sousa-gecko/dom/base/DOMArena.h

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */
#ifndef DOM_Arena_h_
#define DOM_Arena_h_
#include "mozilla/mozalloc_oom.h"  // for mozalloc_handle_oom
#include "mozmemory.h"
#include "nsISupportsImpl.h"
#include "nsString.h"

#define NS_DECL_DOMARENA_DESTROY void Destroy(void);

#define NS_IMPL_DOMARENA_DESTROY(class)                           \
  void class ::Destroy(void) {                                    \
    RefPtr<nsNodeInfoManager> nim = mNodeInfo->NodeInfoManager(); \
    RefPtr<DOMArena> arena =                                      \
        HasFlag(NODE_KEEPS_DOMARENA)                              \
            ? nsContentUtils::TakeEntryFromDOMArenaTable(this)    \
            : nullptr;                                            \
    this->~class();                                               \
    MOZ_ASSERT(nim, "nsNodeInfoManager needs to be initialized"); \
    nim->Free(this);                                              \
  }

namespace mozilla::dom {

class DOMArena {
 public:
  friend class DocGroup;
  explicit DOMArena(const nsACString& aLabel) {
    nsCString label = PromiseFlatCString("DOMArena "_ns + aLabel);

    arena_params_t params;
    params.mMaxDirtyIncreaseOverride = 7;
    params.mFlags = ARENA_FLAG_THREAD_MAIN_THREAD_ONLY;
    params.mLabel = label.get();
    mArenaId = moz_create_arena_with_params(&params);
  }

  NS_INLINE_DECL_REFCOUNTING(DOMArena)

  void* Allocate(size_t aSize) {
    void* ret = moz_arena_malloc(mArenaId, aSize);
    if (!ret) {
      mozalloc_handle_oom(aSize);
    }
    return ret;
  }

 private:
  ~DOMArena() { moz_dispose_arena(mArenaId); }
  arena_id_t mArenaId;
};
}  // namespace mozilla::dom
#endif