src: add helper functions for reading config files

src/config.c

@@ -0,0 +1,83 @@
+/*
+ * Copyright (C) 2020 Arnaud Ferraris <arnaud.ferraris@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#include "config.h"
+#include "toml.h"
+
+gboolean config_get_bool(toml_table_t **config, const gchar *key, gboolean *result)
+{
+    toml_datum_t value = { .ok = 0 };
+
+    if (config[EG25_CONFIG_USER])
+        value = toml_bool_in(config[EG25_CONFIG_USER], key);
+    if (!value.ok)
+        value = toml_bool_in(config[EG25_CONFIG_SYS], key);
+    if (value.ok && result)
+        *result = value.u.b;
+
+    return !!value.ok;
+}
+
+gboolean config_get_int(toml_table_t **config, const gchar *key, gint *result)
+{
+    toml_datum_t value = { .ok = 0 };
+
+    if (config[EG25_CONFIG_USER])
+        value = toml_int_in(config[EG25_CONFIG_USER], key);
+    if (!value.ok)
+        value = toml_int_in(config[EG25_CONFIG_SYS], key);
+    if (value.ok && result)
+        *result = value.u.i;
+
+    return !!value.ok;
+}
+
+gboolean config_get_uint(toml_table_t **config, const gchar *key, guint *result)
+{
+    gint value;
+    gboolean found;
+
+    found = config_get_int(config, key, &value);
+    if (found) {
+        if (value <= 0 || value >= G_MAXUINT) {
+            g_message("Value out of range for [%s], discarding", key);
+            found = FALSE;
+        }
+    }
+
+    if (found && result)
+        *result = (guint) value;
+
+    return found;
+}
+
+gboolean config_get_string(toml_table_t **config, const gchar *key, gchar **result)
+{
+    toml_datum_t value = { .ok = 0 };
+
+    if (config[EG25_CONFIG_USER])
+        value = toml_string_in(config[EG25_CONFIG_USER], key);
+    if (!value.ok)
+        value = toml_string_in(config[EG25_CONFIG_SYS], key);
+    if (value.ok && result)
+        *result = value.u.s;
+
+    return !!value.ok;
+}
+
+gboolean config_get_array(toml_table_t **config, const gchar *key, toml_array_t **result)
+{
+    toml_array_t *array = NULL;
+
+    if (config[EG25_CONFIG_USER])
+        array = toml_array_in(config[EG25_CONFIG_USER], key);
+    if (!array)
+        array = toml_array_in(config[EG25_CONFIG_SYS], key);
+    if (array && result)
+        *result = array;
+
+    return !!array;
+}

src/config.h

@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2020 Arnaud Ferraris <arnaud.ferraris@gmail.com>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <glib.h>
+
+#include "manager.h"
+#include "toml.h"
+
+/*
+ * Helper functions for parsing config files: each function retrieves the
+ * value for key `key`, with the user config file having priority over the
+ * default config file. The values are stored in `result`.
+ *
+ * They all return TRUE if the value was found, FALSE otherwise.
+ */
+
+gboolean config_get_bool(toml_table_t **config, const gchar *key, gboolean *result);
+gboolean config_get_int(toml_table_t **config, const gchar *key, gint *result);
+gboolean config_get_uint(toml_table_t **config, const gchar *key, guint *result);
+gboolean config_get_string(toml_table_t **config, const gchar *key, gchar **result);
+gboolean config_get_array(toml_table_t **config, const gchar *key, toml_array_t **result);

src/manager.h

@@ -62,6 +62,12 @@ enum ModemIface {
     MODEM_IFACE_OFONO
 };
 
+enum EG25Config {
+    EG25_CONFIG_SYS = 0,
+    EG25_CONFIG_USER,
+    EG25_CONFIG_COUNT
+};
+
 struct EG25Manager {
     GMainLoop *loop;
     guint reset_timer;

src/meson.build

@@ -9,6 +9,7 @@ subdir('libgdbofono')
 
 src = [
         'at.c', 'at.h',
+        'config.c', 'config.h',
         'gpio.c', 'gpio.h',
         'manager.c', 'manager.h',
         'ofono-iface.c', 'ofono-iface.h',