Add support for config file

Closes: https://github.com/emersion/xdg-desktop-portal-wlr/issues/60

.builds/alpine.yml

@@ -6,6 +6,7 @@ packages:
   - pipewire-dev
   - wayland-dev
   - wayland-protocols
+  - iniparser-dev
 sources:
   - https://github.com/emersion/xdg-desktop-portal-wlr
 tasks:

.builds/archlinux.yml

@@ -6,6 +6,7 @@ packages:
   - wayland
   - wayland-protocols
   - pipewire
+  - iniparser
 sources:
   - https://github.com/emersion/xdg-desktop-portal-wlr
 tasks:

.builds/freebsd.yml

@@ -6,6 +6,7 @@ packages:
   - pkgconf
   - wayland
   - wayland-protocols
+  - iniparser
 sources:
   - https://github.com/emersion/xdg-desktop-portal-wlr
 tasks:

contrib/config.sample

@@ -0,0 +1,2 @@
+[screencast]
+output=

include/config.h

@@ -0,0 +1,18 @@
+#ifndef CONFIG_H
+#define CONFIG_H
+
+#include "logger.h"
+
+struct config_screencast {
+	char *output_name;
+};
+
+struct xdpw_config {
+	struct config_screencast screencast_conf;
+};
+
+void print_config(enum LOGLEVEL loglevel, struct xdpw_config *config);
+void finish_config(struct xdpw_config *config);
+void init_config(char ** const configfile, struct xdpw_config *config);
+
+#endif

include/logger.h

@@ -3,6 +3,8 @@
 
 #include <stdio.h>
 
+#define DEFAULT_LOGLEVEL ERROR
+
 enum LOGLEVEL { QUIET, ERROR, WARN, INFO, DEBUG, TRACE };
 
 struct logger_properties {

include/screencast_common.h

@@ -57,9 +57,6 @@ struct xdpw_screencast_context {
 	struct zxdg_output_manager_v1* xdg_output_manager;
 	struct wl_shm *shm;
 
-	// cli options
-	const char *output_name;
-
 	// sessions
 	struct wl_list screencast_instances;
 };

include/xdpw.h

@@ -11,6 +11,7 @@
 #endif
 
 #include "screencast_common.h"
+#include "config.h"
 
 struct xdpw_state {
 	struct wl_list xdpw_sessions;
@@ -21,6 +22,7 @@ struct xdpw_state {
 	uint32_t screencast_source_types; // bitfield of enum source_types
 	uint32_t screencast_cursor_modes; // bitfield of enum cursor_modes
 	uint32_t screencast_version;
+	struct xdpw_config *config;
 };
 
 struct xdpw_request {
@@ -41,7 +43,7 @@ enum {
 };
 
 int xdpw_screenshot_init(struct xdpw_state *state);
-int xdpw_screencast_init(struct xdpw_state *state, const char *output_name);
+int xdpw_screencast_init(struct xdpw_state *state);
 
 struct xdpw_request *xdpw_request_create(sd_bus *bus, const char *object_path);
 void xdpw_request_destroy(struct xdpw_request *req);

meson.build

@@ -16,12 +16,17 @@ add_project_arguments(cc.get_supported_arguments([
 	'-D_POSIX_C_SOURCE=200809L',
 ]), language: 'c')
 
+prefix = get_option('prefix')
+sysconfdir = get_option('sysconfdir')
+add_project_arguments('-DSYSCONFDIR="@0@"'.format(join_paths(prefix, sysconfdir)), language : 'c')
+
 inc = include_directories('include')
 
 rt = cc.find_library('rt')
 pipewire = dependency('libpipewire-0.3', version: '>= 0.3.2')
 wayland_client = dependency('wayland-client')
 wayland_protos = dependency('wayland-protocols', version: '>=1.14')
+iniparser = cc.find_library('iniparser', dirs: [join_paths(get_option('prefix'),get_option('libdir'))])
 
 if get_option('sd-bus-provider') == 'auto'
 	assert(get_option('auto_features').auto(), 'sd-bus-provider must not be set to auto since auto_features != auto')
@@ -55,6 +60,7 @@ executable(
 	files([
 		'src/core/main.c',
 		'src/core/logger.c',
+		'src/core/config.c',
 		'src/core/request.c',
 		'src/core/session.c',
 		'src/screenshot/screenshot.c',
@@ -69,6 +75,7 @@ executable(
 		sdbus,
 		pipewire,
 		rt,
+		iniparser,
 	],
 	include_directories: [inc],
 	install: true,

src/core/config.c

@@ -0,0 +1,118 @@
+#include "config.h"
+#include "xdpw.h"
+#include "logger.h"
+
+#include <dictionary.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <iniparser.h>
+
+void print_config(enum LOGLEVEL loglevel, struct xdpw_config *config) {
+	logprint(loglevel, "config: outputname  %s", config->screencast_conf.output_name);
+}
+
+// NOTE: calling finish_config won't prepare the config to be read again from config file
+// with init_config since to pointers and other values won't be reset to NULL, or 0
+void finish_config(struct xdpw_config *config) {
+	logprint(DEBUG, "config: destroying config");
+
+	// screencast
+	free(&config->screencast_conf.output_name);
+}
+
+static void getstring_from_conffile(dictionary *d,
+		const char *key, char **dest, const char *fallback) {
+	if (*dest != NULL) {
+		return;
+	}
+	const char *c = iniparser_getstring(d, key, fallback);
+	if (c == NULL) {
+		return;
+	}
+	// Allow keys without value as default
+	if (strcmp(c, "") != 0) {
+		*dest = strdup(c);
+	} else {
+		*dest = fallback ? strdup(fallback) : NULL;
+	}
+}
+
+static bool file_exists(const char *path) {
+	return path && access(path, R_OK) != -1;
+}
+
+static char *config_path(char *prefix, char *filename) {
+	if (!prefix || !prefix[0] || !filename || !filename[0]) {
+		return NULL;
+	}
+
+	char *config_folder = "xdg-desktop-portal-wlr";
+
+	size_t size = 3 + strlen(prefix) + strlen(config_folder) + strlen(filename);
+	char *path = calloc(size, sizeof(char));
+	snprintf(path, size, "%s/%s/%s", prefix, config_folder, filename);
+	return path;
+}
+
+static void config_parse_file(const char *configfile, struct xdpw_config *config) {
+	dictionary *d = NULL;
+	if (configfile) {
+		logprint(INFO, "config: using config file %s", *configfile);
+		d = iniparser_load(configfile);
+	} else {
+		logprint(INFO, "config: no config file found");
+	}
+	if (configfile && !d) {
+		logprint(ERROR, "config: unable to load config file %s", configfile);
+	}
+
+	// screencast
+	getstring_from_conffile(d, "screencast:output_name", &config->screencast_conf.output_name, NULL);
+
+	iniparser_freedict(d);
+	logprint(DEBUG, "config: config file parsed");
+	print_config(DEBUG, config);
+}
+
+static char *get_config_path(void) {
+	const char *home = getenv("HOME");
+	size_t size_fallback = 1 + strlen(home) + strlen("/.config");
+	char *config_home_fallback = calloc(size_fallback, sizeof(char));
+	snprintf(config_home_fallback, size_fallback, "%s/.config", home);
+
+	char *prefix[4];
+	prefix[0] = getenv("XDG_CONFIG_HOME");
+	prefix[1] = config_home_fallback;
+	prefix[2] = SYSCONFDIR "/xdg";
+	prefix[3] = SYSCONFDIR;
+
+	char *config[2];
+	config[0] = getenv("XDG_CURRENT_DESKTOP");
+	config[1] = "config";
+
+	for (size_t i = 0; i < 4; i++) {
+		for (size_t j = 0; j < 2; j++) {
+			char *path = config_path(prefix[i], config[j]);
+			if (!path) {
+				continue;
+			}
+			logprint(TRACE, "config: trying config file %s", path);
+			if (file_exists(path)) {
+				return path;
+			}
+			free(path);
+		}
+	}
+
+	return NULL;
+}
+
+void init_config(char ** const configfile, struct xdpw_config *config) {
+	if (*configfile == NULL) {
+		*configfile = get_config_path();
+	}
+
+	config_parse_file(*configfile, config);
+}

src/core/logger.c

@@ -5,17 +5,6 @@
 #include <string.h>
 #include <time.h>
 
-static int NUM_LEVELS = 6;
-
-static const char *loglevels[] = {
-	"QUIET",
-	"ERROR",
-	"WARN",
-	"INFO",
-	"DEBUG",
-	"TRACE"
-};
-
 static struct logger_properties logprops;
 
 void init_logger(FILE *dst, enum LOGLEVEL level) {
@@ -24,16 +13,43 @@ void init_logger(FILE *dst, enum LOGLEVEL level) {
 }
 
 enum LOGLEVEL get_loglevel(const char *level) {
-	int i;
-	for (i = 0; i < NUM_LEVELS; i++) {
-		if (!strcmp(level, loglevels[i])) {
-			return (enum LOGLEVEL) i;
-		}
+	if (strcmp(level, "QUIET") == 0) {
+		return QUIET;
+	} else if (strcmp(level, "ERROR") == 0) {
+		return ERROR;
+	} else if (strcmp(level, "WARN") == 0) {
+		return WARN;
+	} else if (strcmp(level, "INFO") == 0) {
+		return INFO;
+	} else if (strcmp(level, "DEBUG") == 0) {
+		return DEBUG;
+	} else if (strcmp(level, "TRACE") == 0) {
+		return TRACE;
 	}
+
 	fprintf(stderr, "Could not understand log level %s\n", level);
 	abort();
 }
 
+static const char *print_loglevel(enum LOGLEVEL loglevel) {
+	switch (loglevel) {
+	case QUIET:
+		return "QUIET";
+	case ERROR:
+		return "ERROR";
+	case WARN:
+		return "WARN";
+	case INFO:
+		return "INFO";
+	case DEBUG:
+		return "DEBUG";
+	case TRACE:
+		return "TRACE";
+	}
+	fprintf(stderr, "Could not find log level %d\n", loglevel);
+	abort();
+}
+
 void logprint(enum LOGLEVEL level, char *msg, ...) {
 	if (!logprops.dst) {
 		fprintf(stderr, "Logger has been called, but was not initialized\n");
@@ -56,7 +72,7 @@ void logprint(enum LOGLEVEL level, char *msg, ...) {
 
 	fprintf(logprops.dst, "%s", timestr);
 	fprintf(logprops.dst, " ");
-	fprintf(logprops.dst, "[%s]", loglevels[level]);
+	fprintf(logprops.dst, "[%s]", print_loglevel(level));
 	fprintf(logprops.dst, " - ");
 
 	va_start(args, msg);

src/core/main.c

@@ -24,6 +24,8 @@ static int xdpw_usage(FILE* stream, int rc) {
 		"                                     QUIET, ERROR, WARN, INFO, DEBUG, TRACE\n"
 		"    -o, --output=<name>              Select output to capture.\n"
 		"                                     metadata (performs no conversion).\n"
+		"    -c, --config=<config file>	      Select config file.\n"
+		"                                     (default is $XDG_CONFIG_HOME/xdg-desktop-portal-wlr/config)\n"
 		"    -r, --replace                    Replace a running instance.\n"
 		"    -h, --help                       Get help (this text).\n"
 		"\n";
@@ -39,14 +41,16 @@ static int handle_name_lost(sd_bus_message *m, void *userdata, sd_bus_error *ret
 }
 
 int main(int argc, char *argv[]) {
-	const char* output_name = NULL;
-	enum LOGLEVEL loglevel = ERROR;
+	struct xdpw_config config = {0};
+	char *configfile = NULL;
+	enum LOGLEVEL loglevel = DEFAULT_LOGLEVEL;
 	bool replace = false;
 
-	static const char* shortopts = "l:o:rh";
+	static const char* shortopts = "l:o:c:rh";
 	static const struct option longopts[] = {
 		{ "loglevel", required_argument, NULL, 'l' },
 		{ "output", required_argument, NULL, 'o' },
+		{ "config", required_argument, NULL, 'c' },
 		{ "replace", no_argument, NULL, 'r' },
 		{ "help", no_argument, NULL, 'h' },
 		{ NULL, 0, NULL, 0 }
@@ -62,7 +66,10 @@ int main(int argc, char *argv[]) {
 			loglevel = get_loglevel(optarg);
 			break;
 		case 'o':
-			output_name = optarg;
+			config.screencast_conf.output_name = strdup(optarg);
+			break;
+		case 'c':
+			configfile = strdup(optarg);
 			break;
 		case 'r':
 			replace = true;
@@ -75,6 +82,7 @@ int main(int argc, char *argv[]) {
 	}
 
 	init_logger(stderr, loglevel);
+	init_config(&configfile, &config);
 
 	int ret = 0;
 
@@ -111,12 +119,13 @@ int main(int argc, char *argv[]) {
 		.screencast_source_types = MONITOR,
 		.screencast_cursor_modes = HIDDEN | EMBEDDED,
 		.screencast_version = XDP_CAST_PROTO_VER,
+		.config = &config,
 	};
 
 	wl_list_init(&state.xdpw_sessions);
 
 	xdpw_screenshot_init(&state);
-	ret = xdpw_screencast_init(&state, output_name);
+	ret = xdpw_screencast_init(&state);
 	if (ret < 0) {
 		logprint(ERROR, "xdpw: failed to initialize screencast");
 		goto error;
@@ -217,6 +226,8 @@ int main(int argc, char *argv[]) {
 	}
 
 	// TODO: cleanup
+	finish_config(&config);
+	free(configfile);
 
 	return EXIT_SUCCESS;
 

src/screencast/screencast.c

@@ -48,8 +48,9 @@ int setup_outputs(struct xdpw_screencast_context *ctx, struct xdpw_session *sess
 	}
 
 	struct xdpw_wlr_output *out;
-	if (ctx->output_name) {
-		out = xdpw_wlr_output_find_by_name(&ctx->output_list, ctx->output_name);
+	if (ctx->state->config->screencast_conf.output_name) {
+		out = xdpw_wlr_output_find_by_name(&ctx->output_list,
+				ctx->state->config->screencast_conf.output_name);
 		if (!out) {
 			logprint(ERROR, "wlroots: no such output");
 			abort();
@@ -434,12 +435,11 @@ static const sd_bus_vtable screencast_vtable[] = {
 	SD_BUS_VTABLE_END
 };
 
-int xdpw_screencast_init(struct xdpw_state *state, const char *output_name) {
+int xdpw_screencast_init(struct xdpw_state *state) {
 	sd_bus_slot *slot = NULL;
 
 	state->screencast = (struct xdpw_screencast_context) { 0 };
 	state->screencast.state = state;
-	state->screencast.output_name = output_name;
 
 	int err;
 	err = xdpw_pwr_core_connect(state);