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.ok b/tests/utils/utils_test.ok
index c150a8d..b603647 100644
--- a/tests/utils/utils_test.ok
+++ b/tests/utils/utils_test.ok
@@ -360,3 +360,20 @@
osmo_str_startswith("abc", "abc") == true
osmo_str_startswith("abc", "abcd") == false
osmo_str_startswith("abc", "xyz") == false
+
+name_c_impl_test
+ 0: "test"
+ OSMO_NAME_C_IMPL(10, "ERROR") -> "test" allocated 1 10 bytes, name 'foo_name_c'
+ OSMO_NAME_C_IMPL(10, NULL) -> "test" allocated 1 10 bytes, name 'foo_name_c_null'
+ OSMO_NAME_C_IMPL(0, "ERROR") -> "test" allocated 1 5 bytes, name 'foo_name_c_zero'
+ OSMO_NAME_C_IMPL(0, NULL) -> "test" allocated 1 5 bytes, name 'foo_name_c_zero_null'
+ 1: "longer than 10 chars"
+ OSMO_NAME_C_IMPL(10, "ERROR") -> "longer than 10 chars" allocated 1 21 bytes, name 'foo_name_c'
+ OSMO_NAME_C_IMPL(10, NULL) -> "longer than 10 chars" allocated 1 21 bytes, name 'foo_name_c_null'
+ OSMO_NAME_C_IMPL(0, "ERROR") -> "longer than 10 chars" allocated 1 21 bytes, name 'foo_name_c_zero'
+ OSMO_NAME_C_IMPL(0, NULL) -> "longer than 10 chars" allocated 1 21 bytes, name 'foo_name_c_zero_null'
+ 2: NULL
+ OSMO_NAME_C_IMPL(10, "ERROR") -> "ERROR" allocated 1 6 bytes, name 'foo_name_c'
+ OSMO_NAME_C_IMPL(10, NULL) -> NULL allocated 0
+ OSMO_NAME_C_IMPL(0, "ERROR") -> "ERROR" allocated 1 6 bytes, name 'foo_name_c_zero'
+ OSMO_NAME_C_IMPL(0, NULL) -> NULL allocated 0