vector, pqueue: add git_vector_reverse and git_pqueue_reverse

This is a convenience function to reverse the contents of a vector and a pqueue
in-place.

The pqueue function is useful in the case where we're treating it as a
LIFO queue.

1 files changed, 29 insertions, 0 deletions

diff --git a/tests/core/vector.c b/tests/core/vector.c
index c351655a7..336254cce 100644
--- a/tests/core/vector.c
+++ b/tests/core/vector.c
@@ -376,3 +376,32 @@ void test_core_vector__grow_and_shrink(void)
 
 	git_vector_free(&x);
 }
+
+void test_core_vector__reverse(void)
+{
+	git_vector v = GIT_VECTOR_INIT;
+	size_t i;
+
+	void *in1[] = {(void *) 0x0, (void *) 0x1, (void *) 0x2, (void *) 0x3};
+	void *out1[] = {(void *) 0x3, (void *) 0x2, (void *) 0x1, (void *) 0x0};
+
+	void *in2[] = {(void *) 0x0, (void *) 0x1, (void *) 0x2, (void *) 0x3, (void *) 0x4};
+	void *out2[] = {(void *) 0x4, (void *) 0x3, (void *) 0x2, (void *) 0x1, (void *) 0x0};
+
+	for (i = 0; i < 4; i++)
+		cl_git_pass(git_vector_insert(&v, in1[i]));
+
+	git_vector_reverse(&v);
+
+	for (i = 0; i < 4; i++)
+		cl_assert_equal_p(out1[i], git_vector_get(&v, i));
+
+	git_vector_clear(&v);
+	for (i = 0; i < 5; i++)
+		cl_git_pass(git_vector_insert(&v, in2[i]));
+
+	git_vector_reverse(&v);
+
+	for (i = 0; i < 5; i++)
+		cl_assert_equal_p(out2[i], git_vector_get(&v, i));
+}