add osmo_hexdump_buf() and test

Add osmo_hexdump_buf() as an all-purpose hexdump function, which all other
osmo_hexdump_*() implementations now call. It absorbs the static
_osmo_hexdump(). Add tests for osmo_hexdump_buf().

Rationale: recently during patch review, a situation came up where two hexdumps
in a single printf would have been useful. Now I've faced a similar situation
again, in ongoing development. So I decided it is time to provide this API.

The traditional osmo_hexdump() API returns a non-const char*, which should
probably have been a const instead. Particularly this new function may return a
string constant "" if the buf is NULL or empty, so return const char*. That is
why the older implementations calling osmo_hexdump_buf() separately return the
buffer instead of the const return value directly.

Change-Id: I590595567b218b24e53c9eb1fd8736c0324d371d

1 files changed, 25 insertions, 0 deletions

diff --git a/tests/utils/utils_test.c b/tests/utils/utils_test.c
index a773b3f5..822861fb 100644
--- a/tests/utils/utils_test.c
+++ b/tests/utils/utils_test.c
@@ -37,6 +37,7 @@
 static void hexdump_test(void)
 {
 	uint8_t data[4098];
+	char buf[256];
 	int i;
 
 	for (i = 0; i < ARRAY_SIZE(data); ++i)
@@ -44,10 +45,34 @@ static void hexdump_test(void)
 
 	printf("Plain dump\n");
 	printf("%s\n", osmo_hexdump(data, 4));
+	printf("%s\n", osmo_hexdump_nospc(data, 4));
 
 	printf("Corner case\n");
 	printf("%s\n", osmo_hexdump(data, ARRAY_SIZE(data)));
 	printf("%s\n", osmo_hexdump_nospc(data, ARRAY_SIZE(data)));
+
+#define _HEXDUMP_BUF_TEST(SIZE, DELIM, DELIM_AFTER) \
+	buf[0] = '!'; \
+	buf[1] = '\0'; \
+	printf("osmo_hexdump_buf(buf, " #SIZE ", data, 4, %s, " #DELIM_AFTER ")\n = \"%s\"\n", \
+	       DELIM ? #DELIM : "NULL", \
+	       osmo_hexdump_buf(buf, SIZE, data, 4, DELIM, DELIM_AFTER))
+#define HEXDUMP_BUF_TEST(DELIM) \
+	_HEXDUMP_BUF_TEST(sizeof(buf), DELIM, false); \
+	_HEXDUMP_BUF_TEST(sizeof(buf), DELIM, true); \
+	_HEXDUMP_BUF_TEST(6, DELIM, false); \
+	_HEXDUMP_BUF_TEST(7, DELIM, false); \
+	_HEXDUMP_BUF_TEST(8, DELIM, false); \
+	_HEXDUMP_BUF_TEST(6, DELIM, true); \
+	_HEXDUMP_BUF_TEST(7, DELIM, true); \
+	_HEXDUMP_BUF_TEST(8, DELIM, true)
+
+	HEXDUMP_BUF_TEST("[delim]");
+	HEXDUMP_BUF_TEST(" ");
+	HEXDUMP_BUF_TEST(":");
+	HEXDUMP_BUF_TEST("::");
+	HEXDUMP_BUF_TEST("");
+	HEXDUMP_BUF_TEST(NULL);
 }
 
 static void hexparse_test(void)