gfx/gl/HeapCopyOfStackArray.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef HEAPCOPYOFSTACKARRAY_H_
   8 #define HEAPCOPYOFSTACKARRAY_H_
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/UniquePtr.h"
  12
  13 #include <string.h>
  14
  15 namespace mozilla {
  16
  17 // Takes a stack array and copies it into a heap buffer.
  18 // Useful to retain the convenience of declaring static arrays, while
  19 // avoiding passing stack pointers to the GL (see bug 1005658).
  20
  21 template <typename ElemType>
  22 class HeapCopyOfStackArray {
  23  public:
  24   template <size_t N>
  25   MOZ_IMPLICIT HeapCopyOfStackArray(const ElemType (&array)[N])
  26       : mArrayLength(N), mArrayData(MakeUnique<ElemType[]>(N)) {
  27     memcpy(mArrayData.get(), &array[0], N * sizeof(ElemType));
  28   }
  29
  30   ElemType* Data() const { return mArrayData.get(); }
  31   size_t ArrayLength() const { return mArrayLength; }
  32   size_t ByteLength() const { return mArrayLength * sizeof(ElemType); }
  33
  34  private:
  35   HeapCopyOfStackArray() = delete;
  36   HeapCopyOfStackArray(const HeapCopyOfStackArray&) = delete;
  37
  38   const size_t mArrayLength;
  39   UniquePtr<ElemType[]> const mArrayData;
  40 };
  41
  42 }  // namespace mozilla
  43
  44 #endif  // HEAPCOPYOFSTACKARRAY_H_