nb/first_fit_reuse_allocator.cc

// Copyright 2017 Google Inc. All Rights Reserved.
//
// 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.

#include "nb/first_fit_reuse_allocator.h"

#include <algorithm>

#include "nb/pointer_arithmetic.h"
#include "starboard/common/log.h"
#include "starboard/types.h"

namespace nb {

FirstFitReuseAllocator::FirstFitReuseAllocator(
    Allocator* fallback_allocator,
    std::size_t initial_capacity,
    std::size_t allocation_increment /*= 0*/)
    : ReuseAllocatorBase(fallback_allocator,
                         initial_capacity,
                         allocation_increment) {}

ReuseAllocatorBase::FreeBlockSet::iterator
FirstFitReuseAllocator::FindFreeBlock(std::size_t size,
                                      std::size_t alignment,
                                      FreeBlockSet::iterator begin,
                                      FreeBlockSet::iterator end,
                                      bool* allocate_from_front) {
  SB_DCHECK(allocate_from_front);

  *allocate_from_front = true;

  // Start looking through the free list from the front.
  for (FreeBlockSet::iterator it = begin; it != end; ++it) {
    if (it->CanFulfill(size, alignment)) {
      return it;
    }
  }

  return end;
}

}  // namespace nb