transform.c

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/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
 * Copyright (C) 2015 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <string.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"

/** @cond PRIVATE */
#define LOG_PREFIX "transform"
/** @endcond */

/**
 * @file
 *
 * Transform module handling.
 */

/**
 * @defgroup grp_transform Transform modules
 *
 * Transform module handling.
 *
 * @{
 */

/** @cond PRIVATE */
extern SR_PRIV struct sr_transform_module transform_nop;
extern SR_PRIV struct sr_transform_module transform_scale;
extern SR_PRIV struct sr_transform_module transform_invert;
/* @endcond */

static const struct sr_transform_module *transform_module_list[] = {
        &transform_nop,
        &transform_scale,
        &transform_invert,
        NULL,
};

/**
 * Returns a NULL-terminated list of all available transform modules.
 *
 * @since 0.4.0
 */
SR_API const struct sr_transform_module **sr_transform_list(void)
{
        return transform_module_list;
}

/**
 * Returns the specified transform module's ID.
 *
 * @since 0.4.0
 */
SR_API const char *sr_transform_id_get(const struct sr_transform_module *tmod)
{
        if (!tmod) {
                sr_err("Invalid transform module NULL!");
                return NULL;
        }

        return tmod->id;
}

/**
 * Returns the specified transform module's name.
 *
 * @since 0.4.0
 */
SR_API const char *sr_transform_name_get(const struct sr_transform_module *tmod)
{
        if (!tmod) {
                sr_err("Invalid transform module NULL!");
                return NULL;
        }

        return tmod->name;
}

/**
 * Returns the specified transform module's description.
 *
 * @since 0.4.0
 */
SR_API const char *sr_transform_description_get(const struct sr_transform_module *tmod)
{
        if (!tmod) {
                sr_err("Invalid transform module NULL!");
                return NULL;
        }

        return tmod->desc;
}

/**
 * Return the transform module with the specified ID, or NULL if no module
 * with that ID is found.
 *
 * @since 0.4.0
 */
SR_API const struct sr_transform_module *sr_transform_find(const char *id)
{
        int i;

        for (i = 0; transform_module_list[i]; i++) {
                if (!strcmp(transform_module_list[i]->id, id))
                        return transform_module_list[i];
        }

        return NULL;
}

/**
 * Returns a NULL-terminated array of struct sr_option, or NULL if the
 * module takes no options.
 *
 * Each call to this function must be followed by a call to
 * sr_transform_options_free().
 *
 * @since 0.4.0
 */
SR_API const struct sr_option **sr_transform_options_get(const struct sr_transform_module *tmod)
{
        const struct sr_option *mod_opts, **opts;
        int size, i;

        if (!tmod || !tmod->options)
                return NULL;

        mod_opts = tmod->options();

        for (size = 0; mod_opts[size].id; size++)
                ;
        opts = g_malloc((size + 1) * sizeof(struct sr_option *));

        for (i = 0; i < size; i++)
                opts[i] = &mod_opts[i];
        opts[i] = NULL;

        return opts;
}

/**
 * After a call to sr_transform_options_get(), this function cleans up all
 * resources returned by that call.
 *
 * @since 0.4.0
 */
SR_API void sr_transform_options_free(const struct sr_option **options)
{
        int i;

        if (!options)
                return;

        for (i = 0; options[i]; i++) {
                if (options[i]->def) {
                        g_variant_unref(options[i]->def);
                        ((struct sr_option *)options[i])->def = NULL;
                }

                if (options[i]->values) {
                        g_slist_free_full(options[i]->values, (GDestroyNotify)g_variant_unref);
                        ((struct sr_option *)options[i])->values = NULL;
                }
        }
        g_free(options);
}

/**
 * Create a new transform instance using the specified transform module.
 *
 * <code>options</code> is a *GHashTable with the keys corresponding with
 * the module options' <code>id</code> field. The values should be GVariant
 * pointers with sunk * references, of the same GVariantType as the option's
 * default value.
 *
 * The sr_dev_inst passed in can be used by the instance to determine
 * channel names, samplerate, and so on.
 *
 * @since 0.4.0
 */
SR_API const struct sr_transform *sr_transform_new(const struct sr_transform_module *tmod,
                GHashTable *options, const struct sr_dev_inst *sdi)
{
        struct sr_transform *t;
        const struct sr_option *mod_opts;
        const GVariantType *gvt;
        GHashTable *new_opts;
        GHashTableIter iter;
        gpointer key, value;
        int i;

        t = g_malloc(sizeof(struct sr_transform));
        t->module = tmod;
        t->sdi = sdi;

        new_opts = g_hash_table_new_full(g_str_hash, g_str_equal, g_free,
                        (GDestroyNotify)g_variant_unref);
        if (tmod->options) {
                mod_opts = tmod->options();
                for (i = 0; mod_opts[i].id; i++) {
                        if (options && g_hash_table_lookup_extended(options,
                                        mod_opts[i].id, &key, &value)) {
                                /* Pass option along. */
                                gvt = g_variant_get_type(mod_opts[i].def);
                                if (!g_variant_is_of_type(value, gvt)) {
                                        sr_err("Invalid type for '%s' option.",
                                                (char *)key);
                                        g_free(t);
                                        return NULL;
                                }
                                g_hash_table_insert(new_opts, g_strdup(mod_opts[i].id),
                                                g_variant_ref(value));
                        } else {
                                /* Option not given: insert the default value. */
                                g_hash_table_insert(new_opts, g_strdup(mod_opts[i].id),
                                                g_variant_ref(mod_opts[i].def));
                        }
                }

                /* Make sure no invalid options were given. */
                if (options) {
                        g_hash_table_iter_init(&iter, options);
                        while (g_hash_table_iter_next(&iter, &key, &value)) {
                                if (!g_hash_table_lookup(new_opts, key)) {
                                        sr_err("Transform module '%s' has no option '%s'.",
                                                tmod->id, (char *)key);
                                        g_hash_table_destroy(new_opts);
                                        g_free(t);
                                        return NULL;
                                }
                        }
                }
        }

        if (t->module->init && t->module->init(t, new_opts) != SR_OK) {
                g_free(t);
                t = NULL;
        }
        if (new_opts)
                g_hash_table_destroy(new_opts);

        /* Add the transform to the session's list of transforms. */
        sdi->session->transforms = g_slist_append(sdi->session->transforms, t);

        return t;
}

/**
 * Free the specified transform instance and all associated resources.
 *
 * @since 0.4.0
 */
SR_API int sr_transform_free(const struct sr_transform *t)
{
        int ret;

        if (!t)
                return SR_ERR_ARG;

        ret = SR_OK;
        if (t->module->cleanup)
                ret = t->module->cleanup((struct sr_transform *)t);
        g_free((gpointer)t);

        return ret;
}

/** @} */