utils.h: add OSMO_NAME_C_IMPL() macro
Provide a common implementation for foo_name_c() functions that base on
foo_name_buf() functions.
char *foo_name_c(void *ctx, example_t arg)
{
OSMO_NAME_C_IMPL(ctx, 64, "ERROR", foo_name_buf, arg)
}
Rationale: the most efficient way of composing strings that have optional parts
or require loops for composition is by writing to a ready char[], and this in
turn is easiest done by using OSMO_STRBUF_* API. Using such a basic name string
implementation which typically returns a length, I often want a more convenient
version that returns a char*, which can just be inlined in a "%s" string format
-- crucially: skipping string composition when inlined in a LOGP(). This common
implementation allows saving code dup, only the function signature is needed.
Why not include the function signature in the macro? The two sets of varargs
(1: signature args, 2: function call args) are hard to do. Also, having an
explicit signature is good for readability and code grepping / ctags.
Upcoming uses: in libosmocore in the mslookup (D-GSM) implementation
(osmo_mslookup_result_name_c()), and in osmo_msc's codec negotiation
implementation (sdp_audio_codecs_name_c(), sdp_msg_name_c(), ...).
I54b6c0810f181259da307078977d9ef3d90458c9 (libosmocore)
If3ce23cd5bab15e2ab4c52ef3e4c75979dffe931 (osmo-msc)
Change-Id: Ida5ba8d9640ea641aafef0236800f6d489d3d322
diff --git a/tests/utils/utils_test.c b/tests/utils/utils_test.c
index 70d017f..55c9e7f 100644
--- a/tests/utils/utils_test.c
+++ b/tests/utils/utils_test.c
@@ -1058,6 +1058,86 @@
startswith_test_str("abc", "xyz", false);
}
+static int foo_name_buf(char *buf, size_t buflen, const char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+ return snprintf(buf, buflen, "%s", arg);
+}
+
+static char *foo_name_c(void *ctx, const char *arg)
+{
+ OSMO_NAME_C_IMPL(ctx, 10, "ERROR", foo_name_buf, arg)
+}
+
+static char *foo_name_c_null(void *ctx, const char *arg)
+{
+ OSMO_NAME_C_IMPL(ctx, 10, NULL, foo_name_buf, arg)
+}
+
+static char *foo_name_c_zero(void *ctx, const char *arg)
+{
+ OSMO_NAME_C_IMPL(ctx, 0, "ERROR", foo_name_buf, arg)
+}
+
+static char *foo_name_c_zero_null(void *ctx, const char *arg)
+{
+ OSMO_NAME_C_IMPL(ctx, 0, NULL, foo_name_buf, arg)
+}
+
+static void name_c_impl_test()
+{
+ char *test_strs[] = {
+ "test",
+ "longer than 10 chars",
+ NULL,
+ };
+ struct {
+ const char *label;
+ char *(*func)(void *, const char*);
+ } funcs[] = {
+ {
+ "OSMO_NAME_C_IMPL(10, \"ERROR\")",
+ foo_name_c,
+ },
+ {
+ "OSMO_NAME_C_IMPL(10, NULL)",
+ foo_name_c_null,
+ },
+ {
+ "OSMO_NAME_C_IMPL(0, \"ERROR\")",
+ foo_name_c_zero,
+ },
+ {
+ "OSMO_NAME_C_IMPL(0, NULL)",
+ foo_name_c_zero_null,
+ },
+ };
+
+ int i;
+ void *ctx = talloc_named_const(NULL, 0, __func__);
+ int allocs = talloc_total_blocks(ctx);
+
+ printf("\n%s\n", __func__);
+ for (i = 0; i < ARRAY_SIZE(test_strs); i++) {
+ char *test_str = test_strs[i];
+ int j;
+ printf("%2d: %s\n", i, osmo_quote_str(test_str, -1));
+
+ for (j = 0; j < ARRAY_SIZE(funcs); j++) {
+ char *str = funcs[j].func(ctx, test_str);
+ printf(" %30s -> %s", funcs[j].label, osmo_quote_str(str, -1));
+ printf(" allocated %d", (int)talloc_total_blocks(ctx) - allocs);
+ if (str) {
+ printf(" %zu bytes, name '%s'", talloc_total_size(str), talloc_get_name(str));
+ talloc_free(str);
+ }
+ printf("\n");
+ }
+ }
+ talloc_free(ctx);
+}
+
int main(int argc, char **argv)
{
static const struct log_info log_info = {};
@@ -1078,5 +1158,6 @@
strbuf_test();
strbuf_test_nolen();
startswith_test();
+ name_c_impl_test();
return 0;
}