
* It consists of one here generic, later correctly prototyped function pointer and
* a unique identifier which is associated with this function.
*/
struct lumiera_interfaceslot_struct
{
void (*func)(void);
lumiera_uid uid;
};
/**
* Header for an interface, just the absolute necessary metadata.
*/
struct lumiera_interface_struct
{
/** name of the interface (type) */
const char* interface;
/** major version, 0 means experimental */
unsigned version;
/** name of this instance */
const char* name;
/** size of the whole interface structure (minor version) */
size_t size;
/** metadata descriptor, itself a interface (or NULL) */
LumieraInterface descriptor;
/**
* Must be called before this interface is used.
* might be nested.
* @param self pointer to the interface to be acquired
* @param interfaces pointer to a 'interfaces' interface giving plugins access to
* opening and closing interfaces, this is already opened and if a plugin
* wants to use other interfaces it has to store this pointer
* @return pointer to the interface or NULL on error
*/
LumieraInterface (*acquire)(LumieraInterface self, LumieraInterface interfaces);
/**
* called when finished using this interface
* must match the acquire calls
* @param self pointer to the interface to be released
*/
void (*release)(LumieraInterface self);
#ifndef __cplusplus
/** placeholder array for the following function slots, C++ doesn't support flexible arrays */
lumiera_interfaceslot functions[];
#endif
};
/*
API to handle interfaces
*/
/**
* Open an interface by version and name.
* Looks up the requested interface, possibly loading it from a plugin.
* @param interface name of the interface definition
* @param version major version of the interface definition
* @param minminorversion required minor version (structure size)
* @param name name of the interface implementation
* @return the queried interface handle on success, else NULL
*/
LumieraInterface
lumiera_interface_open (const char* interface, unsigned version, size_t minminorversion, const char* name);
/**
* Close an interface after use.
* @param self interface to be closed
* consider 'self' to be invalidated after this call
*/
void
lumiera_interface_close (LumieraInterface self);
/**
* Runtime check for interface type and version
* @param self interface to check
* @param iname name of the interface
* @return version of the interface or ~0 (-1) if iname doesn't match the requested name
*/
unsigned
lumiera_interface_version (LumieraInterface self, const char* iname);
/**
* Define an interface for the above
*/
LUMIERA_INTERFACE_DECLARE (lumieraorg_interface, 0,
LUMIERA_INTERFACE_SLOT (LumieraInterface,
open,
(const char* interface, unsigned version, size_t minminorversion, const char* name)),
LUMIERA_INTERFACE_SLOT (void, close, (LumieraInterface self)),
LUMIERA_INTERFACE_SLOT (unsigned, version, (LumieraInterface self, const char* iname)),
);
/**
* registering implementations of the above interface
*/
void
lumiera_interface_init (void);
/**
* deregistering implementations of the above interface
*/
void
lumiera_interface_destroy (void);
/**
* Plugin interface
*/
LUMIERA_INTERFACE_DECLARE (lumieraorg__plugin, 0,
LUMIERA_INTERFACE_SLOT (LumieraInterface*, plugin_interfaces, (void)),
);
#endif /* LUMIERA_INTERFACE_H */
/*
// Local Variables:
// mode: C
// c-file-style: "gnu"
// indent-tabs-mode: nil
// End:
*/