diff options
Diffstat (limited to 'lv2')
| -rw-r--r-- | lv2/lv2plug.in/ns/ext/state/manifest.ttl | 2 | ||||
| -rw-r--r-- | lv2/lv2plug.in/ns/ext/state/state.h | 154 | ||||
| -rw-r--r-- | lv2/lv2plug.in/ns/ext/state/state.ttl | 201 |
3 files changed, 176 insertions, 181 deletions
diff --git a/lv2/lv2plug.in/ns/ext/state/manifest.ttl b/lv2/lv2plug.in/ns/ext/state/manifest.ttl index bff9ad5..84d1af0 100644 --- a/lv2/lv2plug.in/ns/ext/state/manifest.ttl +++ b/lv2/lv2plug.in/ns/ext/state/manifest.ttl @@ -4,5 +4,5 @@ <http://lv2plug.in/ns/ext/state> a lv2:Specification ; lv2:minorVersion 0 ; - lv2:microVersion 5 ; + lv2:microVersion 6 ; rdfs:seeAlso <state.ttl> . diff --git a/lv2/lv2plug.in/ns/ext/state/state.h b/lv2/lv2plug.in/ns/ext/state/state.h index aa272b7..cb00925 100644 --- a/lv2/lv2plug.in/ns/ext/state/state.h +++ b/lv2/lv2plug.in/ns/ext/state/state.h @@ -16,7 +16,7 @@ */ /** - @file + @file state.h C API for the LV2 State extension <http://lv2plug.in/ns/ext/state>. */ @@ -38,9 +38,9 @@ extern "C" { #define LV2_STATE__Interface LV2_STATE_URI "#Interface" #define LV2_STATE__State LV2_STATE_URI "#State" -#define LV2_STATE__state LV2_STATE_URI "#state" -#define LV2_STATE__mapPath LV2_STATE_URI "#mapPath" #define LV2_STATE__makePath LV2_STATE_URI "#makePath" +#define LV2_STATE__mapPath LV2_STATE_URI "#mapPath" +#define LV2_STATE__state LV2_STATE_URI "#state" typedef void* LV2_State_Handle; typedef void* LV2_State_Map_Path_Handle; @@ -58,10 +58,10 @@ typedef enum { Plain Old Data. Values with this flag contain no references to non-persistent or - non-global resources (e.g. pointers, handles, local paths, etc.). It is - safe to copy POD values with a simple memcpy and store them for use at - any time in the future on a machine with a compatible architecture - (e.g. the same endianness and alignment). + non-global resources (e.g. pointers, filenames, etc.). It is safe to + copy POD values with a simple memcpy and store them for use at any time + in the future on a machine with a compatible architecture (e.g. the same + endianness and alignment). 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). @@ -93,22 +93,21 @@ typedef enum { /** A host-provided function to store a property. @param handle Must be the handle passed to LV2_State_Interface.save(). - @param key The key (predicate) to store @c value under (URI mapped integer). - @param value Pointer to the value (object) to be stored. - @param size The size of the data at @c value in bytes. - @param type The type of @c value (URI). - @param flags LV2_State_Flags for @c value. + @param key The key to store @p value under (URID). + @param value Pointer to the value to be stored. + @param size The size of @p value in bytes. + @param type The type of @p value (URID). + @param flags LV2_State_Flags for @p 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 within - LV2_State_Interface.save() to store all the statements that describe its - current state. + 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 you can make - documentation resolvable. If this is not possible, invent a URN scheme, + that point to somewhere you can host documents so documentation can be made + resolvable. 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 @@ -116,8 +115,8 @@ typedef enum { Implementations SHOULD use the types from the LV2 Atom extension (http://lv2plug.in/ns/ext/atom) wherever possible. - Note that @c size MUST be > 0, and @c value MUST point to a valid region of - memory @c size bytes long (this is required to make restore unambiguous). + Note that @p size MUST be > 0, and @p value MUST point to a valid region of + memory @p 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. @@ -131,28 +130,21 @@ typedef int (*LV2_State_Store_Function)(LV2_State_Handle handle, /** A host-provided function to retrieve a property. - @param handle Must be the handle passed to - LV2_State_Interface.restore(). - @param key The key (predicate) of the property to retrieve (URI). + @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 LV2_State_Flags for - the returned 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 @c key. + has been stored under @p key. A callback of this type is passed by the host to - LV2_State_Interface.restore(). This callback is called repeatedly by the - plugin within LV2_State_Interface.restore() to retrieve any properties it - requires to restore its state. + 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. Returned values - MAY be copied for later use if necessary, assuming the plugin knows how to - do so correctly (e.g. the value is POD, or the plugin understands the type). + 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, @@ -161,49 +153,43 @@ typedef const void* (*LV2_State_Retrieve_Function)(LV2_State_Handle handle, uint32_t* flags); /** - State Extension Data. + State Interface (Extension Data). - When the plugin's extension_data is called with argument LV2_STATE_URI, - the plugin MUST return an LV2_State structure, which remains valid for the - lifetime of the plugin. + 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 - for the given function are met). - - The typical use case is to save the plugin's state when a project is saved, - and to restore the state when a project has been loaded. Other uses are - possible (e.g. cloning plugin instances or taking a snapshot of plugin - state). + 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 + 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 compatibility issues in the future. */ typedef struct _LV2_State_Interface { /** - Save plugin state using a host-provided @c store callback. + Save plugin state using a host-provided @p 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, e.g. the map or - file where the values are to be stored. If @c store is called, this MUST - be passed as its handle parameter. - @param flags Flags describing desires properties of this save. The - plugin SHOULD use these values to determine the most appropriate and/or - efficient serialisation, but is not required to do so. + @param handle An opaque pointer to host data which MUST be passed as the + handle parameter to @p 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 (possibly much later, in a different process, on - a completely different machine, etc.) + 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 @c handle pointer and @c store function MUST NOT be used + The @p handle pointer and @p store function MUST NOT be used beyond the scope of save(). This function has its own special threading class: it may not be called @@ -211,7 +197,7 @@ typedef struct _LV2_State_Interface { 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 + 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(), @@ -229,13 +215,12 @@ typedef struct _LV2_State_Interface { const LV2_Feature *const * features); /** - Restore plugin state using a host-provided @c retrieve callback. + Restore plugin state using a host-provided @p 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, e.g. the map or - file from which the values are to be restored. If @c retrieve is - called, this MUST be passed as its handle parameter. + @param handle An opaque pointer to host data which MUST be passed as the + handle parameter to @p retrieve if it is called. @param flags Currently unused. @param features Extensible parameter for passing any additional features to be used for this restore. @@ -244,10 +229,10 @@ typedef struct _LV2_State_Interface { 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. + not be retrieved. This allows the host to reset the plugin state with + an empty map. - The @c handle pointer and @c store function MUST NOT be used + The @p handle pointer and @p store function MUST NOT be used beyond the scope of restore(). This function is in the "Instantiation" threading class as defined by @@ -263,7 +248,7 @@ typedef struct _LV2_State_Interface { } LV2_State_Interface; /** - Feature data for state:mapPath (LV2_STATE_MAP_PATH_URI). + Feature data for state:mapPath (LV2_STATE__mapPath). */ typedef struct { @@ -274,41 +259,38 @@ typedef struct { /** Map an absolute path to an abstract path for use in plugin state. - @param handle MUST be the @a handle member of this struct. + @param handle MUST be the @p 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 files in plugin state. The returned value is an abstract path which - MAY not be an actual file system path; @ref absolute_path MUST be used - to map it to an actual path in order to use the file. + in plugin state. The returned value is an abstract path which MAY not + be an actual file system path; @ref absolute_path() MUST be used to map + it to an actual path in order to use the file. - Hosts MAY map paths in any way (e.g. by creating symbolic links within - the plugin's state directory or storing a list of referenced files - elsewhere). Plugins MUST NOT make any assumptions about abstract paths - except that they can be mapped back to an absolute path using @ref - absolute_path. + 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 @ref absolute_path(). This function may only be called within the context of - LV2_State_Interface.save() or LV2_State_Interface.restore(). The caller - is responsible for freeing the returned value. + 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 @a handle member of this struct. + @param handle MUST be the @p handle member of this struct. @param abstract_path An abstract path (e.g. a path from plugin state). @return An absolute file system path. - Since abstract paths are not necessarily actual file paths (or at least - not necessarily absolute paths), this function MUST be used in order to - actually open or otherwise use the file referred to by an abstract 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.save() or LV2_State_Interface.restore(). The caller - is responsible for freeing the returned value. + 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); @@ -327,9 +309,9 @@ typedef struct { /** Return a path the plugin may use to create a new file. - @param handle MUST be the @a handle member of this struct. - @param path The path of the new file relative to a namespace unique - to this plugin instance. + @param handle MUST be the @p 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, @@ -337,7 +319,7 @@ typedef struct { 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 + 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. diff --git a/lv2/lv2plug.in/ns/ext/state/state.ttl b/lv2/lv2plug.in/ns/ext/state/state.ttl index 4b86eb6..5b4610f 100644 --- a/lv2/lv2plug.in/ns/ext/state/state.ttl +++ b/lv2/lv2plug.in/ns/ext/state/state.ttl @@ -35,8 +35,8 @@ doap:shortdesc "An interface for LV2 plugins to save and restore state." ; doap:license <http://opensource.org/licenses/isc> ; doap:release [ - doap:revision "0.5" ; - doap:created "2012-01-29" ; + doap:revision "0.6" ; + doap:created "2012-03-03" ; dcs:blame <http://drobilla.net/drobilla#me> ] ; doap:developer [ @@ -44,71 +44,86 @@ foaf:name "Leonard Ritter" ; foaf:homepage <http://paniq.org> ] ; - doap:maintainer [ - a foaf:Person ; - foaf:name "David Robillard" ; - foaf:homepage <http://drobilla.net/> ; - rdfs:seeAlso <http://drobilla.net/drobilla.rdf> - ] ; + doap:maintainer <http://drobilla.net/drobilla#me> ; lv2:documentation """ -<p>This extension provides a simple mechanism for plugins to save and restore -state across instances, allowing hosts to save and restore a plugin instance's -state at any time. The goal is for an instance's state to be + +<p>This extension defines a simple mechanism which allows hosts to save and +restore a plugin instance's state. The goal is for an instance's state to be <em>completely</em> described by port values (as with all LV2 plugins) and a -dictionary.</p> +simple dictionary.</p> -<p>The <q>state</q> described by this extension is conceptually a simple -key:value dictionary, where keys are URIDs (URIs mapped to integers) and values -are type-tagged blobs of any type. A single key:value pair is called a -<q>property</q>. To implement state, the plugin provides a state:Interface to -the host. To save or restore, the host calls LV2_State_Interface::save() or -LV2_State_Interface::restore(), passing a callback to be used for handling a -single property. The host is free to implement property storage and retrieval -in any way.</p> +<p>The <q>state</q> defined here is conceptually a key:value dictionary, with +URI keys and values of any type. For performance reasons the key and value +type are actually a <q>URID</q>, a URI mapped to an integer. A single +key:value pair is called a <q>property</q>.</p> <p>This state model is simple yet has many benefits:</p> <ul> - <li>URID keys provide both fast performance and RDF compatibility.</li> - <li>Fully extensible, no limitations on keys or value types.</li> - <li>Easy to serialise in many formats (e.g. any RDF syntax, plain - text, JSON, XML, key:value databases, SQL, s-expressions, etc.).</li> - <li>Elegantly described in Turtle, which is useful for describing presets - or default state in LV2 data files (the predicate state:state is provided - for this purpose).</li> + <li>Both fast and extensible thanks to URID keys.</li> + <li>No limitations on possible value types.</li> + <li>Easy to serialise in almost any format.</li> + <li>Easy to store in a typical <q>map</q> or <q>dictionary</q> data + structure.</li> + <li>Elegantly described in Turtle, so state can be described in LV2 data + files (including presets).</li> <li>Does not impose any file formats, data structures, or file system requirements.</li> <li>Suitable for portable persistent state as well as fast in-memory snapshots.</li> - <li>Easily stored in a typical <q>map</q> or <q>dictionary</q> data - structure.</li> - <li>Keys may be defined by extensions and used by several plugins, - making state meaningful enabling dynamic state control.</li> + <li>Keys <em>may</em> be well-defined and used meaningfully across several + implementations.</li> + <li>State <em>may</em> be dynamic, but plugins are not required to have a + dynamic dictionary data structure available.</li> </ul> -<p>Implementations or further extensions which work with plugin state -(including dynamic plugin control) SHOULD work entirely within this model. -That is, <strong>do not complicate the state model</strong>. <em>All</em> -information required to express an instance's state at any given time can, and -should, be expressed within this model.</p> +<p>To implement state, the plugin provides a state:Interface to the host. To +save or restore, the host calls LV2_State_Interface::save() or +LV2_State_Interface::restore(), passing a callback to be used for handling a +single property. The host is free to implement property storage and retrieval +in any way.</p> + +<p>Since value types are defined by URI, any type is possible. However, a set +of standard types is defined by the <a href="http://lv2plug.in/ns/ext/atom">LV2 +Atom</a> extension. Use of these types is recommended. Hosts MUST implement +at least <a href="http://lv2plug.in/ns/ext/atom#String">atom:String</a>, which +is simply a C string.</p> + +<h3>Referring to Files</h3> + +<p>Plugins may need to refer to existing files (e.g. loaded samples) in their +state. This is done by storing the file's path as a property just like any +other value. However, there are some rules which MUST be followed when storing +paths, see <a href="#mapPath">state:mapPath</a> for details. Plugins MUST use +the type <a href="http://lv2plug.in/ns/ext/atom#Path">atom:Path</a> for all +paths in their state.</p> + +<p>Plugins are strongly encouraged to avoid creating files, instead storing all +state as properties. However, occasionally the ability to create files is +necessary. To make this possible, the host can provide the feature <a +href="#makePath">state:makePath</a> which allocates paths for plugin-created +files. Plugins MUST NOT create files in any other locations.</p> <h3>Plugin Code Example</h3> <pre class="c-code"> -#define NS_EG "http://example.org/" -#define NS_ATOM "http://lv2plug.in/ns/ext/atom#" + +/* Namespace for this plugin's keys. This SHOULD be something that could be + published as a document, even if that document does not exist right now. +*/ +#define NS_MY "http://example.org/myplugin/schema#" LV2_Handle my_instantiate(...) { MyPlugin* plugin = ...; - plugin->uris.atom_String = map_uri(NS_ATOM "String"); - plugin->uris.eg_greeting = map_uri(NS_EG "greeting"); - plugin->state.greeting = strdup("Hello"); + plugin->uris.atom_String = map_uri(LV2_ATOM__String); + plugin->uris.my_greeting = map_uri(NS_MY "greeting"); + plugin->state.greeting = strdup("Hello"); // Default value return plugin; } void my_save(LV2_Handle instance, LV2_State_Store_Function store, - void* handle, + LV2_State_Handle handle, uint32_t flags, const LV2_Feature *const * features) { @@ -116,16 +131,16 @@ void my_save(LV2_Handle instance, const char* greeting = plugin->state.greeting; store(handle, - plugin->uris.eg_greeting, + plugin->uris.my_greeting, greeting, - strlen(greeting) + 1, + strlen(greeting) + 1, // Careful! Need space for terminator plugin->uris.atom_String, LV2_STATE_IS_POD | LV2_STATE_IS_PORTABLE); } void my_restore(LV2_Handle instance, LV2_State_Retrieve_Function retrieve, - void* handle, + LV2_State_Handle handle, uint32_t flags, const LV2_Feature *const * features) { @@ -135,7 +150,7 @@ void my_restore(LV2_Handle instance, uint32_t type; uint32_t flags; const char* greeting = retrieve( - handle, plugin->uris.eg_greeting, &size, &type, &flags); + handle, plugin->uris.my_greeting, &size, &type, &flags); if (greeting) { free(plugin->state->greeting); @@ -157,20 +172,19 @@ const void* my_extension_data(const char* uri) <h3>Host Code Example</h3> <pre class="c-code"> -int store_callback(void* handle, - uint32_t key, - const void* value, - size_t size, - uint32_t type, - uint32_t flags) +int store_callback(LV2_State_Handle handle, + uint32_t key, + const void* value, + size_t size, + uint32_t type, + uint32_t flags) { if ((flags & LV2_STATE_IS_POD)) { /* We only care about POD since we're keeping state in memory only. - If this was for disk or network storage/transmission, - LV2_STATE_IS_PORTABLE would have to be checked as well. + For disk or network use, LV2_STATE_IS_PORTABLE must also be checked. */ Map* state_map = (Map*)handle; - state_map->insert(key, Value(copy(value), size, type, pod)); + state_map->insert(key, Value(copy(value), size, type)); return 0; } else { return 1; /* Non-POD events are unsupported. */ @@ -179,7 +193,7 @@ int store_callback(void* handle, Map get_plugin_state(LV2_Handle instance) { - LV2_State* state = instance.extension_data("http://lv2plug.in/ns/ext/state"); + LV2_State* state = instance.extension_data(LV2_STATE__Interface); Map state_map; /** Request a fast/native/POD save, since we're just copying in memory */ state.save(instance, store_callback, &state_map, @@ -188,22 +202,30 @@ Map get_plugin_state(LV2_Handle instance) } </pre> -<h3>Referring to Existing Files</h3> +<h3>Extensions to this Specification</h3> -<p>Plugins may need to refer to files (e.g. loaded samples) in their state. -This is done by storing the file's path as a property just like any other -value. However, there are some rules which MUST be followed when storing -paths, see <a href="#mapPath">state:mapPath</a> for details. Plugins MUST -use the type <a href="http://lv2plug.in/ns/ext/atom#Path">atom:Path</a> -for all paths in their state.</p> +<p>It is likely that other interfaces for working with plugin state will be +developed as needed. This is encouraged, however everything SHOULD work within +the state <em>model</em> defined here. That is, <strong>do not complicate the +state model</strong>. Implementations can assume the following:</p> -<h3>Creating New Files or Directories</h3> +<ul> +<li>The current port values and state dictionary completely describe a plugin +instance, at least well enough that saving and restoring will yield an +<q>identical</q> instance from the user's perspective.</li> +<li>Hosts are not expected to save and/or restore any other attributes of a +plugin instance.</li> +</ul> -<p>Implementations are strongly encouraged to avoid the use of files and simply -store all state as properties whenever possible. However, occasionally the -ability to create files is necessary. The feature <a -href="#newPath">state:newPath</a> makes this possible, if it is provided by the -host.</p> +<p>The recommended way to add new functionality that may affect state is to +simply define it in terms of properties. For example, instead of defining a +new set of commands, define properties whose values can be set appropriately. +This provides persistence <q>for free</q>, since rather than having to define a +set of commands <em>and</em> a set of properties for storing their effects, +only the properties need to be defined.</p> + +<p>This <q>property principle</q> is summed up in the phrase: <q>Don't +stop; set playing to false</q>.</p> """ . state:Interface @@ -213,8 +235,8 @@ state:Interface <p>A structure (LV2_State_Interface) which contains functions to be called by the host to save and restore state. In order to support this extension, the plugin must return a valid LV2_State_Interface from -LV2_Descriptor::extension_data() when it is called with -LV2_STATE_INTERFACE_URI.</p> +LV2_Descriptor::extension_data() when it is called with URI +LV2_STATE__Interface.</p> <p>The plugin data file should describe this like so:</p> <pre class="turtle-code"> @@ -230,26 +252,20 @@ state:State a rdfs:Class ; rdfs:label "Plugin Instance State" ; lv2:documentation """ -<p>This class is used to express a plugin instance's state in RDF. The -key/value properties of the instance form the predicate/object (respectively) -of triples with a state:State as the subject (see <a -href="#state">state:state</a> for an example). This may be used wherever it is -useful to express a plugin instance's state in RDF (e.g. for serialisation, -storing in a model, or transmitting over a network). Note that this class is -provided because it may be useful for hosts, plugins, or extensions that work -with instance state, but its use is not required to support the LV2 State -extension.</p> +<p>A state dictionary. This type should be used wherever instance state is +described in RDF, or any other context that uses type URIs. The properties of +a resource with this type correspond directly to the properties of the state +dictionary (except the property that states it has this type).</p> """ . state:state a rdf:Property ; + rdfs:label "State" ; rdfs:range state:State ; lv2:documentation """ -<p>Predicate to relate a plugin instance to its State. This may be used -wherever the state of a particular plugin instance needs to be represented. -Note that the domain of this property is unspecified, since LV2 does not define -any RDF class for plugin instance. This predicate may be used wherever it makes -sense to do so, e.g.:</p> +<p>The state of this plugin instance, or similar resource. This property may +be used anywhere a state needs to be described, for example:</p> + <pre class="turtle-code"> @prefix eg: <http://example.org/> . @@ -260,23 +276,20 @@ sense to do so, e.g.:</p> eg:favourite-number 2 ] . </pre> -<p>Note that this property is provided because it may be useful for hosts, -plugins, or extensions that work with instance state, but its use is not -required to support this extension.</p> """ . state:mapPath a lv2:Feature ; - rdfs:label "Support for storing paths in files" ; + rdfs:label "Support for storing paths in state" ; lv2:documentation """ <p>This feature maps absolute paths to/from <q>abstract paths</q> which are stored in state. To support this feature a host must pass an LV2_Feature with -URI LV2_STATE_MAP_PATH_URI and data pointed to an LV2_State_Map_Path to the +URI LV2_STATE__mapPath and data pointed to an LV2_State_Map_Path to the plugin's LV2_State_Interface methods.</p> -<p>The plugin MUST map <em>all</em> paths stored in its state (including in any -files in its state). This is necessary to enable host to handle file system -references correctly, e.g. for distribution or archival.</p> +<p>The plugin MUST map <em>all</em> paths stored in its state (including those +inside any files in its state). This is necessary to enable host to handle +file system references correctly, e.g. for distribution or archival.</p> <p>For example, a plugin may write a path to a state file like so:</p> @@ -308,7 +321,7 @@ state:makePath lv2:documentation """ <p>This feature allows plugins to create new files and/or directories. To support this feature the host passes an LV2_Feature with URI -LV2_STATE_MAKE_PATH_URI and data pointed to an LV2_State_Make_Path to the +LV2_STATE__makePath and data pointed to an LV2_State_Make_Path to the plugin. The host may make this feature available only during save by passing it to LV2_State_Interface::save(), or available any time by passing it to LV2_Descriptor::instantiate(). If passed to LV2_State_Interface::save(), the |