librc-depend.c: split update function into subfunctions

in preparation for dynamic service discovery, modularize the dependency
tree generation and update into distinct functions. also helps with
readability.

Signed-off-by: Anna (navi) Figueiredo Gomes <navi@vlhl.dev>

1 files changed, 89 insertions, 73 deletions

diff --git a/src/librc/librc-depend.c b/src/librc/librc-depend.c
index 9f592cfe..cb38f190 100644
--- a/src/librc/librc-depend.c
+++ b/src/librc/librc-depend.c
@@ -792,38 +792,59 @@ rc_deptree_update_needed(time_t *newest, char *file)
 	return newer;
 }
 
-/* This is a 7 phase operation
-   Phase 1 is a shell script which loads each init script and config in turn
-   and echos their dependency info to stdout
-   Phase 2 takes that and populates a depinfo object with that data
-   Phase 3 adds any provided services to the depinfo object
-   Phase 4 scans that depinfo object and puts in backlinks
-   Phase 5 removes broken before dependencies
-   Phase 6 looks for duplicate services indicating a real and virtual service
-   with the same names
-   Phase 7 saves the depinfo object to disk
-   */
-bool
-rc_deptree_update(void)
+static inline bool
+is_nosys(const char *keyword, const char *sys)
+{
+	return (strncmp(keyword, "no", 2) == 0 && strcasecmp(keyword + 2, sys) == 0)
+		|| (strncmp(keyword, "-", 1) == 0 && strcasecmp(keyword + 1, sys) == 0);
+}
+
+static void
+filter_sys(RC_DEPTREE *deptree, const char *sys)
 {
+	RC_DEPINFO *depinfo, *depinfo_save, *di;
+	RC_DEPTYPE *deptype, *provide, *dt, *dt_save;
+	RC_STRING *s, *s2;
 
+	TAILQ_FOREACH_SAFE(depinfo, deptree, entries, depinfo_save) {
+		if (!(deptype = get_deptype(depinfo, "keyword")))
+			continue;
+		TAILQ_FOREACH(s, deptype->services, entries) {
+			if (!is_nosys(s->value, sys))
+				continue;
+			provide = get_deptype(depinfo, "iprovide");
+			TAILQ_REMOVE(deptree, depinfo, entries);
+			TAILQ_FOREACH(di, deptree, entries) {
+				TAILQ_FOREACH_SAFE(dt, &di->depends, entries, dt_save) {
+					rc_stringlist_delete(dt->services, depinfo->service);
+					if (provide)
+						TAILQ_FOREACH(s2, provide->services, entries)
+							rc_stringlist_delete(dt->services, s2->value);
+					if (!TAILQ_FIRST(dt->services)) {
+						TAILQ_REMOVE(&di->depends, dt, entries);
+						free(dt->type);
+						free(dt->services);
+						free(dt);
+					}
+				}
+			}
+		}
+	}
+}
+
+static bool
+deptree_generate(RC_DEPTREE *deptree, RC_STRINGLIST **config)
+{
 	FILE *fp;
-	RC_DEPTREE *deptree, *providers;
-	RC_DEPINFO *depinfo = NULL, *depinfo_np, *di;
-	RC_DEPTYPE *deptype = NULL, *dt_np, *dt, *provide;
-	RC_STRINGLIST *config, *dupes, *types, *sorted, *visited;
-	RC_STRING *s, *s2, *s2_np, *s3, *s4;
+	RC_DEPTREE *providers;
+	RC_DEPINFO *depinfo = NULL;
+	RC_DEPTYPE *deptype = NULL, *dt;
 	char *line = NULL;
 	size_t len = 0;
 	ssize_t size;
 	char *depend, *depends, *service, *type;
-	char *deptree_cache;
-	char *depconfig;
-	size_t i, l;
-	bool retval = true;
 	const char *sys = rc_sys();
 	struct utsname uts;
-	int serrno;
 
 	/* Some init scripts need RC_LIBEXECDIR to source stuff
 	   Ideally we should be setting our full env instead */
@@ -836,10 +857,8 @@ rc_deptree_update(void)
 	if (!(fp = popen(GENDEP, "r")))
 		return false;
 
-	config = rc_stringlist_new();
+	*config = rc_stringlist_new();
 
-	deptree = xmalloc(sizeof(*deptree));
-	TAILQ_INIT(deptree);
 	while ((size = getline(&line, &len, fp)) != -1) {
 		line[size - 1] = '\0';
 		depends = line;
@@ -871,11 +890,12 @@ rc_deptree_update(void)
 		/* Now add each depend to our type.
 		   We do this individually so we handle multiple spaces gracefully */
 		while ((depend = strsep(&depends, " "))) {
+			size_t l;
 			if (depend[0] == 0)
 				continue;
 
 			if (strcmp(type, "config") == 0) {
-				rc_stringlist_addu(config, depend);
+				rc_stringlist_addu(*config, depend);
 				continue;
 			}
 
@@ -921,55 +941,15 @@ rc_deptree_update(void)
 
 	/* Phase 2 - if we're a special system, remove services that don't
 	 * work for them. This doesn't stop them from being run directly. */
-	if (sys) {
-		char *nosys, *onosys;
-
-		len = strlen(sys);
-		nosys = xmalloc(len + 2);
-		nosys[0] = '-';
-		for (i = 0; i < len; i++)
-			nosys[i + 1] = (char)tolower((unsigned char)sys[i]);
-		nosys[i + 1] = '\0';
-
-		onosys = xmalloc(len + 3);
-		onosys[0] = 'n';
-		onosys[1] = 'o';
-		for (i = 0; i < len; i++)
-			onosys[i + 2] = (char)tolower((unsigned char)sys[i]);
-		onosys[i + 2] = '\0';
-
-		TAILQ_FOREACH_SAFE(depinfo, deptree, entries, depinfo_np) {
-			if (!(deptype = get_deptype(depinfo, "keyword")))
-				continue;
-			TAILQ_FOREACH(s, deptype->services, entries) {
-				if (strcmp(s->value, nosys) != 0 && strcmp(s->value, onosys) != 0)
-					continue;
-				provide = get_deptype(depinfo, "iprovide");
-				TAILQ_REMOVE(deptree, depinfo, entries);
-				TAILQ_FOREACH(di, deptree, entries) {
-					TAILQ_FOREACH_SAFE(dt, &di->depends, entries, dt_np) {
-						rc_stringlist_delete(dt->services, depinfo->service);
-						if (provide)
-							TAILQ_FOREACH(s2, provide->services, entries)
-								rc_stringlist_delete(dt->services, s2->value);
-						if (!TAILQ_FIRST(dt->services)) {
-							TAILQ_REMOVE(&di->depends, dt, entries);
-							free(dt->type);
-							free(dt->services);
-							free(dt);
-						}
-					}
-				}
-			}
-		}
-		free(nosys);
-		free(onosys);
-	}
+	if (sys)
+		filter_sys(deptree, sys);
 
 	/* Phase 3 - add our providers to the tree */
 	providers = xmalloc(sizeof(*providers));
 	TAILQ_INIT(providers);
 	TAILQ_FOREACH(depinfo, deptree, entries) {
+		RC_DEPINFO *di;
+		RC_STRING *s;
 		if (!(deptype = get_deptype(depinfo, "iprovide")))
 			continue;
 		TAILQ_FOREACH(s, deptype->services, entries) {
@@ -981,9 +961,45 @@ rc_deptree_update(void)
 	TAILQ_CONCAT(deptree, providers, entries);
 	free(providers);
 
+	return true;
+}
+
+/* This is a 7 phase operation
+   Phase 1 is a shell script which loads each init script and config in turn
+   and echos their dependency info to stdout
+   Phase 2 takes that and populates a depinfo object with that data
+   Phase 3 adds any provided services to the depinfo object
+   Phase 4 scans that depinfo object and puts in backlinks
+   Phase 5 removes broken before dependencies
+   Phase 6 looks for duplicate services indicating a real and virtual service
+   with the same names
+   Phase 7 saves the depinfo object to disk
+   */
+bool
+rc_deptree_update(void)
+{
+
+	FILE *fp;
+	RC_DEPTREE *deptree;
+	RC_DEPINFO *depinfo = NULL, *di;
+	RC_DEPTYPE *deptype = NULL, *dt;
+	RC_STRINGLIST *config, *dupes, *types, *sorted, *visited;
+	RC_STRING *s, *s2, *s2_np, *s3, *s4;
+	char *deptree_cache;
+	char *depconfig;
+	bool retval = true;
+	int serrno;
+
+	deptree = xmalloc(sizeof(*deptree));
+	TAILQ_INIT(deptree);
+	if (!deptree_generate(deptree, &config)) {
+		free(deptree);
+		return false;
+	}
+
 	/* Phase 4 - backreference our depends */
 	TAILQ_FOREACH(depinfo, deptree, entries) {
-		for (i = 0; deppairs[i].depend; i++) {
+		for (size_t i = 0; deppairs[i].depend; i++) {
 			deptype = get_deptype(depinfo, deppairs[i].depend);
 			if (!deptype)
 				continue;
@@ -1082,7 +1098,7 @@ rc_deptree_update(void)
 	   */
 	xasprintf(&deptree_cache, "%s/%s", rc_service_dir(), RC_DEPTREE_CACHE);
 	if ((fp = fopen(deptree_cache, "w"))) {
-		i = 0;
+		size_t i = 0;
 		TAILQ_FOREACH(depinfo, deptree, entries) {
 			fprintf(fp, "depinfo_%zu_service='%s'\n", i, depinfo->service);
 			TAILQ_FOREACH(deptype, &depinfo->depends, entries) {