filter_config: convert to C++

src/FilterConfig.cxx

@@ -0,0 +1,122 @@
+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "FilterConfig.hxx"
+#include "conf.h"
+
+extern "C" {
+#include "filter/chain_filter_plugin.h"
+}
+
+#include "filter_plugin.h"
+#include "filter_internal.h"
+#include "filter_registry.h"
+
+#include <string.h>
+
+static GQuark
+filter_quark(void)
+{
+	return g_quark_from_static_string("filter");
+}
+
+/**
+ * Find the "filter" configuration block for the specified name.
+ *
+ * @param filter_template_name the name of the filter template
+ * @param error_r space to return an error description
+ * @return the configuration block, or NULL if none was configured
+ */
+static const struct config_param *
+filter_plugin_config(const char *filter_template_name, GError **error_r)
+{
+	const struct config_param *param = NULL;
+
+	while ((param = config_get_next_param(CONF_AUDIO_FILTER, param)) != NULL) {
+		const char *name =
+			config_get_block_string(param, "name", NULL);
+		if (name == NULL) {
+			g_set_error(error_r, filter_quark(), 1,
+				    "filter configuration without 'name' name in line %d",
+				    param->line);
+			return NULL;
+		}
+
+		if (strcmp(name, filter_template_name) == 0)
+			return param;
+	}
+
+	g_set_error(error_r, filter_quark(), 1,
+		    "filter template not found: %s",
+		    filter_template_name);
+
+	return NULL;
+}
+
+/**
+ * Builds a filter chain from a configuration string on the form
+ * "name1, name2, name3, ..." by looking up each name among the
+ * configured filter sections.
+ * @param chain the chain to append filters on
+ * @param spec the filter chain specification
+ * @param error_r space to return an error description
+ * @return the number of filters which were successfully added
+ */
+unsigned int
+filter_chain_parse(struct filter *chain, const char *spec, GError **error_r)
+{
+
+	// Split on comma
+	gchar** tokens = g_strsplit_set(spec, ",", 255);
+
+	unsigned added_filters = 0;
+
+	// Add each name to the filter chain by instantiating an actual filter
+	char **template_names = tokens;
+	while (*template_names != NULL) {
+		struct filter *f;
+		const struct config_param *cfg;
+
+		// Squeeze whitespace
+		g_strstrip(*template_names);
+
+		cfg = filter_plugin_config(*template_names, error_r);
+		if (cfg == NULL) {
+			// The error has already been set, just stop.
+			break;
+		}
+
+		// Instantiate one of those filter plugins with the template name as a hint
+		f = filter_configured_new(cfg, error_r);
+		if (f == NULL) {
+			// The error has already been set, just stop.
+			break;
+		}
+
+		filter_chain_append(chain, f);
+		++added_filters;
+
+		++template_names;
+	}
+
+	g_strfreev(tokens);
+
+	return added_filters;
+}