1 files changed, 77 insertions, 0 deletions
diff --git a/runtime/method_info.h b/runtime/method_info.h
new file mode 100644
index 0000000000..5a72125be4
--- /dev/null
+++ b/runtime/method_info.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ART_RUNTIME_METHOD_INFO_H_
+#define ART_RUNTIME_METHOD_INFO_H_
+
+#include "base/logging.h"
+#include "leb128.h"
+#include "memory_region.h"
+
+namespace art {
+
+// Method info is for not dedupe friendly data of a method. Currently it only holds methods indices.
+// Putting this data in MethodInfo instead of code infos saves ~5% oat size.
+class MethodInfo {
+  using MethodIndexType = uint16_t;
+
+ public:
+  // Reading mode
+  explicit MethodInfo(const uint8_t* ptr) {
+    if (ptr != nullptr) {
+      num_method_indices_ = DecodeUnsignedLeb128(&ptr);
+      region_ = MemoryRegion(const_cast<uint8_t*>(ptr),
+                             num_method_indices_ * sizeof(MethodIndexType));
+    }
+  }
+
+  // Writing mode
+  MethodInfo(uint8_t* ptr, size_t num_method_indices) : num_method_indices_(num_method_indices) {
+    DCHECK(ptr != nullptr);
+    ptr = EncodeUnsignedLeb128(ptr, num_method_indices_);
+    region_ = MemoryRegion(ptr, num_method_indices_ * sizeof(MethodIndexType));
+  }
+
+  static size_t ComputeSize(size_t num_method_indices) {
+    uint8_t temp[8];
+    uint8_t* ptr = temp;
+    ptr = EncodeUnsignedLeb128(ptr, num_method_indices);
+    return (ptr - temp) + num_method_indices * sizeof(MethodIndexType);
+  }
+
+  ALWAYS_INLINE MethodIndexType GetMethodIndex(size_t index) const {
+    // Use bit functions to avoid pesky alignment requirements.
+    return region_.LoadBits(index * BitSizeOf<MethodIndexType>(), BitSizeOf<MethodIndexType>());
+  }
+
+  void SetMethodIndex(size_t index, MethodIndexType method_index) {
+    region_.StoreBits(index * BitSizeOf<MethodIndexType>(),
+                      method_index,
+                      BitSizeOf<MethodIndexType>());
+  }
+
+  size_t NumMethodIndices() const {
+    return num_method_indices_;
+  }
+
+ private:
+  size_t num_method_indices_ = 0u;
+  MemoryRegion region_;
+};
+
+}  // namespace art
+
+#endif  // ART_RUNTIME_METHOD_INFO_H_