commit 78b8a1430debfb9361e425e52e8366409b9e5cd2
author Josh Gao <jmgao@google.com> Wed Nov 09 01:00:41 2016 -0800
committer Josh Gao <jmgao@google.com> Wed Nov 09 18:12:10 2016 -0800
tree 63054645e21f43fc7626156843a511398a61194e
parent b5c496346f19cba410b3191b9c3297507bba854a

versioner: use a virtual filesystem for input files.

Use an InMemoryFileSystem to store and share input files across
compilations.

This improves the result of `time versioner` further, from:
    versioner  109.12s user 17.43s system 2433% cpu 5.201 total
to:
    versioner  112.20s user 1.38s system 2416% cpu 4.700 total

Bug: http://b/32748936
Test: python run_tests.py
Change-Id: I72d37b7c30850b8399cc40338247700fe3e7b2f9

tools/versioner/src/versioner.cpp

diff --git a/tools/versioner/src/versioner.cpp b/tools/versioner/src/versioner.cpp
index f0a2339..5aaf47a 100644
--- a/tools/versioner/src/versioner.cpp
+++ b/tools/versioner/src/versioner.cpp
@@ -44,6 +44,8 @@
 #include "Preprocessor.h"
 #include "SymbolDatabase.h"
 #include "Utils.h"
+#include "VFS.h"
+
 #include "versioner.h"
 
 using namespace std::string_literals;
@@ -138,6 +140,8 @@
     errx(1, "compileHeaders received no CompilationTypes");
   }
 
+  auto vfs = createCommonVFS(header_dir, dependency_dir, add_include);
+
   size_t thread_count = max_thread_count;
   std::vector<std::thread> threads;
 
@@ -151,7 +155,7 @@
     }
   }
 
-  initializeTargetCC1FlagCache(types, requirements);
+  initializeTargetCC1FlagCache(vfs, types, requirements);
 
   std::vector<std::pair<CompilationType, const std::string&>> jobs;
   for (CompilationType type : types) {
@@ -165,16 +169,16 @@
 
   if (thread_count == 1) {
     for (const auto& job : jobs) {
-      compileHeader(result.get(), job.first, job.second);
+      compileHeader(vfs, result.get(), job.first, job.second);
     }
   } else {
     // Spawn threads.
     for (size_t i = 0; i < thread_count; ++i) {
-      threads.emplace_back([&jobs, &result, &header_dir, thread_count, i]() {
+      threads.emplace_back([&jobs, &result, &header_dir, vfs, thread_count, i]() {
         size_t index = i;
         while (index < jobs.size()) {
           const auto& job = jobs[index];
-          compileHeader(result.get(), job.first, job.second);
+          compileHeader(vfs, result.get(), job.first, job.second);
           index += thread_count;
         }
       });