Added a delete element method to the array class in libcitadel.

[citadel.git] / libcitadel / lib / array.c

diff --git a/libcitadel/lib/array.c b/libcitadel/lib/array.c
index c8f433f5d5c3bdf2a070a060a56936854d8468ae..a8adb292d84ba950fbfabd59a3146f97637622ee 100644 (file)
--- a/libcitadel/lib/array.c
+++ b/libcitadel/lib/array.c
@@ -65,7 +65,7 @@ void array_append(Array *arr, void *new_element) {
 
        ++arr->num_elements;
        if (arr->num_elements > arr->num_alloc) {
-               arr->num_alloc = arr->num_alloc * 2;
+               arr->num_alloc = arr->num_alloc * 2;            // whenever we exceed the buffer size, we double it.
                arr->the_elements = realloc(arr->the_elements, (arr->element_size * arr->num_alloc));
        }
 
@@ -96,3 +96,26 @@ int array_len(Array *arr) {
 void array_sort(Array *arr, int (*compar)(const void *, const void *)) {
        qsort(arr->the_elements, arr->num_elements, arr->element_size, compar);
 }
+
+
+/*
+ * Delete an element from an array
+ */
+void array_delete_element_at(Array *arr, int index) {
+
+       if (index >= arr->num_elements) {               // If the supplied index is out of bounds, return quietly.
+               return;
+       }
+
+       --arr->num_elements;
+
+       if (index == arr->num_elements) {               // If we deleted the element at the end, there's no more to be done.
+               return;
+       }
+
+       memcpy(
+               (arr->the_elements + (index * arr->element_size)),
+               arr->the_elements + ((index+1) * arr->element_size),
+               (arr->num_elements - index) * arr->element_size
+       );
+}