Add "documentation" field to node specification

Use it as node type help message

graph.h

@@ -33,6 +33,7 @@ struct graph_node_specification {
 	void (*destroy)(GraphNodeSpecification * self, GraphNode * target);
 	void (*register_io)(GraphNodeSpecification * self, GraphNode * target, ProcessingState * state);
 	char *name;
+	char *documentation;
 };
 
 void graph_channel_init(GraphChannel * ch, GraphNode * start, size_t start_idx, GraphNode * end, size_t end_idx);

main.c

@@ -1,12 +1,89 @@
+#include <getopt.h>
+#include <stdio.h>
 #include "processing.h"
 #include "hash_table.h"
 #include "module_registry.h"
 
+union __attribute__((transparent_union)) option_ident {
+	enum {
+		NCOPT_BASE = 0xFF,
+		NCOPT_MODULE_HELP,
+	} as_nonchar;
+	int as_int;
+	// No "as_char" field, because it can cause problems on big-endian CPUs
+};
+
 int
 main(int argc, char ** argv)
 {
-	(void)argc;
+	const char* config_filename = "config.cfg";
-	(void)argv;
+
+	while (true) {
+		static const struct option long_options [] = {
+			{"config",         required_argument, NULL, 'c'},
+			{"help",           no_argument,       NULL, 'h'},
+			{"list-modules",   no_argument,       NULL, 'l'},
+			{"module-help",    required_argument, NULL, NCOPT_MODULE_HELP},
+		{NULL, 0, NULL, 0}};
+		static const char help_fstring[] =
+			"Usage: %s <[options...]>\n"
+			"Options:\n"
+			"\t--config <filename>, -c <filename>  read configuration from <filename>\n"
+			"\t                                    instead of ./config.cfg\n"
+			"\t--help, -h                          show this message\n"
+			"\t--list-modules, -l                  list currently loaded node types\n"
+			"\t--module-help <name>                print help information provided for node type <name>\n"
+		;
+
+		union option_ident opt = {.as_int = getopt_long(argc, argv, "c:hl", long_options, NULL)};
+		if (opt.as_int < 0) {
+			break;
+		}
+
+		switch (opt.as_int) {
+		case 'c':
+			config_filename = optarg;
+			break;
+		case 'h':
+			printf(help_fstring, argv[0]);
+			return 0;
+		case 'l':
+			{
+				const GraphNodeSpecificationRegistry * reg = get_graph_node_specification_registy();
+				for (size_t i = 0; i < reg->capacity; ++i) {
+					if (!reg->key_array[i].key.bytes) {
+						continue;
+					}
+					printf("%.*s\n", (int) reg->key_array[i].key.length, reg->key_array[i].key.bytes);
+				}
+			};
+			return 0;
+		case NCOPT_MODULE_HELP:
+			{
+				GraphNodeSpecification *spec = lookup_graph_node_specification(optarg);
+				if (!spec) {
+					fprintf(stderr, "Unknown node type \"%s\"\n", optarg);
+					return 1;
+				}
+				const char* module_help = spec->documentation;
+				if (module_help) {
+					printf("Help for node type \"%s\":\n", optarg);
+					printf("%s\n", module_help);
+				} else {
+					printf("No help provided for node type \"%s\"\n", optarg);
+				}
+			};
+			return 0;
+		default:
+			fprintf(stderr, "Unexpected option ");
+			if ((unsigned int) opt.as_int <= 0xFF) {
+				fprintf(stderr, "'%c'\n", (char) opt.as_int);
+			} else {
+				fprintf(stderr, "%d\n", opt.as_int);
+			}
+			return 1;
+		}
+	}
 
 	ProcessingState state = (ProcessingState) {
 		.wait_delay = NULL,
@@ -18,7 +95,7 @@ main(int argc, char ** argv)
 	config_t config_tree;
 	FullConfig loaded_config;
 	config_init(&config_tree);
-	config_read_file(&config_tree, "config.cfg");
+	config_read_file(&config_tree, config_filename);
 	config_set_auto_convert(&config_tree, CONFIG_TRUE);
 	if (!load_config(config_root_setting(&config_tree), &loaded_config)) {
 		perror("Failed to load config");
@@ -92,6 +169,5 @@ main(int argc, char ** argv)
 
 	io_subscription_list_deinit(&state.wait_output);
 	io_subscription_list_deinit(&state.wait_input);
-	destroy_graph_node_specification_registry();
 	return 0;
 }

modifiers.h

@@ -199,7 +199,7 @@ modifier_operation_parse(const char* name)
 	if (strcmp(name, "reset") == 0) {
 		return MODOP_UNSET;
 	}
-	if (strcmp(name, "togggle") == 0) {
+	if (strcmp(name, "toggle") == 0) {
 		return MODOP_TOGGLE;
 	}
 	return -1;

module_registry.c

@@ -1,7 +1,6 @@
 #include "module_registry.h"
-#include "hash_table.h"
 
-static TYPED_HASH_TABLE(GraphNodeSpecification*) registry;
+static GraphNodeSpecificationRegistry registry;
 static bool initialized = false;
 
 static void
@@ -34,7 +33,14 @@ lookup_graph_node_specification(const char * name)
 	return registry.value_array[idx];
 }
 
-void
+const GraphNodeSpecificationRegistry *
+get_graph_node_specification_registy()
+{
+	ensure_initialized();
+	return &registry;
+}
+
+__attribute__((destructor)) void
 destroy_graph_node_specification_registry()
 {
 	ensure_initialized();

module_registry.h

@@ -2,9 +2,13 @@
 #define MODULE_REGISTRY_H_
 
 #include "graph.h"
+#include "hash_table.h"
+
+typedef TYPED_HASH_TABLE(GraphNodeSpecification*) GraphNodeSpecificationRegistry;
 
 void register_graph_node_specification(GraphNodeSpecification * spec);
 GraphNodeSpecification * lookup_graph_node_specification(const char * name);
 void destroy_graph_node_specification_registry();
+const GraphNodeSpecificationRegistry * get_graph_node_specification_registy();
 
 #endif /* end of include guard: MODULE_REGISTRY_H_ */

nodes/evdev.c

@@ -47,7 +47,7 @@ handle_io(EventPositionBase * self, int fd, bool is_output)
 		monotime = absolute_time_sub_relative(realtime, realtime_adj);
 		EventData data = {
 			.code = {
-				.ns = 1,
+				.ns = node->namespace,
 				.major = buf.type,
 				.minor = buf.code,
 			},
@@ -139,6 +139,10 @@ GraphNodeSpecification nodespec_evdev = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = &register_io,
 	.name = "evdev",
+	.documentation = "Reads evdev events of the specified device\nDoes not accept events\nSends events on all connectors with major code, minor code, payload respectively set to evdev event type, code, value"
+	                 "\nOption 'namespace' (optional): set namespace for the generated events"
+	                 "\nOption 'file' (required): device file to read events from (like '/dev/input/eventN'), the process must have sufficient privileges to read the file"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)

nodes/getchar.c

@@ -29,7 +29,7 @@ handle_io(EventPositionBase * self, int fd, bool is_output)
 		},
 		.ttl = 100,
 		.priority = 10,
-		.payload = buf[0],
+		.payload = (unsigned char) buf[0],
 		.modifiers = EMPTY_MODIFIER_SET,
 		.time = get_current_time(),
 	};
@@ -95,6 +95,9 @@ GraphNodeSpecification nodespec_getchar = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = &register_io,
 	.name = "getchar",
+	.documentation = "Converts stdin bytes to events\nDoes not accept events\nSends events on all connectors with major and minor codes (0, 1) and the read byte as payload"
+	                 "\nOption 'namespace' (optional): set namespace for the generated events"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)

nodes/modifiers.c

@@ -91,6 +91,10 @@ GraphNodeSpecification nodespec_modifiers = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = NULL,
 	.name = "modifiers",
+	.documentation = "Sets/unsets/toggles modifiers in an event\nAccepts events on any connector\nSends events on all connectors"
+	                 "\nOption 'operation' (required): the operation to apply to the event modifier set ('set'/'unset'/'toggle')"
+	                 "\nOption 'modifiers' (required): collection of integers --- the set of modifiers to operate on"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)

nodes/modify_predicate.c

@@ -94,6 +94,13 @@ GraphNodeSpecification nodespec_modify_predicate = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = NULL,
 	.name = "modify_predicate",
+	.documentation = "Changes 'enabled' and 'inverted' flags of a predicate\nAccepts events on any connector\nDoes not send events"
+	                 "\nOption 'target' (required): the predicate to modify"
+	                 "\nOption 'enable_on' (optional): the predicate, satisfying events of which set 'enabled' flag of the target predicate to 1"
+	                 "\nOption 'disable_on' (optional): the predicate, satisfying events of which set 'enabled' flag of the target predicate to 0"
+	                 "\nOption 'invert_on' (optional): the predicate, satisfying events of which set 'inverted' flag of the target predicate to 1"
+	                 "\nOption 'uninvert_on' (optional): the predicate, satisfying events of which set 'inverted' flag of the target predicate to 0"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)

nodes/print.c

@@ -60,6 +60,8 @@ GraphNodeSpecification nodespec_print = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = NULL,
 	.name = "print",
+	.documentation = "Prints received events\nAccepts events on any connector\nDoes not send events"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)

nodes/router.c

@@ -88,6 +88,9 @@ GraphNodeSpecification nodespec_router = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = NULL,
 	.name = "router",
+	.documentation = "Conditionally copies the received events\nAccepts events on any connector\nSends events on all connectors with configured predicates"
+	                 "\nOption 'predicates' (required): collection of predicates in the order of output connectors from zero, a received event is copied to the given connector iff it satisfies the predicate"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)

nodes/tee.c

@@ -53,6 +53,8 @@ GraphNodeSpecification nodespec_tee = (GraphNodeSpecification) {
 	.destroy = &destroy,
 	.register_io = NULL,
 	.name = "tee",
+	.documentation = "Copies the received events\nAccepts events on any connector\nSends events on all connectors"
+	,
 };
 
 MODULE_CONSTRUCTOR(init)