examples/reference/c/eina/src/eina_future.c

#define EFL_EO_API_SUPPORT 1
#define EFL_BETA_API_SUPPORT 1

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>

#include <Eina.h>
#include <Efl_Core.h>

/*
 * Eina Future examples.
 *
 * TODO
 */

#define DEFAULT_MSG "the simple example is working!"

#define VALUE_TYPE_CHECK(_v, _type)                                     \
  if (_v.type != _type)                                                 \
    {                                                                   \
       fprintf(stderr, "Value type is not '%s' - received '%s'\n",      \
               _type->name, _v.type->name);                             \
       return _v;                                                       \
    }

typedef struct _Ctx {
   Eina_Promise *p;
   Eina_Bool should_fail;
   Ecore_Timer *timer;
   Eina_Value *value;
} Ctx;

static void
_promise_cancel(void *data, const Eina_Promise *dead EINA_UNUSED)
{
   Ctx *ctx = data;
   if (ctx->timer) efl_del(ctx->timer);
   eina_value_free(ctx->value);
   free(ctx);
}

static Ctx *
_promise_ctx_new(Eina_Value *v)
{
   Ctx *ctx;
   Efl_Loop *loop;
   ctx = calloc(1, sizeof(Ctx));
   EINA_SAFETY_ON_NULL_GOTO(ctx, err_ctx);

   loop = efl_loop_main_get(EFL_LOOP_CLASS);
   ctx->p = eina_promise_new(efl_loop_future_scheduler_get(loop),
                             _promise_cancel, ctx);
   EINA_SAFETY_ON_NULL_GOTO(ctx->p, err_timer);
   ctx->value = v;
   return ctx;
 err_timer:
   free(ctx);
 err_ctx:
   eina_value_free(v);
   return NULL;
}

static void
_timeout(void *data, const Efl_Event *event EINA_UNUSED)
{
   Ctx *ctx = data;

   if (ctx->should_fail)
     {
        eina_promise_reject(ctx->p, ENETDOWN);
     }
   else
     {
        Eina_Value v;
        eina_value_copy(ctx->value, &v);
        eina_promise_resolve(ctx->p, v);
        eina_value_free(ctx->value);
     }

   efl_del(ctx->timer);
   free(ctx);
}

static Eina_Future *
_future_get(Ctx *ctx)
{
   Eina_Future *f;

   f = eina_future_new(ctx->p);
   EINA_SAFETY_ON_NULL_GOTO(f, err_future);

   efl_add(EFL_LOOP_TIMER_CLASS, NULL,
           ctx->timer = efl_added,
           efl_loop_timer_interval_set(efl_added, 0.1),
           efl_event_callback_add(efl_added, EFL_LOOP_TIMER_EVENT_TICK, _timeout, ctx));

   EINA_SAFETY_ON_NULL_GOTO(ctx->timer, err_timer);
   return f;

 err_timer:
   eina_future_cancel(f);
 err_future:
   return NULL;
}

static Eina_Future *
_fail_future_get(void)
{
   Ctx *ctx = _promise_ctx_new(NULL);
   EINA_SAFETY_ON_NULL_RETURN_VAL(ctx, NULL);
   ctx->should_fail = EINA_TRUE;
   return _future_get(ctx);
}

static Eina_Future *
_str_future_get(void)
{
   Eina_Value *v = eina_value_util_string_new(DEFAULT_MSG);
   EINA_SAFETY_ON_NULL_RETURN_VAL(v, NULL);
   Ctx *ctx = _promise_ctx_new(v);
   EINA_SAFETY_ON_NULL_RETURN_VAL(ctx, NULL);
   return _future_get(ctx);
}

static Eina_Value
_simple_ok(void *data EINA_UNUSED, const Eina_Value v, const Eina_Future *dead_future EINA_UNUSED)
{
   VALUE_TYPE_CHECK(v, EINA_VALUE_TYPE_STRING);
   return v;
}

static Eina_Value
_simple_err(void *data EINA_UNUSED, const Eina_Value v, const Eina_Future *dead_future EINA_UNUSED)
{
   VALUE_TYPE_CHECK(v, EINA_VALUE_TYPE_ERROR);
   return v;
}

static void
_simple(void)
{
   eina_future_chain(_str_future_get(),
                     eina_future_cb_console("Expecting the following message: "DEFAULT_MSG "\n  Got: ", NULL),
                     { .cb = _simple_ok, .data = NULL });
   eina_future_chain(_fail_future_get(),
                     eina_future_cb_console("Expecting network down error\n  Got: ", NULL),
                     { .cb = _simple_err, .data = NULL });
}

static Eina_Future *
_int_future_get(void)
{
   Eina_Value *v = eina_value_util_int_new(1);
   EINA_SAFETY_ON_NULL_RETURN_VAL(v, NULL);
   Ctx *ctx = _promise_ctx_new(v);
   EINA_SAFETY_ON_NULL_RETURN_VAL(ctx, NULL);
   return _future_get(ctx);
}

static Eina_Value
_chain_no_errors_cb(void *data EINA_UNUSED, const Eina_Value v, const Eina_Future *dead_future EINA_UNUSED)
{
   int val;

   VALUE_TYPE_CHECK(v, EINA_VALUE_TYPE_INT);
   eina_value_get(&v, &val);

   return *eina_value_util_int_new(val * 2);
}

static Eina_Value
_exit_cb(void *data EINA_UNUSED, const Eina_Value v, const Eina_Future *dead_future EINA_UNUSED)
{
   efl_exit(0);

   return v;
}

static void
_chain_no_errors(void)
{
   eina_future_chain(_int_future_get(),
                     eina_future_cb_console("Expecting number 1\n  Got: ", NULL),
                     {.cb = _chain_no_errors_cb, .data = NULL},
                     eina_future_cb_console("Expecting number 2\n  Got: ", NULL),
                     {.cb = _chain_no_errors_cb, .data = NULL},
                     eina_future_cb_console("Expecting number 4\n  Got: ", NULL),
                     {.cb = _chain_no_errors_cb, .data = NULL},
                     eina_future_cb_console("Expecting number 8\n  Got: ", NULL),
                     {.cb = _chain_no_errors_cb, .data = NULL},
                     eina_future_cb_console("Expecting number 16\n  Got: ", NULL),
                     {.cb = _exit_cb, .data = NULL});
}

static Eina_Value
_chain_with_error_cb(void *data EINA_UNUSED, const Eina_Value v EINA_UNUSED, const Eina_Future *dead_future EINA_UNUSED)
{
   Eina_Value err;
   eina_value_setup(&err, EINA_VALUE_TYPE_ERROR);
   eina_value_set(&err, E2BIG);
   return err;
}

static void
_chain_with_error(void)
{
   eina_future_chain(_int_future_get(),
                     { .cb=_chain_with_error_cb, .data=NULL },
                     eina_future_cb_console("Expecting argument list too long. Got: ", NULL),
                     { .cb = _simple_err, .data = NULL });
 }

static Eina_Value
_canceled_cb(void *data EINA_UNUSED, const Eina_Value v, const Eina_Future *dead_future EINA_UNUSED)
{
   VALUE_TYPE_CHECK(v, EINA_VALUE_TYPE_ERROR);
   return v;
}

static void
_future_cancel(void)
{
   Eina_Future *f;

   f = eina_future_chain(_int_future_get(),
                         eina_future_cb_console("Expecting cancelled operation error.  Got: ", NULL),
                         { .cb = _canceled_cb, .data = NULL },
                         eina_future_cb_console("Expecting cancelled operation error.  Got: ", NULL),
                         { .cb = _canceled_cb, .data = NULL },
                         eina_future_cb_console("Expecting cancelled operation error.  Got: ", NULL));
   eina_future_cancel(f);
}

EAPI_MAIN void
efl_main(void *data EINA_UNUSED, const Efl_Event *ev EINA_UNUSED)
{
   _simple();
   _chain_no_errors();
   _chain_with_error();
   _future_cancel();
}

EFL_MAIN()