daemon-conf: Add conf file parsing

Support to parse configuration files. By default, the default conf file
is parsed ({sysconfdir}/pinos/pinos.conf), but that can be changed with
an environment variable (PINOS_CONFIG_FILE). The file can contain
commands and assignments (no assignment supported this far).

Support for command module-load is added.

pinos/daemon/daemon-config.c

@@ -0,0 +1,218 @@
+/* Pinos
+ * Copyright (C) 2016 Axis Communications <dev-gstreamer@axis.com>
+ * @author Linus Svensson <linus.svensson@axis.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <glib.h>
+#include <string.h>
+
+#include <server/command.h>
+
+#include "pinos/daemon/daemon-config.h"
+
+#define DEFAULT_CONFIG_FILE PINOS_CONFIG_DIR G_DIR_SEPARATOR_S "pinos.conf"
+
+GQuark
+pinos_daemon_config_error_quark (void)
+{
+  static GQuark quark = 0;
+
+  if (quark == 0) {
+    quark = g_quark_from_static_string ("pinos_daemon_config_error");
+  }
+
+  return quark;
+}
+
+static gboolean
+parse_line (PinosDaemonConfig  * config,
+            const gchar        * filename,
+            gchar              * line,
+            guint                lineno,
+            GError            ** err)
+{
+  PinosCommand *command = NULL;
+  gchar *p;
+  gboolean ret = TRUE;
+  GError *local_err = NULL;
+
+  /* search for comments */
+  if ((p = strchr (line, '#')))
+    *p = '\0';
+
+  /* remove whitespaces */
+  g_strstrip (line);
+
+  if (*line == '\0') /* empty line */
+    return TRUE;
+
+  if (!pinos_command_parse (&command, line, &local_err)) {
+    g_set_error (err, PINOS_DAEMON_CONFIG_ERROR,
+        PINOS_DAEMON_CONFIG_ERROR_COMMAND, "%s:%u: %s", filename, lineno,
+        local_err->message);
+    g_error_free (local_err);
+    ret = FALSE;
+  } else {
+    config->commands = g_list_append (config->commands, command);
+  }
+
+  return ret;
+}
+
+/**
+ * pinos_daemon_config_new:
+ *
+ * Returns a new empty #PinosDaemonConfig.
+ */
+PinosDaemonConfig *
+pinos_daemon_config_new (void)
+{
+  PinosDaemonConfig *config;
+
+  config = g_new (PinosDaemonConfig, 1);
+
+  config->commands = NULL;
+
+  return config;
+}
+
+/**
+ * pinos_daemon_config_free:
+ * @config: A #PinosDaemonConfig
+ *
+ * Free all resources associated to @config.
+ */
+void
+pinos_daemon_config_free (PinosDaemonConfig * config)
+{
+  g_return_if_fail (config != NULL);
+
+  g_list_free_full (config->commands, (GDestroyNotify) pinos_command_free);
+
+  g_free (config);
+}
+
+/**
+ * pinos_daemon_config_load_file:
+ * @config: A #PinosDaemonConfig
+ * @filename: A filename
+ * @err: Return location for a #GError, or %NULL
+ *
+ * Loads pinos config from @filename.
+ *
+ * Returns: %TRUE on success, otherwise %FALSE and @err is set.
+ */
+gboolean
+pinos_daemon_config_load_file (PinosDaemonConfig  * config,
+                               const gchar        * filename,
+                               GError            ** err)
+{
+  gchar *data;
+  gchar **lines;
+  gboolean ret = TRUE;
+  guint i;
+
+  g_return_val_if_fail (config != NULL, FALSE);
+  g_return_val_if_fail (filename != NULL && *filename != '\0', FALSE);
+
+  g_debug ("deamon-config %p loading file %s", config, filename);
+
+  if (!g_file_get_contents (filename, &data, NULL, err)) {
+    return FALSE;
+  }
+
+  lines = g_strsplit (data, "\n", 0);
+  for (i = 0; lines[i] != NULL; i++) {
+    if (!parse_line (config, filename, lines[i], i+1, err)) {
+      ret = FALSE;
+      break;
+    }
+  }
+
+  g_strfreev (lines);
+  g_free (data);
+
+  return ret;
+}
+
+/**
+ * pinos_daemon_config_load:
+ * @config: A #PinosDaemonConfig
+ * @err: Return location for a #GError, or %NULL
+ *
+ * Loads the default config file for pinos. The filename can be overridden with
+ * an evironment variable PINOS_CONFIG_FILE.
+ *
+ * Return: %TRUE on success, otherwise %FALSE and @err is set.
+ */
+gboolean
+pinos_daemon_config_load (PinosDaemonConfig  * config,
+                          GError            ** err)
+{
+  const gchar *filename;
+
+  g_return_val_if_fail (config != NULL, FALSE);
+
+  filename = g_getenv ("PINOS_CONFIG_FILE");
+  if (filename != NULL && *filename != '\0') {
+    g_debug ("PINOS_CONFIG_FILE set to: %s", filename);
+  } else {
+    filename = DEFAULT_CONFIG_FILE;
+  }
+
+  return pinos_daemon_config_load_file (config, filename, err);
+}
+
+/**
+ * pinos_daemon_config_run_commands:
+ * @config: A #PinosDaemonConfig
+ * @daemon: A #PinosDaemon
+ *
+ * Run all commands that have been parsed. The list of commands will be cleared
+ * when this function has been called.
+ *
+ * Returns: %TRUE if all commands where executed with success, otherwise %FALSE.
+ */
+gboolean
+pinos_daemon_config_run_commands (PinosDaemonConfig  * config,
+                                  PinosDaemon        * daemon)
+{
+  GList *walk;
+  GError *err = NULL;
+  gboolean ret = TRUE;
+
+  g_return_val_if_fail (config != NULL, FALSE);
+
+  for (walk = config->commands; walk != NULL; walk = walk->next) {
+    PinosCommand *command = (PinosCommand *)walk->data;
+    if (!pinos_command_run (command, daemon, &err)) {
+      g_warning ("could not run command %s: %s",
+          pinos_command_get_name (command), err->message);
+      g_clear_error (&err);
+      ret = FALSE;
+    }
+  }
+
+  g_list_free_full (config->commands, (GDestroyNotify) pinos_command_free);
+
+  return ret;
+}