Config section for integer constants

config.c

@@ -123,6 +123,39 @@ load_channels_section(const config_setting_t *config_section)
 	return result;
 }
 
+static void
+load_constants_section(const config_setting_t *config_section, ConstantRegistry *constants)
+{
+	ssize_t length = config_setting_length(config_section);
+	if (length <= 0) {
+		return;
+	}
+	for (ssize_t i = 0; i < length; ++i) {
+		config_setting_t *item = config_setting_get_elem(config_section, i);
+		if (!item) {
+			continue;
+		}
+		const char *name;
+		long long value;
+		if (!(name = config_setting_name(item))) {
+			config_setting_lookup_string(item, "name", &name);
+		}
+		if (!name) {
+			continue;
+		}
+		if (config_setting_is_scalar(item) == CONFIG_TRUE) {
+			value = config_setting_get_int64(item);
+		} else if (config_setting_is_group(item) == CONFIG_TRUE) {
+			if (config_setting_lookup_int64(item, "value", &value) == CONFIG_FALSE) {
+				continue;
+			}
+		} else {
+			continue;
+		}
+		hash_table_insert(constants, hash_table_key_from_cstr(name), &value);
+	}
+}
+
 bool
 load_config(const config_setting_t *config_root, FullConfig *config)
 {
@@ -131,6 +164,9 @@ load_config(const config_setting_t *config_root, FullConfig *config)
 	}
 	const config_setting_t *node_config = config_setting_get_member(config_root, "nodes");
 	const config_setting_t *channel_config = config_setting_get_member(config_root, "channels");
+	const config_setting_t *constants_config = config_setting_get_member(config_root, "constants");
+	hash_table_init(&config->constants, NULL);
+	load_constants_section(constants_config, &config->constants);
 	config->nodes = load_nodes_section(node_config);
 	config->channels = load_channels_section(channel_config);
 	return true;
@@ -152,4 +188,25 @@ reset_config(FullConfig *config)
 		config->channels.items = NULL;
 		config->channels.length = 0;
 	}
+	hash_table_deinit(&config->constants);
+}
+
+long long
+resolve_constant(const ConstantRegistry * registry, const config_setting_t * setting)
+{
+	if (!setting) {
+		return 0;
+	}
+	if (config_setting_type(setting) == CONFIG_TYPE_STRING) {
+		if (!registry) {
+			return 1;
+		}
+		const char *name = config_setting_get_string(setting);
+		HashTableIndex idx = hash_table_find(registry, hash_table_key_from_cstr(name));
+		if (idx < 0) {
+			return 0;
+		}
+		return registry->value_array[idx];
+	}
+	return config_setting_get_int64(setting);
 }

config.cfg

@@ -1,8 +1,13 @@
+constants = {
+	ns_stdin = 0;
+	ns_clickpad = 1;
+};
+
 nodes = {
 	stdin = {
 		type = "getchar";
 		options = {
-			namespace = 0;
+			namespace = "ns_stdin";
 		};
 	};
 	print = {
@@ -13,7 +18,7 @@ nodes = {
 		type = "evdev";
 		options = {
 			file = "/dev/input/event7";
-			namespace = 1;
+			namespace = "ns_clickpad";
 		};
 	};
 };

config.h

@@ -3,6 +3,7 @@
 
 #include <libconfig.h>
 #include "defs.h"
+#include "hash_table.h"
 
 typedef struct {
 	const char *name;
@@ -27,12 +28,16 @@ typedef struct {
 	GraphChannelConfig *items;
 } GraphChannelConfigSection;
 
+typedef TYPED_HASH_TABLE(long long) ConstantRegistry;
+
 typedef struct {
 	GraphNodeConfigSection nodes;
 	GraphChannelConfigSection channels;
+	ConstantRegistry constants;
 } FullConfig;
 
 bool load_config(const config_setting_t *config_root, FullConfig *config);
 void reset_config(FullConfig *config);
+long long resolve_constant(const ConstantRegistry * registry, const config_setting_t * setting);
 
 #endif /* end of include guard: CONFIG_H_ */

graph.c

@@ -88,12 +88,12 @@ graph_channel_init(GraphChannel * ch, GraphNode * start, size_t start_idx, Graph
 }
 
 GraphNode *
-graph_node_new(GraphNodeSpecification * spec, GraphNodeConfig * config)
+graph_node_new(GraphNodeSpecification * spec, GraphNodeConfig * config, const ConstantRegistry * constants)
 {
 	if (!spec || !spec->create) {
 		return NULL;
 	}
-	return spec->create(spec, config);
+	return spec->create(spec, config, constants);
 }
 
 void

graph.h

@@ -29,14 +29,14 @@ struct graph_channel {
 };
 
 struct graph_node_specification {
-	GraphNode * (*create)(GraphNodeSpecification * self, GraphNodeConfig * config);
+	GraphNode * (*create)(GraphNodeSpecification * self, GraphNodeConfig * config, const ConstantRegistry * constants);
 	void (*destroy)(GraphNodeSpecification * self, GraphNode * target);
 	void (*register_io)(GraphNodeSpecification * self, GraphNode * target, ProcessingState * state);
 	char *name;
 };
 
 void graph_channel_init(GraphChannel * ch, GraphNode * start, size_t start_idx, GraphNode * end, size_t end_idx);
-GraphNode *graph_node_new(GraphNodeSpecification * spec, GraphNodeConfig * config);
+GraphNode *graph_node_new(GraphNodeSpecification * spec, GraphNodeConfig * config, const ConstantRegistry * constants);
 void graph_node_delete(GraphNode * self);
 void graph_node_register_io(GraphNode * self, ProcessingState * state);
 void graph_channel_list_init(GraphChannelList * lst);

main.c

@@ -39,7 +39,7 @@ main(int argc, char ** argv)
 			fprintf(stderr, "Unknown node type \"%s\" for node %ld \"%s\"\n", type_name, i, loaded_config.nodes.items[i].name);
 			exit(1);
 		}
-		if (!(nodes[i] = graph_node_new(spec, &loaded_config.nodes.items[i]))) {
+		if (!(nodes[i] = graph_node_new(spec, &loaded_config.nodes.items[i], &loaded_config.constants))) {
 			perror("Failed to create node");
 			fprintf(stderr, "%ld \"%s\"\n", i, loaded_config.nodes.items[i].name);
 			exit(1);

nodes/evdev.c

@@ -69,7 +69,7 @@ handle_io(EventPositionBase * self, int fd, bool is_output)
 }
 
 static GraphNode *
-create(GraphNodeSpecification * spec, GraphNodeConfig * config)
+create(GraphNodeSpecification * spec, GraphNodeConfig * config, const ConstantRegistry * constants)
 {
 	EvdevGraphNode * node = T_ALLOC(1, EvdevGraphNode);
 	if (!node) {
@@ -77,7 +77,7 @@ create(GraphNodeSpecification * spec, GraphNodeConfig * config)
 	}
 	const char *filename = NULL;
 	if (config) {
-		config_setting_lookup_int(config->options, "namespace", &node->namespace);
+		node->namespace = resolve_constant(constants, config_setting_get_member(config->options, "namespace"));
 		config_setting_lookup_string(config->options, "file", &filename);
 	}
 	if (filename == NULL) {

nodes/getchar.c

@@ -49,7 +49,7 @@ handle_io(EventPositionBase * self, int fd, bool is_output)
 }
 
 static GraphNode *
-create(GraphNodeSpecification * spec, GraphNodeConfig * config)
+create(GraphNodeSpecification * spec, GraphNodeConfig * config, const ConstantRegistry * constants)
 {
 	GetcharGraphNode * node = T_ALLOC(1, GetcharGraphNode);
 	if (!node) {
@@ -70,11 +70,8 @@ create(GraphNodeSpecification * spec, GraphNodeConfig * config)
 			.handle_io = handle_io,
 			.enabled = true,
 		},
-		.namespace = 0,
+		.namespace = resolve_constant(constants, config_setting_get_member(config->options, "namespace")),
 	};
-	if (config) {
-		config_setting_lookup_int(config->options, "namespace", &node->namespace);
-	}
 	return &node->as_GraphNode;
 }
 

nodes/print.c

@@ -28,9 +28,10 @@ handle_event(EventPositionBase * self, EventNode * event)
 }
 
 static GraphNode *
-create(GraphNodeSpecification * spec, GraphNodeConfig * config)
+create(GraphNodeSpecification * spec, GraphNodeConfig * config, const ConstantRegistry * constants)
 {
 	(void) config;
+	(void) constants;
 	GraphNode * node = T_ALLOC(1, GraphNode);
 	if (!node) {
 		return node;

nodes/tee.c

@@ -21,9 +21,10 @@ handle_event(EventPositionBase * self, EventNode * event)
 }
 
 static GraphNode *
-create(GraphNodeSpecification * spec, GraphNodeConfig * config)
+create(GraphNodeSpecification * spec, GraphNodeConfig * config, const ConstantRegistry * constants)
 {
 	(void) config;
+	(void) constants;
 	GraphNode * node = T_ALLOC(1, GraphNode);
 	if (!node) {
 		return node;