Add --trace_folder to aapt2

Add a tracing API and instrument key functions in order to profile
aapt2 bottleneck. The API allows to generate systrace fragment files.

Impact on performance is neglibible with each Trace requiring less
than 1us and the final Flush operation at the end of a command
requiring around 40us.

Bug: None
Test: None
Change-Id: I51b564d3694e9384679f43b878b32295527dddf6

1 files changed, 6 insertions, 1 deletions

diff --git a/tools/aapt2/Main.cpp b/tools/aapt2/Main.cpp
index adf85b0ea8e8..39eb9879f86d 100644
--- a/tools/aapt2/Main.cpp
+++ b/tools/aapt2/Main.cpp
@@ -37,6 +37,7 @@
 #include "cmd/Link.h"
 #include "cmd/Optimize.h"
 #include "io/FileStream.h"
+#include "trace/TraceBuffer.h"
 #include "util/Files.h"
 #include "util/Util.h"
 
@@ -107,9 +108,12 @@ class DaemonCommand : public Command {
       : Command("daemon", "m"), out_(out), diagnostics_(diagnostics) {
     SetDescription("Runs aapt in daemon mode. Each subsequent line is a single parameter to the\n"
         "command. The end of an invocation is signaled by providing an empty line.");
+    AddOptionalFlag("--trace_folder", "Generate systrace json trace fragment to specified folder.",
+                    &trace_folder_);
   }
 
-  int Action(const std::vector<std::string>& /* args */) override {
+  int Action(const std::vector<std::string>& arguments) override {
+    TRACE_FLUSH_ARGS(trace_folder_ ? trace_folder_.value() : "", "daemon", arguments);
     text::Printer printer(out_);
     std::cout << "Ready" << std::endl;
 
@@ -150,6 +154,7 @@ class DaemonCommand : public Command {
  private:
   io::FileOutputStream* out_;
   IDiagnostics* diagnostics_;
+  Maybe<std::string> trace_folder_;
 };
 
 }  // namespace aapt