[PATCH v2 10/10] trace-cmd: Fork record_trace() for the extract case

[Vladislav Valtchev (VMware)]

This patch inlines record_trace() into trace_extract() by removing the code not
related to extract, by replacing IS_EXTRACT(ctx) with true and then removing the
dead code, as well as the if statements when their condition always evalutates
to true. The opposite change [IS_EXTRACT(ctx) evaluated as false] has been
applyed to record_trace().

The purpose of doing that is to reduce the amount of branches in both the cases
(extract and everything else), making the code simpler to understand and follow
but at the price of having some copy-pasted code.

Signed-off-by: Vladislav Valtchev (VMware) <vladislav.valtchev@xxxxxxxxx>
---
 trace-record.c | 172 ++++++++++++++++++++++++++++++++++-----------------------
 1 file changed, 102 insertions(+), 70 deletions(-)

diff --git a/trace-record.c b/trace-record.c
index 749c205..48426e5 100644
--- a/trace-record.c
+++ b/trace-record.c
@@ -4794,7 +4794,7 @@ static void finalize_record_trace(struct common_record_context *ctx)
 
 /*
  * This function contains common code for the following commands:
- * record, start, extract, stream, profile.
+ * record, start, stream, profile.
  */
 static void record_trace(int argc, char **argv,
 			 struct common_record_context *ctx)
@@ -4805,15 +4805,13 @@ static void record_trace(int argc, char **argv,
 	 * If top_instance doesn't have any plugins or events, then
 	 * remove it from being processed.
 	 */
-	if (!IS_EXTRACT(ctx) && !__check_doing_something(&top_instance))
+	if (!__check_doing_something(&top_instance))
 		first_instance = buffer_instances;
 	else
 		ctx->topt = 1;
 
 	update_first_instance(ctx->instance, ctx->topt);
-
-	if (!IS_EXTRACT(ctx))
-		check_doing_something();
+	check_doing_something();
 	check_function_plugin();
 
 	if (ctx->output)
@@ -4831,43 +4829,35 @@ static void record_trace(int argc, char **argv,
 			ctx->instance->tracing_on_init_val = 1;
 	}
 
-	/* Extracting data records all events in the system. */
-	if (IS_EXTRACT(ctx) && !ctx->record_all)
-		record_all_events();
-
-	if (!IS_EXTRACT(ctx))
-		make_instances();
+	make_instances();
 
 	if (ctx->events)
 		expand_event_list();
 
 	page_size = getpagesize();
 
-	if (!IS_EXTRACT(ctx)) {
-		fset = set_ftrace(!ctx->disable, ctx->total_disable);
-		tracecmd_disable_all_tracing(1);
+	fset = set_ftrace(!ctx->disable, ctx->total_disable);
+	tracecmd_disable_all_tracing(1);
 
+	for_all_instances(ctx->instance)
+		set_clock(ctx->instance);
+
+	/* Record records the date first */
+	if (IS_RECORD(ctx) && ctx->date)
+		ctx->date2ts = get_date_to_ts();
+
+	for_all_instances(ctx->instance) {
+		set_funcs(ctx->instance);
+		set_mask(ctx->instance);
+	}
+
+	if (ctx->events) {
 		for_all_instances(ctx->instance)
-			set_clock(ctx->instance);
-
-		/* Record records the date first */
-		if (IS_RECORD(ctx) && ctx->date)
-			ctx->date2ts = get_date_to_ts();
-
-		for_all_instances(ctx->instance) {
-			set_funcs(ctx->instance);
-			set_mask(ctx->instance);
-		}
-
-		if (ctx->events) {
-			for_all_instances(ctx->instance)
-				enable_events(ctx->instance);
-		}
-		set_buffer_size();
+			enable_events(ctx->instance);
 	}
 
+	set_buffer_size();
 	update_plugins(type);
-
 	set_options();
 
 	if (ctx->max_graph_depth) {
@@ -4882,53 +4872,36 @@ static void record_trace(int argc, char **argv,
 		signal(SIGINT, finish);
 		if (!latency)
 			start_threads(type, ctx->global);
-	}
-
-	if (IS_EXTRACT(ctx)) {
-		flush_threads();
-
 	} else {
-		if (!(type & (TRACE_TYPE_RECORD | TRACE_TYPE_STREAM))) {
-			update_task_filter();
-			tracecmd_enable_tracing();
-			exit(0);
-		}
-
-		if (ctx->run_command)
-			run_cmd(type, (argc - optind) - 1, &argv[optind + 1]);
-		else {
-			update_task_filter();
-			tracecmd_enable_tracing();
-			/* We don't ptrace ourself */
-			if (do_ptrace && filter_pid >= 0)
-				ptrace_attach(filter_pid);
-			/* sleep till we are woken with Ctrl^C */
-			printf("Hit Ctrl^C to stop recording\n");
-			while (!finished)
-				trace_or_sleep(type);
-		}
+		update_task_filter();
+		tracecmd_enable_tracing();
+		exit(0);
+	}
 
-		tracecmd_disable_tracing();
-		if (!latency)
-			stop_threads(type);
+	if (ctx->run_command)
+		run_cmd(type, (argc - optind) - 1, &argv[optind + 1]);
+	else {
+		update_task_filter();
+		tracecmd_enable_tracing();
+		/* We don't ptrace ourself */
+		if (do_ptrace && filter_pid >= 0)
+			ptrace_attach(filter_pid);
+		/* sleep till we are woken with Ctrl^C */
+		printf("Hit Ctrl^C to stop recording\n");
+		while (!finished)
+			trace_or_sleep(type);
 	}
 
+	tracecmd_disable_tracing();
+	if (!latency)
+		stop_threads(type);
+
 	record_stats();
 
 	if (!keep)
 		tracecmd_disable_all_tracing(0);
 
-	/* extract records the date after extraction */
-	if (IS_EXTRACT(ctx) && ctx->date) {
-		/*
-		 * We need to start tracing, don't let other traces
-		 * screw with our trace_marker.
-		 */
-		tracecmd_disable_all_tracing(1);
-		ctx->date2ts = get_date_to_ts();
-	}
-
-	if (IS_RECORD(ctx) || IS_EXTRACT(ctx)) {
+	if (IS_RECORD(ctx)) {
 		record_data(ctx->date2ts, ctx->data_flags);
 		delete_thread_data();
 	} else
@@ -4950,9 +4923,68 @@ void trace_start(int argc, char **argv)
 void trace_extract(int argc, char **argv)
 {
 	struct common_record_context ctx;
+	enum trace_type type;
 
 	parse_record_options(argc, argv, CMD_extract, &ctx);
-	record_trace(argc, argv, &ctx);
+
+	type = get_trace_cmd_type(ctx.curr_cmd);
+
+	update_first_instance(ctx.instance, 1);
+	check_function_plugin();
+
+	if (ctx.output)
+		output_file = ctx.output;
+
+	/* Save the state of tracing_on before starting */
+	for_all_instances(ctx.instance) {
+
+		if (!ctx.manual && ctx.instance->profile)
+			enable_profile(ctx.instance);
+
+		ctx.instance->tracing_on_init_val = read_tracing_on(ctx.instance);
+		/* Some instances may not be created yet */
+		if (ctx.instance->tracing_on_init_val < 0)
+			ctx.instance->tracing_on_init_val = 1;
+	}
+
+	/* Extracting data records all events in the system. */
+	if (!ctx.record_all)
+		record_all_events();
+
+	if (ctx.events)
+		expand_event_list();
+
+	page_size = getpagesize();
+	update_plugins(type);
+	set_options();
+
+	if (ctx.max_graph_depth) {
+		for_all_instances(ctx.instance)
+			set_max_graph_depth(ctx.instance, ctx.max_graph_depth);
+		free(ctx.max_graph_depth);
+	}
+
+	allocate_seq();
+	flush_threads();
+	record_stats();
+
+	if (!keep)
+		tracecmd_disable_all_tracing(0);
+
+	/* extract records the date after extraction */
+	if (ctx.date) {
+		/*
+		 * We need to start tracing, don't let other traces
+		 * screw with our trace_marker.
+		 */
+		tracecmd_disable_all_tracing(1);
+		ctx.date2ts = get_date_to_ts();
+	}
+
+	record_data(ctx.date2ts, ctx.data_flags);
+	delete_thread_data();
+	destroy_stats();
+	finalize_record_trace(&ctx);
 	exit(0);
 }
 
-- 
2.14.1