From c3ecca225cd1f13f75250d35e5356ee5f433cff2 Mon Sep 17 00:00:00 2001
From: Thomas Haller <thaller@redhat.com>
Date: Fri, 23 Sep 2016 13:37:22 +0200
Subject: [PATCH] core: add _nm_utils_array_find_binary_search()

Also add nm_cmp_uint32_p_with_data(). Will be used later.
---
 libnm-core/nm-core-internal.h        |  1 +
 libnm-core/nm-utils.c                | 34 +++++++++++++++++++++++
 libnm-core/tests/test-general.c      | 41 ++++++++++++++++++++++++++++
 shared/nm-utils/nm-macros-internal.h | 13 +++++++++
 4 files changed, 89 insertions(+)

diff --git a/libnm-core/nm-core-internal.h b/libnm-core/nm-core-internal.h
index 111b26d588..471353e741 100644
--- a/libnm-core/nm-core-internal.h
+++ b/libnm-core/nm-core-internal.h
@@ -147,6 +147,7 @@ GPtrArray *_nm_utils_copy_object_array (const GPtrArray *array);
 gssize _nm_utils_ptrarray_find_first (gconstpointer *list, gssize len, gconstpointer needle);
 
 gssize _nm_utils_ptrarray_find_binary_search (gconstpointer *list, gsize len, gconstpointer needle, GCompareDataFunc cmpfcn, gpointer user_data);
+gssize _nm_utils_array_find_binary_search (gconstpointer list, gsize elem_size, gsize len, gconstpointer needle, GCompareDataFunc cmpfcn, gpointer user_data);
 
 gssize      _nm_utils_strv_find_first (char **list, gssize len, const char *needle);
 
diff --git a/libnm-core/nm-utils.c b/libnm-core/nm-utils.c
index c55e4ba81f..818b0c43ec 100644
--- a/libnm-core/nm-utils.c
+++ b/libnm-core/nm-utils.c
@@ -724,6 +724,40 @@ _nm_utils_ptrarray_find_binary_search (gconstpointer *list, gsize len, gconstpoi
 	return ~imin;
 }
 
+gssize
+_nm_utils_array_find_binary_search (gconstpointer list, gsize elem_size, gsize len, gconstpointer needle, GCompareDataFunc cmpfcn, gpointer user_data)
+{
+	gssize imin, imax, imid;
+	int cmp;
+
+	g_return_val_if_fail (list || !len, ~((gssize) 0));
+	g_return_val_if_fail (cmpfcn, ~((gssize) 0));
+	g_return_val_if_fail (elem_size > 0, ~((gssize) 0));
+
+	imin = 0;
+	if (len == 0)
+		return ~imin;
+
+	imax = len - 1;
+
+	while (imin <= imax) {
+		imid = imin + (imax - imin) / 2;
+
+		cmp = cmpfcn (&((const char *) list)[elem_size * imid], needle, user_data);
+		if (cmp == 0)
+			return imid;
+
+		if (cmp < 0)
+			imin = imid + 1;
+		else
+			imax = imid - 1;
+	}
+
+	/* return the inverse of @imin. This is a negative number, but
+	 * also is ~imin the position where the value should be inserted. */
+	return ~imin;
+}
+
 GVariant *
 _nm_utils_bytes_to_dbus (const GValue *prop_value)
 {
diff --git a/libnm-core/tests/test-general.c b/libnm-core/tests/test-general.c
index 8d5997ad2c..e71dd8bc56 100644
--- a/libnm-core/tests/test-general.c
+++ b/libnm-core/tests/test-general.c
@@ -5006,10 +5006,51 @@ _test_find_binary_search_do (const int *array, gsize len)
 		}
 	}
 }
+
+static void
+_test_find_binary_search_do_uint32 (const int *int_array, gsize len)
+{
+	gssize idx;
+	const int OFFSET = 100;
+	const int NEEDLE = 0 + OFFSET;
+	gssize expected_result = -1;
+	guint32 array[len];
+
+	/* the test data has negative values. Shift them... */
+	for (idx = 0; idx < len; idx++) {
+		int v = int_array[idx];
+
+		g_assert (v > -OFFSET);
+		g_assert (v < OFFSET);
+		g_assert (idx == 0 || v > int_array[idx - 1]);
+		array[idx] = (guint32) (int_array[idx] + OFFSET);
+		if (array[idx] == NEEDLE)
+			expected_result = idx;
+	}
+
+	idx = _nm_utils_array_find_binary_search (array,
+	                                          sizeof (guint32),
+	                                          len,
+	                                          &NEEDLE,
+	                                          nm_cmp_uint32_p_with_data,
+	                                          NULL);
+	if (expected_result >= 0)
+		g_assert_cmpint (expected_result, ==, idx);
+	else {
+		gssize idx2 = ~idx;
+		g_assert_cmpint (idx, <, 0);
+
+		g_assert (idx2 >= 0);
+		g_assert (idx2 <= len);
+		g_assert (idx2 - 1 < 0 || array[idx2 - 1] < NEEDLE);
+		g_assert (idx2 >= len || array[idx2] > NEEDLE);
+	}
+}
 #define test_find_binary_search_do(...) \
 	G_STMT_START { \
 		const int _array[] = { __VA_ARGS__ }; \
 		_test_find_binary_search_do (_array, G_N_ELEMENTS (_array)); \
+		_test_find_binary_search_do_uint32 (_array, G_N_ELEMENTS (_array)); \
 	} G_STMT_END
 
 static void
diff --git a/shared/nm-utils/nm-macros-internal.h b/shared/nm-utils/nm-macros-internal.h
index 9e9f5d8f3c..003a9e974f 100644
--- a/shared/nm-utils/nm-macros-internal.h
+++ b/shared/nm-utils/nm-macros-internal.h
@@ -516,6 +516,19 @@ nm_strcmp_p_with_data (gconstpointer a, gconstpointer b, gpointer user_data)
 	return strcmp (s1, s2);
 }
 
+static inline int
+nm_cmp_uint32_p_with_data (gconstpointer p_a, gconstpointer p_b, gpointer user_data)
+{
+	const guint32 a = *((const guint32 *) p_a);
+	const guint32 b = *((const guint32 *) p_b);
+
+	if (a < b)
+		return -1;
+	if (a > b)
+		return 1;
+	return 0;
+}
+
 /*****************************************************************************/
 
 /* Taken from systemd's UNIQ_T and UNIQ macros. */