size_report.h

// Copyright 2024 The Pigweed Authors
//
// 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
//
//     https://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.
#pragma once
 
#include <array>
#include <cstddef>
#include <cstdint>
#include <cstring>
 
#include "pw_allocator/allocator.h"
#include "pw_allocator/block/small_block.h"
#include "pw_allocator/block_allocator.h"
#include "pw_bloat/bloat_this_binary.h"
#include "pw_bytes/span.h"
 
namespace pw::allocator::size_report {
 
 
using BlockType = SmallBlock;
 
struct Foo final {
  std::array<std::byte, 16> buffer;
};
 
struct Bar {
  Foo foo;
  size_t number;
 
  Bar(size_t number_) : number(number_) {
    std::memset(foo.buffer.data(), 0, foo.buffer.size());
  }
};
 
struct Baz {
  Foo foo;
  uint16_t id;
};
 
ByteSpan GetBuffer();
 
int SetBaseline(uint32_t mask);
 
template <typename BlockType>
int MeasureBlock(uint32_t mask);
 
template <typename BucketType>
int MeasureBucket(BucketType& bucket, uint32_t mask);
 
int MeasureAllocator(Allocator& allocator, uint32_t mask);
 
int MeasureBlockAllocator(BlockAllocator<BlockType>& allocator, uint32_t mask);
 
 
// Template method implementations.
 
template <typename BlockType>
int MeasureBlock(uint32_t mask) {
  if (SetBaseline(mask) != 0) {
    return 1;
  }
 
  // Measure `Init`.
  auto result = BlockType::Init(GetBuffer());
  BlockType* block = *result;
 
  // Measure `UsableSpace`.
  std::byte* bytes = block->UsableSpace();
 
  // Measure `FromUsableSpace`.
  block = BlockType::FromUsableSpace(bytes);
 
  if constexpr (is_allocatable_v<BlockType>) {
    // Measure `AllocFirst`.
    Layout foo = Layout::Of<Foo>();
    auto block_result = BlockType::AllocFirst(std::move(block), foo);
    if (!block_result.ok()) {
      return 1;
    }
 
    BlockType* first_block = block_result.block();
    block = first_block->Next();
 
    // Measure `AllocLast`.
    if constexpr (is_alignable_v<BlockType>) {
      constexpr Layout kOverlyAligned(128, 64);
      block_result = BlockType::AllocLast(std::move(block), kOverlyAligned);
    } else {
      Layout baz = Layout::Of<Baz>();
      block_result = BlockType::AllocLast(std::move(block), baz);
    }
    if (!block_result.ok()) {
      return 1;
    }
 
    BlockType* last_block = block_result.block();
    block = last_block->Prev();
 
    // Measure `Resize`.
    block_result = block->Resize(sizeof(Bar));
    if (!block_result.ok()) {
      return 1;
    }
 
    // Measure `Free`.
    block_result = BlockType::Free(std::move(first_block));
    return block_result.ok() ? 0 : 1;
  }
}
 
template <typename BucketType>
int MeasureBucket(BucketType& bucket, uint32_t mask) {
  if (int rc = SetBaseline(mask); rc != 0) {
    return rc;
  }
  if (int rc = MeasureBlock<BlockType>(mask); rc != 0) {
    return rc;
  }
 
  auto result = BlockType::Init(GetBuffer());
  BlockType* unallocated = *result;
 
  // Exercise `Add`.
  std::array<BlockType*, 4> blocks;
  for (size_t i = 0; i < blocks.size(); ++i) {
    Layout layout(16 * (i + 1), 1);
    auto block_result = BlockType::AllocFirst(std::move(unallocated), layout);
    blocks[i] = block_result.block();
    unallocated = blocks[i]->Next();
    PW_BLOAT_COND(bucket.Add(*blocks[i]), mask);
  }
 
  // Exercise `Remove`.
  PW_BLOAT_COND(bucket.Remove(*blocks[0]), mask);
 
  // Exercise `RemoveCompatible`.
  BlockType* compatible = bucket.RemoveCompatible(Layout(32, 1));
  PW_BLOAT_COND(compatible != nullptr, mask);
 
  // Exercise `RemoveAny`.
  BlockType* any_block = bucket.RemoveAny();
  PW_BLOAT_COND(any_block != nullptr, mask);
 
  // Exercise `empty` and `Clear`.
  PW_BLOAT_COND(!bucket.empty(), mask);
  PW_BLOAT_EXPR(bucket.Clear(), mask);
  return bucket.empty() ? 0 : 1;
}
 
}  // namespace pw::allocator::size_report