Line data    Source code

       1             : /*
       2             :  * Copyright 2021 Google Inc. All rights reserved.
       3             :  *
       4             :  * Licensed under the Apache License, Version 2.0 (the "License");
       5             :  * you may not use this file except in compliance with the License.
       6             :  * You may obtain a copy of the License at
       7             :  *
       8             :  *     http://www.apache.org/licenses/LICENSE-2.0
       9             :  *
      10             :  * Unless required by applicable law or agreed to in writing, software
      11             :  * distributed under the License is distributed on an "AS IS" BASIS,
      12             :  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      13             :  * See the License for the specific language governing permissions and
      14             :  * limitations under the License.
      15             :  */
      16             : 
      17             : #ifndef FLATBUFFERS_DEFAULT_ALLOCATOR_H_
      18             : #define FLATBUFFERS_DEFAULT_ALLOCATOR_H_
      19             : 
      20             : #include "flatbuffers/allocator.h"
      21             : #include "flatbuffers/base.h"
      22             : 
      23             : namespace flatbuffers {
      24             : 
      25             : // DefaultAllocator uses new/delete to allocate memory regions
      26             : class DefaultAllocator : public Allocator {
      27             :  public:
      28         553 :   uint8_t *allocate(size_t size) FLATBUFFERS_OVERRIDE {
      29         553 :     return new uint8_t[size];
      30             :   }
      31             : 
      32         553 :   void deallocate(uint8_t *p, size_t) FLATBUFFERS_OVERRIDE { delete[] p; }
      33             : 
      34             :   static void dealloc(void *p, size_t) { delete[] static_cast<uint8_t *>(p); }
      35             : };
      36             : 
      37             : // These functions allow for a null allocator to mean use the default allocator,
      38             : // as used by DetachedBuffer and vector_downward below.
      39             : // This is to avoid having a statically or dynamically allocated default
      40             : // allocator, or having to move it between the classes that may own it.
      41         505 : inline uint8_t *Allocate(Allocator *allocator, size_t size) {
      42         505 :   return allocator ? allocator->allocate(size)
      43         505 :                    : DefaultAllocator().allocate(size);
      44             : }
      45             : 
      46         505 : inline void Deallocate(Allocator *allocator, uint8_t *p, size_t size) {
      47         505 :   if (allocator)
      48           0 :     allocator->deallocate(p, size);
      49             :   else
      50         505 :     DefaultAllocator().deallocate(p, size);
      51         505 : }
      52             : 
      53          48 : inline uint8_t *ReallocateDownward(Allocator *allocator, uint8_t *old_p,
      54             :                                    size_t old_size, size_t new_size,
      55             :                                    size_t in_use_back, size_t in_use_front) {
      56          48 :   return allocator ? allocator->reallocate_downward(old_p, old_size, new_size,
      57           0 :                                                     in_use_back, in_use_front)
      58          96 :                    : DefaultAllocator().reallocate_downward(
      59          96 :                          old_p, old_size, new_size, in_use_back, in_use_front);
      60             : }
      61             : 
      62             : }  // namespace flatbuffers
      63             : 
      64             : #endif  // FLATBUFFERS_DEFAULT_ALLOCATOR_H_