[augeas-devel] augeas: master - * src/augeas.c: fix handling of dirty flag

[David Lutterkort]

Gitweb:        http://git.fedorahosted.org/git/augeas.git?p=augeas.git;a=commitdiff;h=7278965b521748b4fcc0971aab5d57903cc338f3
Commit:        7278965b521748b4fcc0971aab5d57903cc338f3
Parent:        41cbcf133eb98352c8837af5c355a4abf17914fc
Author:        David Lutterkort <lutter at redhat.com>
AuthorDate:    Fri Mar 13 15:03:54 2009 -0700
Committer:     David Lutterkort <lutter at redhat.com>
CommitterDate: Fri Mar 13 15:15:58 2009 -0700

* src/augeas.c: fix handling of dirty flag

Under some circumstances, we did not properly propagate the dirty flag up
the tree, leading to files that were not saved even though they should have
been.

This also removes two full sweeps over the tree for dirty handling, and now
only touches nodes that are/need to be marked dirty.
---
 src/augeas.c   |   42 +++++++++++++++++++++---------------------
 src/internal.h |    6 ++++++
 2 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/src/augeas.c b/src/augeas.c
index ba05d66..1dc836a 100644
--- a/src/augeas.c
+++ b/src/augeas.c
@@ -44,21 +44,20 @@ static const char *const static_nodes[][2] = {
     { AUGEAS_META_TREE "/version/save/mode[4]", AUG_SAVE_OVERWRITE_TEXT }
 };
 
-/* Propagate dirty flags towards the root */
-static int tree_propagate_dirty(struct tree *tree) {
-    if (tree->dirty)
-        return 1;
-    list_for_each(c, tree->children) {
-        tree->dirty |= tree_propagate_dirty(c);
-    }
-    return tree->dirty;
+static void tree_mark_dirty(struct tree *tree) {
+    do {
+        tree->dirty = 1;
+        tree = tree->parent;
+    } while (tree != tree->parent && !tree->dirty);
 }
 
 /* Clear the dirty flag in the whole TREE */
 static void tree_clean(struct tree *tree) {
+    if (tree->dirty) {
+        list_for_each(c, tree->children)
+            tree_clean(c);
+    }
     tree->dirty = 0;
-    list_for_each(c, tree->children)
-        tree_clean(c);
 }
 
 /* Parse a path expression. Report errors in /augeas/pathx/error */
@@ -203,9 +202,8 @@ struct augeas *aug_init(const char *root, const char *loadpath,
             continue;
         transform_load(result, xform);
     }
-    list_for_each(tree, result->origin->children) {
-        tree_clean(tree);
-    }
+    tree_clean(result->origin);
+
     return result;
 
  error:
@@ -250,7 +248,7 @@ struct tree *tree_set(struct pathx *p, const char *value) {
         if (tree->value == NULL)
             return NULL;
     }
-    tree->dirty = 1;
+    tree_mark_dirty(tree);
     return tree;
 }
 
@@ -319,7 +317,10 @@ struct tree *make_tree(char *label, char *value, struct tree *parent,
     tree->children = children;
     list_for_each(c, tree->children)
         c->parent = tree;
-    tree->dirty = 1;
+    if (parent != NULL)
+        tree_mark_dirty(tree);
+    else
+        tree->dirty = 1;
     return tree;
 }
 
@@ -364,7 +365,7 @@ int tree_unlink(struct tree *tree) {
 
     assert (tree->parent != NULL);
     list_remove(tree, tree->parent->children);
-    tree->parent->dirty = 1;
+    tree_mark_dirty(tree->parent);
     result = free_tree(tree->children) + 1;
     free_tree_node(tree);
     return result;
@@ -435,6 +436,8 @@ int tree_replace(struct tree *origin, const char *path, struct tree *sub) {
     list_for_each(s, sub) {
         s->parent = parent;
     }
+    if (sub->dirty)
+        tree_mark_dirty(parent);
     free_pathx(p);
     return 0;
  error:
@@ -485,7 +488,7 @@ int aug_mv(struct augeas *aug, const char *src, const char *dst) {
     ts->children = NULL;
 
     tree_unlink(ts);
-    td->dirty = 1;
+    tree_mark_dirty(td);
 
     ret = 0;
  done:
@@ -685,9 +688,6 @@ int aug_save(struct augeas *aug) {
 
     aug_rm(aug, AUGEAS_EVENTS_SAVED);
 
-    list_for_each(t, aug->origin->children) {
-        tree_propagate_dirty(t);
-    }
     if (files->dirty) {
         list_for_each(t, files->children) {
             if (tree_save(aug, t, AUGEAS_FILES_TREE) == -1)
@@ -703,7 +703,7 @@ int aug_save(struct augeas *aug) {
         }
     }
     if (!(aug->flags & AUG_SAVE_NOOP)) {
-        tree_clean(aug->origin->children);
+        tree_clean(aug->origin);
     }
     return ret;
 }
diff --git a/src/internal.h b/src/internal.h
index 7844935..0b49f95 100644
--- a/src/internal.h
+++ b/src/internal.h
@@ -285,6 +285,12 @@ struct augeas {
  * standalone trees with a fake root, called origin. That root is generally
  * not referenced from anywhere. Standalone trees should be created with
  * MAKE_TREE_ORIGIN.
+ *
+ * The DIRTY flag is used to track which parts of the tree might need to be
+ * saved. For any node that is marked dirty, all of its ancestors must be
+ * marked dirty, too. Instead of setting this flag directly, the function
+ * TREE_MARK_DIRTY in augeas.c should be used (and only functions in that
+ * file should have a need to mark nodes as dirty)
  */
 struct tree {
     struct tree *next;