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mirror of https://github.com/cookiengineer/audacity synced 2025-07-25 17:08:07 +02:00
2010-01-24 09:19:39 +00:00

457 lines
13 KiB
C

/* SLV2
* Copyright (C) 2007 Dave Robillard <http://drobilla.net>
*
* This library 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 library 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.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef __SLV2_PLUGIN_H__
#define __SLV2_PLUGIN_H__
#ifdef __cplusplus
extern "C" {
#endif
#include <stdint.h>
#include <stdbool.h>
#include <slv2/types.h>
#include <slv2/port.h>
#include <slv2/values.h>
/** \defgroup slv2_data Plugin data access
*
* These functions work exclusively with the plugin's RDF data,
* they do not access the plugin's shared library in any way.
*
* An SLV2Plugin contains an in-memory cache of the plugin data, loaded
* on demand. Duplicating plugins should be avoided when possible for
* performance reasons.
*
* @{
*/
/** Check if this plugin is valid.
*
* This is used by plugin lists to avoid loading plugins that are not valid
* and will not work with libslv2 (eg plugins missing required fields, or
* having multiple values for mandatory single-valued fields, etc.
*
* Note that normal hosts do NOT need to use this - slv2 does not
* load invalid plugins into plugin lists. This is included for plugin
* testing utilities, etc.
*
* \return true if \a plugin is valid.
*
* Time = Query
*/
bool
slv2_plugin_verify(SLV2Plugin plugin);
/** Get the URI of \a plugin.
*
* Any serialization that refers to plugins should refer to them by this.
* Hosts SHOULD NOT save any filesystem paths, plugin indexes, etc. in saved
* files; save only the URI.
*
* The URI is a globally unique identifier for one specific plugin. Two
* plugins with the same URI are compatible in port signature, and should
* be guaranteed to work in a compatible and consistent way. If a plugin
* is upgraded in an incompatible way (eg if it has different ports), it
* MUST have a different URI than it's predecessor.
*
* \return a shared string which must not be modified or free()'d.
*
* Time = O(1)
*/
SLV2Value
slv2_plugin_get_uri(SLV2Plugin plugin);
/** Get the (resolvable) URI of the plugins "main" bundle.
*
* This returns the URI of the bundle where the plugin itself was found.
* Note that the data for a plugin may be spread over many bundles, that is,
* slv2_plugin_get_data_uris may returns URIs which are not below this one.
*
* Typical hosts should not need to use this function.
*
* Note this always returns a fully qualified URI. If you want a local
* filesystem path, use slv2_uri_to_path.
*
* \return a shared string which must not be modified or freed.
*
* Time = O(1)
*/
SLV2Value
slv2_plugin_get_bundle_uri(SLV2Plugin plugin);
/** Get the (resolvable) URIs of the RDF data files that define a plugin.
*
* Typical hosts should not need to use this function.
*
* Note this always returns fully qualified URIs. If you want local
* filesystem paths, use slv2_uri_to_path.
*
* \return a list of complete URLs eg. "file:///foo/ABundle.lv2/aplug.ttl",
* which is shared and must not be modified or freed.
*
* Time = O(1)
*/
SLV2Values
slv2_plugin_get_data_uris(SLV2Plugin plugin);
/** Get the (resolvable) URI of the shared library for \a plugin.
*
* Note this always returns a fully qualified URI. If you want a local
* filesystem path, use slv2_uri_to_path.
*
* \return a shared string which must not be modified or freed.
*
* Time = O(1)
*/
SLV2Value
slv2_plugin_get_library_uri(SLV2Plugin plugin);
/** Get the name of \a plugin.
*
* This is guaranteed to return the untranslated name (the doap:name in the
* data file without a language tag). Returned value must be freed by
* the caller.
*
* Time = Query
*/
SLV2Value
slv2_plugin_get_name(SLV2Plugin plugin);
/** Get the class this plugin belongs to (ie Filters).
*/
SLV2PluginClass
slv2_plugin_get_class(SLV2Plugin plugin);
/** Get a value associated with the plugin in a plugin's data files.
*
* Returns the ?object of all triples found of the form:
*
* <code>&lt;plugin-uri&gt; predicate ?object</code>
*
* May return NULL if the property was not found, or if object(s) is not
* sensibly represented as an SLV2Values (e.g. blank nodes).
*
* Return value must be freed by caller with slv2_values_free.
*
* \a predicate must be either a URI or a QName.
* See SLV2URIType documentation for examples.
*
* Time = Query
*/
SLV2Values
slv2_plugin_get_value(SLV2Plugin p,
SLV2Value predicate);
/** Get a value associated with the plugin in a plugin's data files.
*
* This function is identical to slv2_plugin_get_value, but takes a QName
* string parameter for a predicate instead of an SLV2Value, which may be
* more convenient.
*/
SLV2Values
slv2_plugin_get_value_by_qname(SLV2Plugin p,
const char* predicate);
/** Get a translated value associated with the plugin in a plugin's data files.
*
* This function is identical to slv2_plugin_get_value, but takes a QName
* string parameter for a predicate instead of an SLV2Value, which may be
* more convenient. It returns the value translated to the current language
* if possible.
*/
SLV2Values
slv2_plugin_get_value_by_qname_i18n(SLV2Plugin p,
const char* predicate);
/** Get a value associated with some subject in a plugin's data files.
*
* Returns the ?object of all triples found of the form:
*
* <code>subject predicate ?object</code>
*
* This can be used to investigate URIs returned by slv2_plugin_get_value
* (if information about it is contained in the plugin's data files).
*
* May return NULL if the property was not found, or if object is not
* sensibly represented as an SLV2Values (e.g. blank nodes).
*
* \a predicate must be either a URI or a QName.
* See SLV2URIType documentation for examples.
*
* Return value must be freed by caller with slv2_values_free.
*
* Time = Query
*/
SLV2Values
slv2_plugin_get_value_for_subject(SLV2Plugin p,
SLV2Value subject_uri,
SLV2Value predicate_uri);
/** Return whether a feature is supported by a plugin.
*
* This will return true if the feature is an optional or required feature
* of the plugin.
*
* Time = Query
*/
bool
slv2_plugin_has_feature(SLV2Plugin p,
SLV2Value feature_uri);
/** Get the LV2 Features supported (required or optionally) by a plugin.
*
* A feature is "supported" by a plugin if it is required OR optional.
*
* Since required features have special rules the host must obey, this function
* probably shouldn't be used by normal hosts. Using slv2_plugin_get_optional_features
* and slv2_plugin_get_required_features separately is best in most cases.
*
* Returned value must be freed by caller with slv2_values_free.
*
* Time = Query
*/
SLV2Values
slv2_plugin_get_supported_features(SLV2Plugin p);
/** Get the LV2 Features required by a plugin.
*
* If a feature is required by a plugin, hosts MUST NOT use the plugin if they do not
* understand (or are unable to support) that feature.
*
* All values returned here MUST be passed to the plugin's instantiate method
* (along with data, if necessary, as defined by the feature specification)
* or plugin instantiation will fail.
*
* Return value must be freed by caller with slv2_values_free.
*
* Time = Query
*/
SLV2Values
slv2_plugin_get_required_features(SLV2Plugin p);
/** Get the LV2 Features optionally supported by a plugin.
*
* Hosts MAY ignore optional plugin features for whatever reasons. Plugins
* MUST operate (at least somewhat) if they are instantiated without being
* passed optional features.
*
* Return value must be freed by caller with slv2_values_free.
*
* Time = Query
*/
SLV2Values
slv2_plugin_get_optional_features(SLV2Plugin p);
/** Get the number of ports on this plugin.
*
* Time = O(1)
*/
uint32_t
slv2_plugin_get_num_ports(SLV2Plugin p);
/** Get the port ranges (minimum, maximum and default values) for all ports.
*
* \a min_values, \a max_values and \a def_values must either point to an array
* of N floats, where N is the value returned by slv2_plugin_get_num_ports()
* for this plugin, or NULL. The elements of the array will be set to the
* the minimum, maximum and default values of the ports on this plugin,
* with array index corresponding to port index. If a port doesn't have a
* minimum, maximum or default value, or the port's type is not float, the
* corresponding array element will be set to NAN.
*
* This is a convenience method for the common case of getting the range of
* all float ports on a plugin, and may be significantly faster than
* repeated calls to slv2_port_get_range.
*/
void
slv2_plugin_get_port_ranges_float(SLV2Plugin p,
float* min_values,
float* max_values,
float* def_values);
/** Get the number of ports on this plugin that are members of some class(es).
*
* Note that this is a varargs function so ports fitting any type 'profile'
* desired can be found quickly. REMEMBER TO TERMINATE THE PARAMETER LIST
* OF THIS FUNCTION WITH NULL OR VERY NASTY THINGS WILL HAPPEN.
*
* Time = O(1)
*/
uint32_t
slv2_plugin_get_num_ports_of_class(SLV2Plugin p,
SLV2Value class_1, ...);
/** Return whether or not the plugin introduces (and reports) latency.
*
* The index of the latency port can be found with slv2_plugin_get_latency_port
* ONLY if this function returns true.
*
* Time = Query
*/
bool
slv2_plugin_has_latency(SLV2Plugin p);
/** Return the index of the plugin's latency port.
*
* It is a fatal error to call this on a plugin without checking if the port
* exists by first calling slv2_plugin_has_latency.
*
* Any plugin that introduces unwanted latency that should be compensated for
* (by hosts with the ability/need) MUST provide this port, which is a control
* rate output port that reports the latency for each cycle in frames.
*
* Time = Query
*/
uint32_t
slv2_plugin_get_latency_port_index(SLV2Plugin p);
/** Query a plugin for a single variable (i.e. SELECT a single ?value).
*
* \param plugin The plugin to query.
* \param sparql_str A SPARQL SELECT query.
* \param variable The index of the variable to return results for
* (e.g. with "<code>SELECT ?foo ?bar</code>" foo=0, bar=1).
* \return All matches for \a variable.
*
* Time = Query
*/
SLV2Values
slv2_plugin_query_variable(SLV2Plugin plugin,
const char* sparql_str,
unsigned variable);
/** Query a plugin and return the number of results found.
*
* Note that this function will work, but is mostly meaningless for queries
* that are not SELECT DISTINCT.
*
* \param plugin The plugin to query.
* \param sparql_str A SPARQL SELECT DISTINCT query.
*
* Time = Query
*/
unsigned
slv2_plugin_query_count(SLV2Plugin plugin,
const char* sparql_str);
/** Get a port on this plugin by \a index.
*
* To perform multiple calls on a port, the returned value should
* be cached and used repeatedly.
*
* Time = O(1)
*/
SLV2Port
slv2_plugin_get_port_by_index(SLV2Plugin plugin,
uint32_t index);
/** Get a port on this plugin by \a symbol.
*
* To perform multiple calls on a port, the returned value should
* be cached and used repeatedly. Note this function is slower
* than slv2_plugin_get_port_by_index, especially on plugins
* with a very large number of ports.
*
* Time = O(n)
*/
SLV2Port
slv2_plugin_get_port_by_symbol(SLV2Plugin plugin,
SLV2Value symbol);
/** Get a list of all UIs available for this plugin.
*
* Note this returns the URI of the UI, and not the path/URI to its shared
* library, use slv2_ui_get_library_uri with the values returned
* here for that.
*
* Returned value must be freed by caller using slv2_uis_free.
*
* \param plugin The plugin to get the UIs for.
*
* Time = Query
*/
SLV2UIs
slv2_plugin_get_uis(SLV2Plugin plugin);
/** Get the full name of the plugin's author.
*
* Returns NULL if author name is not present.
* Returned value must be freed by caller.
*
* Time = Query
*/
SLV2Value
slv2_plugin_get_author_name(SLV2Plugin plugin);
/** Get the email address of the plugin's author.
*
* Returns NULL if author email address is not present.
* Returned value must be freed by caller.
*
* Time = Query
*/
SLV2Value
slv2_plugin_get_author_email(SLV2Plugin plugin);
/** Get the email address of the plugin's author.
*
* Returns NULL if author homepage is not present.
* Returned value must be freed by caller.
*
* Time = Query
*/
SLV2Value
slv2_plugin_get_author_homepage(SLV2Plugin plugin);
/** @} */
#ifdef __cplusplus
}
#endif
#endif /* __SLV2_PLUGIN_H__ */