GPU Program Caching

gpu/command_buffer/service/program_cache_lru_helper.cc

Index: gpu/command_buffer/service/program_cache_lru_helper.cc
diff --git a/gpu/command_buffer/service/program_cache_lru_helper.cc b/gpu/command_buffer/service/program_cache_lru_helper.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9401153e17da08286b26af943d0d8b23b5f6590e
--- /dev/null
+++ b/gpu/command_buffer/service/program_cache_lru_helper.cc
@@ -0,0 +1,40 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "program_cache_lru_helper.h"
+
+namespace gpu {
+namespace gles2 {
+
+void ProgramCacheLruHelper::Clear() {
+  location_map.clear();
+  queue.clear();
+}
+
+bool ProgramCacheLruHelper::IsEmpty() {
+  return queue.empty();
+}
+
+void ProgramCacheLruHelper::KeyUsed(const std::string& key) {
+  IteratorMap::iterator locationIterator = location_map.find(key);
+  if(locationIterator != location_map.end()) {
+    // already exists, erase it
+    queue.erase(locationIterator->second);
+  }
+  queue.push_front(key);
+  location_map[key] = queue.begin();
+}
+
+std::string ProgramCacheLruHelper::EvictKey() {
+  if(queue.empty()) {
+    return "";
+  }
+  const std::string last = queue.back();
+  queue.pop_back();
+  location_map.erase(last);
+  return last;
+}
+
+} // namespace gpu
+} // namespace gles2