test-iov: add iov_discard_front/back() testcases

Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

tests/test-iov.c

@@ -250,11 +250,161 @@ static void test_io(void)
 #endif
 }
 
+static void test_discard_front(void)
+{
+    struct iovec *iov;
+    struct iovec *iov_tmp;
+    unsigned int iov_cnt;
+    unsigned int iov_cnt_tmp;
+    void *old_base;
+    size_t size;
+    size_t ret;
+
+    /* Discard zero bytes */
+    iov_random(&iov, &iov_cnt);
+    iov_tmp = iov;
+    iov_cnt_tmp = iov_cnt;
+    ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, 0);
+    g_assert(ret == 0);
+    g_assert(iov_tmp == iov);
+    g_assert(iov_cnt_tmp == iov_cnt);
+    iov_free(iov, iov_cnt);
+
+    /* Discard more bytes than vector size */
+    iov_random(&iov, &iov_cnt);
+    iov_tmp = iov;
+    iov_cnt_tmp = iov_cnt;
+    size = iov_size(iov, iov_cnt);
+    ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size + 1);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == 0);
+    iov_free(iov, iov_cnt);
+
+    /* Discard entire vector */
+    iov_random(&iov, &iov_cnt);
+    iov_tmp = iov;
+    iov_cnt_tmp = iov_cnt;
+    size = iov_size(iov, iov_cnt);
+    ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == 0);
+    iov_free(iov, iov_cnt);
+
+    /* Discard within first element */
+    iov_random(&iov, &iov_cnt);
+    iov_tmp = iov;
+    iov_cnt_tmp = iov_cnt;
+    old_base = iov->iov_base;
+    size = g_test_rand_int_range(1, iov->iov_len);
+    ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_tmp == iov);
+    g_assert(iov_cnt_tmp == iov_cnt);
+    g_assert(iov_tmp->iov_base == old_base + size);
+    iov_tmp->iov_base = old_base; /* undo before g_free() */
+    iov_free(iov, iov_cnt);
+
+    /* Discard entire first element */
+    iov_random(&iov, &iov_cnt);
+    iov_tmp = iov;
+    iov_cnt_tmp = iov_cnt;
+    ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, iov->iov_len);
+    g_assert(ret == iov->iov_len);
+    g_assert(iov_tmp == iov + 1);
+    g_assert(iov_cnt_tmp == iov_cnt - 1);
+    iov_free(iov, iov_cnt);
+
+    /* Discard within second element */
+    iov_random(&iov, &iov_cnt);
+    iov_tmp = iov;
+    iov_cnt_tmp = iov_cnt;
+    old_base = iov[1].iov_base;
+    size = iov->iov_len + g_test_rand_int_range(1, iov[1].iov_len);
+    ret = iov_discard_front(&iov_tmp, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_tmp == iov + 1);
+    g_assert(iov_cnt_tmp == iov_cnt - 1);
+    g_assert(iov_tmp->iov_base == old_base + (size - iov->iov_len));
+    iov_tmp->iov_base = old_base; /* undo before g_free() */
+    iov_free(iov, iov_cnt);
+}
+
+static void test_discard_back(void)
+{
+    struct iovec *iov;
+    unsigned int iov_cnt;
+    unsigned int iov_cnt_tmp;
+    void *old_base;
+    size_t size;
+    size_t ret;
+
+    /* Discard zero bytes */
+    iov_random(&iov, &iov_cnt);
+    iov_cnt_tmp = iov_cnt;
+    ret = iov_discard_back(iov, &iov_cnt_tmp, 0);
+    g_assert(ret == 0);
+    g_assert(iov_cnt_tmp == iov_cnt);
+    iov_free(iov, iov_cnt);
+
+    /* Discard more bytes than vector size */
+    iov_random(&iov, &iov_cnt);
+    iov_cnt_tmp = iov_cnt;
+    size = iov_size(iov, iov_cnt);
+    ret = iov_discard_back(iov, &iov_cnt_tmp, size + 1);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == 0);
+    iov_free(iov, iov_cnt);
+
+    /* Discard entire vector */
+    iov_random(&iov, &iov_cnt);
+    iov_cnt_tmp = iov_cnt;
+    size = iov_size(iov, iov_cnt);
+    ret = iov_discard_back(iov, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == 0);
+    iov_free(iov, iov_cnt);
+
+    /* Discard within last element */
+    iov_random(&iov, &iov_cnt);
+    iov_cnt_tmp = iov_cnt;
+    old_base = iov[iov_cnt - 1].iov_base;
+    size = g_test_rand_int_range(1, iov[iov_cnt - 1].iov_len);
+    ret = iov_discard_back(iov, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == iov_cnt);
+    g_assert(iov[iov_cnt - 1].iov_base == old_base);
+    iov_free(iov, iov_cnt);
+
+    /* Discard entire last element */
+    iov_random(&iov, &iov_cnt);
+    iov_cnt_tmp = iov_cnt;
+    old_base = iov[iov_cnt - 1].iov_base;
+    size = iov[iov_cnt - 1].iov_len;
+    ret = iov_discard_back(iov, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == iov_cnt - 1);
+    iov_free(iov, iov_cnt);
+
+    /* Discard within second-to-last element */
+    iov_random(&iov, &iov_cnt);
+    iov_cnt_tmp = iov_cnt;
+    old_base = iov[iov_cnt - 2].iov_base;
+    size = iov[iov_cnt - 1].iov_len +
+           g_test_rand_int_range(1, iov[iov_cnt - 2].iov_len);
+    ret = iov_discard_back(iov, &iov_cnt_tmp, size);
+    g_assert(ret == size);
+    g_assert(iov_cnt_tmp == iov_cnt - 1);
+    g_assert(iov[iov_cnt - 2].iov_base == old_base);
+    iov_free(iov, iov_cnt);
+}
+
 int main(int argc, char **argv)
 {
     g_test_init(&argc, &argv, NULL);
     g_test_rand_int();
     g_test_add_func("/basic/iov/from-to-buf", test_to_from_buf);
     g_test_add_func("/basic/iov/io", test_io);
+    g_test_add_func("/basic/iov/discard-front", test_discard_front);
+    g_test_add_func("/basic/iov/discard-back", test_discard_back);
     return g_test_run();
 }