Add payloads, bitmaps to trace API

This is a proposed adjustment to the trace APIs.  This makes the
trace levels into a bitmask so that they can be selectively enabled
and adds a callback-level payload, plus a message-level payload.

This makes it easier for me to a GIT_TRACE_PERF callbacks that
are simply bypassed if the PERF level is not set.

1 files changed, 9 insertions, 6 deletions

diff --git a/src/trace.c b/src/trace.c
index ee5039f56..6ee2cf2ce 100644
--- a/src/trace.c
+++ b/src/trace.c
@@ -17,22 +17,25 @@ struct git_trace_data git_trace__data = {0};
 
 #endif
 
-int git_trace_set(git_trace_level_t level, git_trace_callback callback)
+int git_trace_set(
+	git_trace_level_t level, git_trace_callback cb, void *cb_payload)
 {
 #ifdef GIT_TRACE
-	assert(level == 0 || callback != NULL);
+	assert(level == 0 || cb != NULL);
 
 	git_trace__data.level = level;
-	git_trace__data.callback = callback;
+	git_trace__data.callback = cb;
+	git_trace__data.callback_payload = cb_payload;
 	GIT_MEMORY_BARRIER;
 
 	return 0;
 #else
 	GIT_UNUSED(level);
-	GIT_UNUSED(callback);
+	GIT_UNUSED(cb);
+	GIT_UNUSED(cb_payload);
 
-	giterr_set(GITERR_INVALID,
-		"This version of libgit2 was not built with tracing.");
+	giterr_set(
+		GITERR_INVALID, "This version of libgit2 was not built with tracing.");
 	return -1;
 #endif
 }