badvpn/ncd/modules/choose.c

143 lines
4.2 KiB
C

/**
* @file choose.c
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* Multiple value selection based on boolean conditions.
*
* Synopsis:
* choose({{string cond1, result1}, ..., {string condN, resultN}}, default_result)
*
* Variables:
* (empty) - If cond1="true" then result1,
* else if cond2="true" then result2,
* ...,
* else default_result.
*/
#include <stdlib.h>
#include <string.h>
#include <ncd/module_common.h>
#include <generated/blog_channel_ncd_choose.h>
struct instance {
NCDModuleInst *i;
NCDValRef result;
};
static void func_new (void *vo, NCDModuleInst *i, const struct NCDModuleInst_new_params *params)
{
struct instance *o = vo;
o->i = i;
// read arguments
NCDValRef arg_choices;
NCDValRef arg_default_result;
if (!NCDVal_ListRead(params->args, 2, &arg_choices, &arg_default_result)) {
ModuleLog(i, BLOG_ERROR, "wrong arity");
goto fail0;
}
if (!NCDVal_IsList(arg_choices)) {
ModuleLog(i, BLOG_ERROR, "wrong type");
goto fail0;
}
// iterate choices
int have_result = 0;
size_t count = NCDVal_ListCount(arg_choices);
for (size_t j = 0; j < count; j++) {
NCDValRef c = NCDVal_ListGet(arg_choices, j);
// check choice type
if (!NCDVal_IsList(c)) {
ModuleLog(i, BLOG_ERROR, "wrong choice type");
goto fail0;
}
// read choice
NCDValRef c_cond;
NCDValRef c_result;
if (!NCDVal_ListRead(c, 2, &c_cond, &c_result)) {
ModuleLog(i, BLOG_ERROR, "wrong choice contents arity");
goto fail0;
}
int c_cond_val;
if (!ncd_read_boolean(c_cond, &c_cond_val)) {
ModuleLog(i, BLOG_ERROR, "wrong choice condition");
goto fail0;
}
// update result
if (!have_result && c_cond_val) {
o->result = c_result;
have_result = 1;
}
}
// default?
if (!have_result) {
o->result = arg_default_result;
}
// signal up
NCDModuleInst_Backend_Up(o->i);
return;
fail0:
NCDModuleInst_Backend_DeadError(i);
}
static int func_getvar2 (void *vo, NCD_string_id_t name, NCDValMem *mem, NCDValRef *out)
{
struct instance *o = vo;
if (name == NCD_STRING_EMPTY) {
*out = NCDVal_NewCopy(mem, o->result);
return 1;
}
return 0;
}
static struct NCDModule modules[] = {
{
.type = "choose",
.func_new2 = func_new,
.func_getvar2 = func_getvar2,
.alloc_size = sizeof(struct instance)
}, {
.type = NULL
}
};
const struct NCDModuleGroup ncdmodule_choose = {
.modules = modules
};