id.c

#include <kiba/containers/array.h>
#include <kiba/core/id.h>
#include <kiba/core/memory.h>
 
struct kb_id_generator {
    identifier max;
    array_of(identifier) returned;
    allocator *alloc;
};
 
b8 id_generator_create(id_generator *generator, allocator *alloc) {
    struct kb_id_generator *new_generator = allocator_allocate_aligned(alloc, sizeof(struct kb_id_generator), 8);
    if (!new_generator) {
        KB_ERROR("could not allocate new id generator");
        return false;
    }
    new_generator->max      = 0;
    new_generator->alloc    = alloc;
    new_generator->returned = array_create(identifier, 64, alloc);
    if (!new_generator->returned) {
        KB_ERROR("could not allocate storage for returned ids");
        id_generator_destroy(new_generator);
        return false;
    }
    *generator = new_generator;
    return true;
}
 
void id_generator_destroy(id_generator generator) {
    if (generator->returned) {
        array_destroy(&generator->returned);
    }
    allocator_free(generator->alloc, generator);
}
 
identifier id_request(id_generator generator) {
    if (array_size(generator->returned) > 0) {
        return array_pop(generator->returned);
    } else {
        return generator->max++;
    }
}
 
void id_return(id_generator generator, identifier id) {
    if (!array_push_checked(&generator->returned, &id)) {
        KB_WARN("could not return id {usize} to generator {pointer}, id will not be reused", id, generator);
    }
}