string-list: Add API to remove an item from an unsorted list

Teach the string-list API how to remove an entry in O(1) runtime by
moving the last entry to the vacated spot. As such, the routine works
only for unsorted lists.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt
index 3f575bdcff3a6b38304710b22371784c2e7443c9..ce24eb96f5efdee579f8600323731368fee4048b 100644 (file)
--- a/Documentation/technical/api-string-list.txt
+++ b/Documentation/technical/api-string-list.txt
@@ -29,6 +29,9 @@ member (you need this if you add things later) and you should set the
 
 . Can sort an unsorted list using `sort_string_list`.
 
+. Can remove individual items of an unsorted list using
+  `unsorted_string_list_delete_item`.
+
 . Finally it should free the list using `string_list_clear`.
 
 Example:
@@ -112,6 +115,13 @@ write `string_list_insert(...)->util = ...;`.
 The above two functions need to look through all items, as opposed to their
 counterpart for sorted lists, which performs a binary search.
 
+`unsorted_string_list_delete_item`::
+
+       Remove an item from a string_list. The `string` pointer of the items
+       will be freed in case the `strdup_strings` member of the string_list
+       is set. The third parameter controls if the `util` pointer of the
+       items should be freed or not.
+
 Data structures
 ---------------
 

diff --git a/string-list.c b/string-list.c
index 51681189e8380cc43ed26d35526a6dff78f1a24c..d9810aba421cbbc844b45ea5ca713a480a699eb2 100644 (file)
--- a/string-list.c
+++ b/string-list.c
@@ -185,3 +185,12 @@ int unsorted_string_list_has_string(struct string_list *list,
        return unsorted_string_list_lookup(list, string) != NULL;
 }
 
+void unsorted_string_list_delete_item(struct string_list *list, int i, int free_util)
+{
+       if (list->strdup_strings)
+               free(list->items[i].string);
+       if (free_util)
+               free(list->items[i].util);
+       list->items[i] = list->items[list->nr-1];
+       list->nr--;
+}

diff --git a/string-list.h b/string-list.h
index bda69839832d2030c15bbd86c4d8d79aa3cc4785..0684cb73bfd27846182479a4e192d682a44f201a 100644 (file)
--- a/string-list.h
+++ b/string-list.h
@@ -44,4 +44,5 @@ void sort_string_list(struct string_list *list);
 int unsorted_string_list_has_string(struct string_list *list, const char *string);
 struct string_list_item *unsorted_string_list_lookup(struct string_list *list,
                                                     const char *string);
+void unsorted_string_list_delete_item(struct string_list *list, int i, int free_util);
 #endif /* STRING_LIST_H */