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.

4 files changed, 28 insertions, 22 deletions

diff --git a/src/diff.c b/src/diff.c
index 8b7433c62..5a6b127a1 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -555,7 +555,7 @@ int git_diff__oid_for_entry(
 	if (!entry.mode) {
 		struct stat st;
 
-		git_trace(GIT_TRACE_TRACE, "stat=1");
+		git_trace(GIT_TRACE_PERF, NULL, "stat");
 		if (p_stat(full_path.ptr, &st) < 0) {
 			error = git_path_set_error(errno, entry.path, "stat");
 			git_buf_free(&full_path);
@@ -570,7 +570,7 @@ int git_diff__oid_for_entry(
 	if (S_ISGITLINK(entry.mode)) {
 		git_submodule *sm;
 
-		git_trace(GIT_TRACE_TRACE, "submodule_lookup=1");
+		git_trace(GIT_TRACE_PERF, NULL, "submodule_lookup");
 		if (!git_submodule_lookup(&sm, diff->repo, entry.path)) {
 			const git_oid *sm_oid = git_submodule_wd_id(sm);
 			if (sm_oid)
@@ -583,7 +583,7 @@ int git_diff__oid_for_entry(
 			giterr_clear();
 		}
 	} else if (S_ISLNK(entry.mode)) {
-		git_trace(GIT_TRACE_TRACE, "oid_calculation=1");
+		git_trace(GIT_TRACE_PERF, NULL, "oid_calculation");
 		error = git_odb__hashlink(out, full_path.ptr);
 	} else if (!git__is_sizet(entry.file_size)) {
 		giterr_set(GITERR_OS, "File size overflow (for 32-bits) on '%s'",
@@ -596,7 +596,7 @@ int git_diff__oid_for_entry(
 		if (fd < 0)
 			error = fd;
 		else {
-			git_trace(GIT_TRACE_TRACE, "oid_calculation=1");
+			git_trace(GIT_TRACE_PERF, NULL, "oid_calculation");
 			error = git_odb__hashfd_filtered(
 				out, fd, (size_t)entry.file_size, GIT_OBJ_BLOB, fl);
 			p_close(fd);
@@ -655,7 +655,7 @@ static int maybe_modified_submodule(
 		ign == GIT_SUBMODULE_IGNORE_ALL)
 		return 0;
 
-	git_trace(GIT_TRACE_TRACE, "submodule_lookup=1");
+	git_trace(GIT_TRACE_PERF, NULL, "submodule_lookup");
 
 	if ((error = git_submodule_lookup(
 			&sub, diff->repo, info->nitem->path)) < 0) {
@@ -965,7 +965,7 @@ static int handle_unmatched_new_item(
 		delta_type = GIT_DELTA_ADDED;
 
 	else if (nitem->mode == GIT_FILEMODE_COMMIT) {
-		git_trace(GIT_TRACE_TRACE, "submodule_lookup=1");
+		git_trace(GIT_TRACE_PERF, NULL, "submodule_lookup");
 
 		/* ignore things that are not actual submodules */
 		if (git_submodule_lookup(NULL, info->repo, nitem->path) != 0) {
diff --git a/src/iterator.c b/src/iterator.c
index bebdeba84..0d7e5918d 100644
--- a/src/iterator.c
+++ b/src/iterator.c
@@ -1018,7 +1018,7 @@ static int fs_iterator__expand_dir(fs_iterator *fi)
 		return GIT_ENOTFOUND;
 	}
 
-	git_trace(GIT_TRACE_TRACE, "stat=%ld", (long)ff->entries.length);
+	git_trace(GIT_TRACE_PERF, &ff->entries.length, "stat");
 
 	fs_iterator__seek_frame_start(fi, ff);
 
@@ -1310,7 +1310,7 @@ static int workdir_iterator__enter_dir(fs_iterator *fi)
 		if (!S_ISDIR(entry->st.st_mode) || !strcmp(GIT_DIR, entry->path))
 			continue;
 
-		git_trace(GIT_TRACE_TRACE, "submodule_lookup=1");
+		git_trace(GIT_TRACE_PERF, entry->path, "submodule_lookup");
 		if (git_submodule__is_submodule(fi->base.repo, entry->path)) {
 			entry->st.st_mode = GIT_FILEMODE_COMMIT;
 			entry->path_len--;
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
 }
diff --git a/src/trace.h b/src/trace.h
index 4d4e3bf53..b35e3808f 100644
--- a/src/trace.h
+++ b/src/trace.h
@@ -15,13 +15,16 @@
 struct git_trace_data {
 	git_trace_level_t level;
 	git_trace_callback callback;
+	void *callback_payload;
 };
 
 extern struct git_trace_data git_trace__data;
 
 GIT_INLINE(void) git_trace__write_fmt(
 	git_trace_level_t level,
-	const char *fmt, ...)
+	void *message_payload,
+	const char *fmt,
+	...)
 {
 	git_trace_callback callback = git_trace__data.callback;
 	git_buf message = GIT_BUF_INIT;
@@ -31,18 +34,18 @@ GIT_INLINE(void) git_trace__write_fmt(
 	git_buf_vprintf(&message, fmt, ap);
 	va_end(ap);
 
-	callback(level, git_buf_cstr(&message));
+	callback(
+		level, git_trace__data.callback_payload, message_payload,
+		git_buf_cstr(&message));
 
 	git_buf_free(&message);
 }
 
 #define git_trace_level()		(git_trace__data.level)
-#define git_trace(l, ...)		{ \
-									if (git_trace__data.level >= l && \
-										git_trace__data.callback != NULL) { \
-										git_trace__write_fmt(l, __VA_ARGS__); \
-									} \
-								}
+#define git_trace(l, p, ...)	do { \
+	if ((git_trace__data.level & (l)) != 0 && git_trace__data.callback) { \
+		git_trace__write_fmt((l), (p), __VA_ARGS__); \
+	} } while (0)
 
 #else