lib: Add new implementation of notmuch_filenames_t

The new implementation is simply a talloc-based list of strings. The
former support (a list of database terms with a common prefix) is
implemented by simply pre-iterating over the terms and populating the
list. This should provide no performance disadvantage as callers of
thigns like notmuch_directory_get_child_files are very likely to
always iterate over all filenames anyway.

This new implementation of notmuch_filenames_t is in preparation for
adding API to query all of the filenames for a single message.

1 files changed, 111 insertions, 0 deletions

diff --git a/lib/filenames.c b/lib/filenames.c
new file mode 100644
index 00000000..cff9e830
--- /dev/null
+++ b/lib/filenames.c
@@ -0,0 +1,111 @@
+/* filenames.c - Iterator for a list of filenames
+ *
+ * Copyright © 2010 Intel Corporation
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/ .
+ *
+ * Author: Carl Worth <cworth@cworth.org>
+ */
+
+#include "notmuch-private.h"
+
+typedef struct _notmuch_filenames_node {
+    char *filename;
+    struct _notmuch_filenames_node *next;
+} notmuch_filenames_node_t;
+
+struct _notmuch_filenames {
+    notmuch_filenames_node_t *head;
+    notmuch_filenames_node_t **tail;
+    notmuch_filenames_node_t *iterator;
+};
+
+/* Create a new notmuch_filenames_t object, with 'ctx' as its
+ * talloc owner.
+ *
+ * This function can return NULL in case of out-of-memory.
+ */
+notmuch_filenames_t *
+_notmuch_filenames_create (const void *ctx)
+{
+    notmuch_filenames_t *filenames;
+
+    filenames = talloc (ctx, notmuch_filenames_t);
+    if (unlikely (filenames == NULL))
+	return NULL;
+
+    filenames->head = NULL;
+    filenames->tail = &filenames->head;
+
+    filenames->iterator = NULL;
+
+    return filenames;
+}
+
+/* Append a single 'node' to the end of 'filenames'.
+ */
+void
+_notmuch_filenames_add_filename (notmuch_filenames_t *filenames,
+				 const char *filename)
+{
+    /* Create and initialize new node. */
+    notmuch_filenames_node_t *node = talloc (filenames,
+					     notmuch_filenames_node_t);
+
+    node->filename = talloc_strdup (node, filename);
+    node->next = NULL;
+
+    /* Append the node to the list. */
+    *(filenames->tail) = node;
+    filenames->tail = &node->next;
+}
+
+notmuch_bool_t
+notmuch_filenames_valid (notmuch_filenames_t *filenames)
+{
+    if (filenames == NULL)
+	return FALSE;
+
+    return (filenames->iterator != NULL);
+}
+
+const char *
+notmuch_filenames_get (notmuch_filenames_t *filenames)
+{
+    if (filenames->iterator == NULL)
+	return NULL;
+
+    return filenames->iterator->filename;
+}
+
+void
+_notmuch_filenames_move_to_first (notmuch_filenames_t *filenames)
+{
+    filenames->iterator = filenames->head;
+}
+
+void
+notmuch_filenames_move_to_next (notmuch_filenames_t *filenames)
+{
+    if (filenames->iterator == NULL)
+	return;
+
+    filenames->iterator = filenames->iterator->next;
+}
+
+void
+notmuch_filenames_destroy (notmuch_filenames_t *filenames)
+{
+    talloc_free (filenames);
+}