Split the libfstree add_by_path tree traversal function out

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

3 files changed, 82 insertions, 52 deletions

diff --git a/lib/fstree/Makemodule.am b/lib/fstree/Makemodule.am
index 31bcb31..751d7dc 100644
--- a/lib/fstree/Makemodule.am
+++ b/lib/fstree/Makemodule.am
@@ -2,7 +2,7 @@ libfstree_a_SOURCES = lib/fstree/fstree.c lib/fstree/fstree_from_file.c
 libfstree_a_SOURCES += lib/fstree/fstree_sort.c
 libfstree_a_SOURCES += lib/fstree/post_process.c lib/fstree/get_path.c
 libfstree_a_SOURCES += lib/fstree/mknode.c
-libfstree_a_SOURCES += lib/fstree/add_by_path.c
+libfstree_a_SOURCES += lib/fstree/add_by_path.c lib/fstree/get_by_path.c
 libfstree_a_SOURCES += include/fstree.h lib/fstree/internal.h
 libfstree_a_SOURCES += lib/fstree/source_date_epoch.c
 libfstree_a_SOURCES += lib/fstree/canonicalize_name.c
diff --git a/lib/fstree/add_by_path.c b/lib/fstree/add_by_path.c
index bd47a76..7c9063e 100644
--- a/lib/fstree/add_by_path.c
+++ b/lib/fstree/add_by_path.c
@@ -11,69 +11,23 @@
 #include <string.h>
 #include <errno.h>
 
-static tree_node_t *child_by_name(tree_node_t *root, const char *name,
-				  size_t len)
-{
-	tree_node_t *n = root->data.dir.children;
-
-	while (n != NULL) {
-		if (strncmp(n->name, name, len) == 0 && n->name[len] == '\0')
-			break;
-
-		n = n->next;
-	}
-
-	return n;
-}
-
-static tree_node_t *get_parent_node(fstree_t *fs, tree_node_t *root,
-				    const char *path)
-{
-	const char *end;
-	tree_node_t *n;
-
-	for (;;) {
-		if (!S_ISDIR(root->mode)) {
-			errno = ENOTDIR;
-			return NULL;
-		}
-
-		end = strchr(path, '/');
-		if (end == NULL)
-			break;
-
-		n = child_by_name(root, path, end - path);
-
-		if (n == NULL) {
-			n = fstree_mknode(root, path, end - path, NULL,
-					  &fs->defaults);
-			if (n == NULL)
-				return NULL;
-
-			n->data.dir.created_implicitly = true;
-		}
-
-		root = n;
-		path = end + 1;
-	}
-
-	return root;
-}
-
 tree_node_t *fstree_add_generic(fstree_t *fs, const char *path,
 				const struct stat *sb, const char *extra)
 {
 	tree_node_t *child, *parent;
 	const char *name;
 
-	parent = get_parent_node(fs, fs->root, path);
+	parent = fstree_get_node_by_path(fs, fs->root, path, true, true);
 	if (parent == NULL)
 		return NULL;
 
 	name = strrchr(path, '/');
 	name = (name == NULL ? path : (name + 1));
 
-	child = child_by_name(parent, name, strlen(name));
+	child = parent->data.dir.children;
+	while (child != NULL && strcmp(child->name, name) != 0)
+		child = child->next;
+
 	if (child != NULL) {
 		if (!S_ISDIR(child->mode) || !S_ISDIR(sb->st_mode) ||
 		    !child->data.dir.created_implicitly) {
diff --git a/lib/fstree/get_by_path.c b/lib/fstree/get_by_path.c
new file mode 100644
index 0000000..8742892
--- /dev/null
+++ b/lib/fstree/get_by_path.c
@@ -0,0 +1,76 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * get_by_path.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "fstree.h"
+
+#include <string.h>
+#include <errno.h>
+
+static tree_node_t *child_by_name(tree_node_t *root, const char *name,
+				  size_t len)
+{
+	tree_node_t *n = root->data.dir.children;
+
+	while (n != NULL) {
+		if (strncmp(n->name, name, len) == 0 && n->name[len] == '\0')
+			break;
+
+		n = n->next;
+	}
+
+	return n;
+}
+
+tree_node_t *fstree_get_node_by_path(fstree_t *fs, tree_node_t *root,
+				     const char *path, bool create_implicitly,
+				     bool stop_at_parent)
+{
+	const char *end;
+	tree_node_t *n;
+	size_t len;
+
+	while (*path != '\0') {
+		while (*path == '/')
+			++path;
+
+		if (!S_ISDIR(root->mode)) {
+			errno = ENOTDIR;
+			return NULL;
+		}
+
+		end = strchr(path, '/');
+		if (end == NULL) {
+			if (stop_at_parent)
+				break;
+
+			len = strlen(path);
+		} else {
+			len = end - path;
+		}
+
+		n = child_by_name(root, path, len);
+
+		if (n == NULL) {
+			if (!create_implicitly) {
+				errno = ENOENT;
+				return NULL;
+			}
+
+			n = fstree_mknode(root, path, len, NULL, &fs->defaults);
+			if (n == NULL)
+				return NULL;
+
+			n->data.dir.created_implicitly = true;
+		}
+
+		root = n;
+		path = path + len;
+	}
+
+	return root;
+}