Move shared files in net/quic/ into net/quic/core/

net/quic/quic_one_block_arena.h

-// Copyright (c) 2016 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.
-
-// An arena that consists of a single inlined block of |ArenaSize|. Useful to
-// avoid repeated calls to malloc/new and to improve memory locality. DCHECK's
-// if an allocation out of the arena ever fails in debug builds; falls back to
-// heap allocation in release builds.
-
-#ifndef NET_QUIC_QUIC_ONE_BLOCK_ARENA_H_
-#define NET_QUIC_QUIC_ONE_BLOCK_ARENA_H_
-
-#include "net/quic/quic_arena_scoped_ptr.h"
-#include "net/quic/quic_flags.h"
-#include "net/quic/quic_utils.h"
-
-#define PREDICT_FALSE(x) x
-
-namespace net {
-
-template <uint32_t ArenaSize>
-class QuicOneBlockArena {
-  static const uint32_t kMaxAlign = 8;
-
- public:
-  QuicOneBlockArena();
-
-  // Instantiates an object of type |T| with |args|. |args| are perfectly
-  // forwarded to |T|'s constructor. The returned pointer's lifetime is
-  // controlled by QuicArenaScopedPtr.
-  template <typename T, typename... Args>
-  QuicArenaScopedPtr<T> New(Args&&... args);
-
- private:
-  // Returns the size of |T| aligned up to |kMaxAlign|.
-  template <typename T>
-  static inline uint32_t AlignedSize() {
-    return ((sizeof(T) + (kMaxAlign - 1)) / kMaxAlign) * kMaxAlign;
-  }
-
-  // Actual storage.
-  // Subtle/annoying: the value '8' must be coded explicitly into the alignment
-  // declaration for MSVC.
-  QUIC_ALIGNED(8) char storage_[ArenaSize];
-  // Current offset into the storage.
-  uint32_t offset_;
-
-  DISALLOW_COPY_AND_ASSIGN(QuicOneBlockArena);
-};
-
-template <uint32_t ArenaSize>
-QuicOneBlockArena<ArenaSize>::QuicOneBlockArena() : offset_(0) {}
-
-template <uint32_t ArenaSize>
-template <typename T, typename... Args>
-QuicArenaScopedPtr<T> QuicOneBlockArena<ArenaSize>::New(Args&&... args) {
-  DCHECK_LT(AlignedSize<T>(), ArenaSize)
-      << "Object is too large for the arena.";
-  static_assert(QUIC_ALIGN_OF(T) > 1,
-                "Objects added to the arena must be at least 2B aligned.");
-  if (PREDICT_FALSE(offset_ > ArenaSize - AlignedSize<T>())) {
-    LOG(DFATAL) << "Ran out of space in QuicOneBlockArena at " << this
-                << ", max size was " << ArenaSize << ", failing request was "
-                << AlignedSize<T>() << ", end of arena was " << offset_;
-    return QuicArenaScopedPtr<T>(new T(std::forward<Args>(args)...));
-  }
-
-  void* buf = &storage_[offset_];
-  new (buf) T(std::forward<Args>(args)...);
-  offset_ += AlignedSize<T>();
-  return QuicArenaScopedPtr<T>(buf,
-                               QuicArenaScopedPtr<T>::ConstructFrom::kArena);
-}
-
-}  // namespace net
-
-#endif  // NET_QUIC_QUIC_ONE_BLOCK_ARENA_H_