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Diffstat (limited to 'lv2/lv2plug.in/ns/ext/state/state.h')
| -rw-r--r-- | lv2/lv2plug.in/ns/ext/state/state.h | 363 |
1 files changed, 0 insertions, 363 deletions
diff --git a/lv2/lv2plug.in/ns/ext/state/state.h b/lv2/lv2plug.in/ns/ext/state/state.h deleted file mode 100644 index f2a4afa..0000000 --- a/lv2/lv2plug.in/ns/ext/state/state.h +++ /dev/null @@ -1,363 +0,0 @@ -/* - Copyright 2010-2016 David Robillard <http://drobilla.net> - Copyright 2010 Leonard Ritter <paniq@paniq.org> - - Permission to use, copy, modify, and/or distribute this software for any - purpose with or without fee is hereby granted, provided that the above - copyright notice and this permission notice appear in all copies. - - THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES - WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF - MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR - ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES - WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN - ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF - OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. -*/ - -/** - @defgroup state State - - An interface for LV2 plugins to save and restore state, see - <http://lv2plug.in/ns/ext/state> for details. - - @{ -*/ - -#ifndef LV2_STATE_H -#define LV2_STATE_H - -#include <stddef.h> -#include <stdint.h> - -#include "lv2/lv2plug.in/ns/lv2core/lv2.h" - -#define LV2_STATE_URI "http://lv2plug.in/ns/ext/state" ///< http://lv2plug.in/ns/ext/state -#define LV2_STATE_PREFIX LV2_STATE_URI "#" ///< http://lv2plug.in/ns/ext/state# - -#define LV2_STATE__State LV2_STATE_PREFIX "State" ///< http://lv2plug.in/ns/ext/state#State -#define LV2_STATE__interface LV2_STATE_PREFIX "interface" ///< http://lv2plug.in/ns/ext/state#interface -#define LV2_STATE__loadDefaultState LV2_STATE_PREFIX "loadDefaultState" ///< http://lv2plug.in/ns/ext/state#loadDefaultState -#define LV2_STATE__makePath LV2_STATE_PREFIX "makePath" ///< http://lv2plug.in/ns/ext/state#makePath -#define LV2_STATE__mapPath LV2_STATE_PREFIX "mapPath" ///< http://lv2plug.in/ns/ext/state#mapPath -#define LV2_STATE__state LV2_STATE_PREFIX "state" ///< http://lv2plug.in/ns/ext/state#state -#define LV2_STATE__threadSafeRestore LV2_STATE_PREFIX "threadSafeRestore" ///< http://lv2plug.in/ns/ext/state#threadSafeRestore -#define LV2_STATE__StateChanged LV2_STATE_PREFIX "StateChanged" ///< http://lv2plug.in/ns/ext/state#StateChanged - -#ifdef __cplusplus -extern "C" { -#else -# include <stdbool.h> -#endif - -typedef void* LV2_State_Handle; ///< Opaque handle for state save/restore -typedef void* LV2_State_Map_Path_Handle; ///< Opaque handle for state:mapPath feature -typedef void* LV2_State_Make_Path_Handle; ///< Opaque handle for state:makePath feature - -/** - Flags describing value characteristics. - - These flags are used along with the value's type URI to determine how to - (de-)serialise the value data, or whether it is even possible to do so. -*/ -typedef enum { - /** - Plain Old Data. - - Values with this flag contain no pointers or references to other areas - of memory. It is safe to copy POD values with a simple memcpy and store - them for the duration of the process. A POD value is not necessarily - safe to trasmit between processes or machines (e.g. filenames are POD), - see LV2_STATE_IS_PORTABLE for details. - - Implementations MUST NOT attempt to copy or serialise a non-POD value if - they do not understand its type (and thus know how to correctly do so). - */ - LV2_STATE_IS_POD = 1, - - /** - Portable (architecture independent) data. - - Values with this flag are in a format that is usable on any - architecture. A portable value saved on one machine can be restored on - another machine regardless of architecture. The format of portable - values MUST NOT depend on architecture-specific properties like - endianness or alignment. Portable values MUST NOT contain filenames. - */ - LV2_STATE_IS_PORTABLE = 1 << 1, - - /** - Native data. - - This flag is used by the host to indicate that the saved data is only - going to be used locally in the currently running process (e.g. for - instance duplication or snapshots), so the plugin should use the most - efficient representation possible and not worry about serialisation - and portability. - */ - LV2_STATE_IS_NATIVE = 1 << 2 -} LV2_State_Flags; - -/** A status code for state functions. */ -typedef enum { - LV2_STATE_SUCCESS = 0, /**< Completed successfully. */ - LV2_STATE_ERR_UNKNOWN = 1, /**< Unknown error. */ - LV2_STATE_ERR_BAD_TYPE = 2, /**< Failed due to unsupported type. */ - LV2_STATE_ERR_BAD_FLAGS = 3, /**< Failed due to unsupported flags. */ - LV2_STATE_ERR_NO_FEATURE = 4, /**< Failed due to missing features. */ - LV2_STATE_ERR_NO_PROPERTY = 5, /**< Failed due to missing property. */ - LV2_STATE_ERR_NO_SPACE = 6 /**< Failed due to insufficient space. */ -} LV2_State_Status; - -/** - A host-provided function to store a property. - @param handle Must be the handle passed to LV2_State_Interface.save(). - @param key The key to store `value` under (URID). - @param value Pointer to the value to be stored. - @param size The size of `value` in bytes. - @param type The type of `value` (URID). - @param flags LV2_State_Flags for `value`. - @return 0 on success, otherwise a non-zero error code. - - The host passes a callback of this type to LV2_State_Interface.save(). This - callback is called repeatedly by the plugin to store all the properties that - describe its current state. - - DO NOT INVENT NONSENSE URI SCHEMES FOR THE KEY. Best is to use keys from - existing vocabularies. If nothing appropriate is available, use http URIs - that point to somewhere you can host documents so documentation can be made - resolvable (e.g. a child of the plugin or project URI). If this is not - possible, invent a URN scheme, e.g. urn:myproj:whatever. The plugin MUST - NOT pass an invalid URI key. - - The host MAY fail to store a property for whatever reason, but SHOULD - store any property that is LV2_STATE_IS_POD and LV2_STATE_IS_PORTABLE. - Implementations SHOULD use the types from the LV2 Atom extension - (http://lv2plug.in/ns/ext/atom) wherever possible. The plugin SHOULD - attempt to fall-back and avoid the error if possible. - - Note that `size` MUST be > 0, and `value` MUST point to a valid region of - memory `size` bytes long (this is required to make restore unambiguous). - - The plugin MUST NOT attempt to use this function outside of the - LV2_State_Interface.restore() context. -*/ -typedef LV2_State_Status (*LV2_State_Store_Function)( - LV2_State_Handle handle, - uint32_t key, - const void* value, - size_t size, - uint32_t type, - uint32_t flags); - -/** - A host-provided function to retrieve a property. - @param handle Must be the handle passed to LV2_State_Interface.restore(). - @param key The key of the property to retrieve (URID). - @param size (Output) If non-NULL, set to the size of the restored value. - @param type (Output) If non-NULL, set to the type of the restored value. - @param flags (Output) If non-NULL, set to the flags for the restored value. - @return A pointer to the restored value (object), or NULL if no value - has been stored under `key`. - - A callback of this type is passed by the host to - LV2_State_Interface.restore(). This callback is called repeatedly by the - plugin to retrieve any properties it requires to restore its state. - - The returned value MUST remain valid until LV2_State_Interface.restore() - returns. The plugin MUST NOT attempt to use this function, or any value - returned from it, outside of the LV2_State_Interface.restore() context. -*/ -typedef const void* (*LV2_State_Retrieve_Function)( - LV2_State_Handle handle, - uint32_t key, - size_t* size, - uint32_t* type, - uint32_t* flags); - -/** - LV2 Plugin State Interface. - - When the plugin's extension_data is called with argument - LV2_STATE__interface, the plugin MUST return an LV2_State_Interface - structure, which remains valid for the lifetime of the plugin. - - The host can use the contained function pointers to save and restore the - state of a plugin instance at any time, provided the threading restrictions - of the functions are met. - - Stored data is only guaranteed to be compatible between instances of plugins - with the same URI (i.e. if a change to a plugin would cause a fatal error - when restoring state saved by a previous version of that plugin, the plugin - URI MUST change just as it must when ports change incompatibly). Plugin - authors should consider this possibility, and always store sensible data - with meaningful types to avoid such problems in the future. -*/ -typedef struct _LV2_State_Interface { - /** - Save plugin state using a host-provided `store` callback. - - @param instance The instance handle of the plugin. - @param store The host-provided store callback. - @param handle An opaque pointer to host data which MUST be passed as the - handle parameter to `store` if it is called. - @param flags Flags describing desired properties of this save. These - flags may be used to determine the most appropriate values to store. - @param features Extensible parameter for passing any additional - features to be used for this save. - - The plugin is expected to store everything necessary to completely - restore its state later. Plugins SHOULD store simple POD data whenever - possible, and consider the possibility of state being restored much - later on a different machine. - - The `handle` pointer and `store` function MUST NOT be used - beyond the scope of save(). - - This function has its own special threading class: it may not be called - concurrently with any "Instantiation" function, but it may be called - concurrently with functions in any other class, unless the definition of - that class prohibits it (e.g. it may not be called concurrently with a - "Discovery" function, but it may be called concurrently with an "Audio" - function. The plugin is responsible for any locking or lock-free - techniques necessary to make this possible. - - Note that in the simple case where state is only modified by restore(), - there are no synchronization issues since save() is never called - concurrently with restore() (though run() may read it during a save). - - Plugins that dynamically modify state while running, however, must take - care to do so in such a way that a concurrent call to save() will save a - consistent representation of plugin state for a single instant in time. - */ - LV2_State_Status (*save)(LV2_Handle instance, - LV2_State_Store_Function store, - LV2_State_Handle handle, - uint32_t flags, - const LV2_Feature *const * features); - - /** - Restore plugin state using a host-provided `retrieve` callback. - - @param instance The instance handle of the plugin. - @param retrieve The host-provided retrieve callback. - @param handle An opaque pointer to host data which MUST be passed as the - handle parameter to `retrieve` if it is called. - @param flags Currently unused. - @param features Extensible parameter for passing any additional - features to be used for this restore. - - The plugin MAY assume a restored value was set by a previous call to - LV2_State_Interface.save() by a plugin with the same URI. - - The plugin MUST gracefully fall back to a default value when a value can - not be retrieved. This allows the host to reset the plugin state with - an empty map. - - The `handle` pointer and `store` function MUST NOT be used - beyond the scope of restore(). - - This function is in the "Instantiation" threading class as defined by - LV2. This means it MUST NOT be called concurrently with any other - function on the same plugin instance. - */ - LV2_State_Status (*restore)(LV2_Handle instance, - LV2_State_Retrieve_Function retrieve, - LV2_State_Handle handle, - uint32_t flags, - const LV2_Feature *const * features); -} LV2_State_Interface; - -/** - Feature data for state:mapPath (@ref LV2_STATE__mapPath). -*/ -typedef struct { - /** - Opaque host data. - */ - LV2_State_Map_Path_Handle handle; - - /** - Map an absolute path to an abstract path for use in plugin state. - @param handle MUST be the `handle` member of this struct. - @param absolute_path The absolute path of a file. - @return An abstract path suitable for use in plugin state. - - The plugin MUST use this function to map any paths that will be stored - in plugin state. The returned value is an abstract path which MAY not - be an actual file system path; absolute_path() MUST be used to map - it to an actual path in order to use the file. - - Plugins MUST NOT make any assumptions about abstract paths except that - they can be mapped back to the absolute path of the "same" file (though - not necessarily the same original path) using absolute_path(). - - This function may only be called within the context of - LV2_State_Interface methods. The caller is responsible for freeing the - returned value with free(). - */ - char* (*abstract_path)(LV2_State_Map_Path_Handle handle, - const char* absolute_path); - - /** - Map an abstract path from plugin state to an absolute path. - @param handle MUST be the `handle` member of this struct. - @param abstract_path An abstract path (e.g. a path from plugin state). - @return An absolute file system path. - - The plugin MUST use this function in order to actually open or otherwise - use any paths loaded from plugin state. - - This function may only be called within the context of - LV2_State_Interface methods. The caller is responsible for freeing the - returned value with free(). - */ - char* (*absolute_path)(LV2_State_Map_Path_Handle handle, - const char* abstract_path); -} LV2_State_Map_Path; - -/** - Feature data for state:makePath (@ref LV2_STATE__makePath). -*/ -typedef struct { - /** - Opaque host data. - */ - LV2_State_Make_Path_Handle handle; - - /** - Return a path the plugin may use to create a new file. - @param handle MUST be the `handle` member of this struct. - @param path The path of the new file within a namespace unique to this - plugin instance. - @return The absolute path to use for the new file. - - This function can be used by plugins to create files and directories, - either at state saving time (if this feature is passed to - LV2_State_Interface.save()) or any time (if this feature is passed to - LV2_Descriptor.instantiate()). - - The host MUST do whatever is necessary for the plugin to be able to - create a file at the returned path (e.g. using fopen), including - creating any leading directories. - - If this function is passed to LV2_Descriptor.instantiate(), it may be - called from any non-realtime context. If it is passed to - LV2_State_Interface.save(), it may only be called within the dynamic - scope of that function call. - - The caller is responsible for freeing the returned value with free(). - */ - char* (*path)(LV2_State_Make_Path_Handle handle, - const char* path); -} LV2_State_Make_Path; - -#ifdef __cplusplus -} /* extern "C" */ -#endif - -#endif /* LV2_STATE_H */ - -/** - @} -*/ |