array: Add an array_get() function

src/libstrongswan/collections/array.c

@@ -314,7 +314,7 @@ void array_insert(array_t *array, int idx, void *data)
 	}
 }
 
-bool array_remove(array_t *array, int idx, void *data)
+bool array_get(array_t *array, int idx, void *data)
 {
 	if (!array)
 	{
@@ -337,12 +337,25 @@ bool array_remove(array_t *array, int idx, void *data)
 		memcpy(data, array->data + get_size(array, array->head + idx),
 			   get_size(array, 1));
 	}
+	return TRUE;
+}
+
+bool array_remove(array_t *array, int idx, void *data)
+{
+	if (!array_get(array, idx, data))
+	{
+		return FALSE;
+	}
 	if (idx > array_count(array) / 2)
 	{
 		remove_tail(array, idx);
 	}
 	else
 	{
+		if (idx < 0)
+		{
+			idx = array_count(array) - 1;
+		}
 		remove_head(array, idx);
 	}
 	if (array->head + array->tail > ARRAY_MAX_UNUSED)

src/libstrongswan/collections/array.h

@@ -139,6 +139,18 @@ void array_insert_create(array_t **array, int idx, void *ptr);
  */
 void array_insert_enumerator(array_t *array, int idx, enumerator_t *enumerator);
 
+/**
+ * Get an element from the array.
+ *
+ * If data is given, the element is copied to that position.
+ *
+ * @param array			array to get element from, or NULL
+ * @param idx			index of the item to get
+ * @param data			data to copy element to, or NULL
+ * @return				TRUE if idx valid and item returned
+ */
+bool array_get(array_t *array, int idx, void *data);
+
 /**
  * Remove an element from the array.
  *

src/libstrongswan/tests/suites/test_array.c

@@ -35,6 +35,14 @@ START_TEST(test_append_ptr)
 
 		/* 3, 4 */
 
+		ck_assert(array_get(array, ARRAY_HEAD, &x));
+		ck_assert_int_eq(x, 3);
+		ck_assert(array_get(array, 1, &x));
+		ck_assert_int_eq(x, 4);
+		ck_assert(array_get(array, ARRAY_TAIL, &x));
+		ck_assert_int_eq(x, 4);
+		ck_assert(!array_get(array, 3, &x));
+
 		array_insert(array, ARRAY_HEAD, (void*)(uintptr_t)1);
 		array_insert(array, 1, (void*)(uintptr_t)2);
 		ck_assert_int_eq(array_count(array), 4);
@@ -108,6 +116,14 @@ START_TEST(test_append_obj)
 
 		/* 3, 4 */
 
+		ck_assert(array_get(array, ARRAY_HEAD, &x));
+		ck_assert_int_eq(x, 3);
+		ck_assert(array_get(array, 1, &x));
+		ck_assert_int_eq(x, 4);
+		ck_assert(array_get(array, ARRAY_TAIL, &x));
+		ck_assert_int_eq(x, 4);
+		ck_assert(!array_get(array, 3, &x));
+
 		array_insert(array, ARRAY_HEAD, &y[1]);
 		array_insert(array, 1, &y[2]);
 		ck_assert_int_eq(array_count(array), 4);
@@ -336,11 +352,11 @@ Suite *array_suite_create()
 
 	s = suite_create("array");
 
-	tc = tcase_create("add/remove ptr");
+	tc = tcase_create("add/get/remove ptr");
 	tcase_add_test(tc, test_append_ptr);
 	suite_add_tcase(s, tc);
 
-	tc = tcase_create("add/remove obj");
+	tc = tcase_create("add/get/remove obj");
 	tcase_add_test(tc, test_append_obj);
 	suite_add_tcase(s, tc);