Combine direct_methods_ and virtual_methods_ fields of mirror::Class
Manual cherry-pick of 6286a97 to master
This makes several parts of the overall runtime simpler and reduces
the size of a class object by 32-bits.
Bug: 24618811
Change-Id: I36129b52189e26898ea56fa2b7b45652e06af236
diff --git a/runtime/base/length_prefixed_array.h b/runtime/base/length_prefixed_array.h
new file mode 100644
index 0000000..d632871
--- /dev/null
+++ b/runtime/base/length_prefixed_array.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2015 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_BASE_LENGTH_PREFIXED_ARRAY_H_
+#define ART_RUNTIME_BASE_LENGTH_PREFIXED_ARRAY_H_
+
+#include <stddef.h> // for offsetof()
+
+#include "stride_iterator.h"
+#include "base/bit_utils.h"
+#include "base/casts.h"
+#include "base/iteration_range.h"
+
+namespace art {
+
+template<typename T>
+class LengthPrefixedArray {
+ public:
+ explicit LengthPrefixedArray(size_t length)
+ : size_(dchecked_integral_cast<uint32_t>(length)) {}
+
+ T& At(size_t index, size_t element_size = sizeof(T), size_t alignment = alignof(T)) {
+ DCHECK_LT(index, size_);
+ return AtUnchecked(index, element_size, alignment);
+ }
+
+ const T& At(size_t index, size_t element_size = sizeof(T), size_t alignment = alignof(T)) const {
+ DCHECK_LT(index, size_);
+ return AtUnchecked(index, element_size, alignment);
+ }
+
+ StrideIterator<T> begin(size_t element_size = sizeof(T), size_t alignment = alignof(T)) {
+ return StrideIterator<T>(&AtUnchecked(0, element_size, alignment), element_size);
+ }
+
+ StrideIterator<const T> begin(size_t element_size = sizeof(T),
+ size_t alignment = alignof(T)) const {
+ return StrideIterator<const T>(&AtUnchecked(0, element_size, alignment), element_size);
+ }
+
+ StrideIterator<T> end(size_t element_size = sizeof(T), size_t alignment = alignof(T)) {
+ return StrideIterator<T>(&AtUnchecked(size_, element_size, alignment), element_size);
+ }
+
+ StrideIterator<const T> end(size_t element_size = sizeof(T),
+ size_t alignment = alignof(T)) const {
+ return StrideIterator<const T>(&AtUnchecked(size_, element_size, alignment), element_size);
+ }
+
+ static size_t OffsetOfElement(size_t index,
+ size_t element_size = sizeof(T),
+ size_t alignment = alignof(T)) {
+ DCHECK_ALIGNED_PARAM(element_size, alignment);
+ return RoundUp(offsetof(LengthPrefixedArray<T>, data), alignment) + index * element_size;
+ }
+
+ static size_t ComputeSize(size_t num_elements,
+ size_t element_size = sizeof(T),
+ size_t alignment = alignof(T)) {
+ size_t result = OffsetOfElement(num_elements, element_size, alignment);
+ DCHECK_ALIGNED_PARAM(result, alignment);
+ return result;
+ }
+
+ size_t size() const {
+ return size_;
+ }
+
+ // Update the length but does not reallocate storage.
+ void SetSize(size_t length) {
+ size_ = dchecked_integral_cast<uint32_t>(length);
+ }
+
+ private:
+ T& AtUnchecked(size_t index, size_t element_size, size_t alignment) {
+ return *reinterpret_cast<T*>(
+ reinterpret_cast<uintptr_t>(this) + OffsetOfElement(index, element_size, alignment));
+ }
+
+ const T& AtUnchecked(size_t index, size_t element_size, size_t alignment) const {
+ return *reinterpret_cast<T*>(
+ reinterpret_cast<uintptr_t>(this) + OffsetOfElement(index, element_size, alignment));
+ }
+
+ uint32_t size_;
+ uint8_t data[0];
+};
+
+// Returns empty iteration range if the array is null.
+template<typename T>
+IterationRange<StrideIterator<T>> MakeIterationRangeFromLengthPrefixedArray(
+ LengthPrefixedArray<T>* arr, size_t element_size = sizeof(T), size_t alignment = alignof(T)) {
+ return arr != nullptr ?
+ MakeIterationRange(arr->begin(element_size, alignment), arr->end(element_size, alignment)) :
+ MakeEmptyIterationRange(StrideIterator<T>(nullptr, 0));
+}
+
+} // namespace art
+
+#endif // ART_RUNTIME_BASE_LENGTH_PREFIXED_ARRAY_H_