X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=bluesky%2Futil.c;h=3ac6596808bafd865a7a8c7adb97b588c7ea8997;hb=3d09579f873ce2153651f0b6a520ee8d2ebb2012;hp=2e6f0aa1d64227ce4bc56fc425285bce032161be;hpb=d97af3e024253910cd60350e0504ea64711fbb00;p=bluesky.git

diff --git a/bluesky/util.c b/bluesky/util.c
index 2e6f0aa..3ac6596 100644
--- a/bluesky/util.c
+++ b/bluesky/util.c
@@ -36,6 +36,20 @@ gchar *bluesky_lowercase(const gchar *s)
     return g_ascii_strdown(s, -1);
 }
 
+gboolean bluesky_inode_is_ready(BlueSkyInode *inode)
+{
+    if (inode == NULL)
+        return FALSE;
+
+    g_mutex_lock(inode->lock);
+    gboolean valid = (inode->type != BLUESKY_PENDING
+                      && inode->type != BLUESKY_INVALID);
+
+    g_mutex_unlock(inode->lock);
+
+    return valid;
+}
+
 /**** Reference-counted strings. ****/
 
 /* Create and return a new reference-counted string.  The reference count is
@@ -113,3 +127,64 @@ void bluesky_string_resize(BlueSkyRCStr *string, gsize len)
     string->data = g_realloc(string->data, len);
     string->len = len;
 }
+
+/* Cache LRU list management functions.  These manage the doubly-linked list of
+ * inodes sorted by accessed/modified time.  The FS lock should be held while
+ * calling these.
+ *
+ * _remove will unlink an inode from the linked list.
+ *
+ * _prepend and _append insert an inode at the head or tail of the linked list,
+ * and return a pointer to the linked list element (which should be stored in
+ * the inode); the inode should not already be in the list.
+ *
+ * _head and _tail simply return the first or last item inode in the list. */
+void bluesky_list_unlink(GList *head, GList *item)
+{
+    if (item == NULL)
+        return;
+
+    if (head->prev == item)
+        head->prev = item->prev;
+    head->next = g_list_delete_link(head->next, item);
+}
+
+GList *bluesky_list_prepend(GList *head, BlueSkyInode *inode)
+{
+    head->next = g_list_prepend(head->next, inode);
+    if (head->prev == NULL)
+        head->prev = g_list_last(head->next);
+    return head->next;
+}
+
+GList *bluesky_list_append(GList *head, BlueSkyInode *inode)
+{
+    if (head->next == NULL)
+        return bluesky_list_prepend(head, inode);
+
+    g_assert(head->prev != NULL && head->prev->next == NULL);
+
+    GList *link = g_list_alloc();
+    link->data = inode;
+    link->next = NULL;
+    link->prev = head->prev;
+    head->prev->next = link;
+    head->prev = link;
+    return link;
+}
+
+BlueSkyInode *bluesky_list_head(GList *head)
+{
+    if (head->next == NULL)
+        return NULL;
+    else
+        return (BlueSkyInode *)head->next->data;
+}
+
+BlueSkyInode *bluesky_list_tail(GList *head)
+{
+    if (head->prev == NULL)
+        return NULL;
+    else
+        return (BlueSkyInode *)head->prev->data;
+}