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l---------lv2/lv2plug.in/ns/ext/state/ext.pc.in1
-rw-r--r--lv2/lv2plug.in/ns/ext/state/manifest.ttl8
-rw-r--r--lv2/lv2plug.in/ns/ext/state/state.h359
-rw-r--r--lv2/lv2plug.in/ns/ext/state/state.ttl359
l---------lv2/lv2plug.in/ns/ext/state/waf1
l---------lv2/lv2plug.in/ns/ext/state/wscript1
6 files changed, 729 insertions, 0 deletions
diff --git a/lv2/lv2plug.in/ns/ext/state/ext.pc.in b/lv2/lv2plug.in/ns/ext/state/ext.pc.in
new file mode 120000
index 0000000..03dd044
--- /dev/null
+++ b/lv2/lv2plug.in/ns/ext/state/ext.pc.in
@@ -0,0 +1 @@
+../../../../../ext.pc.in \ No newline at end of file
diff --git a/lv2/lv2plug.in/ns/ext/state/manifest.ttl b/lv2/lv2plug.in/ns/ext/state/manifest.ttl
new file mode 100644
index 0000000..bff9ad5
--- /dev/null
+++ b/lv2/lv2plug.in/ns/ext/state/manifest.ttl
@@ -0,0 +1,8 @@
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+
+<http://lv2plug.in/ns/ext/state>
+ a lv2:Specification ;
+ lv2:minorVersion 0 ;
+ lv2:microVersion 5 ;
+ rdfs:seeAlso <state.ttl> .
diff --git a/lv2/lv2plug.in/ns/ext/state/state.h b/lv2/lv2plug.in/ns/ext/state/state.h
new file mode 100644
index 0000000..b450b93
--- /dev/null
+++ b/lv2/lv2plug.in/ns/ext/state/state.h
@@ -0,0 +1,359 @@
+/*
+ Copyright 2010-2012 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.
+*/
+
+/**
+ @file
+ C API for the LV2 State extension <http://lv2plug.in/ns/ext/state>.
+*/
+
+#ifndef LV2_STATE_H
+#define LV2_STATE_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
+
+#ifdef __cplusplus
+extern "C" {
+#else
+# include <stdbool.h>
+#endif
+
+#define LV2_STATE_URI "http://lv2plug.in/ns/ext/state"
+
+#define LV2_STATE_INTERFACE_URI LV2_STATE_URI "#Interface"
+#define LV2_STATE_PATH_URI LV2_STATE_URI "#Path"
+#define LV2_STATE_MAP_PATH_URI LV2_STATE_URI "#mapPath"
+#define LV2_STATE_MAKE_PATH_URI LV2_STATE_URI "#makePath"
+
+typedef void* LV2_State_Handle;
+typedef void* LV2_State_Map_Path_Handle;
+typedef void* LV2_State_Make_Path_Handle;
+
+/**
+ 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 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).
+
+ 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, i.e. if the value is saved on one machine it can safely be
+ restored on another machine regardless of endianness, alignment, etc.
+ */
+ 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 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.
+ @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.
+
+ 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,
+ 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.
+
+ 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).
+
+ The plugin MUST NOT attempt to use this function outside of the
+ LV2_State_Interface.restore() context.
+*/
+typedef int (*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 (predicate) of the property to retrieve (URI).
+ @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.
+ @return A pointer to the restored value (object), or NULL if no value
+ has been stored under @c 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.
+
+ 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).
+*/
+typedef const void* (*LV2_State_Retrieve_Function)(LV2_State_Handle handle,
+ uint32_t key,
+ size_t* size,
+ uint32_t* type,
+ uint32_t* flags);
+
+/**
+ State 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.
+
+ 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).
+
+ 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 compatibility issues in the future.
+*/
+typedef struct _LV2_State_Interface {
+
+ /**
+ Save plugin state using a host-provided @c 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 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.)
+
+ The @c handle pointer and @c 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.
+ */
+ void (*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 @c 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 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 @c handle pointer and @c 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.
+ */
+ void (*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 (LV2_STATE_MAP_PATH_URI).
+*/
+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 @a 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.
+
+ 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.
+
+ 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.
+ */
+ 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 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.
+
+ 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.
+ */
+ 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_MAKE_PATH_URI).
+*/
+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 @a handle member of this struct.
+ @param path The path of the new file relative to 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 */
diff --git a/lv2/lv2plug.in/ns/ext/state/state.ttl b/lv2/lv2plug.in/ns/ext/state/state.ttl
new file mode 100644
index 0000000..6c0656a
--- /dev/null
+++ b/lv2/lv2plug.in/ns/ext/state/state.ttl
@@ -0,0 +1,359 @@
+# LV2 State Extension
+# Copyright 2010-2012 David Robillard <d@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.
+
+@prefix dcs: <http://ontologi.es/doap-changeset#> .
+@prefix doap: <http://usefulinc.com/ns/doap#> .
+@prefix foaf: <http://xmlns.com/foaf/0.1/> .
+@prefix lv2: <http://lv2plug.in/ns/lv2core#> .
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
+@prefix state: <http://lv2plug.in/ns/ext/state#> .
+
+<http://drobilla.net/drobilla#me>
+ a foaf:Person ;
+ foaf:name "David Robillard" ;
+ foaf:homepage <http://drobilla.net/> ;
+ foaf:mbox <mailto:d@drobilla.net> ;
+ rdfs:seeAlso <http://drobilla.net/drobilla> .
+
+<http://lv2plug.in/ns/ext/state>
+ a lv2:Specification ;
+ doap:name "LV2 State" ;
+ 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" ;
+ dcs:blame <http://drobilla.net/drobilla#me>
+ ] ;
+ doap:developer [
+ a foaf:Person ;
+ 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>
+ ] ;
+ 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
+<em>completely</em> described by port values (as with all LV2 plugins) and a
+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>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>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>
+</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>
+
+<h3>Plugin Code Example</h3>
+
+<pre class="c-code">
+#define NS_EG "http://example.org/"
+#define NS_ATOM "http://lv2plug.in/ns/ext/atom#"
+
+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");
+ return plugin;
+}
+
+void my_save(LV2_Handle instance,
+ LV2_State_Store_Function store,
+ void* handle,
+ uint32_t flags,
+ const LV2_Feature *const * features)
+{
+ MyPlugin* plugin = (MyPlugin*)instance;
+ const char* greeting = plugin->state.greeting;
+
+ store(handle,
+ plugin->uris.eg_greeting,
+ greeting,
+ strlen(greeting) + 1,
+ 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,
+ uint32_t flags,
+ const LV2_Feature *const * features)
+{
+ MyPlugin* plugin = (MyPlugin*)instance;
+
+ size_t size;
+ uint32_t type;
+ uint32_t flags;
+ const char* greeting = retrieve(
+ handle, plugin->uris.eg_greeting, &amp;size, &amp;type, &amp;flags);
+
+ if (greeting) {
+ free(plugin->state->greeting);
+ plugin->state->greeting = strdup(greeting);
+ } else {
+ plugin->state->greeting = strdup("Hello");
+ }
+}
+
+const void* my_extension_data(const char* uri)
+{
+ static const LV2_State_Interface state_iface = { my_save, my_restore };
+ if (!strcmp(uri, LV2_STATE_INTERFACE_URI)) {
+ return &amp;state_iface;
+ }
+}
+</pre>
+
+<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)
+{
+ if ((flags &amp; 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.
+ */
+ Map* state_map = (Map*)handle;
+ state_map->insert(key, Value(copy(value), size, type, pod));
+ return 0;
+ } else {
+ return 1; /* Non-POD events are unsupported. */
+ }
+}
+
+Map get_plugin_state(LV2_Handle instance)
+{
+ LV2_State* state = instance.extension_data("http://lv2plug.in/ns/ext/state");
+ Map state_map;
+ /** Request a fast/native/POD save, since we're just copying in memory */
+ state.save(instance, store_callback, &amp;state_map,
+ LV2_STATE_IS_POD|LV2_STATE_IS_NATIVE);
+ return state_map;
+}
+</pre>
+
+<h3>Referring to Existing Files</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.</p>
+
+<h3>Creating New Files or Directories</h3>
+
+<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>
+""" .
+
+state:Interface
+ a rdfs:Class ;
+ rdfs:subClassOf lv2:ExtensionData ;
+ lv2:documentation """
+<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>
+
+<p>The plugin data file should describe this like so:</p>
+<pre class="turtle-code">
+@prefix state: &lt;http://lv2plug.in/ns/ext/state#&gt; .
+
+&lt;plugin&gt;
+ a lv2:Plugin ;
+ lv2:extensionData state:Interface .
+</pre>
+""" .
+
+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>
+""" .
+
+state:state
+ a rdf:Property ;
+ 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>
+<pre class="turtle-code">
+@prefix eg: &lt;http://example.org/&gt; .
+
+&lt;plugininstance&gt;
+ state:state [
+ eg:somekey "some value" ;
+ eg:someotherkey "some other value" ;
+ 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" ;
+ 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
+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>For example, a plugin may write a path to a state file like so:</p>
+
+<pre class="c-code">
+void write_path(LV2_State_Map_Path* map_path, FILE* myfile, const char* path)
+{
+ char* abstract_path = map_path->abstract_path(map_path->handle, path);
+ fprintf(myfile, "%s", abstract_path);
+ free(abstract_path);
+}
+</pre>
+
+<p>Then, later reload the path like so:</p>
+
+<pre class="c-code">
+char* read_path(LV2_State_Map_Path* map_path, FILE* myfile)
+{
+ /* Obviously this is not production quality code! */
+ char abstract_path[1024];
+ fscanf(myfile, "%s", abstract_path);
+ return map_path->absolute_path(map_path->handle, abstract_path);
+}
+</pre>
+""" .
+
+state:makePath
+ a lv2:Feature ;
+ rdfs:label "Support for creating new files and directories" ;
+ 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
+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
+feature MUST NOT be used beyond the scope of that call.</p>
+
+<p>The plugin is guaranteed a hierarchial namespace unique to that plugin
+instance, and may expect the returned path to have the requested path as a
+suffix. There is <em>one</em> such namespace, even if the feature is passed to
+both LV2_Descriptor::instantiate() <em>and</em>
+LV2_State_Interface::save(). Beyond this, the plugin MUST NOT make any
+assumptions about the returned paths.</p>
+
+<p>Like any other paths, the plugin MUST map these paths using <a
+href="#mapPath">state:mapPath</a> before storing them in state. The plugin
+MUST NOT assume these paths will be available across a save/restore otherwise,
+i.e. only mapped paths saved to state are persistent, any other created paths
+are temporary.</p>
+
+<p>For example, a plugin may create a file in a subdirectory like so:</p>
+
+<pre class="c-code">
+char* save_myfile(LV2_State_Make_Path* make_path)
+{
+ char* path = make_path->path(make_path->handle, "foo/bar/myfile.txt");
+ FILE* myfile = fopen(path, 'w');
+ fprintf(myfile, "Hello");
+ fclose(myfile);
+ return path;
+}
+</pre>
+""" .
+
+state:Path
+ a rdfs:Class ;
+ rdfs:label "Path" ;
+ lv2:documentation """
+<p>A path to a file or directory.</p>
+
+<p>The format of a state:Path is a C string, possibly escaped or otherwise
+restricted in a system-specific manner. This URI (LV2_STATE_PATH_URI), mapped
+to an integer, MUST be used as the <code>type</code> parameter for any files
+passed to the LV2_State_Store_Function; and will likewise be returned by the
+corresponding call to the LV2_State_Retrieve_Function.</p>
+
+<p>When storing and retrieving a path, the plugin MUST NOT assume the same path
+will be restored. However, the restored path will refer to a file with
+equivalent contents to the original.</p>
+""" .
diff --git a/lv2/lv2plug.in/ns/ext/state/waf b/lv2/lv2plug.in/ns/ext/state/waf
new file mode 120000
index 0000000..5235032
--- /dev/null
+++ b/lv2/lv2plug.in/ns/ext/state/waf
@@ -0,0 +1 @@
+../../../../../waf \ No newline at end of file
diff --git a/lv2/lv2plug.in/ns/ext/state/wscript b/lv2/lv2plug.in/ns/ext/state/wscript
new file mode 120000
index 0000000..7e2c01b
--- /dev/null
+++ b/lv2/lv2plug.in/ns/ext/state/wscript
@@ -0,0 +1 @@
+../../../../../ext.wscript \ No newline at end of file