From eb43c8896480114b224755e824fae2e2f7485256 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Mon, 21 Nov 2011 01:36:00 +0000 Subject: Move ns to lv2/ns so repository top level can be used as an include dir directly. --- lv2/ns/ext/atom/atom-helpers.h | 174 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 lv2/ns/ext/atom/atom-helpers.h (limited to 'lv2/ns/ext/atom/atom-helpers.h') diff --git a/lv2/ns/ext/atom/atom-helpers.h b/lv2/ns/ext/atom/atom-helpers.h new file mode 100644 index 0000000..4e51c89 --- /dev/null +++ b/lv2/ns/ext/atom/atom-helpers.h @@ -0,0 +1,174 @@ +/* + Copyright 2008-2011 David Robillard + + 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 atom-helpers.h Helper functions for the LV2 Atom extension. + + These functions are provided for convenience only, use of them is not + required for supporting atoms. + + Note that these functions are all static inline which basically means: + do not take the address of these functions. +*/ + +#ifndef LV2_ATOM_HELPERS_H +#define LV2_ATOM_HELPERS_H + +#include +#include +#include +#include + +#include "lv2/lv2plug.in/ns/ext/atom/atom.h" + +typedef LV2_Atom_Property* LV2_Thing_Iter; + +/** Get an iterator pointing to @c prop in some LV2_Thing */ +static inline LV2_Thing_Iter +lv2_thing_begin(const LV2_Thing* obj) +{ + return (LV2_Thing_Iter)(obj->properties); +} + +/** Return true iff @c iter has reached the end of @c thing */ +static inline bool +lv2_thing_iter_is_end(const LV2_Thing* obj, LV2_Thing_Iter iter) +{ + return (uint8_t*)iter >= ((uint8_t*)obj + sizeof(LV2_Atom) + obj->size); +} + +/** Return true iff @c l points to the same property as @c r */ +static inline bool +lv2_thing_iter_equals(const LV2_Thing_Iter l, const LV2_Thing_Iter r) +{ + return l == r; +} + +/** Return an iterator to the property following @c iter */ +static inline LV2_Thing_Iter +lv2_thing_iter_next(const LV2_Thing_Iter iter) +{ + return (LV2_Thing_Iter)((uint8_t*)iter + + sizeof(LV2_Atom_Property) + + lv2_atom_pad_size(iter->value.size)); +} + +/** Return the property pointed to by @c iter */ +static inline LV2_Atom_Property* +lv2_thing_iter_get(LV2_Thing_Iter iter) +{ + return (LV2_Atom_Property*)iter; +} + +/** + A macro for iterating over all properties of an Thing. + @param thing The thing to iterate over + @param iter The name of the iterator + + This macro is used similarly to a for loop (which it expands to), e.g.: + 
+   LV2_THING_FOREACH(thing, i) {
+   LV2_Atom_Property* prop = lv2_thing_iter_get(i);
+   // Do things with prop here...
+   }
+
+*/ +#define LV2_THING_FOREACH(thing, iter) \ + for (LV2_Thing_Iter (iter) = lv2_thing_begin(thing); \ + !lv2_thing_iter_is_end(thing, (iter)); \ + (iter) = lv2_thing_iter_next(iter)) + +/** + Append a Property body to an Atom that contains properties (e.g. atom:Thing). + @param thing Pointer to the atom that contains the property to add. thing.size + must be valid, but thing.type is ignored. + @param key The key of the new property + @param value_type The type of the new value + @param value_size The size of the new value + @param value_body Pointer to the new value's data + @return a pointer to the new LV2_Atom_Property in @c body. + + This function will write the property body (not including an LV2_Thing + header) at lv2_atom_pad_size(body + size). Thus, it can be used with any + Atom type that contains headerless 32-bit aligned properties. +*/ +static inline LV2_Atom_Property* +lv2_thing_append(LV2_Thing* thing, + uint32_t key, + uint32_t value_type, + uint32_t value_size, + const void* value_body) +{ + thing->size = lv2_atom_pad_size(thing->size); + LV2_Atom_Property* prop = (LV2_Atom_Property*)( + (uint8_t*)thing + sizeof(LV2_Atom) + thing->size); + prop->key = key; + prop->value.type = value_type; + prop->value.size = value_size; + memcpy(prop->value.body, value_body, value_size); + thing->size += sizeof(LV2_Atom_Property) + value_size; + return prop; +} + +/** Return true iff @c atom is NULL */ +static inline bool +lv2_atom_is_null(LV2_Atom* atom) +{ + return !atom || (atom->type == 0 && atom->size == 0); +} + +/** A single entry in an Thing query. */ +typedef struct { + uint32_t key; /**< Key to query (input set by user) */ + const LV2_Atom** value; /**< Found value (output set by query function) */ +} LV2_Thing_Query; + +static const LV2_Thing_Query LV2_THING_QUERY_END = { 0, NULL }; + +/** + "Query" an thing, getting a pointer to the values for various keys. + + The value pointer of each item in @c query will be set to the location of + the corresponding value in @c thing. Every value pointer in @c query MUST + be initialised to NULL. This function reads @c thing in a single linear + sweep. By allocating @c query on the stack, things can be "queried" + quickly without allocating any memory. This function is realtime safe. +*/ +static inline int +lv2_thing_query(const LV2_Thing* thing, LV2_Thing_Query* query) +{ + int matches = 0; + int n_queries = 0; + + /* Count number of query keys so we can short-circuit when done */ + for (LV2_Thing_Query* q = query; q->key; ++q) + ++n_queries; + + LV2_THING_FOREACH(thing, o) { + const LV2_Atom_Property* prop = lv2_thing_iter_get(o); + for (LV2_Thing_Query* q = query; q->key; ++q) { + if (q->key == prop->key && !*q->value) { + *q->value = &prop->value; + if (++matches == n_queries) + return matches; + break; + } + } + } + return matches; +} + +#endif /* LV2_ATOM_HELPERS_H */ -- cgit v1.2.1