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/*
Copyright 2016 David Robillard <http://drobilla.net>
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 util Utilities
@ingroup lv2core
@{
*/
#include <string.h>
#include "lv2/lv2plug.in/ns/lv2core/lv2.h"
#ifdef __cplusplus
extern "C" {
#else
# include <stdbool.h>
#endif
/**
Return the data for a feature in a features array.
If the feature is not found, NULL is returned. Note that this function is
only useful for features with data, and can not detect features that are
present but have NULL data.
*/
static inline void*
lv2_features_data(const LV2_Feature*const* features,
const char* const uri)
{
if (features) {
for (const LV2_Feature*const* f = features; *f; ++f) {
if (!strcmp(uri, (*f)->URI)) {
return (*f)->data;
}
}
}
return NULL;
}
/**
Query a features array.
This function allows getting several features in one call, and detect
missing required features, with the same caveat of lv2_features_data().
The arguments should be a series of const char* uri, void** data, bool
required, terminated by a NULL URI. The data pointers MUST be initialized
to NULL. For example:
@code
LV2_URID_Log* log = NULL;
LV2_URID_Map* map = NULL;
const char* missing = lv2_features_query(
features,
LV2_LOG__log, &log, false,
LV2_URID__map, &map, true,
NULL);
@endcode
@return NULL on success, otherwise the URI of this missing feature.
*/
static inline const char*
lv2_features_query(const LV2_Feature* const* features, ...)
{
va_list args;
va_start(args, features);
const char* uri = NULL;
while ((uri = va_arg(args, const char*))) {
void** data = va_arg(args, void**);
bool required = va_arg(args, int);
*data = lv2_features_data(features, uri);
if (required && !*data) {
return uri;
}
}
return NULL;
}
#ifdef __cplusplus
} /* extern "C" */
#endif
/**
@}
@}
*/
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